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1.
Molecules ; 26(17)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34500562

RESUMO

Gluconeogenesis is a key interface between organic acid/amino acid/lipid and sugar metabolism. The aims of this article are four-fold. First, to provide a concise overview of plant gluconeogenesis. Second, to emphasise the widespread occurrence of gluconeogenesis and its utilisation in diverse processes. Third, to stress the importance of the vacuolar storage and release of Krebs cycle acids/nitrogenous compounds, and of the role of gluconeogenesis and malic enzyme in this process. Fourth, to outline the contribution of fine control of enzyme activity to the coordinate-regulation of gluconeogenesis and malate metabolism, and the importance of cytosolic pH in this.


Assuntos
Aminoácidos/metabolismo , Gluconeogênese/fisiologia , Lipídeos/fisiologia , Plantas/metabolismo , Açúcares/metabolismo , Ciclo do Ácido Cítrico/fisiologia , Malato Desidrogenase/metabolismo , Nitrogênio/metabolismo
2.
Small GTPases ; : 1-16, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34565293

RESUMO

GTP binding proteins known as small GTPases make up one of the largest groups of regulatory proteins and control almost all functions of living cells. Their activity is under, respectively, positive and negative regulation by guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs), which together with their upstream regulators and the downstream targets of the small GTPases form formidable signalling networks. While genomics has revealed the large size of the GTPase, GEF and GAP repertoires, only a small fraction of their interactions and functions have yet to be experimentally explored. Dictyostelid social amoebas have been particularly useful in unravelling the roles of many proteins in the Rac-Rho and Ras-Rap families of GTPases in directional cell migration and regulation of the actin cytoskeleton. Genomes and cell-type specific and developmental transcriptomes are available for Dictyostelium species that span the 0.5 billion years of evolution of the group from their unicellular ancestors. In this work, we identified all GTPases, GEFs and GAPs from genomes representative of the four major taxon groups and investigated their phylogenetic relationships and evolutionary conservation and changes in their functional domain architecture and in their developmental and cell-type specific expression. We performed a hierarchical cluster analysis of the expression profiles of the ~2000 analysed genes to identify putative interacting sets of GTPases, GEFs and GAPs, which highlight sets known to interact experimentally and many novel combinations. This work represents a valuable resource for research into all fields of cellular regulation.

3.
Int J Mol Sci ; 22(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34360556

RESUMO

In grapevines, as in other plants, sucrose and its constituents glucose and fructose are fundamentally important and carry out a multitude of roles. The aims of this review are three-fold. First, to provide a summary of the metabolism and transport of sucrose in grapevines, together with new insights and interpretations. Second, to stress the importance of considering the compartmentation of metabolism. Third, to outline the key role of acid invertase in osmoregulation associated with sucrose metabolism and transport in plants.


Assuntos
Metabolismo dos Carboidratos , Frutas/metabolismo , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Sacarose/metabolismo , Vitis/metabolismo , Frutas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Vitis/crescimento & desenvolvimento
4.
Artigo em Inglês | MEDLINE | ID: mdl-33719405

RESUMO

Mixed matrix membranes (MMMs) for CO2 separation have overcome the trade-off between gas permeability and gas selectivity to some extent. However, most MMMs still are prepared in lab- and pilot-scales since the permeability and selectivity of CO2 are not good enough to reach the economically available requirements. Moreover, the fabrication of few MMMs with good separation performance is time-consuming or need harsh conditions. In this study, a novel MOF-based composite membrane (PAN-γ-CD-MOF-PU membrane) was successfully fabricated by a facile and fast spin-coating method. In the two-step coating process, we applied a uniform selective layer of γ-cyclodextrin-MOF (γ-CD-MOF) on porous polyacrylonitrile and then coated a layer of polyurethane on the γ-CD-MOF layer. The entire membrane formation process was about 30 s. The formation of a unique γ-CD-MOF layer greatly improved the separation ability of CO2 (the CO2 permeability is 70.97 barrers; the selectivity to CO2/N2 and CO2/O2 are 253.46 and 154.28, respectively). The gas separation performance can exceed the Robeson upper limit obviously and the selectivity is better than other MOF-based composite membranes. In addition, the PAN-γ-CD-MOF-PU membrane is strong and flexible. Therefore, the PAN-γ-CD-MOF-PU membrane developed in this study has great potential in large-scale industrial separation of CO2.

5.
J Crohns Colitis ; 15(7): 1161-1173, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-33411893

RESUMO

BACKGROUND AND AIMS: Emerging evidence points to a link between creeping fat and the pathogenesis of Crohn's disease [CD]. Non-invasive assessment of the severity of creeping fat on cross-sectional imaging modality has seldom been investigated. This study aimed to develop and characterize a novel mesenteric creeping fat index [MCFI] based on computed tomography [CT] in CD patients. METHODS: MCFI was developed based on vascular findings on CT in a retrospective cohort [n = 91] and validated in a prospective cohort [n = 30]. The severity of creeping fat was graded based on the extent to which mesenteric fat extended around the intestinal circumference using the vessels in the fat as a marker. The accuracy of MCFI was assessed by comparing it with the degree of creeping fat observed in surgical specimens. The relationship between MCFI and fibrostenosis was characterized by determining if these correlated. The accuracy of MCFI was compared with other radiographic indices [i.e. visceral to subcutaneous fat area ratio and fibrofatty proliferation score]. RESULTS: In the retrospective cohort, MCFI had moderate accuracy in differentiating moderate-severe from mild fibrostenosis (area under the receiver operating characteristic [ROC] curve [AUC] = 0.799; p = 0.000). ROC analysis in the retrospective cohort identified a threshold MCFI of > 3 which accurately differentiated fibrostenosis severity in the prospective cohort [AUC = 0.756; p = 0.018]. An excellent correlation was shown between MCFI and the extent of fat wrapping in specimens in the prospective cohort [r = 0.840, p = 0.000]. Neither visceral to subcutaneous fat area ratio nor fibrofatty proliferation score correlated well with the degree of intestinal fibrosis. CONCLUSIONS: MCFI can accurately characterize the extent of mesenteric fat wrapping in surgical specimens. It may become another non-invasive measure of CD fibrostenosis.

6.
Abdom Radiol (NY) ; 46(3): 936-947, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32964274

RESUMO

PURPOSE: To determine the utility of diffusion kurtosis imaging (DKI) for assessing bowel fibrosis and to establish a new magnetic resonance imaging (MRI)-based classification based on DKI and conventional MRI parameters for characterizing intestinal strictures in Crohn's disease (CD) using the histological evaluation of resected intestine samples as the reference standard. METHODS: Thirty-one patients with CD undergoing preoperative conventional MRI and diffusion-weighted imaging (DWI) (b values = 0-2000 s/mm2) were consecutively enrolled. We classified the mural T2-weighted signal intensity and arterial-phase enhancement patterns on conventional MRI. We also measured DWI-derived apparent diffusion coefficients (ADCs) and DKI-derived apparent diffusion for non-Gaussian distribution (Dapp) and apparent diffusional kurtosis (Kapp). A new MRI-based classification was established to characterize intestinal strictures in CD. Its performance was validated in nine additional patients with CD. RESULTS: Histological inflammation grades were significantly correlated to T2-weighted signal intensity (r = 0.477; P < 0.001) and ADC (r = - 0.226; P = 0.044). Histological fibrosis grades were moderately correlated to Kapp (r = 0.604, P < 0.001); they were also correlated to Dapp (r = - 0.491; P < 0.001) and ADC (r = - 0.270; P = 0.015). T2-weighted signal intensity could differentiate between no-to-mild and moderate-to-severe bowel inflammation (sensitivity, 0.970; specificity, 0.479). Kapp could differentiate between no-to-mild and moderate-to-severe bowel fibrosis (sensitivity, 0.959; specificity, 0.781). The agreement between the new MRI-based classification and the histological classification was moderate in the test (κ = 0.507; P < 0.001) and validation (κ = 0.530; P < 0.001) sets. CONCLUSIONS: DKI can be used to assess bowel fibrosis. The new MRI-based classification can help to distinguish between fibrotic and inflammatory intestinal strictures in patients with CD.


Assuntos
Doença de Crohn , Constrição Patológica/diagnóstico por imagem , Doença de Crohn/complicações , Doença de Crohn/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Humanos , Imageamento por Ressonância Magnética , Sensibilidade e Especificidade
7.
Front Plant Sci ; 11: 572601, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33101339

RESUMO

Stone fruits of the Rosaceae family consist of several distinct parts, and these include the flesh, woody endocarp, and seed. To understand the metabolism of these fruits, it is necessary to have knowledge of both their structure and growth characteristics. The nitrogen metabolism of the different tissues of stone fruits is interlinked. For example, there is an import and storage of nitrogenous compounds in the endocarp that are then exported to the seed. Moreover, there are links between the metabolism of nitrogen and that of malic/citric acids. In this article, the structure and growth characteristics, together with the import/export, contents, metabolism, and functions of nitrogenous compounds and organic acids in the different parts of stone fruits and their seeds are reviewed.

8.
Eur Radiol ; 30(4): 1938-1947, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31900705

RESUMO

OBJECTIVES: Identifying inflammation- or fibrosis-predominant strictures in Crohn's disease (CD) is crucial for treatment strategies. We evaluated the additive value of magnetisation transfer (MT) to conventional MRI for differentiating CD strictures using surgical histopathology as a reference standard. METHODS: Twenty-eight consecutive CD patients who underwent MRI preoperatively were recruited. MRI parameters included T2-weighted imaging (T2WI) hyperintensity, bowel wall thickness, enhancement pattern changes over time, enhancement pattern and gain ratio in dynamic contrast-enhanced phases, and MT ratio. Correlation analysis was performed using Spearman's rank test. Receiver operating characteristic curve analysis and Cohen's κ were used. A model with combined MRI variables characterising intestinal strictures was proposed and validated in 14 additional CD patients. RESULTS: Significant correlations with histological inflammation scores were shown for wall thickness (r = 0.361, p = 0.001) and T2WI hyperintensity (r = 0.396, p < 0.001), whereas histological fibrosis scores were significantly correlated with MT ratio (r = 0.681, p < 0.001) and wall thickness (r = 0.461, p < 0.001). T2WI hyperintensity could differentiate mild from moderate-to-severe inflammation with a sensitivity of 0.871 and a specificity of 0.800. MT ratio could discriminate mild from moderate-to-severe fibrosis with a sensitivity and a specificity of 0.913 and 0.923, respectively. Combining MT ratio and T2WI hyperintensity, the MRI classification moderately agreed with the pathological stricture classification (p < 0.01, κ = 0.549). In the validation set, the diagnostic accuracy of T2WI hyperintensity and MT ratio were 86% and 89%, with good agreement between MRI and histopathological classification (p < 0.01, κ = 0.665). CONCLUSIONS: MT ratio combined with conventional MRI improves the differentiation of fibrotic from inflammatory components of small-bowel strictures in CD patients. KEY POINTS: • MT ratio from magnetisation transfer imaging combined with T2WI from conventional MRI can simultaneously characterise bowel fibrosis and inflammation in adult Crohn's disease.


Assuntos
Doença de Crohn/diagnóstico , Obstrução Intestinal/diagnóstico , Intestino Delgado/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Adulto , Diagnóstico Diferencial , Feminino , Fibrose/diagnóstico , Humanos , Masculino , Curva ROC
9.
J Nanosci Nanotechnol ; 20(4): 2617-2621, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31492285

RESUMO

Pure phase polycrystalline BiFeO3 film was deposited onto FTO substrate by RF magnetron sputtering method. SEM result shows that BiFeO3 film has the obvious porosity and large clusters which lead to the poor ferroelectric and photovoltaic properties in FTO/BiFeO3/Ag device. However, these properties are improved in p-i-n structured FTO/TiO2/BiFeO3/HTM/Ag device by incorporating the electron and hole transport materials. The hysteresis loop measurement demonstrates the excellent ferroelectric property with large remnant polarization (2Pr = 180 µC/cm²) and low leakage current. The J-V curve shows the short-circuit current density is dozens of times larger than that of FTO/BiFeO3/Ag device. Moreover, the photovoltaic output depends on the poling field where the positive poling improves the short-circuit current density to -85 µA/cm2 and the negative poling reduces both the photocurrent and photovoltage. It is believed that the ferroelectric polarization plays a dominant role in the photovoltaic effect.

10.
J Nanosci Nanotechnol ; 20(1): 564-567, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383211

RESUMO

A polycrystalline BiFeO3 film was deposited on ITO substrate by RF magnetron sputtering method. Small crystallite size and compact structure are obtained for BiFeO3 film which has the excellent ferroelectric properties. The measured photovoltaic response reveals an open-circuit voltage of ~0.52 V and a short-circuit current density of ~10 µA/cm² under the illumination of 100 mW/cm² irradiance. Moreover, a tunable photovoltaic effect with light illumination is observed under different voltage sweep mode. High initial sweep voltage can enhance the photovoltaic effect largely, however, the photovoltaic response decreases with the increase of voltage sweep interval. The results indicate the ferroelectric polarization plays an important role in the photovoltaic effect.

11.
BMC Genomics ; 20(1): 890, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31752673

RESUMO

BACKGROUND: Dictyostelid social amoebas self-organize into fruiting bodies, consisting of spores and up to four supporting cell types in the phenotypically most complex taxon group 4. High quality genomes and stage- and cell-type specific transcriptomes are available for representative species of each of the four taxon groups. To understand how evolution of gene regulation in Dictyostelia contributed to evolution of phenotypic complexity, we analysed conservation and change in abundance, functional domain architecture and developmental regulation of their transcription factors (TFs). RESULTS: We detected 440 sequence-specific TFs across 33 families, of which 68% were upregulated in multicellular development and about half conserved throughout Dictyostelia. Prespore cells expressed two times more TFs than prestalk cells, but stalk cells expressed more TFs than spores, suggesting that gene expression events that define spores occur earlier than those that define stalk cells. Changes in TF developmental expression, but not in TF abundance or functional domains occurred more frequently between group 4 and groups 1-3, than between the more distant branches formed by groups 1 + 2 and 3 + 4. CONCLUSIONS: Phenotypic innovation is correlated with changes in TF regulation, rather than functional domain- or TF acquisition. The function of only 34 TFs is known. Of 12 TFs essential for cell differentiation, 9 are expressed in the cell type for which they are required. The information acquired here on conserved cell type specifity of 120 additional TFs can effectively guide further functional analysis, while observed evolutionary change in TF developmental expression may highlight how genotypic change caused phenotypic innovation.


Assuntos
Amebozoários/genética , Evolução Molecular , Fatores de Transcrição/genética , Amebozoários/classificação , Amebozoários/crescimento & desenvolvimento , Amebozoários/metabolismo , Dictyostelium/genética , Regulação da Expressão Gênica no Desenvolvimento , Fenótipo , Filogenia , Domínios Proteicos , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Transcriptoma
12.
Opt Express ; 27(12): A596-A610, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31252840

RESUMO

A silver grating containing three grooves with different depths in one period was proposed as the back electrode for improving light absorption in organic solar cells. We found that the broadband absorption enhancement of the active layer covering the visible and near-infrared bands can be obtained due to the excitation of surface plasmon resonance and the multiple resonances of cavity mode. The integrated absorption efficiency of the proposed structure under TM polarization between 350 nm to 900 nm is 57.4%, with consideration of the weight of AM 1.5G solar spectrum, and is increased by 13.4% with respect to the equivalent planar device. Besides, the wide-angle absorption in proposed structure can be observed in the range from 0 to 50 degrees. These findings are of great importance for rationally designing composite nanostructures of metal gratings-based absorbers for sensing and photon-detecting applications.

13.
J Nanosci Nanotechnol ; 19(9): 5661-5666, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30961722

RESUMO

Well dispersed CeO2 nanoparticles are prepared by azeotropic co-precipitation method. (Ba0.96Ca0.04)(Ti0.90Sn0.10)O3 lead-free piezoelectric ceramics doped with nano-CeO2 (x =0 mol%, 0.03 mol%, and 0.07 mol%) and micro-CeO2 (x = 0.03 mol%) are prepared at 1430 °C for 2 h by the conventional solid state sintering method. XRD diffraction indicates that all components have typical perovskite structure. Both doping of nano-CeO2 and micro-CeO2 can inhibit grain growth. And the average grain size decreased apparently with the increase of nano-CeO2 amount. All the samples exhibit typical diffuse phase transition behavior. The optimized electrical performances are obtained at x = 0.03 mol% with d33 = 512 pC/N, kp = 41.5%, and Pr = 14.00 µC/cm².

14.
Nat Commun ; 9(1): 2335, 2018 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-29899332

RESUMO

Most two-dimensional (2D) covalent organic frameworks (COFs) are non-fluorescent in the solid state even when they are constructed from emissive building blocks. The fluorescence quenching is usually attributed to non-irradiative rotation-related or π-π stacking-caused thermal energy dissipation process. Currently there is a lack of guiding principle on how to design fluorescent, solid-state material made of COF. Herein, we demonstrate that the eclipsed stacking structure of 2D COFs can be used to turn on, and tune, the solid-state photoluminescence from non-emissive building blocks by the restriction of intramolecular bond rotation via intralayer and interlayer hydrogen bonds among highly organized layers in the eclipse-stacked COFs. Our COFs serve as a platform whereby the size of the conjugated linkers and side-chain functionalities can be varied, rendering the emission colour-tuneable from blue to yellow and even white. This work provides a guide to design new solid-state emitters using COFs.

15.
Inflamm Bowel Dis ; 24(10): 2183-2190, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-29718309

RESUMO

Background and aim: The distinction of intestinal fibrosis from inflammation in Crohn's disease (CD) associated strictures has important therapeutic implications. Ultrasound elastography is useful in evaluating the degree of fibrosis in liver, but there is little evidence whether it can assess fibrosis in the bowel. We determined whether shear-wave elastography (SWE), a novel modification of elastography, quantifying tissue stiffness, could differentiate between inflammatory and fibrotic components in strictures of patients with CD. Methods: Consecutive CD patients with ileal/ileocolonic strictures who underwent SWE within 1 week to surgical resection were enrolled. The SWE value of the stenotic bowel wall was compared to the grade and severity of fibrosis and inflammation, respectively, in the resected bowel specimen. Results: Thirty-five patients were enrolled. The mean SWE value of stenotic bowel wall was significantly higher in severe fibrosis (23.0 ± 6.3 Kpa) than that in moderate (17.4 ± 3.8 Kpa) and mild fibrosis (14.4 ± 2.1 Kpa)(P = 0.008). Using 22.55 KPa as the cutoff value in discriminating between mild/moderate and severe fibrosis, the sensitivity and specificity was 69.6 % and 91.7% with an area under the curve (AUC) of 0.822 (P = 0.002). However, no significant difference regarding mean SWE existed among different grades of inflammation. The sensitivity and specificity of bowel vascularization score on conventional ultrasound in differentiating severe inflammation from mild/moderate was 87.5 % and 57.9% with AUC of 0.811 (P = 0.002). Combining SWE and conventional ultrasound (bowel vascularization score), we propose a bowel ultrasound classification of intestinal strictures. A moderate agreement between ultrasound and pathological classification was observed (κ = 0.536, P<0.001). Conclusions: This pilot study suggests that SWE is feasible and accurate in detecting intestinal fibrosis in patients with CD. After validation, combing SWE and bowel vascularization on conventional ultrasound might be applied to guide a management strategy in CD patients through defining the type of intestinal stricture. 10.1093/ibd/izy115_video1izy115.video15777734754001.


Assuntos
Constrição Patológica/diagnóstico , Doença de Crohn/fisiopatologia , Técnicas de Imagem por Elasticidade/métodos , Fibrose/diagnóstico , Inflamação/diagnóstico , Intestinos/patologia , Adolescente , Adulto , Idoso , China/epidemiologia , Constrição Patológica/diagnóstico por imagem , Constrição Patológica/epidemiologia , Estudos Transversais , Feminino , Fibrose/diagnóstico por imagem , Fibrose/epidemiologia , Seguimentos , Humanos , Inflamação/diagnóstico por imagem , Inflamação/epidemiologia , Intestinos/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Prognóstico , Estudos Prospectivos , Índice de Gravidade de Doença , Ultrassonografia , Adulto Jovem
16.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 49(1): 107-112, 2018 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-29737100

RESUMO

OBJECTIVE: To develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detecting tenofovir in human plasma. METHODS: Twenty four healthy male volunteers received a single oral dose of 300 mg tenofovir disoproxil fumarate tablets under fasting and high-fat diet conditions in a randomized four-way crossover bioequivalence study with two preparations of tablets. Plasma samples were taken and analyzed using the LC-MS/MS method. The pharmacokinetic parameters of the two preparations were calculated and compared statistically to evaluate their bioequivalence using Phoenix Winnonlin6.3. RESULTS: Linear detection responses were obtained for tenofovir at the range from 3.13 to 500 ng/mL. The intra- and inter-day precisions were high,with lower than 5.43% [relative standard deviation (RSD)%],high recovery and good stability. The 90% confidence intervals of peak concentration (Cmax) of tenofovir and its area under the curve (AUC0-t and AUC0-∞ ) all fell within the bioequivalence limit 80.00%-125.00% under both fasting and high-fat diet conditions. No significant difference in peak time (Tmax) was demonstrated between the two preparations (P>0.05) . CONCLUSION: The LC-MS/MS method can be used for simultaneous determination of tenofovir in human plasma. The two preparations of tablets are bioequivalent.


Assuntos
Tenofovir/sangue , Equivalência Terapêutica , Área Sob a Curva , Cromatografia Líquida , Estudos Cross-Over , Humanos , Masculino , Comprimidos , Espectrometria de Massas em Tandem , Tenofovir/farmacocinética
17.
Nat Mater ; 17(1): 49-56, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29180776

RESUMO

Erasable conductive domain walls in insulating ferroelectric thin films can be used for non-destructive electrical read-out of the polarization states in ferroelectric memories. Still, the domain-wall currents extracted by these devices have not yet reached the intensity and stability required to drive read-out circuits operating at high speeds. This study demonstrated non-destructive read-out of digital data stored using specific domain-wall configurations in epitaxial BiFeO3 thin films formed in mesa-geometry structures. Partially switched domains, which enable the formation of conductive walls during the read operation, spontaneously retract when the read voltage is removed, reducing the accumulation of mobile defects at the domain walls and potentially improving the device stability. Three-terminal memory devices produced 14 nA read currents at an operating voltage of 5 V, and operated up to T = 85 °C. The gap length can also be smaller than the film thickness, allowing the realization of ferroelectric memories with device dimensions far below 100 nm.

18.
J Gastroenterol Hepatol ; 33(3): 608-614, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28804920

RESUMO

BACKGROUND AND AIM: Thiopurines (TPs) are effective in reducing clinical and endoscopic recurrence in postoperative patients with Crohn's disease (CD). However, whether TPs could prevent surgical recurrence (SR) remains unknown. We aimed to explore whether TPs could prevent SR and identify risk factors associated with SR. METHODS: This was a retrospective cohort study of 246 postoperative patients with CD. Cox proportional hazard model was used to identify risk factors for SR. Patients were stratified according to the presence of risk factors. RESULTS: A total of 50 (20.3%) patients suffered SR after a mean follow up of 54.3±46.4 months. Multivariable analysis showed independent risk factors for SR were penetrating disease behavior (HR 8.628; 95% CI 1.573-47.341; P = 0.01), ileocolonic disease location (HR 2.597; 95% CI 1.047-6.445; P = 0.04) and isolated upper gastrointestinal disease (UGID) location (HR 5.082; 95% CI 1.496-17.267; P = 0.009). However, use of TPs after surgery significantly reduced the risk of SR (HR 0.120; 95% CI 0.063-0.231; P < 0.001). When stratifying patients according to risk factors, there was no statistical difference of SR between patients treated or not by TPs (P = 0.08) in low-risk group (n = 46). However, in high risk group (n = 200), patients with TPs use had a lower risk of SR than those without TPs (HR 0.093; 95% CI 0.048-0.178; P < 0.001). CONCLUSIONS: Penetrating disease behavior and ileocolonic/isolated (UGID) location were associated with SR in CD patients. TPs use was beneficial in decreasing risk for SR in CD patients at high risk.


Assuntos
Azatioprina/uso terapêutico , Colectomia , Doença de Crohn/prevenção & controle , Doença de Crohn/cirurgia , Imunossupressores/uso terapêutico , Intestino Delgado/cirurgia , Mercaptopurina/uso terapêutico , Prevenção Secundária , Adolescente , Adulto , Idoso , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Observacionais como Assunto , Recidiva , Estudos Retrospectivos , Fatores de Risco , Adulto Jovem
19.
Opt Express ; 25(19): 22375-22387, 2017 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-29041549

RESUMO

The simultaneous realization of high Q-factor resonances and strong near-field enhancements around and inside of dielectric nanostructures is important for many applications in nanophotonics. However, the incident fields are often confined within dielectric nanoparticles, which results in poor optical interactions with external environment. Near-field enhancements can be extended outside of dielectric nanostructures with proper design, but the Q-factor is often reduced caused by additional radiation losses. This paper shows that the obstacles to achieve high Q-factor, that is, the radiative losses can be effectively suppressed by using dielectric nanodisk arrays, where the Q-factor is about one order larger than that of the single disks associated with the nonradiating anapole modes and the collective oscillations of the arrays. When the resonance energies of the electric dipole mode and the subradiant mode are degenerate with each other, the destructive interference produces an effect analogous to electromagnetically induced transparency. Furthermore, the Q-factor can be extremely enlarged with dielectric split nanodisk arrays, where the present of the split gap does not induce additional losses. Instead, the coupling between the two interfering modes is modified by adjusting the gap width, which makes it possible to achieve high Q-factor and strong near-field enhancements around and inside of the split disks simultaneously. It is shown that the Q-factor is approaching to 106 when the gap width is about 110 nm, and the near-field enhancements around and inside of the split disks are about two orders stronger than that of the single disk.

20.
J Am Chem Soc ; 139(38): 13579-13584, 2017 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-28862448

RESUMO

A direct hydroalkylation of disubstituted alkynes with unfunctionalized ethers and amides was achieved in an atom-efficient and additive-free manner through the synergistic combination of photoredox and nickel catalysis. The protocol was effective with a wide range of internal alkynes, providing products in a highly selective fashion. Notably, the observed regioselectivity is complementary to conventional radical addition processes. Mechanistic investigations suggest that the photoexcited iridium catalyst facilitated the nickel activation via single-electron transfer.

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