Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
Ann Clin Microbiol Antimicrob ; 22(1): 99, 2023 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-37946238

RESUMEN

BACKGROUND: Clinically, a large part of inflammatory bowel disease (IBD) patients is complicated by oral lesions. Although previous studies proved oral microbial dysbiosis in IBD patients, the bacterial community in the gastrointestinal (GI) tract of those IBD patients combined with oral ulcers has not been profiled yet. METHODS: In this study, we enrolled four groups of subjects, including healthy controls (CON), oral ulcer patients (OU), and ulcerative colitis patients with (UC_OU) and without (UC) oral ulcers. Bio-samples from three GI niches containing salivary, buccal, and fecal samples, were collected for 16S rRNA V3-V4 region sequencing. Bacterial abundance and related bio-functions were compared, and data showed that the fecal microbiota was more potent than salivary and buccal microbes in shaping the host immune system. ~ 22 UC and 10 UC_OU 5-aminosalicylate (5-ASA) routine treated patients were followed-up for six months; according to their treatment response (a decrease in the endoscopic Mayo score), they were further sub-grouped as responding and non-responding patients. RESULTS: We found those UC patients complicated with oral ulcers presented weaker treatment response, and three oral bacterial genera, i.e., Fusobacterium, Oribacterium, and Campylobacter, might be connected with treatment responding. Additionally, the salivary microbiome could be an indicator of treatment responding in 5-ASA routine treatment rather than buccal or fecal ones. CONCLUSIONS: The fecal microbiota had a strong effect on the host's immune indices, while the oral bacterial microbiota could help stratification for ulcerative colitis patients with oral ulcers. Additionally, the oral microbiota had the potential role in reflecting the treatment response of UC patients. Three oral bacteria genera (Fusobacterium, Oribacterium, and Campylobacter) might be involved in UC patients with oral ulcers lacking treatment responses, and monitoring oral microbiota may be meaningful in assessing the therapeutic response in UC patients.


Asunto(s)
Colitis Ulcerosa , Microbioma Gastrointestinal , Enfermedades Inflamatorias del Intestino , Microbiota , Úlceras Bucales , Humanos , Colitis Ulcerosa/tratamiento farmacológico , Colitis Ulcerosa/microbiología , Úlceras Bucales/tratamiento farmacológico , ARN Ribosómico 16S/genética , Microbioma Gastrointestinal/genética , Enfermedades Inflamatorias del Intestino/microbiología , Bacterias/genética , Heces/microbiología , Mesalamina
2.
Inorg Chem ; 61(28): 10756-10767, 2022 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-35794725

RESUMEN

The electronic and nonlinear optical (NLO) properties of BN-substituted graphynes and the corresponding alkali-doped hybrid systems have been determined using density functional theory. When the carbon atoms in the graphyne are replaced by BN pairs, the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap (Egap) increases to some extent, and the static first hyperpolarizabilities (ß0) of the novel systems hardly increase. However, when an alkali atom is introduced on the surface of BN-substituted graphyne, the doping effect can effectively modulate the electronic and NLO properties. Doping the alkali atom can significantly narrow the wide Egap of BN-substituted graphynes in the range of 1.03-2.03 eV. Furthermore, the doping effect brings considerable ß0 values to these alkali-doped systems, which are 52-3609 au for Li-doped systems and 3258-211 053 au for Na/K-doped ones. The result reveals that the ß0 values of alkali-doped complexes are influenced by the atomic number of alkali metals and the proportion of BN pairs. The nature of the excellent NLO responses of alkali-doped complexes can be understood by the low excitation energy of the crucial excited state and the analysis of the first hyperpolarizability density. Besides, these alkali-doped complexes have a deep-ultraviolet working region. Therefore, the combined effect of alkali metal doping and BN substitution can be an excellent strategy to design novel high-performance NLO materials based on graphyne.

3.
Materials (Basel) ; 14(10)2021 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-34069760

RESUMEN

Oil pollution is caused by the frequent discharge of contaminated industrial wastewater and accidental oil spills and is a severe environmental and health concern. Therefore, efficient materials and processes for effective oil-water separation are being developed. Herein, SiO2-Na2SiO3-coated stainless steel fibers (SSF) with underwater superoleophobic and low-adhesion properties were successfully prepared via a one-step hydrothermal process. The modified surfaces were characterized with scanning electron microscopy (SEM), and contact angle measurements to observe the surface morphology, confirm the successful incorporation of SiO2, and evaluate the wettability, as well as with X-ray diffraction (XRD). The results revealed that SiO2 nanoparticles were successfully grown on the stainless-steel fiber surface through the facile hydrothermal synthesis, and the formation of sodium silicate was detected with XRD. The SiO2-Na2SiO3-coated SSF surface exhibited superior underwater superoleophobic properties (153-162°), super-hydrophilicity and high separation efficiency for dichloromethane-water, n-hexane-water, tetrachloromethane-water, paroline-water, and hexadecane-water mixtures. In addition, the as-prepared SiO2-Na2SiO3-coated SSF demonstrated superior wear resistance, long-term stability, and re-usability. We suggest that the improved durability may be due to the presence of sodium silicate that enhanced the membrane strength. The SiO2-Na2SiO3-coated SSF also exhibited desirable corrosion resistance in salty and acidic environments; however, further optimization is needed for their use in basic media. The current study presents a novel approach to fabricate high-performance oil-water separation membranes.

4.
Carbohydr Polym ; 261: 117850, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33766346

RESUMEN

ß-Glucans are widely found in plants and microorganisms, which has a variety of functional activities. During production and application, interactions with other components have a great influence on the structure and functional properties of ß-glucan. In this paper, interactions (including non-covalent interaction and free-radical reaction) between natural product derived ß-glucan and ascorbic acid, polyphenols, bile acids/salts, metal ion or other compounds were summarized. Besides, the mechanism and influence factors of interactions between ß-glucan and small-molecule compounds, and their effects on the functional properties of ß-glucan were detailed. This review aims to develop an understanding and practical suggestions on interactions between ß-glucan and small-molecule compounds, which is expected to provide a useful reference for processing and application.

5.
Brain Stimul ; 11(1): 134-157, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29122535

RESUMEN

We present device standards for low-power non-invasive electrical brain stimulation devices classified as limited output transcranial electrical stimulation (tES). Emerging applications of limited output tES to modulate brain function span techniques to stimulate brain or nerve structures, including transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and transcranial pulsed current stimulation (tPCS), have engendered discussion on how access to technology should be regulated. In regards to legal regulations and manufacturing standards for comparable technologies, a comprehensive framework already exists, including quality systems (QS), risk management, and (inter)national electrotechnical standards (IEC). In Part 1, relevant statutes are described for medical and wellness application. While agencies overseeing medical devices have broad jurisdiction, enforcement typically focuses on those devices with medical claims or posing significant risk. Consumer protections regarding responsible marketing and manufacture apply regardless. In Part 2 of this paper, we classify the electrical output performance of devices cleared by the United States Food and Drug Administration (FDA) including over-the-counter (OTC) and prescription electrostimulation devices, devices available for therapeutic or cosmetic purposes, and devices indicated for stimulation of the body or head. Examples include iontophoresis devices, powered muscle stimulators (PMS), cranial electrotherapy stimulation (CES), and transcutaneous electrical nerve stimulation (TENS) devices. Spanning over 13 FDA product codes, more than 1200 electrical stimulators have been cleared for marketing since 1977. The output characteristics of conventional tDCS, tACS, and tPCS techniques are well below those of most FDA cleared devices, including devices that are available OTC and those intended for stimulation on the head. This engineering analysis demonstrates that with regard to output performance and standing regulation, the availability of tDCS, tACS, or tPCS to the public would not introduce risk, provided such devices are responsibly manufactured and legally marketed. In Part 3, we develop voluntary manufacturer guidance for limited output tES that is aligned with current regulatory standards. Based on established medical engineering and scientific principles, we outline a robust and transparent technical framework for ensuring limited output tES devices are designed to minimize risks, while also supporting access and innovation. Alongside applicable medical and government activities, this voluntary industry standard (LOTES-2017) further serves an important role in supporting informed decisions by the public.


Asunto(s)
Estimulación Transcraneal de Corriente Directa/instrumentación , Estimulación Transcraneal de Corriente Directa/normas , Humanos , Gestión de Riesgos , Estados Unidos , United States Food and Drug Administration/legislación & jurisprudencia
6.
Stem Cells ; 32(1): 116-25, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23939814

RESUMEN

We previously found that human mesenchymal stem cells (MSC) or its conditioned medium restored lung protein permeability and reduced alveolar inflammation following Escherichia coli endotoxin-induced acute lung injury (ALI) in an ex vivo perfused human lung in part through the secretion of soluble factors such as keratinocyte growth factor (KGF). Recently, MSC were found to release microvesicles (MVs) that were biologically active because of the presence of mRNA or miRNA with reparative properties. MVs are circular fragments of membrane released from the endosomal compartment as exosomes or shed from the surface membranes. These studies were designed to determine if MVs released by human bone marrow derived MSCs would be effective in restoring lung protein permeability and reducing inflammation in E. coli endotoxin-induced ALI in C57BL/6 mice. The intratracheal instillation of MVs improved several indices of ALI at 48 hours. Compared to endotoxin-injured mice, MVs reduced extravascular lung water by 43% and reduced total protein levels in the bronchoalveolar lavage (BAL) fluid by 35%, demonstrating a reduction in pulmonary edema and lung protein permeability. MVs also reduced the influx of neutrophils and macrophage inflammatory protein-2 levels in the BAL fluid by 73% and 49%, respectively, demonstrating a reduction in inflammation. KGF siRNA-pretreatment of MSC partially eliminated the therapeutic effects of MVs released by MSCs, suggesting that KGF protein expression was important for the underlying mechanism. In summary, human MSC-derived MVs were therapeutically effective following E. coli endotoxin-induced ALI in mice in part through the expression of KGF mRNA in the injured alveolus.


Asunto(s)
Lesión Pulmonar Aguda/terapia , Micropartículas Derivadas de Células/trasplante , Trasplante de Células Madre Mesenquimatosas/métodos , Células Madre Mesenquimatosas/citología , Lesión Pulmonar Aguda/microbiología , Lesión Pulmonar Aguda/patología , Animales , Endotoxinas/toxicidad , Escherichia coli/metabolismo , Humanos , Lipopolisacáridos/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica
7.
Opt Lett ; 37(12): 2292-4, 2012 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-22739885

RESUMEN

High-power supercontinuum spanning over more than an octave was generated using a high power femtosecond fiber laser amplifier and a multicore nonlinear photonic crystal fiber (PCF). Long multicore PCFs (as long as 20 m in our experiments) are shown to enable supercontinuum generation in an isolated fundamental supermode, with the manifold of other PCF modes suppressed due to the strong evanescent fields coupling between the cores, providing a robust 5.4 W coherent supercontinuum output with a high spatial and spectral quality within the range of wavelengths from 500 to 1700 nm.

8.
Opt Lett ; 35(14): 2326-8, 2010 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-20634818

RESUMEN

We use seven-core Yb-doped large-mode-area (LMA) photonic crystal fiber (PCF) to demonstrate phase-locked amplification of 0.7 W, 1 MHz, 1.9 ps laser pulses delivered by an LMA-PCF-laser-LMA-PCF-preamplifier system. Compression of the 24 W output of the multicore LMA-PCF amplifier with a grating compressor yields 110 fs pulses with a peak power up to 150 MW.

9.
Opt Lett ; 35(4): 493-5, 2010 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-20160795

RESUMEN

We examine a hybrid multicore photonic-crystal fiber, where the cores are separated by high-index solid rods and the microstructure cladding is built on a hexagonal lattice of air holes in silica. Antiresonant reflection from high-index solid rods is shown to assist the field confinement in the cores of such a fiber. When the cores are doped with a laser-active material, the maximum gain is achieved for the in-phase supermode, which translates into a high-quality Gaussian-like beam profile in the far field.

10.
J Physiol ; 587(Pt 11): 2663-76, 2009 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-19359370

RESUMEN

Airway and alveolar fluid clearance is mainly governed by vectorial salt movement via apically located rate-limiting Na(+) channels (ENaC) and basolateral Na(+)/K(+)-ATPases. ENaC is regulated by a spectrum of protein kinases, i.e. protein kinase A (PKA), C (PKC), and G (PKG). However, the molecular mechanisms for the regulation of ENaC by cGMP/PKG remain to be elucidated. In the present study, we studied the pharmacological responses of native epithelial Na(+) channels in human Clara cells and human alphabetagammadelta ENaCs expressed in oocytes to cGMP. 8-pCPT-cGMP increased amiloride-sensitive short-circuit current (I(sc)) across H441 monolayers and heterologously expressed alphabetagammadelta ENaC activity in a dose-dependent manner. Similarly, 8-pCPT-cGMP (a PKGII activator) but not 8-Br-cGMP (a PKGI activator) increased amiloride-sensitive whole cell currents in H441 cells in the presence of CFTRinh-172 and diltiazem. In all cases, the cGMP-activated Na(+) channel activity was inhibited by Rp-8-pCPT-cGMP, a specific PKGII inhibitor. This was substantiated by the evidence that PKGII was the sole isoform expressed in H441 cells at the protein level. Importantly, intratracheal instillation of 8-pCPT-cGMP in BALB/c mice increased amiloride-sensitive alveolar fluid clearance by approximately 30%, consistent with the in vitro results. We therefore conclude that PKGII is an activator of lung epithelial Na(+) channels, which may expedite the resolution of oedematous fluid in alveolar sacs.


Asunto(s)
Proteínas Quinasas Dependientes de GMP Cíclico/metabolismo , Canales Epiteliales de Sodio/metabolismo , Alveolos Pulmonares/enzimología , Mucosa Respiratoria/enzimología , Amilorida/farmacología , Animales , Línea Celular , AMP Cíclico/metabolismo , GMP Cíclico/análogos & derivados , GMP Cíclico/farmacología , Proteína Quinasa Dependiente de GMP Cíclico Tipo I , Proteína Quinasa Dependiente de GMP Cíclico Tipo II , Proteínas Quinasas Dependientes de GMP Cíclico/genética , Relación Dosis-Respuesta a Droga , Bloqueadores del Canal de Sodio Epitelial , Canales Epiteliales de Sodio/genética , Humanos , Potenciales de la Membrana , Ratones , Ratones Endogámicos BALB C , Oocitos , Alveolos Pulmonares/efectos de los fármacos , Conejos , Mucosa Respiratoria/efectos de los fármacos , Bloqueadores de los Canales de Sodio/farmacología , Tionucleótidos/farmacología , Transfección , Xenopus
11.
Opt Express ; 16(19): 14987-96, 2008 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-18795035

RESUMEN

Fiber dispersion and nonlinearity management strategy based on a modification of a photonic-crystal fiber (PCF) core with an air hole is shown to facilitate optimization of PCF components for a stable soliton frequency shift and subpetahertz sideband generation through four-wave mixing. Spectral recoil of an optical soliton by a red-shifted dispersive wave, generated through a soliton instability induced by high-order fiber dispersion, is shown to stabilize the soliton self-frequency shift in a highly nonlinear PCF with an air-hole-modified core relative to pump power variations. A fiber with a 2.3-microm-diameter core modified with a 0.9-microm-diameter air hole is used to demonstrate a robust soliton self-frequency shift of unamplified 50-fs Ti: sapphire laser pulses to a central wavelength of about 960 nm, which remains insensitive to variations in the pump pulse energy within the range from 60 to at least 100 pJ. In this regime of frequency shifting, intense high- and low-frequency branches of dispersive wave radiation are simultaneously observed in the spectrum of PCF output. An air-hole-modified-core PCF with appropriate dispersion and nonlinearity parameters is shown to provide efficient four-wave mixing, giving rise to Stokes and anti-Stokes sidebands whose frequency shift relative to the pump wavelength falls within the subpetahertz range, thus offering an attractive source for nonlinear Raman microspectroscopy.


Asunto(s)
Diseño Asistido por Computadora , Cristalización/métodos , Tecnología de Fibra Óptica/instrumentación , Modelos Teóricos , Aire , Simulación por Computador , Diseño de Equipo , Análisis de Falla de Equipo , Fotones , Porosidad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...