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1.
Environ Res ; 252(Pt 3): 119059, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38701891

RESUMEN

Recent studies revealed the un-negligible impact of airborne organophosphate esters (OPEs) on phosphorus (P)-limited ecosystems. Subtropical forests, the global prevalence P-limited ecosystems, contain canopy structures that can effectively sequester OPEs from the atmosphere. However, little is known about the behavior and fate of OPEs in subtropical forest ecosystem, and the impact on the P cycling in this ecosystem. OPE concentrations in the understory air (at two heights), foliage, and litterfall were investigated in a subtropical forest in southern China. The median ∑OPE concentrations were 3149 and 2489 pg/m3 in the upper and bottom air, respectively. Foliage exhibited higher ∑OPE concentrations (median = 386 ng/g dry weight (dw)) compared to litter (median = 267 ng/g dw). The air OPE concentrations were ordered by broadleaved forest > mixed forest > coniferous forest, which corresponds to the results of canopy coverage or leaf area index. The spatial variation of OPEs in foliage and litter was likely caused by the leaf surface functional traits. Higher OPE concentrations were found in the wet season for understory air while in the dry season for foliage and litter, which were attributed to the changes in emission sources and meteorological conditions, respectively. The inverse temporal variation suggests the un-equilibrium partitioning of OPEs between leaf and air. The OPE concentrations during the litter-incubation presented similar temporal trends with those in foliage and litter, indicating the strong interaction of OPEs between the litter layer and the near-soil air, and the efficient buffer of litter layer played in the OPEs partitioning between soil and air. The median OPEs-associated P deposition fluxes through litterfall were 270, 186, and 249 µg P/m2·yr in the broadleaved, mixed, and coniferous forests, respectively. Although the fluxes accounted for approximately 0.2% of the total atmospheric P deposition, their significance to this P-limited ecosystem may not be negligible.


Asunto(s)
Contaminantes Atmosféricos , Monitoreo del Ambiente , Bosques , Hojas de la Planta , China , Hojas de la Planta/química , Contaminantes Atmosféricos/análisis , Organofosfatos/análisis , Ésteres/análisis , Estaciones del Año , Análisis Espacio-Temporal , Árboles
2.
Ecotoxicol Environ Saf ; 277: 116392, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38677065

RESUMEN

Smoking disrupts bone homeostasis and serves as an independent risk factor for the development and progression of osteoporosis. Tobacco toxins inhibit the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), promote BMSCs aging and exhaustion, but the specific mechanisms are not yet fully understood. Herein, we successfully established a smoking-related osteoporosis (SROP) model in rats and mice through intraperitoneal injection of cigarette smoke extract (CSE), which significantly reduced bone density and induced aging and inhibited osteogenic differentiation of BMSCs both in vivo and in vitro. Bioinformatics analysis and in vitro experiments confirmed that CSE disrupts mitochondrial homeostasis through oxidative stress and inhibition of mitophagy. Furthermore, we discovered that CSE induced BMSCs aging by upregulating phosphorylated AKT, which in turn inhibited the expression of FOXO3a and the Pink1/Parkin pathway, leading to the suppression of mitophagy and the accumulation of damaged mitochondria. MitoQ, a mitochondrial-targeted antioxidant and mitophagy agonist, was effective in reducing CSE-induced mitochondrial oxidative stress, promoting mitophagy, significantly downregulating the expression of aging markers in BMSCs, restoring osteogenic differentiation, and alleviating bone loss and autophagy levels in CSE-exposed mice. In summary, our results suggest that BMSCs aging caused by the inhibition of mitophagy through the AKT/FOXO3a/Pink1/Parkin axis is a key mechanism in smoking-related osteoporosis.


Asunto(s)
Células Madre Mesenquimatosas , Mitofagia , Osteoporosis , Animales , Mitofagia/efectos de los fármacos , Células Madre Mesenquimatosas/efectos de los fármacos , Ratones , Ratas , Osteoporosis/inducido químicamente , Osteoporosis/patología , Nicotiana/efectos adversos , Proteína Forkhead Box O3/metabolismo , Estrés Oxidativo/efectos de los fármacos , Masculino , Ratas Sprague-Dawley , Osteogénesis/efectos de los fármacos , Senescencia Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Humo/efectos adversos , Ubiquitina-Proteína Ligasas/metabolismo , Mitocondrias/efectos de los fármacos , Proteínas Quinasas/metabolismo , Ratones Endogámicos C57BL , Células de la Médula Ósea/efectos de los fármacos
3.
Small ; 19(6): e2205540, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36461727

RESUMEN

Solid catalyst is widely recognized as an effective strategy to control the chirality of single-walled carbon nanotubes (SWNTs). However, it is still not compatible with high density in horizontal arrays. "Trojan" catalysts strategy is one of the most effective methods to realize SWNTs with high density and has great potential in chirality control. Here, the co-realization of high density and chirality controlling for SWNTs in a low-temperature growth process is reported based on the developed solid "Trojan" catalyst. High temperature "Trojan" catalyst formation process provides sufficient catalyst number to acquire high density. These liquid "Trojan" catalysts are cooled to solid state by adopting low growth temperature (540 °C), which can be good template to realize the chirality controlling of SWNTs with exposing six-fold symmetry face, (111). Finally, (9, 6) and (13, 1) SWNTs enriched horizontal array with the purity of ≈90% and density of 4 tubes µm-1 is realized. The comparison between the distribution of initial catalysts and the density of as-grown tubes indicates no sacrificing on catalysts number to improve chirality selectivity. This work opens a new avenue on the catalyst's design and chirality controlling in SWNTs growth.

4.
Fish Shellfish Immunol ; 135: 108643, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36871630

RESUMEN

Rainbow trout (Oncorhynchus mykiss), an important economic cold-water fish worldwide, is severely threatened by viruses and bacteria in the farming industry. The vibriosis outbreak has caused a significant setback to aquaculture. Vibrio anguillarum, one of the common disease-causing vibriosis associated with severe lethal vibriosis in aquaculture, infects fish mainly by adsorption and invasion of the skin, gills, lateral line and intestine. To investigate the defense mechanism of rainbow trout against the pathogen after infection with Vibrio anguillarum, trout were intraperitoneally injected by Vibrio anguillarum and divided into symptomatic group (SG) and asymptomatic group (AG) according to the phenotype. RNA-Seq technology was used to evaluate the transcriptional signatures of liver, gill and intestine of trout injected with Vibrio anguillarum (SG and AG) and corresponding control groups (CG(A) and CG(B)). The GO and KEGG enrichment analyses were used to investigate the mechanisms underlying the differences in susceptibility to Vibrio anguillarum. Results showed that in SG, immunomodulatory genes in the cytokine network were activated and tissue function-related genes were down-regulated, while apoptosis mechanisms were activated. However, AG responded to Vibrio anguillarum infection by activating complement related immune defenses, while metabolism and function related genes were up-regulated. Conclusively, a rapid and effective immune and inflammatory response can successfully defend Vibrio anguillarum infection. However, a sustained inflammatory response can lead to tissue and organ damage and cause death. Our results may provide a theoretical basis for breeding rainbow trout for disease resistance.


Asunto(s)
Enfermedades de los Peces , Oncorhynchus mykiss , Vibriosis , Vibrio , Animales , Branquias , Vibrio/fisiología , Perfilación de la Expresión Génica/veterinaria , Hígado , Intestinos
5.
J Periodontal Res ; 58(5): 1082-1095, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37533377

RESUMEN

BACKGROUND AND OBJECTIVES: Cigarette smoking has been reported as an independent risk factor for periodontitis. Tobacco toxins affect periodontal tissue not only locally but also systemically, leading to the deterioration and recurrence of periodontitis. However, the mechanism of cigarette smoke-related periodontitis (CSRP) is unclear and thus lacks targeted treatment strategies. Quercetin, a plant-derived polyphenolic flavonoid, has been reported to have therapeutic effects on periodontitis due to its documented antioxidant activity. This study aimed to evaluate the effects of quercetin on CSRP and elucidated the underlying mechanism. METHODS: The cigarette smoke-related ligature-induced periodontitis mouse model was established by intraperitoneal injection of cigarette smoke extract (CSE) and silk ligation of bilateral maxillary second molars. Quercetin was adopted by gavage as a therapeutic strategy. Micro-computed tomography was used to evaluate the alveolar bone resorption. Immunohistochemistry detected the oxidative stress and autophagy markers in vivo. Cell viability was determined by Cell Counting Kit-8, and oxidative stress levels were tested by 2,7-dichlorodihydrofluorescein diacetate probe and lipid peroxidation malondialdehyde assay kit. Alkaline phosphatase and alizarin red staining were used to determine osteogenic differentiation. Network pharmacology analysis, molecular docking, and western blot were utilized to elucidate the underlying molecular mechanism. RESULTS: Alveolar bone resorption was exacerbated and oxidative stress products were accumulated during CSE exposure in vivo. Oxidative stress damage induced by CSE caused inhibition of osteogenic differentiation in vitro. Quercetin effectively protected the osteogenic differentiation of human periodontal ligament cells (hPDLCs) and periodontal tissue by upregulating the expression of Beclin-1 thus to promote autophagy and reduce oxidative stress damage. CONCLUSION: Our results established a role of oxidative stress damage and autophagy dysfunction in the mechanism of CSE-induced destruction of periodontal tissue and hPDLCs, and provided a potential application value of quercetin to ameliorate CSRP.


Asunto(s)
Resorción Ósea , Fumar Cigarrillos , Periodontitis , Ratones , Animales , Humanos , Quercetina/farmacología , Quercetina/uso terapéutico , Osteogénesis , Fumar Cigarrillos/efectos adversos , Simulación del Acoplamiento Molecular , Microtomografía por Rayos X , Periodontitis/metabolismo , Diferenciación Celular , Autofagia , Células Cultivadas
6.
Altern Ther Health Med ; 29(5): 278-283, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37083649

RESUMEN

Background and Objective: miR-22-3p functions as a tumor suppressor by targeting a variety of downstream genes, while its role and downstream targets in gastric cancer (GC) remain to be determined. We aimed to explore the role of miR-22-3p in gastric cancer and the potential mechanism. Methods: miR-22-3p mimic and inhibitor were used to overexpress or knockdown the expression of miR-22-3p separately. Quantitative real-time PCR (RT-qPCR) and Western blot were used to analyse the abundance of mRNA or protein level respectively. CCK-8 assay, cell colony formation assay, and flow cytometry were implemented to investigate the effect of miR-22-3p on gastric cancer cell proliferation and apoptosis. Luciferase assay was used to evaluate the role of miR-22-3p on the expression of glycolytic enzyme enolase 1 (ENO1). Results: In this study, we found that miR-22-3p was downregulated in GC cells. By transfecting the cells with miR-22-3p inhibitors or mimics, we showed that miR-22-3p suppressed GC cell proliferation and migration, as well as triggered cell death. In addition, we discovered that miR-22-3p was engaged in glycolysis by controlling the generation of lactate as well as the consumption of glucose. TargetScan database suggested that the ENO1 may be a target of the miR-22-3p, and the luciferase experiment verified this hypothesis. Recovery assays showed that the proliferation and migration of GC cells suppressed by miR-22-3p could be rescued by overexpression of ENO1. Conclusion: Collectively, we identified a new axis of miR-22-3p/ENO1 for GC development, which could be investigated as a therapeutic target for GC.


Asunto(s)
MicroARNs , Neoplasias Gástricas , Humanos , MicroARNs/genética , MicroARNs/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Línea Celular Tumoral , Proliferación Celular , Fosfopiruvato Hidratasa/genética , Proteínas de Unión al ADN , Biomarcadores de Tumor , Proteínas Supresoras de Tumor/genética
7.
Fish Shellfish Immunol ; 121: 1-11, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34974153

RESUMEN

Mitogen-activated protein kinase kinases (MKKs) are intermediate kinases of mitogen-activated protein kinases (MAPKs) signaling pathways. MKKs are activated by mitogen-activated protein kinase kinase kinase (MKKK) and then the activated MKKs trigger the activation of downstream MAPKs. MAPK signaling pathways play an important role in regulating immune functions including apoptosis and inflammation. However, studies on identification and characterization of mkk repertoire in rainbow trout (Oncorhynchus mykiss) are still limited. Trout experienced 4 rounds (4R) of whole genome duplication (WGD), thus exhibiting increased paralogs of mkks with potentially functional diversity. In this study, we identified 17 mkk genes in trout and the following bacterial challenge (Vibrio anguillarum) studies showed functional diversity of different mkk subtypes. Vibrio anguillarum infection resulted in significantly up-regulated mkk2 subtypes in spleen and liver, and mkk4b3 in spleen, suggesting immunomodulation was regulated by activation of ERK, p38 and JNK pathways. Compared to other mkk subtypes, mkk6s were down-regulated in symptomatic group, rather than asymptomatic group. The organisms present negative feedback on MAPK activation, thus reducing extra damage to cells. We observed down-regulated mkk6s with up-regulated genes (dusp1 & dusp2) involved in negative feedback of MAPK activation. Based on these results, we might propose the distinct expression patterns of genes associated with MAPK pathways resulted in different phenotypes and symptoms of trout in response to bacterial challenge.


Asunto(s)
Proteínas de Peces , Quinasas de Proteína Quinasa Activadas por Mitógenos , Oncorhynchus mykiss , Vibriosis , Animales , Proteínas de Peces/genética , Proteínas de Peces/metabolismo , Quinasas de Proteína Quinasa Activadas por Mitógenos/genética , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Oncorhynchus mykiss/genética , Oncorhynchus mykiss/metabolismo , Vibrio , Vibriosis/veterinaria
8.
Environ Res ; 214(Pt 1): 113840, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35810804

RESUMEN

Combustion of domestic solid fuels is a significant source of polycyclic aromatic hydrocarbons (PAHs). Some oxygenated PAHs (o-PAHs) and PAHs with molecular weight of 302 (MW302 PAHs) are more toxic than the traditional 16 priority PAHs, whereas their emissions were much less elucidated. This study characterized the size-dependent emissions of parent PAHs (p-PAHs), o-PAHs, and MW302 PAHs from various combustion sources. The estimated emission factors (eEFs) from biomass burning sources were highest for most of the PAHs (391-8928 µg/kg), much higher than that of anthracite coal combustion (43.0-145 µg/kg), both which were operated in an indoor stove. Cigarette smoking had a high eEF of o-PAHs (240 ng/g). MW302 PAHs were not found in the emissions of smoking, cooking, and vehicular exhausts. Particle-size distributions of PAHs were compound- and source-dependent, and the tendency to associate with smaller particles was observed especially in biomass burning and cigarette smoking sources. Furthermore, the inter-source differences in PAH eEFs were associated with their dominance in fine particles. PAH composition profiles also varied with the particle size, showing increasing contributions of large-molecule PAHs with decreasing sizes in most cases. The size distributions of p-PAHs are much more significantly dependent on their n-octanol/air partition coefficients and vapor pressures than those of o-PAHs, suggesting differences in mechanisms governing their distributions. Several molecular diagnostic ratios (MDRs), including two based on MW302 PAHs, specific to these combustion scenarios were identified. However, the MDRs within some sources are also strongly size-dependent, providing a new explanation for the uncertainty in their application for source identification of PAHs. This work also highlights the necessity for understanding the size-resolved atmospheric behaviors and fate of PAHs after their emission.


Asunto(s)
Contaminantes Atmosféricos , Hidrocarburos Policíclicos Aromáticos , China , Carbón Mineral , Monitoreo del Ambiente , Tamaño de la Partícula , Emisiones de Vehículos
9.
BMC Pulm Med ; 22(1): 299, 2022 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-35927662

RESUMEN

OBJECTIVE: To investigate the circumstances that lead to acute exacerbation readmission of elderly patients with chronic obstructive pulmonary disease (COPD) within 30 days and to explore the influencing factors of readmission using a structural equation model to provide evidence for medical staff so that effective intervention measures can be taken. METHODS: The convenience sampling method was used to select 1120 elderly patients with COPD from the respiratory departments of thirteen general hospitals in the Ningxia region, China, from April 2019 to August 2020, who then completed a survey questionnaire. The survey questionnaire contained a general data questionnaire and the modified Medical Research Council, activities of daily living, geriatric depression scale and COPD assessment test scales. RESULTS: The readmission rate of patients with COPD presenting with acute exacerbation within 30 days was determined to be 21.52%. Therefore, the modified model measures data accurately. The results showed that seasonal factors, family rehabilitation, age factors and overall health status were direct factors in the acute exacerbation readmission of patients with COPD within 30 days of hospital discharge. Smoking is not only a direct factor for acute exacerbation readmission within 30 days but also an indirect factor through disease status; disease status and chronic disease are not only direct factors for acute exacerbation readmission within 30 days but also indirect factors through the patient's overall health status. CONCLUSIONS: The rate of patients with COPD presenting with acute exacerbation within 30 days is high; while taking measures to prevent readmission based on influencing factors that directly impact admission rates, attention should also be paid to the interaction between these factors.


Asunto(s)
Readmisión del Paciente , Enfermedad Pulmonar Obstructiva Crónica , Actividades Cotidianas , Anciano , Progresión de la Enfermedad , Humanos , Alta del Paciente , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Estudios Retrospectivos
10.
Appl Environ Microbiol ; 87(24): e0155221, 2021 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-34586903

RESUMEN

Silicate mineral weathering (dissolution) plays important roles in soil formation and global biogeochemical cycling. In this study, a combination of genomics, transcriptomics, and genetics was used to identify the molecular basis of mineral weathering activity and acid tolerance in Pseudomonas azotoformans F77. Biotite was chosen as a silicate mineral to investigate mineral weathering. The genome of strain F77 was sequenced, and the genes significantly upregulated when grown in the presence of biotite included mineral weathering-related genes associated with gluconic acid metabolism, flagellar assembly, and pilus biosynthesis and acid tolerance-related genes associated with neutralizing component production, reducing power, and proton efflux. The biotite-weathering behaviors of strain F77 and its mutants that were created by deleting the tkt, tal, and gntP genes, which are involved in gluconic acid metabolism, and the potF, nuoF, and gdtO genes, which are involved in acid tolerance, were determined. The Fe and Al concentrations in the strain F77-inoculated medium increased 2.2- to 13.7-fold compared to the controls. The cell numbers of strain F77 increased over time, while the pH values in the medium ranged from 3.75 to 3.90 between 20 and 36 h of incubation. The release of Al and Fe was significantly reduced in the F77 Δtal, F77 ΔgntP, F77 ΔpotF, and F77 ΔnuoF mutants. Bacterial growth was significantly reduced in the presence of biotite in the F77 ΔpotF and F77 ΔnuoF mutants. Our results demonstrated the acid tolerance of strain F77 and suggested that multiple genes and metabolic pathways in strain F77 are involved in biotite weathering and acid tolerance during the mineral weathering process. IMPORTANCE Acid production and tolerance play important roles in effective and persistent mineral weathering in bacteria, although the molecular mechanisms governing acid production and acid tolerance in bacteria have not been fully elucidated. In this study, the molecular mechanisms underlying biotite (as a silicate mineral) weathering (dissolution) and acid tolerance of P. azotoformans F77 were characterized using genomics, transcriptomics, and genetics analyses. Our results showed that the genes and metabolic pathways for gluconic acid metabolism, flagellar assembly, and pilus biosynthesis may play important roles in mineral weathering by strain F77. Notably, the genes associated with neutralizing component production, reducing power, and proton efflux may be related to acid tolerance in strain F77. The expression of these acid production- and acid tolerance-related genes was observed to be increased by biotite in strain F77. Our findings may help to elucidate the molecular mechanisms governing mineral weathering and, especially, acid tolerance in mineral-weathering bacteria.


Asunto(s)
Minerales/metabolismo , Pseudomonas , Silicatos/metabolismo , Genómica , Fenotipo , Protones , Pseudomonas/genética , Pseudomonas/metabolismo , Transcriptoma
11.
Org Biomol Chem ; 19(18): 4043-4047, 2021 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-33885129

RESUMEN

Herein, we report the synthesis of 2-spirocyclohexylindolines based on a Lewis acid mediated cyclization. This diastereoselective procedure provides the target structures in a straightforward way via dual activation.

12.
Molecules ; 25(1)2020 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-31947805

RESUMEN

Thermal reactions of cobalt(II) salts with flexible N,N'-bis(pyrid-3-ylmethyl)adipoamide (L) and angular 4,4'-sulfonyldibenzoic acid (H2SDA) in H2O and CH3OH afforded a pair of supramolecular isomers: [Co2(L)(SDA)2], 1, and [Co2(L)(SDA)2]⋅CH3OH⋅H2O, 2. The structure of complex 1 can be simplified as a one-dimensional (1D) looped chain with L ligands penetrating into the middles of squares, forming a new type of self-catenated net with the (42⋅54)(4)2(5)2 topology, whereas complex 2 displays a 2-fold interpenetrated 2D net with the rare (42⋅68⋅8⋅104)(4)2-2,6L1 topology. While both complexes 1 and 2 display antiferromagnetism with strong spin-orbital coupling, the antiferromagnetism of 2 is accompanied by a cross-over behavior and probably a spin canting phenomenon.


Asunto(s)
Amidas/química , Ácidos Carboxílicos/química , Cobalto/química , Complejos de Coordinación , Modelos Químicos , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Estructura Molecular
13.
Fish Physiol Biochem ; 45(5): 1627-1647, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31161532

RESUMEN

The 56-day feeding trial was carried out to investigate the effects of dietary tryptophan (Trp) on growth performance, digestive and absorptive enzyme activities, intestinal antioxidant capacity, and appetite and GH-IGF axis-related genes expression of hybrid catfish (Pelteobagrus vachelli♀ × Leiocassis longirostris♂). A total of 864 hybrid catfish (21.82 ± 0.14 g) were fed six different experimental diets containing graded levels of Trp at 2.6, 3.1, 3.7, 4.2, 4.7, and 5.6 g kg-1 diet. The results indicated that dietary Trp increased (P < 0.05) (1) final body weight, percent weight gain, specific growth rate, feed intake, feed efficiency, and protein efficiency ratio; (2) fish body protein, lipid and ash contents, protein, and ash production values; (3) stomach weight, stomach somatic index, liver weight, intestinal weight, length and somatic index, and relative gut length; and (4) activities of pepsin in the stomach; trypsin, chymotrypsin, lipase, and amylase in the pancreas and intestine; and γ-glutamyl transpeptidase, Na+, K+-ATPase, and alkaline phosphatase in the intestine. Dietary Trp decreased malondialdehyde content, increased antioxidant enzyme activities and glutathione content, but downregulated Keap1 mRNA expression, and upregulated the expression of NPY, ghrelin, GH, GHR, IGF1, IGF2, IGF1R, PIK3Ca, AKT1, TOR, 4EBP1, and S6K1 genes. These results indicated that Trp improved hybrid catfish growth performance, digestive and absorptive ability, antioxidant status, and appetite and GH-IGF axis-related gene expression. Based on the quadratic regression analysis of PWG, SGR, and FI, the dietary Trp requirement of hybrid catfish (21.82-39.64 g) was recommended between 3.96 and 4.08 g kg-1 diet (9.4-9.7 g kg-1 of dietary protein).


Asunto(s)
Apetito/efectos de los fármacos , Bagres/genética , Bagres/fisiología , Cruzamientos Genéticos , Intestinos/efectos de los fármacos , Triptófano/farmacología , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Antioxidantes/metabolismo , Dieta/veterinaria , Digestión/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Hormona del Crecimiento/genética , Hormona del Crecimiento/metabolismo , Factor I del Crecimiento Similar a la Insulina/genética , Factor I del Crecimiento Similar a la Insulina/metabolismo , Factor II del Crecimiento Similar a la Insulina/genética , Factor II del Crecimiento Similar a la Insulina/metabolismo , Intestinos/enzimología , Intestinos/fisiología , Triptófano/administración & dosificación
14.
J Xray Sci Technol ; 27(2): 257-272, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30741716

RESUMEN

The total variation (TV) regularization has been widely used in statistically iterative cone-beam computed tomography (CBCT) reconstruction, showing ability to preserve object edges. However, the TV regularization can also produce staircase effect and tend to over-smooth the reconstructed images due to its piecewise constant assumption. In this study, we proposed to use the structure tensor total variation (STV) that penalizes the eigenvalues of the structure tensor for CBCT reconstruction. The STV penalty extends the TV penalty, with many important properties maintained such as convexity and rotation and translation invariance. The STV penalty utilizes gradient information more effectively and has a stronger ability to capture local image structural variation. The objective function was constructed with the penalized weighted least-square (PWLS) strategy and the gradient descent (GD) method was used to optimize the objective function. Besides, we investigated whether the norms involved in the STV penalty affected the reconstruction performance and found that the l1-norm gave the better performance than the l2-norm and l ∞-norm. We also examined performance of the STV penalties constructed using different kernel functions and found that the STV with the Gaussian kernel had the best performance, and the STVs with Uniform, Logistic, and Sigmoid kernels had similar performance to each other. We evaluated our reconstruction method with the STV penalty on computer simulated phantoms and physical phantoms. The results demonstrated that STV led to better reconstruction performance than TV, both visually and quantitatively. For the Catphan 600 physical phantom, the STV1 penalty was 175% and 623% better than the low-dose FDK and the high-dose FDK, and 14% better than the TV penalty at the matched noise level, according to the average contrast-to-noise ratio (CNR); while for the Compressed Sensing simulation phantom, the peak signal to noise ratio (PSNR) of reconstructed results using STV1, STV2, and STV ∞ were 40.67 dB, 38.72 dB, and 37.40 dB, respectively, all being significantly better than 36.84 dB using TV.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Tomografía Computarizada de Haz Cónico Espiral/métodos , Algoritmos , Simulación por Computador , Cabeza/diagnóstico por imagen , Humanos , Fantasmas de Imagen
15.
Nano Lett ; 17(3): 1696-1702, 2017 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-28221809

RESUMEN

Virtually all intercalation compounds exhibit significant changes in unit cell volume as the working ion concentration varies. NaxFePO4 (0 < x < 1, NFP) olivine, of interest as a cathode for sodium-ion batteries, is a model for topotactic, high-strain systems as it exhibits one of the largest discontinuous volume changes (∼17% by volume) during its first-order transition between two otherwise isostructural phases. Using synchrotron radiation powder X-ray diffraction (PXD) and pair distribution function (PDF) analysis, we discover a new strain-accommodation mechanism wherein a third, amorphous phase forms to buffer the large lattice mismatch between primary phases. The amorphous phase has short-range order over ∼1nm domains that is characterized by a and b parameters matching one crystalline end-member phase and a c parameter matching the other, but is not detectable by powder diffraction alone. We suggest that this strain-accommodation mechanism may generally apply to systems with large transformation strains.

16.
Sensors (Basel) ; 17(11)2017 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-29099766

RESUMEN

Air pollution is one of the major problems of the modern world. The popularization and powerful functions of smartphone applications enable people to participate in urban sensing to better know about the air problems surrounding them. Data sampling is one of the most important problems that affect the sensing performance. In this paper, we propose an Adaptive Sampling Scheme for Urban Air Quality (AS-air) through participatory sensing. Firstly, we propose to find the pattern rules of air quality according to the historical data contributed by participants based on Apriori algorithm. Based on it, we predict the on-line air quality and use it to accelerate the learning process to choose and adapt the sampling parameter based on Q-learning. The evaluation results show that AS-air provides an energy-efficient sampling strategy, which is adaptive toward the varied outside air environment with good sampling efficiency.

17.
Nano Lett ; 16(4): 2375-80, 2016 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-26930492

RESUMEN

Alkali ion intercalation compounds used as battery electrodes often exhibit first-order phase transitions during electrochemical cycling, accompanied by significant transformation strains. Despite ∼30 years of research into the behavior of such compounds, the relationship between transformation strain and electrode performance, especially the rate at which working ions (e.g., Li) can be intercalated and deintercalated, is still absent. In this work, we use the LiMnyFe1-yPO4 system for a systematic study, and measure using operando synchrotron radiation powder X-ray diffraction (SR-PXD) the dynamic strain behavior as a function of the Mn content (y) in powders of ∼50 nm average diameter. The dynamically produced strain deviates significantly from what is expected from the equilibrium phase diagrams and demonstrates metastability but nonetheless spans a wide range from 0 to 8 vol % with y. For the first time, we show that the discharge capacity at high C-rates (20-50C rate) varies in inverse proportion to the transformation strain, implying that engineering electrode materials for reduced strain can be used to maximize the power capability of batteries.

18.
Nano Lett ; 15(5): 2917-21, 2015 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-25811762

RESUMEN

In this work we investigated an energy-efficient biotemplated route to synthesize nanostructured FePO4 for sodium-based batteries. Self-assembled M13 viruses and single wall carbon nanotubes (SWCNTs) have been used as a template to grow amorphous FePO4 nanoparticles at room temperature (the active composite is denoted as Bio-FePO4-CNT) to enhance the electronic conductivity of the active material. Preliminary tests demonstrate a discharge capacity as high as 166 mAh/g at C/10 rate, corresponding to composition Na0.9FePO4, which along with higher C-rate tests show this material to have the highest capacity and power performance reported for amorphous FePO4 electrodes to date.

19.
Neurochem Res ; 40(3): 550-60, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25488154

RESUMEN

Chronic neuropathic pain is an unfavourable pathological pain characterised by allodynia and hyperalgesia which has brought considerable trouble to people's physical and mental health, but effective therapeutics are still lacking. MicroRNAs (miRNAs) have been widely studied in the development of neuropathic pain and neuronal inflammation. Among various miRNAs, miR-155 has been widely studied. It is intensively involved in regulating inflammation-associated diseases. However, the role of miR-155 in regulating neuropathic pain development is poorly understood. In the present study, we aimed to investigate whether miR-155 is associated with neuropathic pain and delineate the underlying mechanism. Using a neuropathic pain model of chronic constriction injury (CCI), miR-155 expression levels were markedly increased in the spinal cord. Inhibition of miR-155 significantly attenuated mechanical allodynia, thermal hyperalgesia and proinflammatory cytokine expression. We also demonstrated that miR-155 directly bound with the 3'-untranslated region of the suppressor of cytokine signalling 1 (SOCS1). The expression of SOCS1 significantly decreased in the CCI rat model, but this effect could be reversed by miR-155 inhibition. Furthermore, knockdown of SOCS1 abrogated the inhibitory effects of miR-155 inhibition on neuropathic development and neuronal inflammation. Finally, we demonstrated that inhibition of miR-155 resulted in the suppression of nuclear factor-κB and p38 mitogen-activated protein kinase activation by mediating SOCS1. Our data demonstrate the critical role of miR-155 in regulating neuropathic pain through SOCS1, and suggest that miR-155 may be an important and potential target in preventing neuropathic pain development.


Asunto(s)
MicroARNs/antagonistas & inhibidores , MicroARNs/biosíntesis , Neuralgia/prevención & control , Proteínas Supresoras de la Señalización de Citocinas/fisiología , Animales , Células Cultivadas , Técnicas de Silenciamiento del Gen/métodos , Neuralgia/metabolismo , Oligonucleótidos Antisentido/administración & dosificación , Dimensión del Dolor/efectos de los fármacos , Dimensión del Dolor/métodos , Ratas , Ratas Sprague-Dawley , Transducción de Señal/fisiología , Proteína 1 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/deficiencia
20.
Appl Microbiol Biotechnol ; 99(24): 10639-54, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26278540

RESUMEN

Autotransporters (ATs) are associated with pathogenesis of Avian Pathogenic Escherichia coli (APEC). The molecular characterization of APEC ATs can provide insights about their relevance to APEC pathogenesis. Here, we characterized a conventional autotransporter UpaB in APEC DE205B genome. The upaB existed in 41.9 % of 236 APEC isolates and was predominantly associated with ECOR B2 and D. Our studies showed that UpaB mediates the DE205B adhesion in DF-1 cells, and enhances autoaggregation and biofilm formation of fimbria-negative E. coli AAEC189 (MG1655Δfim) in vitro. Deletion of upaB of DE205B attenuates the virulence in duck model and early colonization in the duck lungs during APEC systemic infection. Furthermore, double and triple deletion of upaB, aatA, and aatB genes cumulatively attenuated DE205B adhesion in DF-1 cells, accompanying with decreased 50 % lethal dose (LD50) in duck model and the early colonization in the duck lungs. However, DE205BΔupaB/ΔaatA/ΔaatB might "compensate" the influence of gene deletion by upregulating the expression of fimbrial adhesin genes yqiL, yadN, and vacuolating autotransporter vat during early colonization of APEC. Finally, we demonstrated that vaccination with recombinant UpaB, AatA, and AatB proteins conferred protection against colisepticemia caused by DE205B infection in duck model.


Asunto(s)
Proteínas de la Membrana Bacteriana Externa/genética , Enfermedades de las Aves/patología , Infecciones por Escherichia coli/veterinaria , Proteínas de Escherichia coli/genética , Escherichia coli/patogenicidad , Eliminación de Gen , Proteínas de Transporte de Membrana/genética , Factores de Virulencia/genética , Animales , Adhesión Bacteriana , Proteínas de la Membrana Bacteriana Externa/metabolismo , Enfermedades de las Aves/microbiología , Patos , Escherichia coli/genética , Infecciones por Escherichia coli/microbiología , Infecciones por Escherichia coli/patología , Proteínas de Escherichia coli/metabolismo , Dosificación Letal Mediana , Pulmón/microbiología , Proteínas de Transporte de Membrana/metabolismo , Virulencia
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