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1.
Org Biomol Chem ; 21(42): 8494-8499, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37861427

RESUMEN

A facile one-pot transformation of benzyl esters into esters, amides, and anhydrides is described. α,α-Dichlorodiphenylmethane and FeCl3 were employed as the chlorinating agent and catalyst respectively to convert benzyl esters into acid chloride intermediates, which directly reacted with alcohols, amines, and carboxylic acids. Various esters, amides, and anhydrides were readily obtained with high yields under mild conditions. This method is promising for the practical synthesis of esters, amides, and anhydrides from benzyl esters.

2.
Nano Lett ; 22(24): 10147-10153, 2022 12 28.
Artículo en Inglés | MEDLINE | ID: mdl-36475760

RESUMEN

The paper demonstrates the effect of the chemical conformation of the -COOH group on the transport characteristic including conductance, rectification, and length effect in molecular junctions (MJs) formed by self-assembled monolayers of carboxylic-terminated thiol molecules. For an alkyl chain shorter than C11, the transport mechanism was attributed to a direct off-resonant tunneling of a hole carrier, located at the Au-S interface, whereas a hopping mechanism was assigned to the alkyl chain longer than the C11 chain located at the -COOH group. The hopping mechanism may be operated by electron transport associated with the breaking of the -OH bonding likely driven by a voltage. Importantly, at the C11 alkyl chain, we observed that the transport carrier operating in MJs could change from a hole carrier into an electron carrier. The result strongly proves that the chemical conformation should be considered in analyzing molecular electronics and provides a basis for the rational design of molecular electronic devices.


Asunto(s)
Electrónica , Compuestos de Sulfhidrilo , Compuestos de Sulfhidrilo/química , Conformación Molecular , Electrodos
3.
Int J Mol Sci ; 23(2)2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-35055132

RESUMEN

Anterior gradient protein 2 homolog (AGR2), an endoplasmic reticulum protein, is secreted in the tumor microenvironment. AGR2 is a member of the disulfide isomerase family, is highly expressed in multiple cancers, and promotes cancer metastasis. In this study, we found that etravirine, which is a non-nucleoside reverse transcriptase inhibitor, could induce AGR2 degradation via autophagy. Moreover, etravirine diminished proliferation, migration, and invasion in vitro. Moreover, in an orthotopic xenograft mouse model, the combination of etravirine and paclitaxel significantly suppressed cancer progression and metastasis. This drug may be a promising therapeutic agent for the treatment of ovarian cancer.


Asunto(s)
Mucoproteínas/metabolismo , Nitrilos/administración & dosificación , Proteínas Oncogénicas/metabolismo , Neoplasias Ováricas/tratamiento farmacológico , Paclitaxel/administración & dosificación , Pirimidinas/administración & dosificación , Inhibidores de la Transcriptasa Inversa/administración & dosificación , Animales , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Sinergismo Farmacológico , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Ratones , Mucoproteínas/genética , Metástasis de la Neoplasia , Nitrilos/farmacología , Proteínas Oncogénicas/genética , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , Paclitaxel/farmacología , Proteolisis , Pirimidinas/farmacología , Inhibidores de la Transcriptasa Inversa/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto
4.
BMC Anesthesiol ; 21(1): 95, 2021 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-33784987

RESUMEN

BACKGROUND: Pneumoperitoneum and Trendelenburg position in laparoscopic surgeries could contribute to postoperative pulmonary dysfunction. In recent years, intraoperative lung-protective mechanical ventilation (LPV) has been reportedly able to attenuate ventilator-induced lung injuries (VILI). Our objectives were to test the hypothesis that LPV could improve intraoperative oxygenation function, pulmonary mechanics and early postoperative atelectasis in laparoscopic surgeries. METHODS: In this randomized controlled clinical trial, 62 patients indicated for elective abdominal laparoscopic surgeries with an expected duration of greater than 2 h were randomly assigned to receive either lung-protective ventilation (LPV) with a tidal volume (Vt) of 7 ml kg- 1 ideal body weight (IBW), 10 cmH2O positive end-expiratory pressure (PEEP) combined with regular recruitment maneuvers (RMs) or conventional ventilation (CV) with a Vt of 10 ml kg- 1 IBW, 0 cmH2O in PEEP and no RMs. The primary endpoints were the changes in the ratio of PaO2 to FiO2 (P/F). The secondary endpoints were the differences between the two groups in PaO2, alveolar-arterial oxygen gradient (A-aO2), intraoperative pulmonary mechanics and the incidence of atelectasis detected on chest x-ray on the first postoperative day. RESULTS: In comparison to CV group, the intraoperative P/F and PaO2 in LPV group were significantly higher while the intraoperative A-aO2 was clearly lower. Cdyn and Cstat at all the intraoperative time points in LPV group were significantly higher compared to CV group (p < 0.05). There were no differences in the incidence of atelectasis on day one after surgery between the two groups. CONCLUSIONS: Lung protective mechanical ventilation significantly improved intraoperative pulmonary oxygenation function and pulmonary compliance in patients experiencing various abdominal laparoscopic surgeries, but it could not ameliorate early postoperative atelectasis and oxygenation function on the first day after surgery. TRIAL REGISTRATION: https://www.clinicaltrials.gov/identifier: NCT04546932 (09/05/2020).


Asunto(s)
Abdomen/cirugía , Respiración con Presión Positiva/métodos , Lesión Pulmonar Inducida por Ventilación Mecánica/prevención & control , Adulto , Anciano , Procedimientos Quirúrgicos Electivos , Femenino , Humanos , Laparoscopía , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Complicaciones Posoperatorias/epidemiología , Atelectasia Pulmonar/epidemiología , Volumen de Ventilación Pulmonar
5.
Molecules ; 26(23)2021 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-34885962

RESUMEN

Halide moieties are essential structures of compounds in organic chemistry due to their popularity and wide applications in many fields such as natural compounds, agrochemicals, and pharmaceuticals. Thus, many methods have been developed to introduce halides into various organic molecules. Recently, visible-light-driven reactions have emerged as useful methods of organic synthesis. Particularly, halogenation strategies using visible light have significantly improved the reaction efficiency and reduced toxicity, as well as promoted reactions under mild conditions. In this review, we have summarized recent studies in visible-light-mediated halogenation (chlorination, bromination, and iodination) with photocatalysts.

6.
Korean J Physiol Pharmacol ; 25(5): 459-466, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34448463

RESUMEN

Cardiovascular disease (CVD) and its complications are the leading cause of morbidity and mortality in the world. Because of the side effects and incomplete recovery from current therapy, stem cell therapy emerges as a potential therapy for CVD treatment, and endothelial progenitor cell (EPC) is one of the key stem cells used for therapeutic applications. The effect of this therapy required the expansion of EPC function. To enhance the EPC activation, proliferation, and angiogenesis using dronedarone hydrochloride (DH) is the purpose of this study. DH received approval for atrial fibrillation treatment and its cardiovascular protective effects were already reported. In this study, DH significantly increased EPC proliferation, tube formation, migration, and maintained EPCs surface marker expression. In addition, DH treatment up-regulated the phosphorylation of AKT and reduced the reactive oxygen species production. In summary, the cell priming by DH considerably improved the functional activity of EPCs, and the use of which might be a novel strategy for CVD treatment.

7.
Biochem Biophys Res Commun ; 516(1): 149-156, 2019 08 13.
Artículo en Inglés | MEDLINE | ID: mdl-31202462

RESUMEN

Anterior gradient protein 2 homolog (AGR2) belongs to the disulfide isomerase family of endoplasmic reticulum proteins. Itis overexpressed in several types of solid tumors, including tumors of the prostate, lung, and pancreas. However, the role of AGR2 in breast cancer and the regulatory mechanisms underlying AGR2 protein expressionare not fullyunderstood. We demonstrated that AGR2 levels are increased under hypoxic conditions and in breast cancer tumors. Mechanistically, Twist1 binds to, and activates the AGR2 promoter via an E-box sequence. Under hypoxic conditions, the increased expression of ARG2 is attenuated when Twist1 levels are reduced by shRNA. Conversely, Twist1 overexpression fully reverses decreased AGR2 levels upon HIF-1α knockdown. Notably, AGR2 is required for Twist1-induced proliferation, migration, and invasion of breast cancer cells. Collectively, these findings extend our understanding of AGR2 regulation in breast cancer and may contribute to development of Twist1-AGR2 targeting therapeutics for breast cancer.


Asunto(s)
Neoplasias de la Mama/genética , Regulación Neoplásica de la Expresión Génica , Mucoproteínas/genética , Proteínas Nucleares/genética , Proteínas Oncogénicas/genética , Proteína 1 Relacionada con Twist/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Femenino , Humanos , Persona de Mediana Edad , Regiones Promotoras Genéticas
8.
Anal Bioanal Chem ; 411(28): 7539-7549, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31641825

RESUMEN

Starting from simple graphite flakes, an electrochemical sensor for sunset yellow monitoring is developed by using a very simple and effective strategy. The direct electrochemical reduction of a suspension of exfoliated graphene oxide (GO) onto a glassy carbon electrode (GCE) surface leads to the electrodeposition of electrochemically reduced oxide at the surface, obtaining GCE/ERGO-modified electrodes. They are characterized by cyclic voltammetry (CV) measurements and field emission scanning electron spectroscopy (FE-SEM). The GCE/ERGO electrode has a high electrochemically active surface allowing efficient adsorption of SY. Using differential pulse voltammetry (DPV) technique with only 2 min accumulation, the GCE/ERGO sensor exhibits good performance to SY detection with a good linear calibration for concentration range varying 50-1000 nM (R2 = 0.996) and limit of detection (LOD) estimated to 19.2 nM (equivalent to 8.9 µg L-1). The developed sensor possesses a very high sensitivity of 9 µA/µM while fabricated with only one component. This electrochemical sensor also displays a good reliability with RSD value of 2.13% (n = 7) and excellent reusability (signal response change < 3.5% after 6 measuring/cleaning cycles). The GCE/ERGO demonstrates a successful practical application for determination of sunset yellow in commercial soft drinks. Graphical abstract.


Asunto(s)
Compuestos Azo/análisis , Bebidas/análisis , Técnicas Electroquímicas/instrumentación , Colorantes de Alimentos/análisis , Grafito/química , Calibración , Cromatografía Líquida de Alta Presión , Límite de Detección , Reproducibilidad de los Resultados
9.
JAMA ; 322(19): 1877-1886, 2019 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-31742630

RESUMEN

Importance: Umbilical cord milking as an alternative to delayed umbilical cord clamping may provide equivalent benefits to preterm infants, but without delaying resuscitation. Objective: To determine whether the rates of death or severe intraventricular hemorrhage differ among preterm infants receiving placental transfusion with umbilical cord milking vs delayed umbilical cord clamping. Design, Setting, and Participants: Noninferiority randomized clinical trial of preterm infants (born at 23-31 weeks' gestation) from 9 university and private medical centers in 4 countries were recruited and enrolled between June 2017 and September 2018. Planned enrollment was 750 per group. However, a safety signal comprising an imbalance in the number of severe intraventricular hemorrhage events by study group was observed at the first interim analysis; enrollment was stopped based on recommendations from the data and safety monitoring board. The planned noninferiority analysis could not be conducted and a post hoc comparison was performed instead. Final date of follow-up was December 2018. Interventions: Participants were randomized to umbilical cord milking (n = 236) or delayed umbilical cord clamping (n = 238). Main Outcomes and Measures: The primary outcome was a composite of death or severe intraventricular hemorrhage to determine noninferiority of umbilical cord milking with a 1% noninferiority margin. Results: Among 540 infants randomized, 474 (88%) were enrolled and completed the trial (mean gestational age of 28 weeks; 46% female). Twelve percent (29/236) of the umbilical cord milking group died or developed severe intraventricular hemorrhage compared with 8% (20/238) of the delayed umbilical cord clamping group (risk difference, 4% [95% CI, -2% to 9%]; P = .16). Although there was no statistically significant difference in death, severe intraventricular hemorrhage was statistically significantly higher in the umbilical cord milking group than in the delayed umbilical cord clamping group (8% [20/236] vs 3% [8/238], respectively; risk difference, 5% [95% CI, 1% to 9%]; P = .02). The test for interaction between gestational age strata and treatment group was significant for severe intraventricular hemorrhage only (P = .003); among infants born at 23 to 27 weeks' gestation, severe intraventricular hemorrhage was statistically significantly higher with umbilical cord milking than with delayed umbilical cord clamping (22% [20/93] vs 6% [5/89], respectively; risk difference, 16% [95% CI, 6% to 26%]; P = .002). Conclusions and Relevance: In this post hoc analysis of a prematurely terminated randomized clinical trial of umbilical cord milking vs delayed umbilical cord clamping among preterm infants born at less than 32 weeks' gestation, there was no statistically significant difference in the rate of a composite outcome of death or severe intraventricular hemorrhage, but there was a statistically significantly higher rate of severe intraventricular hemorrhage in the umbilical cord milking group. The early study termination and resulting post hoc nature of the analyses preclude definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT03019367.


Asunto(s)
Hemorragia Cerebral Intraventricular/prevención & control , Constricción , Enfermedades del Prematuro/prevención & control , Recien Nacido Prematuro , Cordón Umbilical , Terminación Anticipada de los Ensayos Clínicos , Femenino , Edad Gestacional , Humanos , Lactante , Muerte del Lactante , Recién Nacido , Enfermedades del Prematuro/mortalidad , Masculino , Evaluación de Resultado en la Atención de Salud , Embarazo
10.
J Am Chem Soc ; 140(31): 10025-10033, 2018 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-29990425

RESUMEN

One major goal of organometallic chemists is the direct functionalization of the bonds most recurrent in organic molecules: C-H, C-C, C-O, and C-N. An even grander challenge is C-C bond formation when both precursors are of this category. Parallel to this is the synthetic goal of achieving reaction selectivity that contrasts with conventional methods. Electrophilic aromatic substitution (EAS) via Friedel-Crafts acylation is the most renowned method for the synthesis of aryl ketones, a common structural motif of many pharmaceuticals, agrochemicals, fragrances, dyes, and other commodity chemicals. However, an EAS synthetic strategy is only effective if the desired site for acylation is in accordance with the electronic-controlled regioselectivity of the reaction. Herein we report steric-controlled regioselective arene acylation with salicylate esters via iridium catalysis to access distinctly substituted benzophenones. Experimental and computational data indicate a unique reaction mechanism that integrates C-O activation and C-H activation with a single iridium catalyst without an exogenous oxidant or base. We disclose an extensive exploration of the synthetic scope of both the arene and the ester components, culminating in the concise synthesis of the potent anticancer agent hydroxyphenstatin.

11.
J Pediatr ; 194: 76-80, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29246467

RESUMEN

OBJECTIVE: To compare the effect of umbilical cord milking vs delayed cord clamping (DCC) on neurodevelopmental and health outcomes in very preterm infants at 22-26 months of corrected age. STUDY DESIGN: Neurodevelopmental outcomes at 2 years of age were assessed using the Bayley Scales of Infant Development, third edition, and a standardized neurologic examination. Data regarding pulmonary morbidities, neurosensory impairments, and hospitalizations were obtained by parental interview. Intention-to-treat was used for primary analyses. RESULTS: Of the 197 infants enrolled in the original study there were 15 deaths, 5 in the umbilical cord milking group and 10 in DCC group. Of the remaining infants, 135 (74%) were assessed at 22-26 months of corrected age. Demographics in umbilical cord milking (n = 70) and DCC (n = 65) groups were similar. Infants randomized to umbilical cord milking at birth had significantly higher cognitive and language composite scores, and were less likely to have a cognitive composite score of <85 (4% vs 15%; P = .04). Motor function was similar in both groups. There were no differences in the incidences of mild or moderate to severe neurodevelopmental impairment, hearing or visual impairments, pulmonary morbidities, or rehospitalizations between the 2 groups. CONCLUSIONS: Infants randomized to umbilical cord milking had higher language and cognitive scores compared with those randomized to DCC. There was no difference in rates of mild or moderate to severe neurodevelopmental impairment. TRIAL REGISTRATION: clinicaltrials.gov: NCT01434732.


Asunto(s)
Desarrollo Infantil/fisiología , Actividad Motora/fisiología , Cordón Umbilical/cirugía , Preescolar , Cognición , Estudios de Cohortes , Femenino , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Masculino , Factores de Tiempo
12.
Fish Shellfish Immunol ; 79: 284-293, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29778843

RESUMEN

In this study, we examined the synergistic effects of a diet-administered synbiotic comprising galactooligosaccharide (GOS) and the probiotic Lactobacillus plantarum 7-40 on immune responses, immune-related gene expressions, and disease resistance to Vibrio alginolyticus in white shrimp Litopenaeus vannamei. To unravel the regulatory role of the synbiotic in activating the immune system of shrimp, 1H nuclear magnetic resonance (NMR)-based metabolomic analysis were used to investigate hepatopancreas metabolites, then significantly altered metabolites were confirmed in both the hepatopancreas and plasma by reverse-phase high-performance liquid chromatography (RP-HPLC) and spectrophotometric analysis. Shrimp were fed four experimental diets for 60 days, including a basal diet with no GOS or probiotic (control), 0.4% GOS (PRE), probiotic (PRO), and 0.4% GOS in combination with the probiotic (SYN). Results showed that the SYN diet significantly increased survival of L. vannamei 24 h after a V. alginolyticus injection. Immune parameters such as phenoloxidase activity, respiratory bursts, phagocytic activity and gene expressions, including prophenoloxidase I, serine proteinase, and peroxinectin, of shrimp fed the SYN diet significantly increased, compared to the other treatments and control. In addition, results from the 1H NMR analysis revealed that 22 hepatopancreas metabolites were matched and identified between the SYN and control groups, among which three metabolites, i.e., inosine monophosphate (IMP), valine, and betaine, significantly increased in the SYN group. Confirmation using RP-HPLC and spectrophotometric methods showed that IMP presented high amounts in the hepatopancreas, but not in the plasma of shrimp; in contrast, valine and betaine metabolites were in high concentrations in both the hepatopancreas and plasma. Our results suggested that GOS and the probiotic had a synergistic effect on enhancing immunity and disease resistance of L. vannamei against V. alginolyticus infection through inducing syntheses of a nucleotide (IMP), a branched amino acid (valine), and a methyl group donor (betaine) in the hepatopancreas, which were then released into the plasma and directly taken up by hemocytes, resulting in a triggering of melanization and phagocytosis processes in cells.


Asunto(s)
Expresión Génica/inmunología , Metaboloma/inmunología , Penaeidae/genética , Penaeidae/inmunología , Simbióticos , Vibrio alginolyticus/fisiología , Animales , Proteínas de Artrópodos/genética , Proteínas de Artrópodos/inmunología , Proteínas de Artrópodos/metabolismo , Galactosa/farmacología , Inmunidad Innata , Lactobacillus plantarum/química , Oligosacáridos/farmacología
13.
Sensors (Basel) ; 18(7)2018 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-29973538

RESUMEN

Photogrammetric processing is available in various software solutions and can easily deliver 3D pointclouds as accurate as 1 pixel. Certain applications, e.g., very accurate shape reconstruction in industrial metrology or change detection for deformation studies in geosciences, require results of enhanced accuracy. The tie-point extraction step is the opening in the photogrammetric processing chain and therefore plays a key role in the quality of the subsequent image orientation, camera calibration and 3D reconstruction. Improving its precision will have an impact on the obtained 3D. In this research work we describe a method which aims at enhancing the accuracy of image orientation by adding a second iteration photogrammetric processing. The result from the classical processing is used as a priori information to guide the extraction of refined tie-points of better photogrammetric quality. Evaluated on indoor and UAV acquisitions, the proposed methodology shows a significant improvement on the obtained 3D point accuracy.

14.
Molecules ; 23(11)2018 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-30380637

RESUMEN

The reaction of the previously known bis(6-diphenylphosphinoacenaphthyl-5-)telluride (6-Ph2P-Ace-5-)2Te (IV) with (CO)5ReCl and (CO)5MnBr proceeded with the liberation of CO and provided fac-(6-Ph2P-Ace-5-)2TeM(X)(CO)3 (fac-1: M = Re, X = Cl; fac-2: M = Mn, X = Br), in which IV acts as bidentate ligand. In solution, fac-1 and fac-2 are engaged in a reversible equilibrium with mer-(6-Ph2P-Ace-5-)2TeM(X)(CO)3 (mer-1: M = Re, X = Cl; mer-2: M = Mn, X = Br). Unlike fac-1, fac-2 is prone to release another equivalent of CO to give (6-Ph2P-Ace-5-)2TeMn(Br)(CO)2 (3), in which IV serves as tridentate ligand.


Asunto(s)
Manganeso/química , Compuestos Organometálicos/química , Renio/química , Técnicas de Química Sintética , Cristalografía por Rayos X , Ligandos , Espectroscopía de Resonancia Magnética , Estructura Molecular , Compuestos Organometálicos/síntesis química , Telurio/química
15.
Fish Shellfish Immunol ; 65: 235-243, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28454818

RESUMEN

This study aimed to unravel the regulatory roles of choline in activating immune responses and disease resistance of the orange-spotted grouper Epinephelus coioides. Fish were fed a choline-supplemented diet at 1 g kg-1 of feed for 30 days. Fish fed a fish meal basal diet without choline-supplement served as controls. At the end of the feeding trial, fish were challenged with Vibrio alginolyticus. Meanwhile, plasma proteomics of fish in each group were also evaluated by two-dimensional gel electrophoresis (2-DE), and differentially expressed proteins were identified by tandem mass spectrophotometry (MS/MS), then a Western blot analysis or real-time polymerase chain reaction was used to confirm differential expressions of immune-enhancing proteins. Results showed that choline significantly increased survival of E. coioides 48 days after being injected with V. alginolyticus. From maps of plasma proteins, a comparative analysis between the control and choline groups revealed that 111 spots matched, with 26 altered expression spots in the choline group. Of these 26 spots, 16 were upregulated and 10 downregulated. After protein identification by reverse-phase nano-high-performance liquid chromatography-electrospray ionization MS/MS analysis, eight of 26 proteins were found to be immune-related proteins, all of which were upregulated, including complement 3 (C3), alpha-2-macroglobulin-P-like isoform (A2M), fibrinogen beta chain precursor (FBG), and immunoglobulin heavy constant mu (Ighm) proteins. Expression of the A2M protein and A2M enzyme activity in plasma of fish fed choline significantly increased compared to the control group. Additionally, A2M messenger (m)RNA transcripts were also upregulated in the liver and kidneys. Significantly higher C3 expressions at both the mRNA and protein levels were detected in the liver of fish in the choline group. Moreover, FBG gene expressions in the liver and kidneys significantly increased, while Ighm increased in the kidneys and spleen of fish in the choline group. Our results suggest that dietary administration of choline can protect grouper against bacterial infections through activating the complement system, thereby inducing antiprotease activity and natural antibodies that play important roles in the innate immune system of fish.


Asunto(s)
Lubina , Colina , Dieta/veterinaria , Suplementos Dietéticos , Resistencia a la Enfermedad , Inmunidad Innata/fisiología , Inmunomodulación/fisiología , Adyuvantes Inmunológicos , Alimentación Animal/análisis , Animales , Proteínas Sanguíneas/genética , Proteínas Sanguíneas/metabolismo , Enfermedades de los Peces/genética , Enfermedades de los Peces/inmunología , Enfermedades de los Peces/microbiología , Proteínas de Peces/genética , Proteínas de Peces/metabolismo , Especificidad de Órganos , Vibriosis/inmunología , Vibriosis/microbiología , Vibriosis/veterinaria , Vibrio alginolyticus/fisiología
16.
Fish Shellfish Immunol ; 64: 367-382, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28336489

RESUMEN

Synbiotics, a conjunction between prebiotics and probiotics, have been used in aquaculture for over 10 years. However, the mechanisms of how synbiotics work as growth and immunity promoters are far from being unraveled. Here, we show that a prebiotic as part of a synbiotic is hydrolyzed to mono- or disaccharides as the sole carbon source with diverse mechanisms, thereby increasing biomass and colonization that is established by specific crosstalk between probiotic bacteria and the surface of intestinal epithelial cells of the host. Synbiotics may indirectly and directly promote the growth of aquatic animals through releasing extracellular bacterial enzymes and bioactive products from synbiotic metabolic processes. These compounds may activate precursors of digestive enzymes of the host and augment the nutritional absorptive ability that contributes to the efficacy of food utilization. In fish immune systems, synbiotics cause intestinal epithelial cells to secrete cytokines which modulate immune functional cells as of dendritic cells, T cells, and B cells, and induce the ability of lipopolysaccharides to trigger tumor necrosis factor-α and Toll-like receptor 2 gene transcription leading to increased respiratory burst activity, phagocytosis, and nitric oxide production. In shellfish, synbiotics stimulate the proliferation and degranulation of hemocytes of shrimp due to the presence of bacterial cell walls. Pathogen-associated molecular patterns are subsequently recognized and bound by specific pattern-recognition proteins, triggering melanization and phagocytosis processes.


Asunto(s)
Acuicultura , Prebióticos/análisis , Probióticos/análisis , Simbióticos/análisis , Animales , Crustáceos/fisiología , Peces/fisiología , Moluscos/fisiología
17.
Asian-Australas J Anim Sci ; 30(2): 181-186, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27165024

RESUMEN

OBJECTIVE: Leucaena leucocephala (Leucaena) is a perennial tropical legume that can be directly grazed or harvested and offered to ruminants as hay, silage, or fresh. However, Leucaena contain phenolic compounds, which are considered anti-nutritional factors as these may reduce intake, digestibility and thus animal performance. Therefore, the objective of this experiment was to determine effects of Leucaena silage (LS) feeding levels on rumen microbial populations, N-balance and microbial protein synthesis in dairy steers. METHODS: Four, rumen fistulated dairy steers with initial weight of 167±12 kg were randomly assigned to receive dietary treatments according to a 4×4 Latin square design. Treatments were as followings: T1 = untreated rice straw (RS; Control), T2 = 70% RS+30% LS, T3 = 40% RS+60% LS, and T4 = 100% LS. Dairy steers were fed rice straw and LS ad libitum and supplemented with concentrate at 0.2% of body weight/d. RESULTS: Results revealed that the rumen microbial population, especially cellulolytic, proteolytic bacteria and fungal zoospores were enhanced in steers that received 60% of LS (p<0.05), whereas the amylolytic bacteria population was not affected by treatments (p>0.05). Protozoal population was linearly decreased with increasing level of LS (p<0.05). Moreover, N-balance and microbial protein synthesis were enhanced by LS feeding (p<0.05) and were the highest in 60% LS group. CONCLUSION: Based on this study, it could be concluded that replacement of RS with 60% LS significantly improved microbial population and microbial protein synthesis in diary steers.

18.
J Physiol ; 592(8): 1785-94, 2014 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-24535441

RESUMEN

Nitrite has been postulated to provide a reservoir for conversion to nitric oxide (NO), especially in tissues with reduced oxygen levels as in the fetus. Nitrite would thus provide local vasodilatation and restore a balance between oxygen supply and need, a putative mechanism of importance especially in the brain. The current experiments test the hypothesis that exogenous nitrite acts as a vasodilator in the cephalic vasculature of the intact, near term fetal sheep. Fetuses were first instrumented to measure arterial blood pressure and carotid artery blood flow and then studied 4-5 days later while in utero without anaesthesia. Initially l-nitro-arginine (LNNA) was given to block endogenous NO production. Carotid resistance to flow increased 2-fold from 0.54 ± 0.01 (SEM) to 1.20 ± 0.08 mmHg min ml(-1) (in 13 fetuses, P < 0.001), indicating NO tonically reduces cerebral vascular tone. Sodium nitrite (or saline as control) was then infused in increasing step-doses from 0.01 to 33 µm in half-log increments over a period of 2 h. Carotid artery pressure, blood flow and vascular resistance did not change compared to fetuses receiving saline, even at plasma nitrite concentrations two orders of magnitude above the physiological range. The results indicate that while cephalic vascular tone is controlled by endogenous nitric oxide synthase activity, exogenously administered nitrite is not a vasodilator at physiological concentrations in the vasculature served by the carotid artery of fetal sheep.


Asunto(s)
Encéfalo/irrigación sanguínea , Arterias Carótidas/fisiología , Feto/irrigación sanguínea , Nitritos/farmacología , Resistencia Vascular/efectos de los fármacos , Vasodilatación/efectos de los fármacos , Animales , Encéfalo/embriología , Arterias Carótidas/efectos de los fármacos , Femenino , Embarazo , Ovinos
19.
Opt Express ; 22(2): 1673-9, 2014 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-24515174

RESUMEN

Stokes polarimeters are most commonly used to measure the state of polarization of optical wave. Dependence of Stokes parameters, degree of polarization on external magnetic field are presented for garnet and groove films on garnet in the transmission and reflection modes. The Stokes parameters S1, S2, S3 of different modes show different tendency and asymmetrically change when the external magnetic field change, while the degree of polarization basically unchange.

20.
Biomimetics (Basel) ; 9(1)2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-38248609

RESUMEN

Automated guided vehicles (AGVs) are vital for optimizing the transport of material in modern industry. AGVs have been widely used in production, logistics, transportation, and commerce, enhancing productivity, lowering labor costs, improving energy efficiency, and ensuring safety. However, path planning for AGVs in complex and dynamic environments remains challenging due to the computation of obstacle avoidance and efficient transport. This study proposes a novel approach that combines multi-objective particle swarm optimization (MOPSO) and the dynamic-window approach (DWA) to enhance AGV path planning. Optimal AGV trajectories considering energy consumption, travel time, and collision avoidance were used to model the multi-objective functions for dealing with the outcome-feasible optimal solution. Empirical findings and results demonstrate the approach's effectiveness and efficiency, highlighting its potential for improving AGV navigation in real-world scenarios.

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