Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Phys Chem Chem Phys ; 26(16): 12709-12716, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38605665

RESUMEN

The electronic structures and elastic properties of metastable Zr3N4 phases have been investigated using the first-principles calculations with the Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional, in comparison with those of the stable ZrN phase. All three metastable Zr3N4 phases (including orthorhombic, spinel and Th3P4-type phases) are found to be semiconducting with bandgaps of 1.72-1.94 eV. In particular, the computationally indirect bandgap of 1.72 eV of orthorhombic Zr3N4 is consistent with the experimental value of 1.8 eV. The detailed analyses of the electronic structures reveal that the change of electrical conductivity from metallic ZrN to semiconducting Zr3N4 is mainly due to the electron transfer from Zr to N atoms, which weakens the Zr-Zr interactions and reduces the proportion of metallic bonding. In addition, the elastic properties of Zr3N4 and ZrN phases have been calculated. The theoretical hardness values of ZrN and orthorhombic Zr3N4 are 18.06 and 6.98 GPa, respectively, agreeing well with the experimental values of 19.26 and 7.90 GPa. This work may further promote the understanding of the promising Zr-N material system.

2.
Nanotechnology ; 32(40)2021 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-34161926

RESUMEN

In this work, the electrical conductivity and optical transparency of the In-Sn-Zn-O (ITZO) films annealed at different temperatures were investigated. The results show that the ITZO films transformed from amorphous phase to crystalline phase after annealed in the air. The transmittance of the films improves significantly and all exceed 88%. Meanwhile, the annealed ITZO films exhibit a significant enhancement in conductivity. In particular, ITZO film annealed at 650 °C has high electrical conductivity (∼4.94 × 102S cm-1) and an excellent figure of merit (∼5.94 × 10-4Ω-1). Moreover, ITZO thin film transistors were prepared and their performance was tested. After annealing, the high electrical properties of the active layer make the gate regulation ability of the thin film transistors degrade. The annealed films with excellent optoelectronic properties can be applied to transparent electrodes.

3.
Exp Appl Acarol ; 85(2-4): 319-330, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34591210

RESUMEN

Coinfections with the tick-borne pathogens Theileria luwenshuni and Anaplasma phagocytophilum can cause significant economic losses in sheep and goat farming. The difficulty in detecting these two pathogens by microscopic examination warrants the development of a rapid detection test to discriminate them. In this study, a duplex polymerase chain reaction (PCR) assay was developed to simultaneously detect T. luwenshuni and A. phagocytophilum. Alignment of the sequences from related pathogens allowed us to design a primer pair targeting the 18S ribosomal RNA gene in T. luwenshuni and generate a target product of 962 bp, whereas a previously reported species-specific primer (SSAP2f/SSAP2r) for A. phagocytophilum was used in the same reaction to generate a product of 641 bp. Genomic DNA from T. luwenshuni and A. phagocytophilum was 10-fold serially diluted for testing PCR sensitivity. Under the optimal PCR conditions we established, the lower limit of detection of the assay was 29.13 fg/µL for T. luwenshuni and 1.53 fg/µL for A. phagocytophilum, and PCR primers used in this study were confirmed to be 100% species-specific using other hemoparasites previously identified by other methods. No significant difference was found between conventional and duplex PCR protocols used to detect the two species. Our study provides an effective, sensitive, specific, and accurate tool for the diagnosis and epidemiological surveillance of mixed infections of the two pathogens in sheep and goats.


Asunto(s)
Anaplasma phagocytophilum , Enfermedades de las Cabras , Enfermedades de las Ovejas , Theileria , Anaplasma/genética , Anaplasma phagocytophilum/genética , Animales , Enfermedades de las Cabras/diagnóstico , Cabras , Reacción en Cadena de la Polimerasa/veterinaria , Sensibilidad y Especificidad , Ovinos , Enfermedades de las Ovejas/diagnóstico , Theileria/genética
4.
J Am Chem Soc ; 141(40): 16003-16013, 2019 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-31508958

RESUMEN

Elementary reaction steps, including adsorption and dissociation, of a range of molecular adsorbates on transition metal surfaces have been elucidated in the context of chemical catalysis. Here we leverage this knowledge to design liquid crystals (LCs) supported on ultrathin polycrystalline gold films (predominant crystallographic face is (111)) that are triggered to undergo orientational transitions by dissociative adsorption and dehydrogenation reactions involving chlorine and carboxylic acids, respectively, thus amplifying these atomic-scale surface processes in situ into macroscopic optical signals. We use electronic structure calculations to predict that 4'-n-pentyl-4-biphenylcarbonitrile (5CB), a room temperature nematic LC, does not bind to Au(111) in an orientation that changes upon dissociative adsorption of molecular chlorine, a result validated by experiments. In contrast, 4-cyano-4-biphenylcarboxylic acid (CBCA) is calculated to bind strongly to Au(111) in a perpendicular orientation via dehydrogenation of the carboxylic acid group, which we confirmed using polarization-modulation infrared reflection-absorption spectroscopy. A maximum coverage of 0.07 monolayer of CBCA on the gold surface is sufficient to cause a perpendicular orientation of the LC. Dissociative adsorption of Cl2 gas on the gold surface, resulting in 0.5 monolayer coverage of Cl, displaces CBCA from Au(111) and thus triggers a strikingly visible change in orientation of the LC. Infrared spectroscopy established the orientation of adsorbed CBCA to be parallel to the Cl covered surface, with the COOH plane perpendicular to the surface, as predicted by first-principles calculations. These results demonstrate the use of first-principles calculations and transition metal surfaces to design LCs that report in situ targeted atomic-scale surface processes.

5.
J Immunol ; 199(9): 3094-3105, 2017 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-28978693

RESUMEN

Resolution of viral infections requires activation of innate cells to initiate and maintain adaptive immune responses. In this study, we examined Japanese encephalitis virus (JEV) infection leading to acute encephalopathy depending on suppression of the adaptive immune responses mediated by innate cells. Infection with P3 strains of JEV enhanced myeloid-derived suppressor cell (MDSC) populations, and the survival rate of JEV-infected mice improved after MDSC depletion. Mechanically, P3-induced MDSCs suppressed CD4+ T cell immune responses, especially responses of T follicular helper (Tfh) cells, leading to decreased splenic B cells (CD19+) and blood plasma cells (CD19+CD138+) and reduced levels of total IgM and JEV-specific neutralizing Abs. Upon depleting P3-induced MDSCs in vivo, the Tfh cell population, B cells, plasma cells, and Ab production recovered. These findings provide unique insights regarding MDSC functions in mediating immune suppression via inhibiting Tfh cell responses and further impairing humoral immunity, which facilitate the progression of infection.


Asunto(s)
Virus de la Encefalitis Japonesa (Especie)/inmunología , Encefalitis Japonesa/inmunología , Células Supresoras de Origen Mieloide/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Antígenos CD19/inmunología , Encefalitis Japonesa/patología , Femenino , Inmunidad Humoral , Ratones , Células Supresoras de Origen Mieloide/patología , Células Plasmáticas/inmunología , Células Plasmáticas/patología , Bazo/inmunología , Bazo/patología , Sindecano-1/inmunología , Linfocitos T Colaboradores-Inductores/patología
6.
Exp Parasitol ; 201: 21-25, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31029698

RESUMEN

Anaplasma phagocytophilum, the bacterial pathogen responsible for tick-borne fever and human granulocytic anaplasmosis, can seriously affect the health of humans and a wide range of other mammals. In this study, we developed a recombinase polymerase amplification (RPA) assay to detect A. phagocytophilum in clinical samples. Following alignment of the relevant DNA sequences, a pair of specific primers based on the 16S rRNA gene was designed to specifically detect A. phagocytophilum. The assay was performed at a constant temperature of 38 °C for 30 min, with a final primer concentration of 0.4 µM. The specificity of the primers was confirmed when DNA from A. phagocytophilum was used as the positive control, and DNA from other related pathogens were used as the negative controls, with ddH2O acting as the blank control. The results showed that the primers did not cross-react with DNA from the other related pathogens. The assay's detection limit was 1.77 × 10-5 ng/µl, a 10 × higher sensitivity level than that determined for nested PCR. The RPA assay's performance was evaluated using 44 clinical samples, and the prevalence results for A. phagocytophilum were found to not differ significantly between the RPA assay and the nested PCR. Thus, we have developed a specific, sensitive, rapid and cost-effective RPA method, requiring only a water bath, for the detection of A. phagocytophilum. The assay should be especially useful in resource-limited areas where access to laboratory equipment is limited.


Asunto(s)
Anaplasma phagocytophilum/aislamiento & purificación , Ehrlichiosis/veterinaria , Reacción en Cadena de la Polimerasa/veterinaria , Enfermedades de las Ovejas/microbiología , Anaplasma phagocytophilum/genética , Animales , Análisis Costo-Beneficio , ADN Bacteriano/sangre , ADN Bacteriano/química , ADN Bacteriano/aislamiento & purificación , ADN Polimerasa Dirigida por ADN , Ehrlichiosis/diagnóstico , Ehrlichiosis/microbiología , Sistemas de Atención de Punto/economía , Sistemas de Atención de Punto/normas , Reacción en Cadena de la Polimerasa/economía , Reacción en Cadena de la Polimerasa/normas , ARN Ribosómico 16S/genética , Recombinasas , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Ovinos , Enfermedades de las Ovejas/diagnóstico , Factores de Tiempo
7.
J Virol ; 91(3)2017 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-27852854

RESUMEN

Rabies remains a public health threat in most parts of the world, and approximately 99% of the cases are transmitted by dogs. There is an urgent need to develop an efficacious and affordable vaccine to control canine-transmitted rabies in developing countries. Our previous studies demonstrate that overexpression of chemokines/cytokines such as CCL-3 (MIP-1α) and granulocyte-macrophage colony-stimulating factor (GM-CSF) can enhance the immunogenicity of rabies vaccines. In the present study, the chemokine CXCL13 was inserted into the genome of the recombinant rabies virus (rRABV) strain LBNSE, and the effect of the chemokine CXCL13 on the immunogenicity of RABV was investigated. It was found that LBNSE-CXCL13 recruited follicular helper T (Tfh) and germinal center (GC) B cells, promoted the formation of GCs, and increased the population of plasma cells in immunized mice. Further studies showed that mice immunized with LBNSE-CXCL13 produced more rabies virus-neutralizing antibodies (VNAs) and developed better protection than those immunized with the parent virus LBNSE or the GM-CSF-expressing RABV (LBNSE-GM-CSF). Collectively, these findings provide a better understanding of the role of CXCL13 expression in the immunogenicity of the RABV, which may help in designing more-efficacious rabies vaccines. IMPORTANCE: Rabies is endemic in most parts of the world, and more effort is needed to develop affordable and effective vaccines to control or eliminate this disease. The chemokine CXCL13 recruits both Tfh and B cells, which is essential for the homing of Tfh cells and the development of B cell follicles. In this study, the effect of the overexpression of CXCL13 on the immunogenicity of the RABV was evaluated in a mouse model. We found that CXCL13 expression promoted humoral immunity by recruiting Tfh and GC B cells, facilitating the formation of GCs, and increasing the number of plasma cells. As expected, the overexpression of CXCL13 resulted in enhanced virus-neutralizing antibody (VNA) production and protection against a virulent RABV challenge. These findings provide a better understanding of the role of CXCL13 in RABV-induced immune responses, which will help in designing more efficacious rabies vaccines.


Asunto(s)
Linfocitos B/inmunología , Quimiocina CXCL13/genética , Expresión Génica , Centro Germinal/inmunología , Inmunidad Humoral , Vacunas Antirrábicas/genética , Vacunas Antirrábicas/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Linfocitos B/metabolismo , Quimiocina CXCL13/sangre , Quimiotaxis/inmunología , Cricetinae , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Ratones , Células Plasmáticas/inmunología , Células Plasmáticas/metabolismo , Rabia/inmunología , Rabia/prevención & control , Virus de la Rabia/inmunología , Linfocitos T Colaboradores-Inductores/metabolismo
8.
J Gen Virol ; 97(12): 3154-3160, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27902338

RESUMEN

Previous studies have demonstrated that the lack of interleukin-21 (IL-21) signalling could affect specific antibody induction after rabies vaccination. Here, to further investigate the over-expression of IL-21 on the immunogenicity of rabies virus (RABV), a recombinant RABV expressing murine IL-21, designated LBNSE-IL21, was constructed and evaluated in a mouse model. It was found that in mice immunized with LBNSE-IL21, there was a substantial increase in the number of T follicular helper cells and germinal centre B cells but no enhancement of dendritic cell activation. Furthermore, significantly higher rabies virus-neutralizing antibody (VNA) titres were produced in mice immunized with LBNSE-IL21 than in mice immunized with the parent virus LBNSE in the first six weeks, resulting in higher protection. Together, these results suggest that LBNSE-IL21 can induce a rapid and robust VNA titre, and it has the potential to be developed as a promising rabies vaccine.


Asunto(s)
Centro Germinal/inmunología , Interleucinas/inmunología , Vacunas Antirrábicas/inmunología , Virus de la Rabia/inmunología , Rabia/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Anticuerpos Antivirales/inmunología , Células Dendríticas/inmunología , Modelos Animales de Enfermedad , Femenino , Humanos , Interleucinas/administración & dosificación , Interleucinas/genética , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos ICR , Rabia/prevención & control , Rabia/virología , Vacunas Antirrábicas/administración & dosificación , Vacunas Antirrábicas/genética , Virus de la Rabia/genética
9.
J Virol ; 89(10): 5602-14, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25762733

RESUMEN

UNLABELLED: Japanese encephalitis is an acute zoonotic, mosquito-borne disease caused by Japanese encephalitis virus (JEV). Japanese encephalitis is characterized by extensive inflammation in the central nervous system (CNS) and disruption of the blood-brain barrier (BBB). However, the pathogenic mechanisms contributing to the BBB disruption are not known. Here, using a mouse model of intravenous JEV infection, we show that virus titers increased exponentially in the brain from 2 to 5 days postinfection. This was accompanied by an early, dramatic increase in the level of inflammatory cytokines and chemokines in the brain. Enhancement of BBB permeability, however, was not observed until day 4, suggesting that viral entry and the onset of inflammation in the CNS occurred prior to BBB damage. In vitro studies revealed that direct infection with JEV could not induce changes in the permeability of brain microvascular endothelial cell monolayers. However, brain extracts derived from symptomatic JEV-infected mice, but not from mock-infected mice, induced significant permeability of the endothelial monolayer. Consistent with a role for inflammatory mediators in BBB disruption, the administration of gamma interferon-neutralizing antibody ameliorated the enhancement of BBB permeability in JEV-infected mice. Taken together, our data suggest that JEV enters the CNS, propagates in neurons, and induces the production of inflammatory cytokines and chemokines, which result in the disruption of the BBB. IMPORTANCE: Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia, resulting in 70,000 cases each year, in which approximately 20 to 30% of cases are fatal, and a high proportion of patients survive with serious neurological and psychiatric sequelae. Pathologically, JEV infection causes an acute encephalopathy accompanied by BBB dysfunction; however, the mechanism is not clear. Thus, understanding the mechanisms of BBB disruption in JEV infection is important. Our data demonstrate that JEV gains entry into the CNS prior to BBB disruption. Furthermore, it is not JEV infection per se, but the inflammatory cytokines/chemokines induced by JEV infection that inhibit the expression of TJ proteins and ultimately result in the enhancement of BBB permeability. Neutralization of gamma interferon (IFN-γ) ameliorated the enhancement of BBB permeability in JEV-infected mice, suggesting that IFN-γ could be a potential therapeutic target. This study would lead to identification of potential therapeutic avenues for the treatment of JEV infection.


Asunto(s)
Barrera Hematoencefálica/virología , Sistema Nervioso Central/virología , Encefalitis Japonesa/virología , Animales , Anticuerpos Neutralizantes/administración & dosificación , Barrera Hematoencefálica/inmunología , Barrera Hematoencefálica/patología , Permeabilidad Capilar , Moléculas de Adhesión Celular/biosíntesis , Sistema Nervioso Central/inmunología , Sistema Nervioso Central/patología , Quimiocinas/biosíntesis , Citocinas/biosíntesis , Modelos Animales de Enfermedad , Virus de la Encefalitis Japonesa (Subgrupo)/patogenicidad , Virus de la Encefalitis Japonesa (Subgrupo)/fisiología , Encefalitis Japonesa/inmunología , Encefalitis Japonesa/patología , Femenino , Humanos , Mediadores de Inflamación/metabolismo , Interferón gamma/antagonistas & inhibidores , Interferón gamma/biosíntesis , Ratones , Ratones Endogámicos C57BL , Factores de Tiempo , Replicación Viral
10.
Am J Cancer Res ; 14(4): 1501-1522, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38726265

RESUMEN

Considering the limited research and the prevailing evidence of STAT4's tumor-suppressing role in breast carcinoma (BC) or in breast radiotherapy (RT) sensitivity requires more in-depth exploration. Our study delves into how STAT4, a transcription factor, affects BC cell resistance to radiotherapy by regulating the MALAT1/miR-21-5p/THRB axis. Bioinformatics analysis was performed to predict the regulatory mechanisms associated with STAT4 in BC. Subsequently, we identified the expression profiles of STAT4, MALAT1, miR-21-5p, and THRB in various tissues and cell lines, exploring their interactions and impact on RT resistance in BC cells. Moreover, animal models were established with X-ray irradiation for further validation. We discovered that STAT4, which is found to be minimally expressed in breast carcinoma (BC) tissues and cell lines, has been associated with a poorer prognosis. In vitro cellular assays indicated that STAT4 could mitigate radiotherapy resistance in BC cells by transcriptional activation of MALAT1. Additionally, MALAT1 up-regulated THRB expression by adsorbing miR-21-5p. As demonstrated in vitro and in vivo, overexpressing STAT4 inhibited miR-21-5p and enhanced THRB levels through transcriptional activation of MALAT1, which ultimately contributes to the reversal of radiotherapy resistance in BC cells and the suppression of tumor formation in nude mice. Collectively, STAT4 could inhibit miR-21-5p and up-regulate THRB expression through transcriptional activation of MALAT1, thereby mitigating BC cell resistance to radiotherapy and ultimately preventing BC development and progression.

11.
Front Nutr ; 11: 1391601, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38846546

RESUMEN

Acanthopanax senticosus (AS) is a geo-authentic crude medicinal plant that grows in China, Korea, Russia, and Japan. AS contains bioactive compounds such as eleutherosides, polysaccharides, and flavonoids. It is also a key traditional herb in the Red List of Chinese Species. AS is mainly distributed in Northeast China, specifically in Heilongjiang, Jilin, and Liaoning provinces. Its active compounds contribute to significant biological activities, including neuroprotective, antioxidant, anti-fatigue, and antitumor effects. However, the extraction methods of active compounds are complex, the extraction efficiency is poor, and the structure-activity relationship is unclear. This study focused on the nutrients in AS, including protein, carbohydrates, and lipids. Particularly, the active ingredients (eleutherosides, polysaccharides, and flavonoids) in AS and their extraction and purification methods were analyzed and summarized. The biological activities of extracts have been reviewed, and the mechanisms of anti-oxidation, antitumor, anti-inflammation, and other activities are introduced in detail. The applications of AS in various domains, such as health foods, medicines, and animal dietary supplements, are then reported. Compared with other extraction methods, ultrasonic or microwave extraction improves efficiency, yet they can damage structures. Challenges arise in the recovery of solvents and in achieving extraction efficiency when using green solvents, such as deep eutectic solvents. Improvements can be made by combining extraction methods and controlling conditions (power, temperature, and time). Bioactive molecules and related activities are exposited clearly. The applications of AS have not been widely popularized, and the corresponding functions require further development.

12.
Front Bioeng Biotechnol ; 12: 1365814, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38476966

RESUMEN

D-Allulose has become a promising alternative sweetener due to its unique properties of low caloric content, moderate sweetness, and physiological effects. D-Allulose 3-epimerase (DAEase) is a promising enzyme for D-Allulose production. However, the low catalytic efficiency limited its large-scale industrial applications. To obtain a more effective biocatalyst, a putative DAEase from Christensenellaceae bacterium (CbDAE) was identified and characterized. The recombinant CbDAE exhibited optimum activity at pH 7.5°C and 55°C, retaining more than 60% relative activity from 40°C to 70°C, and the catalytic activity could be significantly increased by Co2+ supplementation. These enzymatic properties of purified CbDAE were compared with other DAEases. CbDAE was also found to possess desirable thermal stability at 55°C with a half-life of 12.4 h. CbDAE performed the highest relative activity towards D-allulose and strong affinity for D-fructose but relatively low catalytic efficiency towards D-fructose. Based on the structure-guided design, the best double-mutation variant G36N/W112E was obtained which reached up to 4.21-fold enhancement of catalytic activity compared with wild-type (WT) CbDAE. The catalytic production of G36N/W112E with 500 g/L D-fructose was at a medium to a higher level among the DAEases in 3.5 h, reducing 40% catalytic reaction time compared to the WT CbDAE. In addition, the G36N/W112E variant was also applied in honey and apple juice for D-allulose conversion. Our research offers an extra biocatalyst for D-allulose production, and the comprehensive report of this enzyme makes it potentially interesting for industrial applications and will aid the development of industrial biocatalysts for D-allulose.

13.
IEEE Open J Eng Med Biol ; 5: 238-249, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38606403

RESUMEN

Goal: Contractile response and calcium handling are central to understanding cardiac function and physiology, yet existing methods of analysis to quantify these metrics are often time-consuming, prone to mistakes, or require specialized equipment/license. We developed BeatProfiler, a suite of cardiac analysis tools designed to quantify contractile function, calcium handling, and force generation for multiple in vitro cardiac models and apply downstream machine learning methods for deep phenotyping and classification. Methods: We first validate BeatProfiler's accuracy, robustness, and speed by benchmarking against existing tools with a fixed dataset. We further confirm its ability to robustly characterize disease and dose-dependent drug response. We then demonstrate that the data acquired by our automatic acquisition pipeline can be further harnessed for machine learning (ML) analysis to phenotype a disease model of restrictive cardiomyopathy and profile cardioactive drug functional response. To accurately classify between these biological signals, we apply feature-based ML and deep learning models (temporal convolutional-bidirectional long short-term memory model or TCN-BiLSTM). Results: Benchmarking against existing tools revealed that BeatProfiler detected and analyzed contraction and calcium signals better than existing tools through improved sensitivity in low signal data, reduction in false positives, and analysis speed increase by 7 to 50-fold. Of signals accurately detected by published methods (PMs), BeatProfiler's extracted features showed high correlations to PMs, confirming that it is reliable and consistent with PMs. The features extracted by BeatProfiler classified restrictive cardiomyopathy cardiomyocytes from isogenic healthy controls with 98% accuracy and identified relax90 as a top distinguishing feature in congruence with previous findings. We also show that our TCN-BiLSTM model was able to classify drug-free control and 4 cardiac drugs with different mechanisms of action at 96% accuracy. We further apply Grad-CAM on our convolution-based models to identify signature regions of perturbations by these drugs in calcium signals. Conclusions: We anticipate that the capabilities of BeatProfiler will help advance in vitro studies in cardiac biology through rapid phenotyping, revealing mechanisms underlying cardiac health and disease, and enabling objective classification of cardiac disease and responses to drugs.

14.
Front Nutr ; 11: 1359813, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38585610

RESUMEN

Perilla frutescens (L.) Britton is an annual herb plant of the Perilla genus in the Labiatae family, which is commonly utilized as an edible and medicinal resource. Polysaccharides are among the major components and essential bioactive compounds of P. frutescens, which exhibit a multitude of biological activities, including antioxidant, antitumor, anti-fatigue, immunoregulation, hepatoprotective, anti-inflammatory, and lipid-lowering effects. As a natural carbohydrate, P. frutescens polysaccharide has the potential to be utilized in the development of drugs and functional materials. In this paper, we provide an overview of progress made on the extraction, purification, structural characterization, and bioactivity of polysaccharides from different parts of P. frutescens. The challenges and opportunities for research are discussed, along with the potential development prospects and future areas of focus in the study of P. frutescens polysaccharides.

15.
BMC Anesthesiol ; 13(1): 48, 2013 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-24330775

RESUMEN

BACKGROUND: Procalcitonin (PCT) is a reliable biomarker of sepsis and infection. The level of PCT associated with sepsis and infection in patients with traumatic brain injury is currently unknown. The purpose of this study was to investigate the value of PCT and C-reactive protein (CRP) as diagnostic markers of sepsis and to evaluate the prognostic value of these markers related to the severity of injury, sepsis and mortality. METHODS: 105 adult patients with neurotrauma were enrolled in this study from June 2011 to February 2013. PCT and CRP were measured at admission and 2, 3, 5 and 7 days after admission. The sepsis criteria established by American College of Chest Physicians /Society of Critical Care Medicine Consensus Conference were used to identify patients. Injury Severity Score (ISS) and Glasgow Coma Score (GCS) were used to assess the severity of the injury. All these patients were monitored for 28 days. RESULTS: At admission, the median level of PCT was consistent with the severity of brain injury as follows: mild 0.08 ng/ml (0.05 - 0.13), moderate 0.25 ng/ml (0.11 - 0.55) and severe 0.31 ng/ml (0.17 - 0.79), but the range of CRP levels varied greatly within the given severity of brain injury. Seventy-one (67.6%) patients developed sepsis. The initial levels of PCT at admission were statistically higher in patients with sepsis, compared with patients with systemic inflammatory response syndrome (SIRS), but there were no differences in the initial concentration of CRP between sepsis and SIRS. After adjusting for these parameters, multivariate logistic regression analysis revealed that PCT was an independent risk factor for septic complications (p < 0.05). The areas under the ROCs at admission for the prediction of mortality were 0.76 (p < 0.05) and 0.733 for PCT and CRP, respectively. CONCLUSIONS: Increased levels of PCT during the course of the ICU stay could be an important indicator for the early diagnosis of sepsis after neurotrauma. In addition, high serum levels of PCT in patients with neurotrauma at admission indicate an increased risk of septic complications, and the daily measurement of PCT assists in guiding antibiotic therapy in neurotrauma patients.

16.
ISA Trans ; 137: 248-262, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36577622

RESUMEN

The dual-motor driving servo system is continuously developed to satisfy strict safety and reliability requirements. However, several factors may degrade the system's performance, such as transmission backlash, parameter drift, and motor dynamic characteristic differences. To overcome these factors, this study proposes a finite-time tracking and synchronization control method for dual-motor servo systems that suffer from backlash and time-varying uncertainties. Our solution utilizes an adaptive dynamic surface and cross-coupling control scheme to deal with tracking and synchronization control issues and compensate for the unknown time-varying uncertainties. Through synchronizing the speed and acceleration states, the proposed controller guarantees high control performance and eliminates the force fighting caused by the motor's dynamic characteristic differences. In addition, finite-time control ensures the tracking error converges to an arbitrarily small neighborhood of zero in finite time. Moreover, the singularity problem in the derivative of the virtual control signal is avoided by introducing a new compensation term. Several simulations prove the proposed controller's stability and effectiveness.

17.
Biomimetics (Basel) ; 8(2)2023 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-37366831

RESUMEN

A realistic and visible dynamic simulation platform can significantly facilitate research on underwater robots. This paper uses the Unreal Engine to generate a scene that resembles real ocean environments, before building a visual dynamic simulation platform in conjunction with the Air-Sim system. On this basis, the trajectory tracking of a biomimetic robotic fish is simulated and assessed. More specifically, we propose a particle swarm optimization algorithm-based control strategy to optimize the discrete linear quadratic regulator controller for the trajectory tracking problem, as well as tracking and controlling discrete trajectories with misaligned time series through introducing a dynamic time warping algorithm. Simulation analyses of the biomimetic robotic fish following a straight line, a circular curve without mutation, and a four-leaf clover curve with mutation are carried out. The obtained results verify the feasibility and effectiveness of the proposed control strategy.

18.
Aging (Albany NY) ; 15(6): 1931-1943, 2023 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-37000151

RESUMEN

Ischemia/reperfusion (I/R) damage induced by stroke poses a serious hazard to human life, while mechanism of blood-brain barrier (BBB) dysfunction is still unknown. To imitate stroke induced ischemia conditions in vivo, the rat model of cerebral I/R damage was created by middle cerebral artery occlusion (MCAO). In vitro, the rat microvascular endothelial cell line bEND.3 was subjected to oxygen-glucose deprivation/reperfusion (OGD/R). Evans blue was used to evaluate the permeability of the blood-brain barrier (BBB). To evaluate gene expression at the mRNA and protein levels, researchers used real-time PCR and western blotting. Infarct volume and BBB permeability were considerably higher in cerebral (I/R) animals than in the Sham group. Exosomal miR-370-3p expression was shown to be higher in the brains of I/R injured rats and OGD/R treatment bEND.3. The BBB permeability was considerably increased when miR-370-3p was downregulated in OGD/R pretreated bEND.3. miR-370-3p regulates MAPK1 expression by targeting it. In bEND.3, OGD/R therapy increased BBB permeability substantially. OGD/R was inhibited by miR-370-3p mimic transfection, while miR-370-3p mimic was abolished by co-transfection with MAPK1 overexpression lentivirus. In cerebral I/R damage, exosomal miR-370-3p targets MAPK1 and aggregates BBB permeability.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , MicroARNs , Daño por Reperfusión , Accidente Cerebrovascular , Animales , Ratas , Apoptosis , Barrera Hematoencefálica/metabolismo , Encéfalo/metabolismo , Isquemia Encefálica/genética , Isquemia Encefálica/metabolismo , Infarto de la Arteria Cerebral Media/genética , Accidente Cerebrovascular Isquémico/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Reperfusión , Daño por Reperfusión/genética , Daño por Reperfusión/metabolismo , Accidente Cerebrovascular/genética , Accidente Cerebrovascular/metabolismo
19.
Front Endocrinol (Lausanne) ; 14: 1266318, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37955009

RESUMEN

Objective: Patients with pancreatic cancer (PC) have a poor prognosis. Radiotherapy (RT) is a standard palliative treatment in clinical practice, and there is no effective clinical prediction model to predict the prognosis of PC patients receiving radiotherapy. This study aimed to analyze PC's clinical characteristics, find the factors affecting PC patients' prognosis, and construct a visual Nomogram to predict overall survival (OS). Methods: SEER*Stat software was used to collect clinical data from the Surveillance, Epidemiology, and End Results (SEER) database of 3570 patients treated with RT. At the same time, the relevant clinical data of 115 patients were collected from the Affiliated Cancer Hospital of Zhengzhou University. The SEER database data were randomly divided into the training and internal validation cohorts in a 7:3 ratio, with all patients at The Affiliated Cancer Hospital of Zhengzhou University as the external validation cohort. The lasso regression was used to screen the relevant variables. All non-zero variables were included in the multivariate analysis. Multivariate Cox proportional risk regression analysis was used to determine the independent prognostic factors. The Kaplan-Meier(K-M) method was used to plot the survival curves for different treatments (surgery, RT, chemotherapy, and combination therapy) and calculate the median OS. The Nomogram was constructed to predict the survival rates at 1, 3, and 5 years, and the time-dependent receiver operating characteristic curves (ROC) were plotted with the calculated curves. Calculate the area under the curve (AUC), the Bootstrap method was used to plot the calibration curve, and the clinical efficacy of the prediction model was evaluated using decision curve analysis (DCA). Results: The median OS was 25.0, 18.0, 11.0, and 4.0 months in the surgery combined with chemoradiotherapy (SCRT), surgery combined with radiotherapy, chemoradiotherapy (CRT), and RT alone cohorts, respectively. Multivariate Cox regression analysis showed that age, N stage, M stage, chemotherapy, surgery, lymph node surgery, and Grade were independent prognostic factors for patients. Nomogram models were constructed to predict patients' OS. 1-, 3-, and 5-year Time-dependent ROC curves were plotted, and AUC values were calculated. The results suggested that the AUCs were 0.77, 0.79, and 0.79 for the training cohort, 0.79, 0.82, and 0.81 for the internal validation cohort, and 0.73, 0.93, and 0.88 for the external validation cohort. The calibration curves Show that the model prediction probability is in high agreement with the actual observation probability, and the DCA curve shows a high net return. Conclusion: SCRT significantly improves the OS of PC patients. We developed and validated a Nomogram to predict the OS of PC patients receiving RT.


Asunto(s)
Nomogramas , Neoplasias Pancreáticas , Humanos , Pueblos del Este de Asia , Modelos Estadísticos , Neoplasias Pancreáticas/radioterapia , Pronóstico , Programa de VERF , Neoplasias Pancreáticas
20.
Front Oncol ; 13: 1220047, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37810984

RESUMEN

Purpose: To compare Whole-brain radiation therapy with simultaneous integrated boost (WBRT+SIB) to stereotactic radiosurgery (SRS)for non-small cell lung cancer (NSCLC)with brain metastases (BMs)in terms of overall survival (OS), intracranial progression-free-survival(iPFS), toxicity and objective response rate (ORR). Methods: A retrospective review was performed in our hospital of 90 patients diagnosed with NSCLC- BM who received either SRS (n = 48) or WBRT+SIB (n = 42) from January 2016 to January 2022. 76 (84.44%) patients received systemic drug therapy after radiotherapy, including chemotherapy(n=53), targeted therapy(n=40), immunotherapy(n=23), and anti-vascular drug therapy(n=45). OS and iPFS were estimated by the Kaplan-Meier method and compared using the log-rank test. Univariate and Multivariate analysis of the prognostic factors was performed using the Cox proportional hazard regression model. Results: The WBRT+SIB cohort had a longer median iPFS (20.0 versus (VS) 12.0 months, P = 0.0069) and a similar median OS (32.0 vs 28.0 months, P = 0.195) than the SRS cohort. Intracranial objective response rates in WBRT +SIB and SRS cohorts were 76.19% and 70.09%, respectively (P = 0.566). Disease control rates were 88.09% and 83.33%, respectively (P = 0.521). Multivariate analysis showed that WBRT+SIB is the only factor affecting iPFS(hazard ratio (HR):0.597 {95%confidence interval(CI):0.370-0.966}, P=0.035). Sex, Liver metastasis and Lymph node metastasis are risk factors for NSCLC-BM. Conclusion: In the context of systemic drug therapy, WBRT+SIB may have better intracranial local control than SRS in NSCLC-BM patients.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA