Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 115
Filtrar
1.
Coron Artery Dis ; 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38767051

RESUMEN

BACKGROUND: Previous reports have suggested that coronary computed tomography angiography (CCTA)-based radiomics analysis is a potentially helpful tool for assessing vulnerable plaques. We aimed to investigate whether coronary radiomic analysis of CCTA images could identify vulnerable plaques in patients with stable angina pectoris. METHODS: This retrospective study included patients initially diagnosed with stable angina pectoris. Patients were randomly divided into either the training or test dataset at an 8 : 2 ratio. Radiomics features were extracted from CCTA images. Radiomics models for predicting vulnerable plaques were developed using the support vector machine (SVM) algorithm. The model performance was assessed using the area under the curve (AUC); the accuracy, sensitivity, and specificity were calculated to compare the diagnostic performance using the two cohorts. RESULTS: A total of 158 patients were included in the analysis. The SVM radiomics model performed well in predicting vulnerable plaques, with AUC values of 0.977 and 0.875 for the training and test cohorts, respectively. With optimal cutoff values, the radiomics model showed accuracies of 0.91 and 0.882 in the training and test cohorts, respectively. CONCLUSION: Although further larger population studies are necessary, this novel CCTA radiomics model may identify vulnerable plaques in patients with stable angina pectoris.

2.
Cell Commun Signal ; 22(1): 252, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38698453

RESUMEN

BACKGROUND: Ischemic postconditioning (IPostC) has been reported as a promising method for protecting against myocardial ischemia-reperfusion (MI/R) injury. Our previous study found that the infarct-limiting effect of IPostC is abolished in the heart of diabetes whose cardiac expression of DJ-1 (also called PARK7, Parkinsonism associated deglycase) is reduced. However, the role and in particular the underlying mechanism of DJ-1 in the loss of sensitivity to IPostC-induced cardioprotection in diabetic hearts remains unclear. METHODS: Streptozotocin-induced type 1 diabetic rats were subjected to MI/R injury by occluding the left anterior descending artery (LAD) and followed by reperfusion. IPostC was induced by three cycles of 10s of reperfusion and ischemia at the onset of reperfusion. AAV9-CMV-DJ-1, AAV9-CMV-C106S-DJ-1 or AAV9-DJ-1 siRNA were injected via tail vein to either over-express or knock-down DJ-1 three weeks before inducing MI/R. RESULTS: Diabetic rats subjected to MI/R exhibited larger infarct area, more severe oxidative injury concomitant with significantly reduced cardiac DJ-1 expression and increased PTEN expression as compared to non-diabetic rats. AAV9-mediated cardiac DJ-1 overexpression, but not the cardiac overexpression of DJ-1 mutant C106S, restored IPostC-induced cardioprotection and this effect was accompanied by increased cytoplasmic DJ-1 translocation toward nuclear and mitochondrial, reduced PTEN expression, and increased Nrf-2/HO-1 transcription. Our further study showed that AAV9-mediated targeted DJ-1 gene knockdown aggravated MI/R injury in diabetic hearts, and this exacerbation of MI/R injury was partially reversed by IPostC in the presence of PTEN inhibition or Nrf-2 activation. CONCLUSIONS: These findings suggest that DJ-1 preserves the cardioprotective effect of IPostC against MI/R injury in diabetic rats through nuclear and mitochondrial DJ-1 translocation and that inhibition of cardiac PTEN and activation of Nrf-2/HO-1 may represent the major downstream mechanisms whereby DJ-1 preserves the cardioprotective effect of IPostC in diabetes.


Asunto(s)
Diabetes Mellitus Experimental , Poscondicionamiento Isquémico , Daño por Reperfusión Miocárdica , Fosfohidrolasa PTEN , Proteína Desglicasa DJ-1 , Ratas Sprague-Dawley , Animales , Proteína Desglicasa DJ-1/metabolismo , Proteína Desglicasa DJ-1/genética , Fosfohidrolasa PTEN/metabolismo , Fosfohidrolasa PTEN/genética , Diabetes Mellitus Experimental/metabolismo , Masculino , Ratas , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/patología , Daño por Reperfusión Miocárdica/genética , Factor 2 Relacionado con NF-E2/metabolismo , Factor 2 Relacionado con NF-E2/genética , Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 1/complicaciones , Transporte de Proteínas , Estreptozocina , Infarto del Miocardio/metabolismo , Infarto del Miocardio/patología
3.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(5): 450-455, 2024 May 15.
Artículo en Chino | MEDLINE | ID: mdl-38802903

RESUMEN

OBJECTIVES: To investigate the incidence rate, clinical characteristics, and prognosis of neonatal stroke in Shenzhen, China. METHODS: Led by Shenzhen Children's Hospital, the Shenzhen Neonatal Data Collaboration Network organized 21 institutions to collect 36 cases of neonatal stroke from January 2020 to December 2022. The incidence, clinical characteristics, treatment, and prognosis of neonatal stroke in Shenzhen were analyzed. RESULTS: The incidence rate of neonatal stroke in 21 hospitals from 2020 to 2022 was 1/15 137, 1/6 060, and 1/7 704, respectively. Ischemic stroke accounted for 75% (27/36); boys accounted for 64% (23/36). Among the 36 neonates, 31 (86%) had disease onset within 3 days after birth, and 19 (53%) had convulsion as the initial presentation. Cerebral MRI showed that 22 neonates (61%) had left cerebral infarction and 13 (36%) had basal ganglia infarction. Magnetic resonance angiography was performed for 12 neonates, among whom 9 (75%) had involvement of the middle cerebral artery. Electroencephalography was performed for 29 neonates, with sharp waves in 21 neonates (72%) and seizures in 10 neonates (34%). Symptomatic/supportive treatment varied across different hospitals. Neonatal Behavioral Neurological Assessment was performed for 12 neonates (33%, 12/36), with a mean score of (32±4) points. The prognosis of 27 neonates was followed up to around 12 months of age, with 44% (12/27) of the neonates having a good prognosis. CONCLUSIONS: Ischemic stroke is the main type of neonatal stroke, often with convulsions as the initial presentation, involvement of the middle cerebral artery, sharp waves on electroencephalography, and a relatively low neurodevelopment score. Symptomatic/supportive treatment is the main treatment method, and some neonates tend to have a poor prognosis.


Asunto(s)
Accidente Cerebrovascular , Humanos , Masculino , Recién Nacido , Femenino , China/epidemiología , Accidente Cerebrovascular/epidemiología , Pronóstico , Electroencefalografía , Incidencia , Imagen por Resonancia Magnética
4.
Small Methods ; : e2400159, 2024 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-38697928

RESUMEN

Regular blood glucose monitoring and control is necessary for people with type 1 or advanced type 2 diabetes, yet diagnosing and treating patients with diabetes in an accurate, sustained and patient-friendly manner remains limited. Here, a glucose-responsive bifunctional nanosystem (PGOxMns) is constructed via one-pot biomineralisation of manganese dioxide with glucose oxidase and ε-poly-L-lysine. Under hyperglycaemic conditions, the cascade reactions that occur when glucose interacts with PGOxMns can trigger the production of Mn(II), which enhances the magnetic resonance imaging signal. Simultaneously, manganese dioxide catalyses the decomposition of toxic hydrogen peroxide into oxygen, which also maintains glucose oxidase (GOx) activity. In an in vivo model of diabetes, PGOxMns is used to monitor glucose levels (0-20 mm) and allowed identification of diabetic mice via T1-weighted MRI. Furthermore, PGOxMns is found to have a high insulin-loading capacity (83.6%), likely due to its positive charge. A single subcutaneous injection of insulin-loaded nanosystem (Ins-PGOxMns) into diabetic mice resulted in a rapid and efficient response to a glucose challenge and prolonged blood glucose level control (< 200 mg dL-1) for up to 50 h. Overall, this proof-of-concept study demonstrates the feasibility of using biomineralised nanosystems to develop patient-friendly strategies for glucose monitoring and control.

5.
Burns Trauma ; 12: tkad055, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38601971

RESUMEN

Background: Prevention of diabetic heart myocardial ischemia-reperfusion (IR) injury (MIRI) is challenging. Propofol attenuates MIRI through its reactive oxygen species scavenging property at high doses, while its use at high doses causes hemodynamic instability. Salvianolic acid A (SAA) is a potent antioxidant that confers protection against MIRI. Both propofol and SAA affect metabolic profiles through regulating Adenosine 5'-monophosphate-activated protein kinase (AMPK). The aim of this study was to investigate the protective effects and underlying mechanisms of low doses of propofol combined with SAA against diabetic MIRI. Methods: Diabetes was induced in mice by a high-fat diet followed by streptozotocin injection, and MIRI was induced by coronary artery occlusion and reperfusion. Mice were treated with propofol at 46 mg/kg/h without or with SAA at 10 mg/kg/h during IR. Cardiac origin H9c2 cells were exposed to high glucose (HG) and palmitic acid (PAL) for 24 h in the absence or presence of cluster of differentiation 36 (CD36) overexpression or AMPK gene knockdown, followed by hypoxia/reoxygenation (HR) for 6 and 12 h. Results: Diabetes-exacerbated MIRI is evidenced as significant increases in post-ischemic infarction with reductions in phosphorylated (p)-AMPK and increases in CD36 and ferroptosis. Propofol moderately yet significantly attenuated all the abovementioned changes, while propofol plus SAA conferred superior protection against MIRI to that of propofol. In vitro, exposure of H9c2 cells under HG and PAL decreased cell viability and increased oxidative stress that was concomitant with increased levels of ferroptosis and a significant increase in CD36, while p-AMPK was significantly reduced. Co-administration of low concentrations of propofol and SAA at 12.5 µM in H9c2 cells significantly reduced oxidative stress, ferroptosis and CD36 expression, while increasing p-AMPK compared to the effects of propofol at 25 µM. Moreover, either CD36 overexpression or AMPK silence significantly exacerbated HR-induced cellular injuries and ferroptosis, and canceled propofol- and SAA-mediated protection. Notably, p-AMPK expression was downregulated after CD36 overexpression, while AMPK knockdown did not affect CD36 expression. Conclusions: Combinational usage of propofol and SAA confers superior cellular protective effects to the use of high-dose propofol alone, and it does so through inhibiting HR-induced CD36 overexpression to upregulate p-AMPK.

6.
Life Sci ; 345: 122594, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38537900

RESUMEN

A large number of patients are affected by classical heart failure (HF) symptomatology with preserved ejection fraction (HFpEF) and multiorgan syndrome. Due to high morbidity and mortality rate, hospitalization and mortality remain serious socioeconomic problems, while the lack of effective pharmacological or device treatment means that HFpEF presents a major unmet medical need. Evidence from clinical and basic studies demonstrates that systemic inflammation, increased oxidative stress, and impaired mitochondrial function are the common pathological mechanisms in HFpEF. Tetrahydrobiopterin (BH4), beyond being an endogenous co-factor for catalyzing the conversion of some essential biomolecules, has the capacity to prevent systemic inflammation, enhance antioxidant resistance, and modulate mitochondrial energy production. Therefore, BH4 has emerged in the last decade as a promising agent to prevent or reverse the progression of disorders such as cardiovascular disease. In this review, we cover the clinical progress and limitations of using downstream targets of nitric oxide (NO) through NO donors, soluble guanylate cyclase activators, phosphodiesterase inhibitors, and sodium-glucose co-transporter 2 inhibitors in treating cardiovascular diseases, including HFpEF. We discuss the use of BH4 in association with HFpEF, providing new evidence for its potential use as a pharmacological option for treating HFpEF.


Asunto(s)
Biopterinas/análogos & derivados , Insuficiencia Cardíaca , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Humanos , Insuficiencia Cardíaca/tratamiento farmacológico , Volumen Sistólico , Biopterinas/uso terapéutico , Inflamación , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología
7.
Sci Rep ; 14(1): 5537, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38448447

RESUMEN

In industry, the task of defect classification and defect localization is an important part of defect detection system. However, existing studies only focus on one task and it is difficult to ensure the accuracy of both tasks. This paper proposes a defect detection system based on improved Yolo_v4, which greatly improves the detection ability of minor defects. For K_Means algorithm clustering prianchors question with strong subjectivity, the paper proposes the Density Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm to determine the number of Anchors. To solve the problem of low detection rate of small targets caused by insufficient reuse rate of low-level features in CSPDarknet53 feature extraction network, this paper proposes an ECA-DenseNet-BC-121 feature extraction network to improve it. And the Dual Channel Feature Enhancement (DCFE) module is proposed to improve the local information loss and gradient propagation obstruction caused by quad chain convolution in PANet networks to improve the robustness of the model. The experimental results on the fabric surface defect detection datasets show that the mAP of the improved Yolo_v4 is 98.97%, which is 7.67% higher than SSD, 3.75% higher than Faster_RCNN, 10.82% higher than Yolo_v4 tiny, and 5.35% higher than Yolo_v4, and the detection speed reaches 39.4 fps. It can meet the real-time monitoring needs of industrial sites.

8.
BJPsych Bull ; 48(2): 92-99, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37309186

RESUMEN

AIMS AND METHOD: Non-Western literature on the core competencies of mental health peer supporters remains limited. Therefore, we used a three-round Delphi study with peer supporters, service users (i.e. someone using peer support services) and mental health professionals to develop a core competency framework for peer supporters in the Chinese context. RESULTS: The final framework included 35 core competencies, the conceptual origins of which were local (14.3%), Western (20%) and both local and Western (65.7%). They were grouped into five categories in ascending peer supporter role specificity: (1) self-care and self-development, (2) general work ethics, (3) work with others, (4) work with service users and (5) peer support knowledge. CLINICAL IMPLICATIONS: A culturally valid mental health peer support competency framework can minimise role confusion and refine training and practice guidelines. In a Chinese context, peer supporters were valued as generic support companions, whereas functions highlighted in the West, such as role modelling, were perceived as less critical.

9.
Opt Express ; 31(25): 41160-41177, 2023 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-38087522

RESUMEN

Multipartite entanglement has emerged as a valuable quantum resource for constructing large-scale quantum networks. However, the presence of non-Hermitian features induced by natural microscopic quantum systems significantly modifies the overall response of nonlinear parametric processes, thereby enabling direct manipulation of multipartite entanglement properties. In this study, we demonstrate the generation of multimode entanglement through atomic four-wave mixing (FWM) and analyze the properties of exceptional points (EP) under dressing control in non-Hermitian systems. By leveraging dressing-controlled atomic nonlinearity, we achieve versatile EPs and higher-order EPs by carefully tuning the atomic multi-parameter in the cascading FWM system. Additionally, we investigate the entanglement properties of various permutations of the output signal modes using the positive partial transpose (PPT) criterion. Notably, under non-Hermitian control, the application of single-, double-, and N-dressing splits leads to coherent multichannel control and further extends the scale of quantum entanglement. The outcomes of our research offer a novel approach to actively control non-Hermitian quantum phenomena without relying on artificial photonic structures. Furthermore, this paves the way for the realization of complex quantum information tasks by exploiting the non-Hermitian characteristics of the light-matter interaction.

10.
IEEE Open J Eng Med Biol ; 4: 226-233, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38059069

RESUMEN

Goal: The purpose of this work is to improve malaria diagnosis efficiency by integrating smartphones with microscopes. This integration involves image acquisition and algorithmic detection of malaria parasites in various thick blood smear (TBS) datasets sourced from different global regions, including low-quality images from Sub-Saharan Africa. Methods: This approach combines image segmentation and a convolutional neural network (CNN) to distinguish between white blood cells, artifacts, and malaria parasites. A portable system integrates a microscope with a graphical user interface to facilitate rapid malaria detection from smartphone images. We trained the CNN model using open-source data from the Chittagong Medical College Hospital, Bangladesh. Results: The validation process, using microscopic TBS from both the training dataset and an additional dataset from Sub-Saharan Africa, demonstrated that the proposed model achieved an accuracy of 97.74% ± 0.05% and an F1-score of 97.75% ± 0.04%. Remarkably, our proposed model with AlexNet surpasses the reported literature performance of 96.32%. Conclusions: This algorithm shows promise in aiding malaria-stricken regions, especially those with limited resources.

11.
Cancer Cell Int ; 23(1): 274, 2023 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-37974194

RESUMEN

BACKGROUND: Limited benefit population of immunotherapy makes it urgent to select effective biomarkers for screening appropriate treatment population. Herein, we have investigated the predictive values of circulating CD8+ T cells and CD8+T/CD4+T cell ratio in advanced gastric cancer patients receiving immunotherapy. METHODS: A retrospective cohort analysis of 187 advanced gastric cancer patients receiving sintilimab combined with oxaliplatin and capecitabine therapy in The Affiliated Xinghua People's Hospital, Medical School of Yangzhou University between December 2019 and February 2023 was conducted. The corresponding clinical outcomes of the variables were analyzed by receiver operating characteristic (ROC) curve, chi-square test, Kaplan-Meier methods and Cox proportional hazards regression models. RESULTS: The optimal cutoff values for percentages of CD8+ T cells, naive CD8+ T cells (CD8+ Tn) and memory CD8+ T cells (CD8+ Tm) expressing programmed cell death -1(PD-1) as well as PD-1+CD8+T/PD-1+CD4+T cell ratio were 21.0, 21.5, 64.3 and 0.669, respectively. It was found that the mean percentages of CD8+ T and CD8+ Tm expressing PD-1 as well as PD-1+CD8+T/PD-1+CD4+T cell ratio were significantly higher in responder (R) than non-responder (NonR) advanced gastric cancer patients associated with a longer progression free survival (PFS) and overall survival (OS). We also observed this correlation in programmed cell death-ligand 1(PD-L1) combined positive score (CPS) ≥ 5 subgroups. Univariate and multivariate Cox regression analyses demonstrated that lower CD8+ T and CD8+ Tm expressing PD-1 as well as PD-1+CD8+T/PD-1+CD4+T cell ratio were independent risk factors in advanced gastric cancer patients receiving immunotherapy plus chemotherapy. CONCLUSION: The circulating memory PD-1+CD8+ T cells and PD-1+CD8+T/PD-1+CD4+T cell ratio revealed high predictive values for response and prolonged survival outcomes in advanced gastric cancer patients receiving immunotherapy. Memory PD-1+CD8+ T cells and PD-1+CD8+T/PD-1+CD4+T cell ratio might be effective for screening benefit population of immunotherapy in advanced gastric cancer patients based on this preliminary evidence.

12.
ACS Appl Mater Interfaces ; 15(48): 56203-56212, 2023 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-38009758

RESUMEN

Hemimyzon formosanus, a species of ray-finned fish, makes use of crescent-shaped abdominal suckers for adhering to irregular, rough, and slippery gravel in fast-flowing headwaters and minor tributaries. Bioinspired by the adhesion characteristics, two-dimensional non-close-packed colloidal crystals are self-assembled and serve as templates to pattern crescent-shaped shape memory polymer-based nanostructure arrays. By the manipulation of the configuration of nanosuckers through applying common solvent stimulations, the corresponding adhesion performances on glass, sandpaper, or even porcine kidney surfaces can be switched instantaneously and reversibly under ambient conditions. The biomimetic nanostructures indicate possible solutions to a variety of challenges, such as wound nursing, and so on.

13.
Opt Express ; 31(17): 27749-27760, 2023 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-37710843

RESUMEN

The photonic spin-orbit (SO) coupling is a widely investigated effect in optical microcavities leading to various interesting physical phenomena and potential applications. We report the full sets of eigenenergies and eigenstates in a symmetrically confined potential under the effect of SO coupling induced by the transverse-electric transverse-magnetic (TE-TM) splitting, which are derived analytically via the degenerate perturbation theory. We obtained the eigenenergies and the eigenstates from the 1st to the 6th orders of excited manifold, and demonstrate unambiguously that universal rules governing the mode formation exist in such complicated photonic systems, making the modes exhibiting the features of solid and hollow skyrmions as well as spin vortices. We show that these eigenstates can be described by the SO coupled hyperspheres that can be decomposed into a series of higher-order Poincare spheres. Our results significantly extend the area of microcavity spin-optronics to the general theory of eigenvalues in confined systems, and provide an efficient theoretical frame for the information processing using microcavity-based high-dimensional vector states.

14.
ACS Appl Mater Interfaces ; 15(35): 41337-41350, 2023 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-37615350

RESUMEN

Despite the acknowledged advantages of combined immunochemotherapy for tumor treatment, the high efficiency of co-delivery of these combined agents into the targeted tumor tissue is still challenging. Herein, based on a "three-birds-with-one-stone" strategy, a facile glycyrrhizic acid (GL)-lipid hybrid nanoplatform loading triptolide (TP/GLLNP) is designed to better address the dilemma. Differing from the traditional liposomes with dual-drug co-delivery NPs, GL with a cholesterol-like structure is primarily employed to construct the lipid membrane skeleton of the GL-based lipid nanoparticle (GLLNP), and then triptolide (TP) is readily loaded in the lipid bilayer of GLLNP. The fabricated GLLNP possessed similar drug loading efficacy, particle size, and storage stability; none of the hemolysis; even higher membrane fluidity; and lower absorbed opsonin proteins compared with the conventional liposomes. Compared to TP-loaded traditional liposomes (TP/Lipo), TP/GLLNP exhibits significantly enhanced cellular uptake, cytotoxicity, and apoptosis of HepG2 cells. In addition, GLLNP could ameliorate tumor immunosuppression by promoting tumor-associated macrophage polarization from M2 to M1 phenotype. Furthermore, enhanced retention and accumulation in the tumor area of GLLNP could be found. As expected, TP/GLLNP displayed synergistic anti-hepatocellular carcinoma efficacy in vivo. In conclusion, this study provides an inspirational strategy to combine the anti-HCC benefits of GL and TP using a novel dual-drug co-delivery nanosystem.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Liposomas , Ácido Glicirrínico , Lípidos
15.
Nanotechnology ; 34(33)2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-37196644

RESUMEN

Two-dimensional black phosphorus (2D BP), a novel 2D photoelectric material with excellent near-infrared optical absorption, biocompatibility, and degradability, has shown enormous potential in biomedical field. However, under the action of light, oxygen and water, 2D BP is easily degraded to phosphate and phosphonate. In this work, trastuzumab (Tmab) as a positively charged protein was used to modify 2D BP through electrostatic interaction to form BP-Tmab. The Tmab layer on the surface of 2D BP can effectively protect BP from water, which significantly enhanced the water stability of BP. PEGylated 2D BP (BP-PEG) as a control was also prepared. After 7 days in air-exposed water, the attenuation value of BP-Tmab was only 6.62 ± 2.72% at room temperature, which was much lower than that of naked 2D BP (52.47 ± 2.26%) and BP-PEG (25.84 ± 2.80%) under the same conditions. The result was further confirmed by the temperature changes at different time points under laser irradiation, suggesting that the degradation of BP was effectively reduced by Tmab modification. In addition, BP-Tmab displayed satisfactory biocompatibility and can effectively destroy cancer cells under laser irradiation, showing an excellent photothermal therapy effect.


Asunto(s)
Antineoplásicos , Fósforo , Proteínas , Fósforo/química , Proteínas/química , Antineoplásicos/química , Humanos , Línea Celular Tumoral , Fotoquimioterapia
16.
Rev Sci Instrum ; 94(3): 035010, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-37012803

RESUMEN

Temperature measurement is of great significance for research in the health monitoring of large structures and earthquake precursors. Against the frequently reported low sensitivity of fiber Bragg grating (FBG) temperature sensors, a bimetallic-sensitized FBG temperature sensor was proposed. The sensitization structure of the FBG temperature sensor was designed, and the sensor sensitivity was analyzed; the lengths and materials of the substrate and strain transfer beam were analyzed theoretically; 7075 aluminum and 4J36 invar were chosen as bimetallic materials, and the ratio of the substrate length to the sensing fiber length was determined. The structural parameters were optimized; the real sensor was developed, and its performance was tested. The results suggested that the sensitivity of the FBG temperature sensor was 50.2 pm/°C, about five times than that of a bare FBG sensor, and its linearity was more than 0.99. The findings offer a reference for developing sensors of the same type and further improving the sensitivity of the FBG temperature sensors.

17.
Cell Biol Int ; 47(5): 943-953, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36934412

RESUMEN

The activity of phosphatase and tensin homolog (PTEN) can be inhibited by miR-17-3p, which results in attenuating myocardial ischemia/reperfusion injury (IRI), however, the mechanism behind this phenomenon is still elusive. Suppression of PTEN leads to augmented protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling strength and constrained autophagy activation, which might be the one mechanism for the ameliorated myocardial IRI. Thus, we tested the hypothesis that miR-17-3p attenuated hypoxia/reoxygenation (H/R)-mediated damage in cardiomyocytes by downregulating excessive autophagy via the PTEN-Akt-mTOR axis. The expression of miR-17-3p was remarkably increased after H/R treatment (6-h hypoxia followed by 6-h reoxygenation; H6/R6), which was concomitant with the increase of the release of lactic acid dehydrogenase (cell injury marker) and the enhancement LC3II/I ratio (autophagy markers) in H9C2 cardiomyocytes. Ectoexpression of miR-17-3p agomir led to remarkable augmentation of miR-17-3p expression and evidently attenuated H/R-mediated cell damage and excessive autophagy. Furthermore, an increase in miR-17-3p expression elicited constrained phosphorylation of PTEN (Ser380 ) while enhanced the phosphorylation of Akt (Thr308 , Ser473 ) and mTOR (Ser536 ) after H/R stimulation. In addition, pretreatment with LY-294002 (an Akt selective inhibitor) and rapamycin (an mTOR selective inhibitor) significantly abrogated the protective function of miR-17-3p on H/R-mediated cell damage and autophagy in H9C2 cardiomyocytes. Taken together, these observations indicated that the enhancement of the PTEN/Akt/mTOR axis and the consequent suppression of autophagy overactivation might represent an underlying mechanism by which miR-17-3p attenuated H/R-mediated damage in H9C2 cells.


Asunto(s)
MicroARNs , Proteínas Proto-Oncogénicas c-akt , Animales , Proteínas Proto-Oncogénicas c-akt/metabolismo , Miocitos Cardíacos/metabolismo , Línea Celular , MicroARNs/metabolismo , Apoptosis , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo , Mamíferos/metabolismo , Hipoxia/metabolismo , Autofagia
19.
Mil Med Res ; 10(1): 9, 2023 02 27.
Artículo en Inglés | MEDLINE | ID: mdl-36843103

RESUMEN

Gene therapy has shown great potential to treat various diseases by repairing the abnormal gene function. However, a great challenge in bringing the nucleic acid formulations to the market is the safe and effective delivery to the specific tissues and cells. To be excited, the development of ionizable drug delivery systems (IDDSs) has promoted a great breakthrough as evidenced by the approval of the BNT162b2 vaccine for prevention of coronavirus disease 2019 (COVID-19) in 2021. Compared with conventional cationic gene vectors, IDDSs can decrease the toxicity of carriers to cell membranes, and increase cellular uptake and endosomal escape of nucleic acids by their unique pH-responsive structures. Despite the progress, there remain necessary requirements for designing more efficient IDDSs for precise gene therapy. Herein, we systematically classify the IDDSs and summarize the characteristics and advantages of IDDSs in order to explore the underlying design mechanisms. The delivery mechanisms and therapeutic applications of IDDSs are comprehensively reviewed for the delivery of pDNA and four kinds of RNA. In particular, organ selecting considerations and high-throughput screening are highlighted to explore efficiently multifunctional ionizable nanomaterials with superior gene delivery capacity. We anticipate providing references for researchers to rationally design more efficient and accurate targeted gene delivery systems in the future, and indicate ideas for developing next generation gene vectors.


Asunto(s)
COVID-19 , Ácidos Nucleicos , Humanos , Vacuna BNT162 , COVID-19/terapia , Sistemas de Liberación de Medicamentos , Terapia Genética
20.
Opt Express ; 31(4): 6982-6995, 2023 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-36823944

RESUMEN

The nonlinear parametric process is of great significance for achieving high-quality coherent optical signals and quantum correlated photons. With the development of classical and quantum information processing, the study of the properties of parametric processes is evolving in complex scenarios of multimode, which is limited in conventional nonlinear media due to strict phase matching, e.g. nonlinear crystals. Here we study the dressing-energy-level-cascaded four-wave mixing process to generate multimode optical parametric signals. Via cascading double-Λ type configuration of 85Rb D1 line, the non-degenerate energy-level-cascaded FWM is constructed to generate multimode self-parametric amplification. Moreover, with the dressing effects based on atomic coherence, the spatial and frequency multimode characteristics of energy-level-cascaded FWM parametric amplification, i.e., the modes number and pattern, are actively modulated by the pump fields detuning. Also, the spatial modes from the coupling of two coexisting spontaneous parametric FWMs can be controlled to reach tremendous scalability via the atomic coherence and Kerr non-linearity. The atomic coherence effects and unique phase-matching symmetry nature allow flexible modulation of the multimode property of the generated parametric signals within a nonlinear device, which paves a way for multimode classical and quantum information processing.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA