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1.
J Environ Manage ; 370: 122464, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39265495

RESUMEN

In the context of global warming, comprehending the dynamics of terrestrial water storage (TWS) and its responses to natural and anthropogenic factors is paramount for hydrological research and the management of water resources in China. This study utilized GRACE (Gravity Recovery and Climate Experiment)/GRACE-Follow On (GRACE-FO) satellite data to analyze terrestrial water storage across nine basins in China from 2005 to 2020 at multiple temporal and spatial scales. Subsequently, employing a Geographic detector model, potential influencing factors were identified, and an enhanced Geographically Weighted Regression (GWR) method was proposed for attributing changes in TWS in China. The findings reveal a consistent declining trend in TWS based on GRACE/GRACE-FO data across different temporal scales, with the most pronounced decreases observed in August and September. Geographic Detector analysis unveils significant interactions among various environmental factors, with climate variables playing a pivotal role in modulating hydrological characteristics of major river basins, where rising temperatures can exacerbate the severity of precipitation events, thus increasing the risk of floods and droughts. Moreover, analysis of the primary influencing factors indicates significant impacts of population density and topography on water resources in the southeastern and southwestern regions, particularly amidst increasing human activities and urbanization expansion. The results of this study are crucial for comprehending the dynamic changes and mechanisms of TWS in China, as well as for formulating water resource management strategies.

2.
Small ; : e2402841, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38693072

RESUMEN

Developing lightweight composite with reversible switching between microwave (MW) absorption and electromagnetic interference (EMI) shielding is promising yet remains highly challenging due to the completely inconsistent attenuation mechanism for electromagnetic (EM) radiation. Here, a lightweight vanadium dioxide/expanded polymer microsphere composites foam (VO2/EPM) is designed and fabricated with porous structures and 3D VO2 interconnection, which possesses reversible switching function between MW absorption and EMI shielding under thermal stimulation. The VO2/EPM exhibits MW absorption with a broad effective absorption bandwidth of 3.25 GHz at room temperature (25 °C), while provides EMI shielding of 23.1 dB at moderately high temperature (100 °C). This reversible switching performance relies on the porous structure and tunability of electrical conductivity, complex permittivity, and impedance matching, which are substantially induced by the convertible crystal structure and electronic structure of VO2. Finite element simulation is employed to qualitatively investigate the change in interaction between EM waves and VO2/EPM before and after the phase transition. Moreover, the application of VO2/EPM is demonstrated with a reversible switching function in controlling wireless transmission on/off, showcasing its excellent cycling stability. This kind of smart material with a reversible switching function shows great potential in next-generation electronic devices.

3.
Nanomicro Lett ; 16(1): 134, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38411757

RESUMEN

The remarkable properties of carbon nanotubes (CNTs) have led to promising applications in the field of electromagnetic interference (EMI) shielding. However, for macroscopic CNT assemblies, such as CNT film, achieving high electrical and mechanical properties remains challenging, which heavily depends on the tube-tube interactions of CNTs. Herein, we develop a novel strategy based on metal-organic decomposition (MOD) to fabricate a flexible silver-carbon nanotube (Ag-CNT) film. The Ag particles are introduced in situ into the CNT film through annealing of MOD, leading to enhanced tube-tube interactions. As a result, the electrical conductivity of Ag-CNT film is up to 6.82 × 105 S m-1, and the EMI shielding effectiveness of Ag-CNT film with a thickness of ~ 7.8 µm exceeds 66 dB in the ultra-broad frequency range (3-40 GHz). The tensile strength and Young's modulus of Ag-CNT film increase from 30.09 ± 3.14 to 76.06 ± 6.20 MPa (~ 253%) and from 1.12 ± 0.33 to 8.90 ± 0.97 GPa (~ 795%), respectively. Moreover, the Ag-CNT film exhibits excellent near-field shielding performance, which can effectively block wireless transmission. This innovative approach provides an effective route to further apply macroscopic CNT assemblies to future portable and wearable electronic devices.

4.
Sensors (Basel) ; 23(16)2023 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-37631661

RESUMEN

In this paper, a liquid crystal-modulated metastructure sensor (MS) is proposed that can detect the refractive index (RI) of a liquid and change the detection range under different applied voltages. The regulation of the detection range is based on the different bias states of the liquid crystal at different voltages. By changing the sample in the cavity that is to be detected, the overall electromagnetic characteristics of the device in the resonant state are modified, thus changing the position of the absorption peaks so that different RI correspond to different absorption peaks, and finally realizing the sensing detection. The refractive index unit is denoted as RIU. The range of the refractive index detection is 1.414-2.828 and 2.121-3.464, and the corresponding absorption peak variation range is 0.8485-1.028 THz and 0.7295-0.8328 THz, with a sensitivity of 123.8 GHz/RIU and 75.6 GHz/RIU, respectively. In addition, an approach to optimizing resonant absorption peaks is explored, which can suppress unwanted absorption generated during the design process by analyzing the energy distribution and directing the current flow on the substrate. Four variables that have a more obvious impact on performance are listed, and the selection and change trend of the numerical values are focused on, fully considering the errors that may be caused by manufacturing and actual use. At the same time, the incident angle and polarization angle are also included in the considered range, and the device shows good stability at these angles. Finally, the influence of the number of resonant rings on the sensing performance is also discussed, and its conclusion has guiding value for optimizing the sensing demand. This new liquid crystal-modulated MS has the advantages of a small size and high sensitivity and is expected to be used for bio-detection, sensing, and so on. All results in this work were obtained with the aid of simulations based on the finite element method.


Asunto(s)
Cristales Líquidos , Comercio , Refracción Ocular
5.
Environ Pollut ; 331(Pt 1): 121895, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37236593

RESUMEN

Organic pollutants in aquatic environment could have important implications on pollution stress on aquatic organisms and even on the risk of human exposure. Thus, revealing their occurrence in aquatic environment is essential for water quality monitoring and ecological risk purposes. In this study, a comprehensive two-dimensional gas chromatography connected with time-of-flight mass spectrometry (GC × GC-TOF-MS) was applied, to enable non-target and target analysis of pollutants in the Yongding River Basin. Based on the isotopic patterns, accurate masses and standard substances, certain environmental contaminants were tentatively identified which including polycyclic aromatic hydrocarbon (PAHs), organochlorine pesticides (OCPs), phenols, amines, etc. The compounds with the highest concentration were naphthalene (109.0 ng/L), 2,3-benzofuran (51.5 ng/L) and 1,4-dichlorobenzene (35.9 ng/L) in Guishui River. Wastewater treatment plants (WWTPs) discharges were a main source of pollutants in Yongding River Basin, as the types of compounds screened in the downstream river were relatively similar to those from WWTPs. According to the target analysis, a number of pollutants were selected due to the acute toxicity and cumulative discharge from WWTPs and downstream rivers. Three PAHs (naphthalene, Benzo(b)fluoranthene and pyrene) homologues showed moderate risk to fish and H. Azteca in Yongding River Basin, while the rest of the measured chemicals showed low ecological impact across the entire study area based on the risk assessment. The results are helpful for understanding the necessity of high-throughput screening analysis for assessing water quality of rivers and the discharge emissions of pollutants from WWTPs to the river environment.


Asunto(s)
Contaminantes Ambientales , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Animales , Humanos , Contaminantes Ambientales/análisis , Monitoreo del Ambiente , Hidrocarburos Policíclicos Aromáticos/análisis , Naftalenos/análisis , Medición de Riesgo , Contaminantes Químicos del Agua/análisis , China
6.
Small Methods ; 7(4): e2201694, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36802141

RESUMEN

MXenes with unique physicochemical properties have shown substantial potential in electromagnetic interference (EMI) shielding. However, the chemical instability and mechanical fragility of MXenes has become a major hurdle for their application. Abundant strategies have been dedicated to improving the oxidation stability of colloidal solution or mechanical properties of films, which always come at the expense of electrical conductivity and chemical compatibility. Here, hydrogen bond (H-bond) and coordination bond are employed to achieve chemical and colloidal stability of MXenes (0.1 mg mL-1 ) by occupying the reaction sites of Ti3 C2 Tx attacking of water and oxygen molecules. Compared to the Ti3 C2 Tx , the Ti3 C2 Tx modified with alanine via H-bond shows significantly improved oxidation stability (at room temperature over 35 days), while the Ti3 C2 Tx modified with cysteine by synergy of H-bond and coordination bond can be maintained even after 120 days. Simulation and experimental results verify the formation of H-bond and Ti-S bond by a Lewis acid-base interaction between Ti3 C2 Tx and cysteine. Furthermore, the synergy strategy significantly improves the mechanical strength of the assembled film (up to 78.1 ± 7.9 MPa), corresponding the increment of 203% compared to untreated one, almost without compromising the electrical conductivity and EMI shielding performance.

7.
Opt Express ; 30(19): 34172-34187, 2022 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-36242437

RESUMEN

This article proposed a metastructure device that can realize polarization conversion (PC) and absorption function switching in the terahertz (THz) range based on the photoconductivity effect. The photoconductance is formed by exposing silicon to different intensities of light, then the PC and absorption function can be switched. At the same time, the absorption bandwidth is expanded by inserting air resonant cavities into the dielectric substrate, changing the thickness of the dielectric locally, and cutting rectangular slots at the metal bottom plate. When the device works as a polarization converter, linear-to-linear PC with a polarization conversion rate of over 90% at 0.96-1.47 THz can be achieved, and its relative bandwidth is 42%. And when the silicon conductivity is fixed at 3500 S/m through illuminating, the device switches to an ultra-broadband absorber with over 90% absorption at 0.75-1.73 THz and a relative bandwidth of 79%. The designed device can be applied efficiently in many fields, such as electromagnetic cloaking and communication.

8.
ACS Appl Mater Interfaces ; 14(2): 3302-3314, 2022 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-34991311

RESUMEN

Highly conductive polymer foam with light weight, flexibility, and high-performance electromagnetic interference (EMI) shielding is highly desired in the fields of aerospace, communication, and high-power electronic equipment, especially in the board-level packaging. However, traditional technology for preparing conductive polymer foam such as electroless plating and electroplating involves serious pollution, a complex fabrication process, and high cost. It is urgent to develop a facile method for the fabrication of highly conductive polymer foam. Herein, we demonstrated a lightweight and flexible silver-wrapped melamine foam (Ag@ME) via in situ sintering of metal-organic decomposition (MOD) at a low temperature (200 °C) on the ME skeleton modified with poly(ethylene imine). The Ag@ME with a continuous 3D conductive network exhibits good compressibility, an excellent conductivity of 158.4 S/m, and a remarkable EMI shielding effectiveness of 63 dB in the broad frequency of 8.2-40 GHz covering X-, Ku-, K-, and Ka-bands, while the volume content is only 2.03 vol %. The attenuation mechanism of Ag@ME for EM waves is systematically investigated by both EM simulation and experimental analysis. Moreover, the practical EMI shielding application of Ag@ME in board-level packaging is demonstrated and it shows outstanding near-field shielding performance. This novel strategy for fabrication of highly conductive polymer foam with low cost and non-pollution could potentially promote the practical applications of Ag@ME in the field of EMI shielding.

9.
Opt Lett ; 47(23): 6065-6068, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37219173

RESUMEN

A non-reciprocity sensor based on a layered structure with multitasking is proposed, which realizes biological detection and angle sensing. Through an asymmetrical arrangement of different dielectrics, the sensor obtains non-reciprocity on the forward and backward scales, thus achieving multi-scale sensing in different measurement ranges. The structure sets the analysis layer. Injecting the analyte into the analysis layers by locating the peak value of the photonic spin Hall effect (PSHE) displacement, cancer cells can accurately be distinguished from normal cells via refractive index (RI) detection on the forward scale. The measurement range is 1.569∼1.662, and the sensitivity (S) is 2.97 × 10-2 m/RIU. On the backward scale, the sensor is able to detect glucose solution with 0∼400 g/L concentrations (RI = 1.3323∼1.38), with S = 1.16 × 10-3 m/RIU. When the analysis layers are filled with air, high-precision angle sensing can be achieved in the terahertz range by locating the incident angle of the PSHE displacement peak; 30°âˆ¼45°, and 50°âˆ¼65° are the detection ranges, and the highest S can reach 0.032 THz/°. This sensor contributes to detecting cancer cells and biomedical blood glucose and offers a new way to the angle sensing.

10.
ACS Nano ; 14(10): 14134-14145, 2020 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-33044056

RESUMEN

Flexible and lightweight high-performance electromagnetic interference shielding materials with minimal thickness, excellent mechanical properties, and outstanding reliability are highly desired in the field of fifth-generation (5G) communication, yet remain extremely challenging to manufacture. Herein, we prepared an ultrathin densified carbon nanotube (CNT) film with superior mechanical properties and ultrahigh shielding effectiveness. Upon complete removal of impurities in pristine CNT film, charge separation in individual CNTs induced by polar molecules leads to strong CNT-CNT attraction and film densification, which significantly improve the electrical conductivity, shielding performance, and mechanical strength. The tensile strength is up to 822 ± 21 MPa, meanwhile the electrical conductivity is as high as 902,712 S/m, and the density is only 1.39 g cm-3. Notably, the shielding effectiveness is over 51 dB with a thickness of merely 1.85 µm in the broad frequency range of 4-18 GHz, and it reaches to ∼82 dB at 6.36 µm and ∼101 dB at 14.7 µm, respectively. Further, such CNT film exhibits excellent reliability after an extended period in strong acid/alkali, high temperature, and high humidity. It demonstrates the best overall performance among representative shielding materials by far, representing a critical breakthrough in the preparation of shielding film toward applications in wearable electronics and 5G communication.

11.
Aging (Albany NY) ; 12(12): 11781-11793, 2020 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-32568100

RESUMEN

Excess salt (NaCl) intake is closely related to a variety of central nervous system (CNS) diseases characterized by increased cerebral microvascular permeability. However, the link between a high salt diet (HSD) and the breakdown of tight junctions (TJs) remains unclear. In the present study, we found that high salt does not directly influence the barrier between endothelial cells, but it suppresses expression of TJ proteins when endothelial cells are co-cultured with astrocytes. This effect is independent of blood pressure, but depends on the astrocyte activation via the NFκB/MMP-9 signaling pathway, resulting in a marked increase in VEGF expression. VEGF, in turn, induces disruption of TJs by inducing phosphorylation and activation of ERK and eNOS. Correspondingly, the HSD-induced disruption of TJ proteins is attenuated by blocking VEGF using the specific monoclonal antibody Bevacizumab. These results reveal a new axis linking a HSD to increased cerebral microvascular permeability through a VEGF-initiated inflammatory response, which may be a potential target for preventing the deleterious effects of HSD on the CNS.


Asunto(s)
Astrocitos/metabolismo , Barrera Hematoencefálica/patología , Permeabilidad Capilar/efectos de los fármacos , Cloruro de Sodio Dietético/efectos adversos , Factor A de Crecimiento Endotelial Vascular/metabolismo , Animales , Astrocitos/efectos de los fármacos , Bevacizumab , Barrera Hematoencefálica/citología , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/inmunología , Permeabilidad Capilar/inmunología , Células Cultivadas , Técnicas de Cocultivo , Modelos Animales de Enfermedad , Regulación hacia Abajo/efectos de los fármacos , Regulación hacia Abajo/inmunología , Células Endoteliales , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/inmunología , Endotelio Vascular/patología , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Sistema de Señalización de MAP Quinasas/inmunología , Masculino , Metaloproteinasa 9 de la Matriz/metabolismo , Ratones , Ratones Transgénicos , FN-kappa B/metabolismo , Óxido Nítrico Sintasa de Tipo III/genética , Óxido Nítrico Sintasa de Tipo III/metabolismo , Fosforilación , Cultivo Primario de Células , Ratas , Cloruro de Sodio Dietético/administración & dosificación , Organismos Libres de Patógenos Específicos , Proteínas de Uniones Estrechas/metabolismo , Uniones Estrechas/efectos de los fármacos , Uniones Estrechas/patología , Factor A de Crecimiento Endotelial Vascular/antagonistas & inhibidores
12.
J Neuroinflammation ; 16(1): 242, 2019 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-31779652

RESUMEN

BACKGROUND: Preserving the integrity of the blood-brain barrier (BBB) is beneficial to avoid further brain damage after acute ischemic stroke (AIS). Astrocytes, an important component of the BBB, promote BBB breakdown in subjects with AIS by secreting inflammatory factors. The glucagon-like peptide-1 receptor (GLP-1R) agonist exendin-4 (Ex-4) protects the BBB and reduces brain inflammation from cerebral ischemia, and GLP-1R is expressed on astrocytes. However, the effect of Ex-4 on astrocytes in subjects with AIS remains unclear. METHODS: In the present study, we investigated the effect of Ex-4 on astrocytes cultured under oxygen-glucose deprivation (OGD) plus reoxygenation conditions and determined whether the effect influences bEnd.3 cells. We used various methods, including permeability assays, western blotting, immunofluorescence staining, and gelatin zymography, in vitro and in vivo. RESULTS: Ex-4 reduced OGD-induced astrocyte-derived vascular endothelial growth factor (VEGF-A), matrix metalloproteinase-9 (MMP-9), chemokine monocyte chemoattractant protein-1 (MCP-1), and chemokine C-X-C motif ligand 1 (CXCL-1). The reduction in astrocyte-derived VEGF-A and MMP-9 was related to the increased expression of tight junction proteins (TJPs) in bEnd.3 cells. Ex-4 improved neurologic deficit scores, reduced the infarct area, and ameliorated BBB breakdown as well as decreased astrocyte-derived VEGF-A, MMP-9, CXCL-1, and MCP-1 levels in ischemic brain tissues from rats subjected to middle cerebral artery occlusion. Ex-4 reduced the activation of the JAK2/STAT3 signaling pathway in astrocytes following OGD. CONCLUSION: Based on these findings, ischemia-induced inflammation and BBB breakdown can be improved by Ex-4 through an astrocyte-dependent manner.


Asunto(s)
Astrocitos/efectos de los fármacos , Barrera Hematoencefálica/efectos de los fármacos , Exenatida/farmacología , Receptor del Péptido 1 Similar al Glucagón/agonistas , Infarto de la Arteria Cerebral Media/metabolismo , Inflamación/tratamiento farmacológico , Accidente Cerebrovascular/metabolismo , Animales , Astrocitos/metabolismo , Barrera Hematoencefálica/patología , Quimiocina CCL2/metabolismo , Quimiocina CXCL1/metabolismo , Exenatida/uso terapéutico , Infarto de la Arteria Cerebral Media/patología , Inflamación/metabolismo , Inflamación/patología , Masculino , Metaloproteinasa 9 de la Matriz/metabolismo , Ratas , Ratas Sprague-Dawley , Accidente Cerebrovascular/patología , Factor A de Crecimiento Endotelial Vascular/metabolismo
13.
Neuropsychiatr Dis Treat ; 15: 1009-1014, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31114207

RESUMEN

BACKGROUND: Cognitive impairment in patients with cerebral small vessel disease (CSVD) is common, but the pathogenic mechanism is not well understood. The situation of non-breathing-related sleep fragmentation in CSVD patients and its influence on cognitive impairment is not clear. The aim of this study was to investigate the influence of non-breathing-related sleep fragmentation on cognitive function in patients with CSVD. METHODS: A group of 89 CSVD patients without breathing-related sleep disorders in the Department of Neurology, Third Affiliated Hospital of Sun Yat-sen University was enrolled. The patients underwent magnetic resonance scan, polysomnography, cognitive function evaluation using Montreal Cognitive Assessment scale (MoCA), and Mini-Mental State Examination. The patients were assigned to study group (arousal index [ArI] ≥26.8/hour) or control group (ArI <26.8/hour) based on the average level of ArI (mean =26.8, SD =7.5) at night, and the cognitive function of the patients in the two groups was analyzed. RESULTS: The total MoCA score, the subscale scores of visuospatial ability and delayed recall in the study group were significantly lower than that in the control group (P<0.05). The cognitive impairment measured by MoCA was positively related to ArI level and %N-3 sleep according to the results of logistic regression (P<0.05). CONCLUSION: Non-breathing-related sleep fragmentation is associated with cognitive impairment in CSVD patients, especially executive function and delayed recall ability.

14.
FASEB J ; 33(3): 4376-4387, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30694693

RESUMEN

Astrocytes mediate the destruction of the blood-brain barrier (BBB) during ischemic stroke (IS). IL-9 is a pleiotropic cytokine that we previously found to be highly expressed in peripheral blood mononuclear cells from patients with IS, and the presence of IL-9 receptors on astrocytes has been reported in the literature. Here, we detected the effect of IL-9 on astrocytes using an anti-IL-9-neutralizing antibody to treat rats with experimental stroke. Supernatants from astrocytes treated with or without oxygen-glucose deprivation and/or IL-9 were incubated with bEnd.3 cell monolayers after blocking the IL-9 receptor on the endothelium. Immunofluorescence staining and Western blot analyses were conducted to observe the change in tight junction proteins (TJPs) in bEnd.3 cells as well as the level of VEGF-A and possible signal pathways in astrocytes. We also applied middle cerebral artery occlusion (MCAO) models to determine the effect of anti-IL-9-neutralizing antibodies on IS. As a result, astrocyte-conditioned medium treated with IL-9 aggravated the disruption of the BBB accomplished by the degradation of TJPs in endothelial cells. In addition, IL-9 increased the level of VEGF-A in astrocytes, and blocking the effect of VEGF-A reversed the breakdown of the BBB. In the MCAO model, anti-IL-9-neutralizing antibody reduced the infarct volume and BBB destruction. Mechanistically, the anti-IL-9-neutralizing antibody repaired the damaged TJPs (zonula occludens 1, occludin, and claudin-5) and induced a decrease in VEGF-A expression in ischemic lateral brain tissue. In contrast, a local injection of recombinant murine IL-9 to the brain resulted in a marked up-regulation of VEGF-A in the striatum. In conclusion, anti-IL-9-neutralizing antibody can reduce the severity of IS partially by alleviating the destruction of the BBB via down-regulation of astrocyte-derived VEGF-A. This finding suggests that targeting IL-9 or VEGF-A could provide a new direction for the treatment of IS.-Tan, S., Shan, Y., Lin, Y., Liao, S., Zhang, B., Zeng, Q., Wang, Y., Deng, Z., Chen, C., Hu, X., Peng, L., Qiu, W., Lu, Z. Neutralization of IL-9 ameliorates experimental stroke by repairing the blood-brain barrier via down-regulation of astrocyte-derived vascular endothelial growth factor-A.


Asunto(s)
Astrocitos/efectos de los fármacos , Barrera Hematoencefálica/efectos de los fármacos , Interleucina-9/antagonistas & inhibidores , Factor A de Crecimiento Endotelial Vascular/biosíntesis , Animales , Anticuerpos Neutralizantes/farmacología , Anticuerpos Neutralizantes/uso terapéutico , Astrocitos/metabolismo , Hipoxia de la Célula , Células Cultivadas , Cuerpo Estriado/efectos de los fármacos , Medios de Cultivo Condicionados/farmacología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Glucosa/farmacología , Hipoxia-Isquemia Encefálica , Infarto de la Arteria Cerebral Media/tratamiento farmacológico , Infarto de la Arteria Cerebral Media/metabolismo , Infarto de la Arteria Cerebral Media/patología , Inflamación , Interleucina-9/administración & dosificación , Interleucina-9/inmunología , Interleucina-9/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Oxígeno/farmacología , Ratas , Ratas Sprague-Dawley , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/farmacología , Factor de Transcripción STAT3/biosíntesis , Factor de Transcripción STAT3/genética , Transducción de Señal/efectos de los fármacos , Proteínas de Uniones Estrechas/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Factor A de Crecimiento Endotelial Vascular/genética
15.
J Neurol ; 266(10): 2347-2362, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30291424

RESUMEN

Cerebral small vessel disease (CSVD) is a broad category of cerebrovascular diseases which primarily affect the perforating arterioles, capillaries and venules with multiple distinct etiologies. In spite of distinctive pathogenesis, CSVD shares similar neuroimaging markers, including recent small subcortical infarct, lacune of presumed vascular origin, white matter hyperintensity of presumed vascular origin, perivascular space and cerebral microbleeds. The radiological features of neuroimaging markers are indicative for etiological analysis. Furthermore, in sporadic arteriosclerotic pathogenesis associated CSVD, the total CSVD burden is a significant predictor for stroke events, global cognitive impairment, psychiatric disorders and later life quality. This review aims to summarize the radiological characteristics as well as the clinical implication of CSVD markers and neuroimaging interpretation for CSVD symptomatology.


Asunto(s)
Enfermedades de los Pequeños Vasos Cerebrales , Sistema Glinfático , Hemorragias Intracraneales , Neuroimagen , Sustancia Blanca , Enfermedades de los Pequeños Vasos Cerebrales/diagnóstico por imagen , Enfermedades de los Pequeños Vasos Cerebrales/etiología , Enfermedades de los Pequeños Vasos Cerebrales/patología , Sistema Glinfático/diagnóstico por imagen , Sistema Glinfático/patología , Humanos , Hemorragias Intracraneales/diagnóstico por imagen , Hemorragias Intracraneales/patología , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología
17.
Front Neurol ; 9: 657, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30294295

RESUMEN

Purpose: Perforating Artery Infarcts (PAIs) can be divided into two subtypes based on their etiologies: branch Atheromatous Disease (BAD) and Lacunar Infarct (LI). Recent studies have shown that while both subtypes can be caused by large artery lesions, the different mechanisms that underlie their development are not clear. This study was designed to use High-Resolution Magnetic Resonance Imaging (HRMRI) to explore the differences that contribute to the occurrence of these two subtypes in large artery lesions in the anterior circulation. Methods: Fifty patients with an acute PAI in the anterior circulation were enrolled (32 BAD and 18 LI patients). The ipsilateral middle cerebral artery (MCA) was scanned with HRMRI to analyze the atherosclerosis plaques. Artery remodeling and plaque characteristics of MCA lesions were compared between the two subtypes. Results: The rate of MCA lesions was significantly higher in BAD and substantially lower in LI (P = 0.033). LAs for the lumen areas in Bad, they were smaller than LI (P < 0.001), Additionally, the plaque area (P = 0.001) and plaque burden (P < 0.001) were superior in the BAD group. Most BAD patients displayed non-positive remodeling, while the great majority of LI patients showed positive remodeling (P < 0.001). Conclusion: In the anterior circulation, a considerable amount of BAD and LI share similarities with atherosclerotic plaques in large arteries. BAD patients mainly showed relatively large and stable atherosclerotic plaques in large arteries, while LI patients mainly exhibited relatively small and unstable atherosclerotic plaques. Clinical Trial Registration: This clinical trial is a retrospective study and therefore does not require registration.

19.
Neurochem Int ; 118: 91-95, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29729873

RESUMEN

25-Hydroxyvitamin D (25(OH)D) deficiency is a frequent condition in patients who suffer acute ischemic stroke (AIS), and several studies suggested that it may be associated with a poorer prognosis. Whether this association is affected by hypertension is unclear. Our aim was to investigate the association between 25(OH)D levels and both clinical severity and outcome after 3 months in AIS patients stratified by the history of hypertension. Consecutive first-ever AIS patients admitted to the Third Affiliated Hospital of Sun Yat-sen University, China were identified. Clinical information was collected. Serum 25(OH)D levels were measured at baseline. Stroke severity was assessed at admission using the National Institutes of Health Stroke Scale (NIHSS) score. Functional outcome was evaluated after 3 months of onset using the modified Rankin Scale (mRS). Multivariate analyses were performed using logistic regression models. During the study period, 377 patients were diagnosed as AIS and were included in the analysis. 25(OH)D deficiency was not associated with the risk of NIHSS at admission and 3 months mRS both in total patients and the hypertension subgroup. Among AIS without hypertension, 25(OH)D deficiency subjects had a significantly higher of NIHSS at admission and 3 months mRS compared with those with 25(OH)D ≥ 50 nmol/L. The odds ratios (95% confidence interval) were 5.51(1.83-16.60) and 4.63(1.53-14.05) in the multivariable adjusted model (P for linear trend < 0.05). Serum lower 25(OH)D levels can be seen as an independent prognostic factor of functional outcome in AIS without hypertension. Additional studies about improving prognosis of AIS by vitamin D supplementation could be first applied to these patients.


Asunto(s)
Isquemia Encefálica/sangre , Hipertensión , Accidente Cerebrovascular/sangre , Deficiencia de Vitamina D/sangre , Vitamina D/análogos & derivados , Anciano , Biomarcadores/sangre , Isquemia Encefálica/diagnóstico por imagen , Isquemia Encefálica/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/epidemiología , Resultado del Tratamiento , Vitamina D/sangre , Deficiencia de Vitamina D/diagnóstico por imagen , Deficiencia de Vitamina D/epidemiología
20.
Front Neurol ; 8: 497, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29018401

RESUMEN

BACKGROUND AND OBJECTIVE: White matter hyperintensities can be easily identified by brain imaging. Juxtacortical small lesion (JCSL) is a special type of white matter lesion, defined as no greater than 5 mm in diameter and adjacent to the cerebral cortex in location. We notice lately that JCSLs alone may be associated to various neurological symptoms. Here, we design the present study to determine the risk factors for JCSLs and their clinical manifestations in patients in our neurology clinic. METHODS: 206 participants suffered from neurological disorders and completed magnetic resonance imaging (MRI) examinations were divided into two groups: patients with JCSLs and patients without lesions on MRI. Meanwhile, 129 age- and sex-matched healthy volunteers were also recruited. Laboratory examinations and the phenotypes and distributions of the symptoms of the three groups were compared. RESULTS: The serum levels of apoB and homocysteine (HCY) were independently related to the appearance of JCSLs and HCY level was also associated with the number of JCSLs. Patients with JCSLs might present with headache, insomnia, and/or anxiety/depression, which were related with the anatomical locations of the lesions. CONCLUSION: These data suggest that JCSLs are symptomatic and might in result fromarteriole atherosclerosis, which should raise our attention.

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