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BACKGROUND: Glaucoma patients frequently present with depressive symptoms, the development of which is closely associated with amygdalar activity. However, no studies to date have documented glaucoma-related changes in the functional connectivity (FC) of the amygdala. Accordingly, resting-state functional magnetic resonance imaging (rs-fMRI) analyses were herein used to evaluate changes in amygdalar FC in primary angle-closure glaucoma (PACG) patients. METHODS: In total, this study enrolled 36 PACG patients and 33 healthy controls (HCs). Complete eye exams were conducted for all PACG patients. After the preprocessing of magnetic resonance imaging (MRI) data, the bilateral amygdala was selected as a seed point, followed by the comparison of resting-state FC between the PACG and HC groups. Then, those brain regions exhibiting significant differences between these groups were identified, and relationships between the FC coefficient values for these regions and clinical variables of interest were assessed. RESULTS: These analyses revealed that as compared to HC individuals, PACG patients exhibited reductions in FC between the amygdala and the cerebellum_8, vermis_4_5, anterior central gyrus, supplementary motor area, paracentral lobule, putamen, middle frontal gyrus, and posterior cingulate gyrus, while enhanced FC was detected between the right and left amygdala. No significant correlations between these changes in amygdalar any any disease-related clinical parameters or disease duration were noted. CONCLUSIONS: Patients with PACG exhibit extensive resting state abnormalities with respect to the FC between the amygdala and other regions of the brain, suggesting that dysregulated amygdalar FC may play a role in the pathophysiology of PACG.
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Tonsila do Cerebelo , Glaucoma de Ângulo Fechado , Imageamento por Ressonância Magnética , Humanos , Glaucoma de Ângulo Fechado/fisiopatologia , Glaucoma de Ângulo Fechado/diagnóstico por imagem , Masculino , Feminino , Pessoa de Meia-Idade , Tonsila do Cerebelo/diagnóstico por imagem , Tonsila do Cerebelo/fisiopatologia , Idoso , Conectoma , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiopatologiaRESUMO
OBJECTIVE: Spinal arteriovenous fistulas (SAVF) was often neglected and misdiagnosed as acute transverse myelitis (ATM) due to its insidious onset and non-specific clinical symptoms. This study aims to investigate the differential diagnostic value of high-resolution T2-weighted volumetric sequence (3D sampling perfection with application-optimized contrasts using different flip-angle evolutions [SPACE]) in patients with SAVF and ATM. METHODS: Retrospectively analyzed the clinical and radiological findings of 32 SDAVF patients and 32 ATM patients treated at our institutions from May 2018 to January 2023. They all underwent conventional spinal MRI and T2-SPACE examination, compared their performance in identifying lesions, to estimate the value of T2 SPACE sequence in the diagnosis of SAVF and ATM patients. RESULTS: The clue of cauda equina area change (CEAC) in conventional MRI and T2-SPACE sequences is specific for the diagnosis of SAVF. The diagnostic model composed of perimedullary flow voids (PFV) and CEAC has good diagnostic performance (AUCMRI = 0.95; AUCSPACE = 0.935). Compared with conventional MRI, the T2-SPACE sequence has a higher detection rate, sensitivity, and negative predictive value for PFV and CEAC in SAVF patients, but lower specificity and positive predictive value. In T2-SPACE images, there are significant differences in the distribution range, quadrant, and maximum diameter of PFV vessels between SAVF and ATM patients. Moreover, T2-SPACE sequence can determine the site of fistula in most SAVF patients preferably, and the inter-rater agreement was good in the assessment of the fistula. CONCLUSION: The CEAC is a new and useful clue for the diagnosis of thoracolumbar SAVF. And T2-SPACE sequence can more intuitively observe the lesions of SAVF, has good differential diagnostic value for SAVF and ATM patients.
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Fístula Arteriovenosa , Mielite Transversa , Humanos , Estudos Retrospectivos , Mielite Transversa/diagnóstico por imagem , Diagnóstico Diferencial , Imageamento por Ressonância Magnética/métodos , Fístula Arteriovenosa/diagnóstico , Imageamento Tridimensional/métodosRESUMO
Monitoring and analyzing radio interference sources play a crucial role in ensuring the safe operation of civil aviation navigation, communication, airport management, and air traffic control. Traditional ground monitoring methods are slow and inadequate for tracking aerial and mobile interference sources effectively. Although flight methods such as helicopters and airships can effectively monitor aerial interference, the flight approval process is time-consuming and expensive. This paper investigates a novel approach to locating civil aviation radio interference sources using four unmanned aerial vehicles (UAVs) to address this issue. It establishes a model for aerial positioning of radio interference sources with the four UAVs and proposes a method for time synchronization and data communication among them. The paper conducts simulations of the four-UAV time-frequency difference positioning method, analyzing the geometric accuracy dilution with different deployment configurations of the UAVs, positioning biases, and root mean square errors (RMSEs) under varying interference source movement speeds. The simulation results provide crucial data to support subsequent experiments.
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BACKGROUND: Intracranial artery dissection (IAD) is a pathological dissection of the arterial wall. .However, the morphological features and imaging characteristics of patients with intracranial artery dissection (IAD) remain poorly understood. METHODS: The study reports on 70 IAD patients (30 culprit and 40 non-culprit). All participants underwent high-resolution magnetic resonance imaging (HR-MRI) scans. The morphological features and imaging characteristics of artery dissection were carefully investigated. Demographics and clinical characteristics of culprit and non-culprit patients were also collected. Apparent differences between the two groups, which could be used as biomarkers for ischemic event caused by the culprit dissection, were identified by receiver operating characteristic (ROC) curve analysis. RESULTS: The IAD patients studied could be classified into five different types on the basis of morphological features: classical dissection (n = 31), fusiform aneurysm (n = 2), long dissected aneurysm (n = 9), dolichoectatic dissecting aneurysm (n = 6), and saccular aneurysm (n = 22). The direct sites of artery dissection (double lumen and intimal flap) can be seen in most IAD patients on HR-MRI. Additionally, the presence of hypertension, double lumen and intimal flap were associated with culprit lesions and might be considered biomarkers for the ischemic event caused by the culprit dissection. CONCLUSIONS: Analysis showed that HR-MRI allowed easy visualization of abnormal morphology of artery dissection lesions. This was of great significance for the diagnosis of IAD and gave a better understanding of its pathophysiological mechanism.
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Dissecção Aórtica , Aneurisma Intracraniano , Humanos , Dissecção Aórtica/diagnóstico por imagem , Dissecção Aórtica/complicações , Imageamento por Ressonância Magnética/métodos , Aneurisma Intracraniano/complicações , ArtériasRESUMO
BACKGROUND: The neuroprotective roles of mesenchymal stem cells (MSCs) in brain injury are elicited at least partially through the secretion exosomes containing microRNAs (miRNAs). We herein investigate the protective function of bone marrow MSCs (BMSCs)-derived exosomes harboring miR-455-3p against hippocampal neuronal injury in mouse and N2a cell damage model. METHODS: First, BMSC surface markers were detected by flow cytometry, followed by extraction of BMSCs-derived exosomes (BMSCs-Exos). A mouse model of neuronal injury was induced by middle cerebral artery occlusion/reperfusion (MCAO/R), and N2a cells were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) for in vitro experiments. BMSCs-Exos were administrated in mice and N2a cells. We subsequently determined viability- and apoptosis-features using EdU staining, CCK-8, flow cytometry and Caspase-3 kits. Subsequently, we used RT-qPCR to assess miR-455-3p expression in brain tissues as well as N2a cells, and bioinformatic tools to predict the targeting mRNA of miR-455-3p, which was validated by dual-luciferase assays. RESULTS: BMSCs-Exos improved hippocampal neuronal injury in MCAO/R-treated mice and OGD/R-induced injury to N2a cells. BMSCs-Exos upregulated miR-455-3p expression in brain tissues of mice and OGD/R-treated N2a cells. miR-455-3p targeted and conversely regulated PDCD7 expression. The protective effect of BMSCs-Exos on OGD/R-treated N2a cells was markedly mitigated following miR-455-3p downregulation. Moreover, overexpression of miR-455-3p contributed to increased N2a cell activity and decreased apoptosis, while the rescue experiment results were opposite. CONCLUSION: MSCs-derived exosomal miR-455-3p targeted PDCD7 to alleviate hippocampal neuronal injury in MCAO/R-treated mice and injury of OGD/R-treated N2a cells.
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Exossomos , Células-Tronco Mesenquimais , MicroRNAs , Traumatismo por Reperfusão , Apoptose , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Medula Óssea/metabolismo , Exossomos/genética , Exossomos/metabolismo , Hipocampo/metabolismo , Humanos , Infarto da Artéria Cerebral Média/genética , Infarto da Artéria Cerebral Média/metabolismo , Infarto da Artéria Cerebral Média/terapia , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Traumatismo por Reperfusão/metabolismo , Fatores de Transcrição/metabolismoRESUMO
The solid acid catalyst, N-F codoped TiO2/SiO2 composite oxide was prepared by a sol-gel method using NH4F as nitrogen and fluorine source. The prepared materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-Visible diffuse reflectance spectroscopy (UV-Vis), ammonia adsorption and temperature-programmed desorption (NH3-TPD), in situ Fourier transform infrared spectroscopy (FT-IR) and N2 physical adsorption isotherm. The photocatalytic activity of the catalyst for acrylonitrile degradation was investigated under simulant solar irradiation. The results showed that strong Lewis and Brønsted acid sites appear on the surface of the sample after N-F doping. Systematic investigation showed that the highest photocatalytic activity for acrylonitrile degradation was obtained for samples calcined at 450°C with molar ratio (NH4F to Ti) of 0.8. The degradation ratio of 71.5% was achieved with the prepared catalyst after 6-min irradiation, demonstrating the effectiveness of photocatalytic degradation of acrylonitrile with N-F codoped TiO2/SiO2 composite oxide. The photocatalyst is promising for application under solar light irradiation. Moreover, the intermediates generated after irradiation were verified by gas chromatography-mass spectrometry (GC-MS) analysis and UV-Vis spectroscopy to be simple organic acids with lower toxicity, and the degradation pathway was also proposed for acrylonitrile degradation with the prepared catalyst.
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Acrilonitrila/química , Fluoretos/química , Fotólise , Compostos de Amônio Quaternário/química , Dióxido de Silício/química , Titânio/química , Adsorção , Compostos de Amônio , Animais , Catálise , Poluentes Ambientais/química , Microscopia Eletrônica de Varredura , Espectroscopia Fotoeletrônica , TemperaturaRESUMO
The dense extracellular matrix and high interstitial pressure affect the diffusion of nanodrug in tumor tissue, resulting in a small range of action of the active components in nanodrug, thereby affecting its anticancer efficacy. In order to enhance the diffusion ability of nanodrug, a dual-bubble/photothermal-driven nanomissile (HA@MnO2@TA/Fe/ICG/TPZ, HMTAFIT) was designed through "four in one" anti-tumor strategy. Harnessing the capabilities of hyaluronic acid, a biomacromolecule, the nanomotor transforms into a nanomissile, targeting cancer cells with precision. The oxygen generated by the reaction of manganese dioxide with hydrogen peroxide and the local temperature rise of indocyanine green under near-infrared light endow HMTAFIT with the ability of bubble/photothermal dual-driven, and the outermost layer of modified hyaluronic acid incubates the targeting properties of HMTAFIT which could avoid damage to normal cells. The bubble/photothermal-dual-driven increases motion speed of HMTAFIT by 13.8 µm/s, and the enhanced "four in one" anti-tumor strategy effectively improved the anticancer efficacy. The precision-guided nanomissile boasts the capability to eliminate deep-seated cancer cells and overcome multidrug resistance via optimized diffusion and a cutting-edge "four-in-one" approach.
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The problem of antibiotic resistance seriously affects the treatment of bacterial infections, so there is an urgent need to develop novel antibiotic-independent antimicrobial strategies. Herein, a urease-driven bowl-like mesoporous polydopamine nanorobot (MPDA@ICG@Ur@Man) based on single-wavelength near-infrared (NIR) remote photothermal acceleration to achieve antibiotic-free phototherapy(photothermal therapy, PTT, plus photodynamic therapy, PDT) is first reported. The smart nanorobots can perform active movement by decomposing urea to produce carbon dioxide and ammonia. Particularly, the elevated local temperature during PTT can increase urease activity to enhance the autonomous movement and thus increase the contact between the antimicrobial substance and bacteria. Compared with a nanomotor propelled by urea only, the diffusion coefficient (De) of photothermal-accelerated nanorobots is increased from 1.10 to 1.26 µm2 s-1. More importantly, urease-driven bowl-like nanorobots with photothermal enhancement can specifically identify Escherichia coli (E. coli) and achieve simultaneous PTT/PDT at a single wavelength with 99% antibactericidal activity in vitro. In a word, the urease-driven bowl-like nanorobots guided by photothermal-accelerated strategy could provide a novel perspective for increasing PTT/PDT antibacterial therapeutic efficacy and be promising for various antibiotic-free sterilization applications.
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Escherichia coli , Indóis , Polímeros , Urease , Urease/metabolismo , Urease/química , Indóis/química , Indóis/farmacologia , Polímeros/química , Escherichia coli/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Fotoquimioterapia/métodos , Terapia Fototérmica/métodos , HumanosRESUMO
Zinc metal suffers from violent and long-lasting water-induced side reactions and uncontrollable dendritic Zn growth, which seriously reduce the coulombic efficiency (CE) and lifespan of aqueous zinc-metal batteries (AZMBs). To suppress the corresponding harmful effects of the highly active water, a stable zirconium-based metal-organic framework with water catchers decorated inside its sub-nano channels is used to protect Zn-metal. Water catchers within narrow channels can constantly trap water molecules from the solvated Zn-ions and facilitate step-by-step desolvation/dehydration, thereby promoting the formation of an aggregative electrolyte configuration, which consequently eliminates water-induced corrosion and side reactions. More importantly, the functionalized sub-nano channels also act as ion rectifiers and promote fast but even Zn-ions transport, thereby leading to a dendrite-free Zn metal. As a result, the protected Zn metal demonstrates an unprecedented cycling stability of more than 10 000 h and an ultra-high average CE of 99.92% during 4000 cycles. More inspiringly, a practical NH4V4O10//Zn pouch-cell is fabricated and delivers a capacity of 98 mAh (under high cathode mass loading of 25.7 mg cm-2) and preserves 86.2% capacity retention after 150 cycles. This new strategy in promoting highly reversible Zn metal anodes would spur the practical utilization of AZMBs.
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PURPOSE: To investigate the association between the intravascular enhancement sign (IVES) and intraluminal thrombus (ILT) detected by high-resolution magnetic resonance vessel wall imaging (HR-VWI) in patients with middle cerebral artery (MCA) atherosclerosis. METHOD: The data of patients who underwent HR-VWI between May 2021 and May 2023, including clinical information, the number of IVES vessels, stenosis degree, ILT, plaque features on 3D T1-weighted turbo spin echo sequences, and signal intensity ratio (SIR) on 3D time-of-flight magnetic resonance angiography, were retrospectively analyzed. Correlation and logistic regression analyses were performed. RESULTS: A total of 194 MCA plaques were identified in 132 patients (103 [53 %] on the left). Atherosclerosis with, relative to without, ILT was associated with a higher incidence of ischemic events, higher plaque enhancement and stenosis degrees, more vessels with IVES, and lower remodeling ratio, lumen area, wall area, total vessel area, and SIR. Multivariate logistic regression analysis showed significant and independent associations of the number of IVES vessels (OR = 1.089; 95 % CI [1.013-1.170]; P = 0.020) and SIR (OR = 0.007; 95 % CI [0.0004-0.124]; P < 0.001) with ILT. The number of vessels with the IVES (AUC = 0.81, 95 % CI [0.75-0.87]; P < 0.001) and SIR (AUC = 0.88, 95 % CI [0.82-0.94]; P < 0.001) sufficiently diagnosed ILT, and the AUC of the combination of the IVES and SIR was 0.89 (95 % CI [0.84-0.94]; P < 0.001). CONCLUSION: The number of IVES vessels and SIR are independent risk factors for ILT. They may provide new monitoring targets for stroke prevention in patients with atherosclerotic stenosis.
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Imageamento Tridimensional , Arteriosclerose Intracraniana , Angiografia por Ressonância Magnética , Humanos , Masculino , Feminino , Arteriosclerose Intracraniana/diagnóstico por imagem , Arteriosclerose Intracraniana/complicações , Pessoa de Meia-Idade , Angiografia por Ressonância Magnética/métodos , Imageamento Tridimensional/métodos , Estudos Retrospectivos , Artéria Cerebral Média/diagnóstico por imagem , Idoso , Trombose/diagnóstico por imagemRESUMO
The regioselective installation of chalcogen atoms into biaryl scaffolds is an important synthetic task due to the great value of chalcogen-containing biaryl derivatives in many fields. Here we undertake this task by developing a regioselective 2,2'-dichalcogenation of 2-bromobiaryls with common chalcogen sources using an organolanthanum-mediated one-pot, two-step protocol. This strategy features high regioselectivity, readily available substrates, transition-metal-free conditions, and performance superior to those of previous methods, thereby demonstrating the unique advantages of organolanthanum reagents in organic synthesis.
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The photocatalytic degradation of phenol and 4-chlorophenol (4-CP) in aqueous suspensions with the use of titanium dioxide (TiO2) under UV irradiation was examined. The effects of different supporting materials mixed physically with TiO2 were studied to achieve maximum degradation efficiency. Among the three supports, namely activated carbon (AC), silica (SiO2) and zeolite (ZSM-5), all exhibited paramount efficiency for degradation of phenol and 4-CP and was better than TiO2 alone. The optimum concentration was found to be 50 mg for all supporting materials. The efficiency order of the three supports was as follows: AC > ZSM-5 > SiO2, respectively. Whilst, the degradation of phenol and 4-CP was improved from 70.6% to 87.6% and 80.6% to 89.7%, respectively, within 120 min photocatalysis in the presence of optimal amount of AC. The degradation was also comparatively enhanced in the presence of cheaper rice husk and the activity was closed to ZSM-5 and lower than AC.
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Clorofenóis/química , Fenol/química , Fotoquímica/métodos , Titânio/químicaRESUMO
A series of precious metals catalysts (M/TiO2, M = Ru, Rh, Pd, Ag, Ir, Pt or Au) were prepared by a light deposition method and the synergistic photocatalytic degradations of pyridine (20 mg/L) under UV irradiation (365 nm) using M/TiO2 with electron capture agent KBrO3 have been investigated. The results show that KBrO3 has a greatly synergistic role on M/TiO2 and the photocatalytic activity of M/TiO2 is closely related to its work function. Ag could greatly enhance the activity of TiO2 due to the binding characteristics of pyridine on Ag. Under the conditions of 0.5 wt.% Ag loading, Ag/TiO2 concentration of 0.1 g/L, KBrO3 concentration of 10 mmol/L and reaction liquid pH value at 9, the pyridine can be degraded by 64% within 3 hr, doubled than TiO2 photocatalytic system. The degradation kinetics of pyridine follows first-order kinetics and k = 5.53 x 10(-3) min-1.
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Bromatos/química , Luz , Piridinas/química , Titânio/química , Catálise , Cinética , Microscopia Eletrônica de VarreduraRESUMO
We report an efficient one-pot, two-step procedure for the modular synthesis of α-difunctionalized alkynes and trisubstituted allenes by sequential cross-coupling of benzal gem-diacetates with organozinc or -copper reagents in the absence of external transition metals. The intermediacy of propargylic acetates enables the divergent and selective synthesis of these valuable products. This method features its readily accessible substrates, relatively mild conditions, wide scope, and scalability in practical synthesis.
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PURPOSE: Patients with intracranial artery occlusion have high rates of ischaemic events and recurrence. Early identification of patients with high-risk factors is therefore beneficial for prevention. Here we assessed the association between the intravascular enhancement sign (IVES) on high-resolution vessel wall imaging (HR-VWI) and acute ischaemic stroke (AIS) in a population with middle cerebral artery (MCA) occlusion. METHOD: We retrospectively analysed the records of 106 patients with 111 MCA occlusions, including 60 with and 51 without AIS, who had undergone HR-VWI and computed tomography angiography (CTA) examinations from November 2016 to February 2023. Numbers of IVES vessels were counted and compared to the CTA findings. Statistical analyses of demographic and medical data were also performed. RESULTS: Occurrence rates and numbers of IVES vessels were significantly higher in the AIS than the non-AIS group (P < 0.05), and most vessels were detected on CTA. Numbers of vessels positively correlated with AIS occurrence (rho = 0.664; P < 0.0001). A multivariable ordinal logistic regression model adjusted for age, degree of wall enhancement, hypertension, and heart status identified the number of IVES vessels as an independent predictor for AIS (odds ratio = 1.6; 95% CI, 1.3-1.9; P < 0.0001). CONCLUSION: Number of IVES vessels is an independent risk factor for AIS events, and may represent poor cerebral blood flow status and collateral compensation level. It thus provides cerebral haemodynamic information for patients with MCA occlusion for clinical use.
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Isquemia Encefálica , Acidente Vascular Cerebral , Humanos , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Isquemia Encefálica/diagnóstico por imagem , Estudos Retrospectivos , Angiografia por Tomografia Computadorizada , Angiografia Cerebral/métodos , Artéria Cerebral Média/diagnóstico por imagemRESUMO
OBJECTIVE: The significance of the intravascular enhancement sign (IVES) on high-resolution magnetic resonance vascular wall imaging (HR-VWI) remains unclear. This study aimed to investigate the correlation between the IVES and collateral assessment derived from digital subtraction angiography (DSA). METHOD: A total of 75 patients with occlusion of the first segment of the middle cerebral artery (MCA) who underwent HR-VWI and DSA examinations at our research institution between November 2016 and February 2023 were included. The number of vessels with IVES, IVES-Alberta Stroke Program Early Computed Tomography Score (ASPECTS), American Society of Interventional and Therapeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) collateral grade, and DSA collateral blood flow grade were retrospectively evaluated. Correlations between these indicators were assessed using Spearman's correlation. RESULTS: Interrater agreement was good for the assessment of HR-VWI and DSA indicators. After adjustments for age, degree of wall enhancement, and hypertension, a multivariable ordinal logistic regression model identified both the number of IVES vessels (OR = 1.37; 95%CI [1.06-1.78]; P = 0.017) and IVES-ASPECTS (OR = 2.00; 95%CI [1.03-3.87]; P = 0.041) as independent predictors of ischemic stroke. In the patient group with acute ischemic stroke, we found weak correlations between the number of IVES vessels and the ASITN/SIR collateral grade (rho = -0.35; P = 0.002) and between the IVES-ASPECTS and ASITN/SIR collateral grade (rho = -0.27; P = 0.02). Moreover, there were strong correlations between the number of IVES vessels and the DSA collateral blood flow grade (rho = -0.74; P < 0.001) and between the IVES-ASPECTS and the DSA collateral blood flow grade (rho = -0.65; P < 0.001). The number of IVES vessels correlated strongly with the IVES-ASPECTS (rho = 0.92, P < 0.001). CONCLUSION: We find that the IVES is closely associated with sluggish collateral blood flow, which further confirms the hemodynamic mechanism underlying the IVES in MCA occlusion.
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Isquemia Encefálica , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Estudos Retrospectivos , AVC Isquêmico/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Artéria Cerebral Média/diagnóstico por imagem , Angiografia Cerebral/métodosRESUMO
In this study, we investigated the deactivation kinetics and mechanism of N-F-TiO2/SiO2 nanopowder as a model photocatalyst for the purpose of facilitating the photocatalytic degradation of acrylonitrile (AN) in aqueous environment. Prior research has already displayed the proficient degradation of AN through the utilization of N-F-TiO2/SiO2 catalysts, revealing a degradation efficiency of 81.2% within a span of 6 min at an initial AN concentration of 10 mg/L. Multiple variables including the initial AN concentration, illumination intensity, and initial pH value were extensively analyzed during the degradation process. The kinetics of photocatalytic degradation of AN, facilitated by the N-F-TiO2/SiO2 photocatalyst, were modeled by fitting the pseudo first-order reaction kinetics to each individual factor. Furthermore, the adverse effect of catalyst poisoning during the photocatalytic breakdown of AN using the N-F-TiO2/SiO2 photocatalyst was analyzed through a range of different techniques including SEM, XPS, BET, XRD, TG, and NH3-TPD. The incorporation of findings from these diverse techniques revealed that, the primary factors contributing to the photocatalyst's poisoning were as follows: (i) During the degradation process, the build-up of intermediate molecules on active sites hindered their functionality, leading to a decrease in the efficiency of the photocatalytic reaction, (ii) Carbonaceous deposits formed when the catalyst's pore structure was obstructed by pollutants or intermediate products that had not undergone timely photocatalytic breakdown and (iii) The persistent erosion of active sites due to hydraulic forces resulted in inadequate performance of the N-F-TiO2/SiO2 photocatalyst in aqueous solutions. A comprehensive analysis of the deactivation kinetics was conducted, deciding in the formulation of a detailed poisoning mechanism for the N-F-TiO2/SiO2 photocatalyst. Additionally, we explored the catalysts regeneration, involving thermal treatment, ultrasonic irradiation, and catalyst reloading. This study not only advances our insight into the waning performance of catalysts in aqueous media but also establishes a conceptual framework for extrapolating analogous deactivation dynamics in other catalysts, grounded in precedent experimental knowledge. This research contributes to the development of a deactivation model for catalysts in the aqueous environment, based on existing experimental research, providing a theoretical framework for understanding the deactivation process of photocatalysts.
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Acrilonitrila , Nanopartículas , Flúor , Dióxido de Silício , NitrogênioRESUMO
BACKGROUND: Paralleling the rapid growth in computers and internet connections, adolescent internet addiction (AIA) is becoming an increasingly serious problem, especially in developing countries. This study aims to explore the prevalence of AIA and associated symptoms in a large population-based sample in Shanghai and identify potential predictors related to personal characteristics. METHODS: In 2007, 5,122 adolescents were randomly chosen from 16 high schools of different school types (junior, senior key, senior ordinary and senior vocational) in Shanghai with stratified-random sampling. Each student completed a self-administered and anonymous questionnaire that included DRM 52 Scale of Internet-use. The DRM 52 Scale was adapted for use in Shanghai from Young's Internet Addiction Scale and contained 7 subscales related to psychological symptoms of AIA. Multiple linear regression and logistic regression were both used to analyze the data. RESULTS: Of the 5,122 students, 449 (8.8%) were identified as internet addicts. Although adolescents who had bad (vs. good) academic achievement had lower levels of internet-use (p < 0.0001), they were more likely to develop AIA (odds ratio 4.79, 95% CI: 2.51-9.73, p < 0.0001) and have psychological symptoms in 6 of the 7 subscales (not in Time-consuming subscale). The likelihood of AIA was higher among those adolescents who were male, senior high school students, or had monthly spending >100 RMB (all p-values <0.05). Adolescents tended to develop AIA and show symptoms in all subscales when they spent more hours online weekly (however, more internet addicts overused internet on weekends than on weekdays, p < 0.0001) or when they used the internet mainly for playing games or real-time chatting. CONCLUSIONS: This study provides evidence that adolescent personal factors play key roles in inducing AIA. Adolescents having aforementioned personal characteristics and online behaviors are at high-risk of developing AIA that may compound different psychological symptoms associated with AIA. Spending excessive time online is not in itself a defining symptom of AIA. More attention is needed on adolescent excessive weekend internet-use in prevention of potential internet addicts.
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Comportamento do Adolescente/psicologia , Comportamento Aditivo/epidemiologia , Internet/estatística & dados numéricos , Estudantes/psicologia , Adolescente , Criança , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Fatores de Risco , Fatores Socioeconômicos , Estudantes/estatística & dados numéricos , Inquéritos e Questionários , Adulto JovemRESUMO
The treatment efficacy of anticancer drugs in complex physiological environments is still restricted by multi-drug resistance. To overcome this issue, a nanodrug system of HA-SS@CuS@ZIF-8@TPZ&TBMACN (HSCZTT) that breaks through the detoxification barrier for tirapazamine (TPZ) delivery was developed in this manuscript. In addition to the photothermal effect aroused by CuS in HSCZTT, which can damage tumour cells, TBMACN with photostable fluorescence in the aggregate state can also generate sufficient reactive oxygen species (ROS) to destroy tumour cells. The continuous consumption of oxygen in PDT aggravates the hypoxic environment of tumours, which further activates the TPZ released in the acidic microenvironment of the tumour to achieve apoptosis of the tumour cells. The HSCZTT can not only target the CD44 receptor overexpressed on the surface of the cancer cell, but can also effectively consume a large amount of glutathione (GSH) through the disulphide bond-modified hyaluronic acid, which serves as a targeted disulphide bond, interfering with the detoxification barrier. Our finding presents a rational strategy to overcome multidrug resistance for the improved efficacy of anticancer drugs by the targeting of Hyaluronic acid (HA), release of the drug by the acid response of ZIF-8, breakthrough of the detoxification barrier, precise positioning of the drug release and combined treatment with phototherapy and hypoxia-activated chemotherapy.
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Antineoplásicos , Nanopartículas , Neoplasias , Fotoquimioterapia , Antineoplásicos/química , Linhagem Celular Tumoral , Dissulfetos , Humanos , Ácido Hialurônico/química , Hipóxia , Nanopartículas/química , Neoplasias/patologia , Fármacos Fotossensibilizantes/química , Tirapazamina/química , Tirapazamina/metabolismo , Tirapazamina/farmacologia , Microambiente TumoralRESUMO
The low-temperature SCR of NOx by NH3 is restricted in application since the catalysts is easily poisoned by sulfur and water. The Fe modified Mn-Co-Ce/TiO2/SiO2 catalysts synthesized via impregnation method and sulfating were evaluated for low-temperature NH3-SCR in the presence of SO2 and H2O. The calcination temperature and loading amounts of Mn, Fe, Co and Ce were optimized. Adding of Fe into S-MnCoCe/Ti/Si played an important role in resistance to sulfur and water poisoning. The optimal calcination temperature was 380 °C and the optical mass loading of the catalyst was 10% of Mn, 10% of Fe, 1% of Co and 4% of Ce. The optimal S-MnFeCoCe/Ti/Si catalyst maintained high NOx conversion of 93% at reaction temperature of 160 °C in the presence of 50 ppm SO2 and 10 vol% H2O. The catalytic activity did not continue to fall after two times of repeated used in the temperature range of 100-200 °C, indicating its excellent sulfur and water durability and stability in the presence of SO2 and H2O. The interaction between MnOx and FeOx enhanced sulfur and water durability rather than other bi-metal interactions. Furthermore, the mechanism of Fe improving resistance to SO2 and H2O was discussed.