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Layered black phosphorus (LBP) is drawing increasing attention because of its excellent potential in biomedical applications. Properties and bioeffects of LBP depend on its layer number (LN). However, the variation of LN during applications, especially in organisms, is largely unknown. Herein, LBP is found to be exfoliated by human serum albumin (HSA) after the formation of protein coronas. The sorption of HSA on LBP exhibits multiple intermediate equilibrium and size-dependent capacity and is distinguished from traditional multilayer sorption. The loss of LN for LBP increases with the increase of HSA concentrations, e.g., 2, 4, and 6 layers of LBP are exfoliated at 35, 135, and 550 mg/L HSA, respectively. The energy distribution shows that at low HSA concentrations, exfoliation is mainly driven by electrostatic and hydrogen bond interactions. With middle or high HSA concentrations, exfoliation is mainly driven by p-π or hydrophobic interactions, respectively. Layer exfoliation causes the continuous emergence of an unsaturated LBP surface available for adsorbing further HSA, breaking previous sorption saturations. The complete exfoliation of LBP weakens cytotoxicity and promotes internalization to the A-549 cell line compared with pristine or less exfoliated LBP. This finding unveils the exfoliation mechanism of proteins toward LBP and is of benefit to evaluating application performance and biosafety of LBP.
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Fósforo , Albúmina Sérica Humana , Humanos , Albúmina Sérica Humana/químicaRESUMEN
The production scalability and increasing demand for nano-black phosphorus materials (nano-BPs) inevitably lead to their environmental leakage, thereby raising the risk of human exposure through inhalation, ingestion, dermal, and even intravenous pathways. Consequently, a systematic evaluation of their potential impacts on human health is necessary. This Review outlines recent progress in the understanding of various biological responses to nano-BPs. Attention is particularly given to the inconsistent toxicological findings caused by a wide variation of nano-BPs' physicochemical properties, toxicological testing methods, and cell types examined in each study. Additionally, cellular uptake and intracellular trafficking, cell death modes, immunological effects, and other biologically relevant processes are discussed in detail, providing evidence for the potential health implications of nano-BPs. Finally, we address the remaining challenges related to the health risk evaluation of nano-BPs and propose a broader range of applications for these promising nanomaterials.
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Nanoestructuras , Fósforo , Humanos , Fósforo/química , Nanoestructuras/toxicidad , Transporte BiológicoRESUMEN
Mountainous background areas are typically considered to have a clean atmosphere where peroxyacetyl nitrate (PAN) can be decomposed. This study demonstrated that PAN was photochemically formed with a simulated production rate of 0.28 ± 0.06 ppbv h-1 in the Nanling mountains (1690 m a.s.l.) of South China and that net PAN formation was dependent on both volatile organic compounds (VOCs) and NOx precursors (transition regime). In contrast to dominated acetaldehyde oxidation in previous urban and rural research, PAN at Nanling was primarily formed by methylglyoxal (38%), acetaldehyde (28%), radicals (20%), and other oxygenated volatile organic compounds (OVOCs) (13%). Moreover, when polluted air masses invaded the Nanling mountains, the PAN production rate was altered, primarily because anthropogenic aromatics intensified PAN formation via the oxidized pathways of methylglyoxal, other OVOCs, and radicals. Finally, net PAN formation at Nanling reduced the hydroxyl radical level by consuming NOx, impaired local radical cycling, and thereby suppressed local O3 production. This suppressing effect was exacerbated on polluted days. The findings of this study deepen our understanding of PAN photochemistry and the impact of anthropogenic intrusions on the background atmosphere of mountainous regions.
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Contaminantes Atmosféricos , Contaminantes Ambientales , Ozono , Compuestos Orgánicos Volátiles , Contaminantes Atmosféricos/análisis , Compuestos Orgánicos Volátiles/análisis , Piruvaldehído , China , Atmósfera/química , Acetaldehído , Ozono/análisis , Monitoreo del AmbienteRESUMEN
In this paper, a variety of 2D materials on the surface plasmon resonance sensor based on Al-Ni bimetallic layer are compared. Simulation results indicate that lateral position shift, which is calculated according to the real and imaginary parts of the refractive index of material, can be used as an effective parameter to optimize the sensitivity. By using the parameters for optimizing the SPR structures, the results show that the multiple layer models of Al(40 nm)-Ni(22 nm)-black phosphorus (BP)(1 L) and Al(40 nm)-Ni(22 nm)-blue phosphorus (BlueP)/WS2(1 L) exhibit average angular sensitivities of 507.0 °/RIU and 466 °/RIU in the refractive index range of 1.330-1.335, and maximum sensitivity of 542 °/RIU and 489 °/RIU at the refractive index of 1.333, respectively. We expect more applications can be explored based on the highly sensitive SPR sensor in different fields of optical sensing.
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Malaria, one of the major global public health events, is a leading cause of mortality and morbidity among children and adults in tropical and subtropical regions(mainly in sub-Saharan Africa), threatening human health. It is well known that malaria can cause various complications including anemia, blackwater fever, cerebral malaria, and kidney damage. Conventionally, cardiac involvement has not been listed as a common reason affecting morbidity and mortality of malaria, which may be related to ignored cases or insufficient diagnosis. However, the serious clinical consequences such as acute coronary syndrome, heart failure, and malignant arrhythmia caused by malaria have aroused great concern. At present, antimalarials are commonly used for treating malaria in clinical practice. However, inappropriate medication can increase the risk of cardiovascular diseases and cause severe consequences. This review summarized the research advances in the cardiovascular complications including acute myocardial infarction, arrhythmia, hypertension, heart failure, and myocarditis in malaria. The possible mechanisms of cardiovascular diseases caused by malaria were systematically expounded from the hypotheses of cell adhesion, inflammation and cytokines, myocardial apoptosis induced by plasmodium toxin, cardiac injury secondary to acute renal failure, and thrombosis. Furthermore, the effects of quinolines, nucleoprotein synthesis inhibitors, and artemisinin and its derivatives on cardiac structure and function were summarized. Compared with the cardiac toxicity of quinolines in antimalarial therapy, the adverse effects of artemisinin-derived drugs on heart have not been reported in clinical studies. More importantly, the artemisinin-derived drugs demonstrate favorable application prospects in the prevention and treatment of cardiovascular diseases, and are expected to play a role in the treatment of malaria patients with cardiovascular diseases. This review provides reference for the prevention and treatment of malaria-related cardiovascular complications as well as the safe application of antimalarials.
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Antimaláricos , Artemisininas , Enfermedades Cardiovasculares , Insuficiencia Cardíaca , Malaria Cerebral , Quinolinas , Niño , Adulto , Humanos , Antimaláricos/farmacología , Enfermedades Cardiovasculares/tratamiento farmacológico , Artemisininas/farmacología , Malaria Cerebral/tratamiento farmacológico , Insuficiencia Cardíaca/tratamiento farmacológico , Arritmias Cardíacas/tratamiento farmacológicoRESUMEN
The remarkable progress of applied black phosphorus nanomaterials (BPNMs) is attributed to BP's outstanding properties. Due to its potential for applications, environmental release and subsequent human exposure are virtually inevitable. Therefore, how BPNMs impact biological systems and human health needs to be considered. In this comprehensive Minireview, the most recent advancements in understanding the mechanisms and regulation factors of BPNMs' endogenous toxicity to mammalian systems are presented. These achievements lay the groundwork for an understanding of its biological effects, aimed towards establishing regulatory principles to minimize the adverse health impacts.
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Nanoestructuras , Fósforo , Animales , Humanos , Nanoestructuras/toxicidad , MamíferosRESUMEN
ß-elemene (Bel) is a sesquiterpene compound that has shown potential in the antinociceptive treatment. This study focused on the function of Bel in neuropathic pain relief in mice. A murine model with spared nerve injury (SNI) was established and treated with Bel. The paw withdrawal thresholds in response to mechanical and thermal stimulations were examined using von Frey filaments. The L4-L6 spinal dorsal horn tissue samples were collected for histological examination. Bel treatment reduced the sensitivities of model mice to mechanical and thermal stimulations, and it inhibited activation of microglia and the secretion of inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6 in tissues. Bel treatment reduced the expression of nociceptor excitatory N-methyl-D-aspartate receptor (NMDAR), whereas it enhanced the expression of nociceptor inhibitory gamma-aminobutyric acid A (GABAA) receptor to relieve the nociception of mice. The C-X-C motif chemokine receptor 3 (CXCR3) is a downstream molecule mediated by Bel. Either overexpression of CXCR3 or downregulation of GABAA receptor in the tissues aggravated the neuropathic pain in SNI mice which was initially relieved by Bel. In conclusion, this study suggested that Bel might serve as a drug for nociception management by inhibiting CXCR3 and upregulating GABAA receptor. This study may offer novel insights into the field of neuropathic pain relief.
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Neuralgia , Receptores CXCR3 , Receptores de GABA-A , Sesquiterpenos , Animales , Hiperalgesia/tratamiento farmacológico , Hiperalgesia/metabolismo , Ratones , Neuralgia/tratamiento farmacológico , Neuralgia/metabolismo , Receptores de GABA-A/metabolismo , Sesquiterpenos/farmacología , Sesquiterpenos/uso terapéutico , Médula Espinal/metabolismoRESUMEN
The acousto-optic interaction is strongly modified and different in subwavelength confinement. Here, the optical propagation and acoustic propagation in a subwavelength-diameter fiber (SDF) have been investigated through adopting a two-layer fiber model of air-coated silica rod. Theoretical investigation indicates that SDF with a diameter below 1.2 µm supports the single mode of light propagation, and various Brillouin acoustic modes with well-spaced spectral distribution can be also excited. Due to the light propagation with the outer environment as the cladding layer, the surrounding medium will greatly affect Brillouin scattering of SDFs. Both the simulation and experiment results indicate a relatively good linear relationship between the Brillouin frequency shift of the lower acoustic modes and surrounding environmental refractive index (RI), and the higher RI sensitivity in finer SDFs can be obtained. In addition, hybrid acoustic waves have shown higher sensitivity and stability than surface acoustic modes. A RI sensitivity of about 5.1 GHz/RIU has been achieved in a 1.1 µm SDF, demonstrating its potential application in RI sensing.
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BACKGROUND: Synovial mesenchymal stem cells (SMSCs) have been discussed as promising tools for protecting chondrocytes from loss and inhibiting osteoarthritis (OA). This work infocuses on the function of SMSC-derived extracellular vesicles (EVs) in chondrocytes during OA and the molecular mechanism. METHODS: EVs were extracted from SMSCs and identified. Chondrocytes were treated with interleukin (IL)-1ß to induce an OA-like condition in vitro and then treated with EVs. The proliferation, apoptosis, migration, extracellular matrix (ECM) degradation and inflammation in chondrocytes were examined. Key microRNAs (miRNAs) carried by EVs were screened using a microarray analysis, and the downstream molecules involved were explored using bioinformatic analysis. Rescue experiments were performed to validate the involvements of these molecules in EV-mediated events. RESULTS: EVs restored proliferation and migration while reduced apoptosis, ECM degradation and the secretion of pro-inflammatory cytokines in chondrocytes induced by IL-1ß. miR-130b-3p was significantly elevated in chondrocytes after EVs treatment. Knockdown of miR-130b-3p blocked the protective roles of EVs against IL-1ß-induced damage to chondrocytes. miR-130b-3p was found to target LDL receptor related protein 12 (LRP12) mRNA in chondrocytes. Overexpression of LRP12 counteracted the effects of EVs as well and activated the AKT/ß-catenin signaling pathway. CONCLUSION: This study provided evidence that EVs alleviate chondrocyte damage during OA through miR-130b-3p-mediated inhibition of the LRP12/AKT/ß-catenin axis. This study may offer novel thoughts into the protection of chondrocytes and the management of OA.
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Vesículas Extracelulares , Células Madre Mesenquimatosas , MicroARNs , Osteoartritis , beta Catenina , Apoptosis , Condrocitos , Vesículas Extracelulares/metabolismo , Humanos , Interleucina-1beta/metabolismo , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/metabolismo , Células Madre Mesenquimatosas/metabolismo , MicroARNs/genética , MicroARNs/metabolismo , Osteoartritis/metabolismo , Osteoartritis/terapia , Proteínas Proto-Oncogénicas c-akt/metabolismo , beta Catenina/metabolismoRESUMEN
Gold and silver have an extremely low refractive index value of about 0.04 in the visible to near infrared (NIR) regions, and this induces a relative error of about 50% in refractive index measurements. This can lead to a large uncertainty in the imaginary part of the dielectric constants. A large difference exists between the experimental results and the classic models. The surface plasmon resonance (SPR) sensors, which use tens of nanometer thick noble metal film as the sensing layer, show ultra-high sensitivity (reaching 10-8 RIU) in this spectral range. As the spectral sensitivity and amplitude of SPR curves depend on the thickness and the dielectric constant of the sensing layer, we obtained high precision optical constants of the noble metal film using a multi-wavelength angle-modulated SPR sensing technology. The dielectric constant inferred from the parameters of the SPR curves, rather than from the refractive index and absorption ratio of noble metals, introduced a relative error within 10% of the resonance angle measurement. The measurement results demonstrate that the dielectric constants of gold and silver nano-films are more consistent with the widely used experimental results than with the classical theoretical model and always fall in the upper half of the imaginary part of the uncertainty range in the spectra of 500-900 nm.
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Corona virus disease 2019(COVID-19) has brought untold human sufferings and economic tragedy worldwide. It causes acute myocardial injury and chronic damage of cardiovascular system, which has attracted much attention from researchers. For the immediate strategy for COVID-19, "drug repurposing" is a new opportunity for developing drugs to fight COVID-19. Artemisinin and its derivatives have a wide range of pharmacological activities. Recent studies have shown that artemisinin has clear cardiovascular protective effects. This paper summarizes the research progress on the pathogenesis the pathogenesis of COVID-19 in cardiovascular damage by 2019 novel coronavirus(2019-nCoV) virus from myocardial cell injury directly by 2019-nCoV virus,viral ligands competitively bind to ACE2 and then reduce the protective effect of ACE2 on cardiovascular disease, "cytokine storm" related myocardial damage, arrhythmia and sudden cardiac death induced by the infection and stress, myocardial injury by hypoxemia, heart damage side effects from COVID-19 drugs and summarizing the cardiovascular protective effects of artemisinin and its derivatives have activities of anti-arrhythmia, anti-myocardial ischemia, anti-atherosclerosis and plaque stabilization. Then analyzed the possible multi-pathway intervention effects of artemisinin-based drugs on multiple complications of COVID-19 based on its specific immunomodulatory effects, protective effects of tissue and organ damage and broad-spectrum antiviral effect, to provide clues for the treatment of cardiovascular complications of COVID-19, and give a new basis for the therapy of COVID-19 through "drug repurposing".
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Artemisininas , COVID-19 , Enfermedades Cardiovasculares , Cardiopatías , Humanos , SARS-CoV-2RESUMEN
Autophagy, also known as macroautophagy, is a tightly regulated process involved in the stress responses, such as starvation. It is a vacuolar, lysosomal pathway for the degradation of damaged proteins and organelles in eukaryotic cells. Autophagy also plays a key role in various tissue processes and immune responses and in the regulation of inflammation. Over the past decade, three levels of autophagy regulation have been identified in mammalian cells: 1) signaling, 2) autophagosome formation, and 3) autophagosome maturation and lysosomal degradation. Any deregulation of the autophagy processes can lead to the development of diverse chronic diseases, such as diabetes, obesity, cardiovascular disease, neurodegenerative disease, and malignancies. However, the potential role of autophagy in cancer is rather complex and has been associated with both the induction and the inhibition of neoplasia. Several synthetic autophagy modulators have been identified as promising candidates for cancer therapy. In addition, diverse phytochemicals derived from natural sources, such as curcumin, ursolic acid, resveratrol, thymoquinone, and γ-tocotrienol, also have attracted attention as promising autophagy modulators with minimal side effects. In this review, the authors discuss the importance of autophagy regulators and various natural compounds that induce and/or inhibit autophagy in the prevention and therapy of cancer.
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Antineoplásicos/farmacología , Autofagia/efectos de los fármacos , Productos Biológicos/farmacología , Neoplasias/tratamiento farmacológico , Animales , Antineoplásicos/uso terapéutico , Proteínas Relacionadas con la Autofagia/efectos de los fármacos , Proteínas Relacionadas con la Autofagia/metabolismo , Productos Biológicos/uso terapéutico , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Terapia Molecular Dirigida , Neoplasias/metabolismo , Neoplasias/prevención & control , Transducción de Señal/efectos de los fármacosRESUMEN
Graphene has many superlative thermal, electrical and mechanical properties. However, the thermoelectric performance of graphene is limited by its high thermal conductivity and small Seebeck coefficient. To address this problem, monolayer and bilayer MoSSe nanoribbons together with graphene/MoSSe heterostructures have been investigated in this work. The electron and phonon transport, and the thermoelectric properties of the monolayer and bilayer MoSSe nanoribbons, together with the graphene/MoSSe heterostructures, have been analyzed by first-principles methods in conjunction with non-equilibrium Green's function and the Landauer equation. The results indicate that figure of merit (ZT) values of 2.01 and 1.64 can be achieved for graphene/SeMoS stacked nanoribbons and symmetric armchair MoSSe nanoribbons respectively at 300 K, which are much higher than the ZT value of prime graphene (ZT â¼ 0.05). The maximum ZT values of these structures increase at T < 350 K, while the maximum ZT decreases at high temperatures (T > 350 K). However, the maximum ZT values of the symmetric armchair MoSSe nanoribbons show an increase with temperatures up to 550 K. From our analysis, phonon thermal conductivity and temperature are key factors determining the ZT values in MoSSe nanoribbons. The significantly enhanced ZT values make graphene/SeMoS stacking nanoribbons and symmetric armchair MoSSe nanoribbons promising candidates for application in thermoelectric devices.
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A nano spherical CaCO3 (NSC) derived from solid waste (precipitated from tris(α-chloropropyl) phosphate and triethyl phosphate mixed wastewater) was prepared as adsorbent for phosphorus removal from aqueous solution. Response surface methodology (RSM) was used to develop an approach for the evaluation of phosphorus adsorption process, and Box-Behnken design was performed to investigate the effects of various experimental parameters (temperature, contact time, initial pH and dosage of absorbent) on phosphorus adsorption. The model results of experimental data gave a high correlation coefficient (R2 = 0.9658), and a predictive model of quadratic polynomial regression equation and optimum level values were established successfully. It was found that the adsorption efficiency and adsorption capacity reached 97.05% and 123.79 mg/g, respectively, under conditions of temperature of 45 °C, initial pH 5.3, contact time of 11 h, and absorbent amount of 392 mg/L. X-ray diffraction (XRD) analysis testified new phase, Ca10(PO4)6CO3, was produced in the adsorption process. Apart from that, adsorption behavior fitted well with the Langmuir isotherm model and logistic growth model. The thermodynamic study indicated that phosphorus removal by NSC as adsorbent was a spontaneous, endothermic, and mainly chemical adsorption process.
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Carbonato de Calcio/química , Fósforo/química , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/química , Adsorción , Concentración de Iones de Hidrógeno , Cinética , Fósforo/análisis , Contaminantes Químicos del Agua/análisisRESUMEN
Schwannomas rarely occur in seminal vesicles. Here, we report a schwannoma of the left seminal vesicle. A 55-year-old man presented no clinical symptoms, and a mass in the left region of the seminal vesicle was found incidentally in a medical examination. A computed tomography and magnetic resonance imaging of pelvic were obtained and revealed a 5.17 × 2.59 × 3.5 cm mass on the left seminal vesicle. Transrectal ultrasound-guided seminal biopsy revealed a diagnosis of seminal vesical schwannoma. Laparoscopic resection of the tumour was performed. Postoperative pathology and immunohistochemical analysis revealed schwannoma arising from seminal vesical.
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Neoplasias de los Genitales Masculinos/patología , Neurilemoma/patología , Neoplasias Pélvicas/patología , Vesículas Seminales/patología , Humanos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVE: The aim of this study was to examine if inequity in healthcare among the urban elderly in China has been improved through the implementation of Urban Resident Basic Medical Insurance (URBMI).METHODS AND DATA SOURCE: We used the data from a nationwide household health survey conducted between December 2011 and February 2012 to compare the needs, uses, and non-uses of health services of the 7618 urban Chinese elderly 60 years and older covered by two different health insurance schemes. Frequency and percentages were used to examine the data. RESULTS: Significant inequity in health service uses existed among different socioeconomic groups and the people covered by two different health insurance schemes. Compared with the elderly covered by Urban Employee Basic Medical Insurance, the elderly covered by URBMI had much lower rates of service use and higher non-use rates of health services. CONCLUSIONS: Universal health insurance coverage alone cannot mitigate the existing inequity in healthcare; the Chinese government must develop appropriate financial policies and measures to provide more financial support to URBMI in order to improve equitable and affordable access to healthcare.
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Accesibilidad a los Servicios de Salud/organización & administración , Disparidades en Atención de Salud/organización & administración , Seguro de Salud , Anciano , China , Atención a la Salud/organización & administración , Atención a la Salud/estadística & datos numéricos , Femenino , Encuestas de Atención de la Salud , Necesidades y Demandas de Servicios de Salud/organización & administración , Humanos , Seguro de Salud/organización & administración , Masculino , Persona de Mediana Edad , Factores Socioeconómicos , Cobertura Universal del Seguro de Salud/organización & administración , Población UrbanaRESUMEN
BACKGROUND: While prior studies have explored the efficacy of Morinda officinalis oligosaccharides (MOs) as a treatment for patients with major depressive disorder (MDD), the mechanistic basis for the effects of MOs on brain function or the default-mode network (DMN) has yet to be characterized. The objective of this was to examine the effects of MOs treatment on functional connectivity in different regions of the DMN. METHODS: In total, 27 MDD patients and 29 healthy control subjects (HCs) underwent resting-state functional magnetic resonance imaging. The patients were then treated with MOs for 8 weeks, and scanning was performed at baseline and the end of the 8-week treatment period. Changes in DMN homogeneity associated with MOs treatment were assessed using network homogeneity (NH) analyses of the imaging data, and pattern classification approaches were employed to determine whether abnormal baseline NH deficits could differentiate between MDD patients and controls. The ability of NH abnormalities to predict patient responses to MOs treatment was also evaluated. RESULTS: Relative to HCs, patients exhibited a baseline reduction in NH values in the right precuneus (PCu). At the end of the 8-week treatment period, the MDD patients showed reduced and increased NH values in the right PCu and left superior medial frontal gyrus (SMFG), respectively. Compared to these patients at baseline, the 8-week MOs treatment was associated with reduced NH values in the right angular gyrus and increased NH values in the left middle temporal gyrus and the right PCu. Support vector machine (SVM) analyses revealed that NH abnormalities in the right PCu and left SMFG were the most accurate (87.50%) for differentiating between MDD patients and HCs. CONCLUSION: These results indicated that MOs treatment could alter default-mode NH in patients with MDD. The results provide a foundation for elucidation of the effects of MOs on brain function and suggest that the distinctive NH patterns observed in this study may be useful as imaging biomarkers for distinguishing between patients with MDD and healthy subjects.
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Exposure to environmental pollutants, including nanomaterials, has a significant impact on tumor progression. The increased demand for black phosphorus nanosheets (BPNSs), driven by their exceptional properties, raises concerns about potential environmental contamination. Assessing their toxicity on tumor growth is essential. Herein, we employed a range of biological techniques, including cytotoxicity measurement, bioinformatics tools, proteomics, target gene overexpression, Western blot analysis, and apoptosis detection, to investigate the toxicity of BPNSs across A549, HepG-2, MCF-7, and Caco-2 cell lines. Our results demonstrated that BPNSs downregulated the expression of ADIPOQ and its associated downstream pathways, such as AMP-activated protein kinase (AMPK), nuclear factor erythroid 2-related factor 2 (Nrf2), and other unidentified pathways. These downregulated pathways ultimately led to mitochondria-dependent apoptosis. Notably, the specific downstream pathways involved varied depending on the type of tumors. These insightful findings not only confirm the consistent inhibitory effects of BPNSs across different tumor cells, but also elucidate the cytotoxicity mechanisms of BPNSs in different tumors, providing valuable information for their safe application and health risk assessment.
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Adiponectina , Apoptosis , Proliferación Celular , Regulación hacia Abajo , Nanoestructuras , Fósforo , Transducción de Señal , Humanos , Fósforo/química , Proliferación Celular/efectos de los fármacos , Adiponectina/metabolismo , Regulación hacia Abajo/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Nanoestructuras/química , Nanoestructuras/toxicidad , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proteínas Quinasas Activadas por AMP/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Factor 2 Relacionado con NF-E2/genéticaRESUMEN
Formaldehyde (HCHO) is one of the key indicators of severe photochemical pollution and strong atmospheric oxidation capacity in southern China. However, current information on the origins of regional HCHO and the impacts of polluted air masses remains scarce and unclear. In this study, an intensive observation of HCHO was conducted at a mountainous background site in southern China during typical photochemical pollution episodes. The concentrations of HCHO reached up to 6.14 ppbv and averaged at 2.68 ± 1.11 ppbv. Source appointment using a photochemical age-based parameterization method revealed significant contributions of secondary formation (50 %) and biomass burning (42 %). Meanwhile, under the influence of the East Asian Winter Monsoon, polluted air masses from central and western China can significantly increase the regional HCHO levels. The simulation results adopting the Rapid Adaptive Optimization Model for Atmospheric Chemistry model further demonstrated that the intrusion of active anthropogenic pollutants (e.g., small-molecule alkenes) can accelerate the net production rate of HCHO, particularly through BVOC-oxidation pathways. This study suggests a potential enhanced mechanism of HCHO production resulting from anthropogenic-biogenic interactions. It highlights that polluted air masses carrying abundant HCHO from upwind areas may facilitate severe photochemical pollution in the Greater Bay Area.
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Open biomass burning (OBB) is one of the largest primary emission sources for atmospheric carbonyl compounds, key precursors for ozone and secondary organic aerosol pollution. To clarify the carbonyl emissions, the comprehensive characteristics of C1-C10 carbonyl compounds from open burning of seven typical subtropical biomass in China were investigated in this study, which included subtropical plants and agricultural residues. Total 27 carbonyl compounds were detected. The total EFs were 2824 mg kg-1 with 95% confidence interval (CI) [2418, 3322] for burning subtropical plants and 4080 mg kg-1 with 95% CI [3446, 4724] for burning agriculture residues, respectively. The EFs were 2-3 orders of magnitude larger than previous values in China. Aliphatic aldehydes were the largest group of carbonyl groups, with acetaldehyde, as the most abundant carbonyl species (about 30% contribution). Formaldehyde, acetone, acrolein, glyoxal, methylglyoxal, butanone, isovaleraldehyde, and m-tolualdehyde were also found to be abundant and varying with the types of biomass burnt. Formaldehyde emission ratios to acetonitrile and CO were lower than those in previous studies both for burning plants and agricultural residues. There were significant variabilities in the emission ratios and factors among different types of OBBs. Strong positive correlations were found between carbonyl emissions and CO emissions and water content in biomass; furthermore, total carbonyl concentrations measured in the flaming stage were higher than those in the smoldering one. This study provides important fundamental measurement data on carbonyl emissions from burning typical subtropical plants and agricultural residues, which will help improve the quality of emission inventories and better understand the potential impacts of OBB on regional air quality in southern China.