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1.
Nature ; 597(7875): 239-244, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34408325

RESUMO

Social isolation and loneliness have potent effects on public health1-4. Research in social psychology suggests that compromised sleep quality is a key factor that links persistent loneliness to adverse health conditions5,6. Although experimental manipulations have been widely applied to studying the control of sleep and wakefulness in animal models, how normal sleep is perturbed by social isolation is unknown. Here we report that chronic, but not acute, social isolation reduces sleep in Drosophila. We use quantitative behavioural analysis and transcriptome profiling to differentiate between brain states associated with acute and chronic social isolation. Although the flies had uninterrupted access to food, chronic social isolation altered the expression of metabolic genes and induced a brain state that signals starvation. Chronically isolated animals exhibit sleep loss accompanied by overconsumption of food, which resonates with anecdotal findings of loneliness-associated hyperphagia in humans. Chronic social isolation reduces sleep and promotes feeding through neural activities in the peptidergic fan-shaped body columnar neurons of the fly. Artificial activation of these neurons causes misperception of acute social isolation as chronic social isolation and thereby results in sleep loss and increased feeding. These results present a mechanistic link between chronic social isolation, metabolism, and sleep, addressing a long-standing call for animal models focused on loneliness7.


Assuntos
Encéfalo/metabolismo , Drosophila melanogaster/metabolismo , Comportamento Alimentar , Modelos Animais , Sono , Isolamento Social , Inanição/metabolismo , Animais , Encéfalo/citologia , Drosophila melanogaster/citologia , Drosophila melanogaster/genética , Feminino , Fome , Hiperfagia/genética , Solidão , Masculino , Neurônios/metabolismo , Sono/genética , Privação do Sono/genética , Privação do Sono/metabolismo , Inanição/genética , Fatores de Tempo , Transcriptoma
2.
Proc Natl Acad Sci U S A ; 119(5)2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-35082154

RESUMO

Histological imaging is essential for the biomedical research and clinical diagnosis of human cancer. Although optical microscopy provides a standard method, it is a persistent goal to develop new imaging methods for more precise histological examination. Here, we use nitrogen-vacancy centers in diamond as quantum sensors and demonstrate micrometer-resolution immunomagnetic microscopy (IMM) for human tumor tissues. We immunomagnetically labeled cancer biomarkers in tumor tissues with magnetic nanoparticles and imaged them in a 400-nm resolution diamond-based magnetic microscope. There is barely magnetic background in tissues, and the IMM can resist the impact of a light background. The distribution of biomarkers in the high-contrast magnetic images was reconstructed as that of the magnetic moment of magnetic nanoparticles by employing deep-learning algorithms. In the reconstructed magnetic images, the expression intensity of the biomarkers was quantified with the absolute magnetic signal. The IMM has excellent signal stability, and the magnetic signal in our samples had not changed after more than 1.5 y under ambient conditions. Furthermore, we realized multimodal imaging of tumor tissues by combining IMM with hematoxylin-eosin staining, immunohistochemistry, or immunofluorescence microscopy in the same tissue section. Overall, our study provides a different histological method for both molecular mechanism research and accurate diagnosis of human cancer.


Assuntos
Diamante/química , Magnetismo/métodos , Microscopia de Fluorescência/métodos , Neoplasias/patologia , Pontos Quânticos/química , Humanos , Processamento de Imagem Assistida por Computador/métodos , Nanopartículas/química , Nitrogênio/química
3.
Nano Lett ; 23(7): 2636-2643, 2023 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-36971403

RESUMO

Biomolecular interactions compose a fundamental element of all life forms and are the biological basis of many biomedical assays. However, current methods for detecting biomolecular interactions have limitations in sensitivity and specificity. Here, using nitrogen-vacancy centers in diamond as quantum sensors, we demonstrate digital magnetic detection of biomolecular interactions with single magnetic nanoparticles (MNPs). We first developed a single-particle magnetic imaging (SiPMI) method on 100 nm-sized MNPs with negligible magnetic background, high signal stability, and accurate quantification. The single-particle method was performed on biotin-streptavidin interactions and DNA-DNA interactions in which a single-base mismatch was specifically differentiated. Subsequently, SARS-CoV-2-related antibodies and nucleic acids were examined by a digital immunomagnetic assay derived from SiPMI. In addition, a magnetic separation process improved the detection sensitivity and dynamic range by more than 3 orders of magnitude and also the specificity. This digital magnetic platform is applicable to extensive biomolecular interaction studies and ultrasensitive biomedical assays.


Assuntos
COVID-19 , Nanopartículas , Humanos , SARS-CoV-2 , DNA , Fenômenos Magnéticos
4.
Ecotoxicol Environ Saf ; 262: 115326, 2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-37556958

RESUMO

Manganese (Mn) is an essential trace element that maintains many normal physiological functions. However, multi-system disorders would occur once overexposure to Mn, especially neurotoxicity. Despite evidence demonstrating the critical role of ROS-activated JNK/FOXO3a signaling pathway in neuronal survival, the specific mechanisms by which it contributes to Mn-induced neurotoxicity are still unclear. The objectives of this study was to examine the modulation of the JNK/FOXO3a signaling pathway, which is activated by ROS, in Mn-induced apoptosis, using a rat brain astrocyte cell line (CTX cells). This study found that a dose-dependent decrease in cell viability of CTX cells was observed with 150, 200, 250, 300 µmol/L Mn. The results of apoptosis-related protein assay showed that Mn decreased the expression of anti-apoptotic protein Bcl-2 and enhanced the expression of apoptosis-related proteins like Bax and Cleaved-Caspase3. In addition, treatment with Mn resulted in elevated ROS levels and increased phosphorylation levels of JNK. Conversely, phosphorylation of nuclear transcription factors FOXO3a, which regulates expression of transcription factors including Bim and PUMA, was decreased. Depletion of ROS by N-acetyl-L-cysteine (NAC) and inhibition of the JNK pathway by SP600125 prevented Mn-induced JNK/FOXO3a pathway activation and, more importantly, the level of apoptosis was also significantly reduced. Confirmation of Mn-induced apoptosis in CTX cells through ROS generation and activation of the JNK/FOXO3a signaling pathway was the outcome of this study. These findings offer fresh insights into the neurotoxic mechanisms of Mn and therapeutic targets following Mn exposure.

5.
Ecotoxicol Environ Saf ; 259: 115026, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37210997

RESUMO

Despite the ubiquity and prevalence of lead (Pb) in the environment and industry, the mechanism of lead-induced neurotoxicity in the brain remains unclear, let alone its prevention and treatment. In this study, we hypothesized that exogenous cholesterol supplementation acts as an effective remedy for lead-induced neurodevelopmental impairments caused by lead. Forty 21-day-old male rats were randomly divided into four groups and administered 0.1 % lead water and/or 2 % cholesterol-containing feed for 30 d. Ultimately, rats in the lead group lost weight, accompanied by spatial learning and memory impairments as verified by the Morris water maze test, in which the escape latency of rats was prolonged, and the number of crossings in the target platform and the residence time in the target quadrant were significantly diminished compared to the control group. Hematoxylin-Eosin (H&E) staining and Nissl staining illustrated that typical pathological morphology occurred in the brain tissue of the lead group, where the tissue structure was loose, the number of hippocampal neurons and granulosa cells decreased significantly and were arranged loosely, along with enlarged intercellular space, light matrix staining, and decline in Nissl bodies. In addition, inflammatory response and oxidative stress were significantly induced by lead. Immunofluorescence experiments showed apparent activation of astrocytes and microglia, followed by the enhancement of TNF-α and IL-ß levels. Moreover, the MDA content in the lead group was elevated dramatically, whereas the activities of SOD and GSH were significantly inhibited. As for the mechanism, western blot and qRT-PCR experiments were performed, where lead could significantly inhibit the BDNF-TrkB signaling pathway, lowering the protein expression of BDNF and TrkB. Cholesterol metabolism was also affected by lead exposure, in which cholesterol metabolism-related protein expression and gene transcription, including SREBP2, HMGCR, and LDLR, were downregulated. However, cholesterol supplementation efficiently detoxified the negative effects of lead-induced neurotoxicity, reversing the inflammatory response, oxidative stress, inactivation of the BDNF signaling pathway, and imbalance of cholesterol metabolism, thus improving the learning and memory ability of rats. In brief, our study demonstrated that cholesterol supplementation could ameliorate the deficiency of learning and memory induced by lead, which is closely associated with the initiation of the BDNF/TrkB signaling pathway and regulation of cholesterol metabolism.


Assuntos
Fator Neurotrófico Derivado do Encéfalo , Chumbo , Feminino , Ratos , Animais , Masculino , Ratos Sprague-Dawley , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Chumbo/metabolismo , Transdução de Sinais , Hipocampo/metabolismo , Suplementos Nutricionais , Aprendizagem em Labirinto
6.
Nature ; 598(7881): 423-424, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34588643
7.
Ecotoxicol Environ Saf ; 248: 114307, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36423370

RESUMO

Lead (Pb), as a deleterious heavy metal, ubiquitously exists in environment and industry, which engenders multi-organ disfunction, especially the brain of infants who are vulnerable to attack from lead-induced neurotoxicity. Although cholesterol sulfate (CS) is crucial constituent of cell membranes and precursor of neurosteroids, which maintains the function and survival of neurons, the role of CS in lead-induced neurological damage still remains incomplete. In this work, Rat Brain Astrocytes cell line (CTX cells) was applied into exploration that protective effects of CS on CTX cell apoptosis induced by lead via the regulation of BDNF/TrkB signaling pathway mediated cholesterol metabolism. We found that CTX cells exposed to lead manifested apparent cytotoxicity, where the viability of CTX cells was significantly suppressed, accompanied with the elevation of apoptosis, in response to a trend towards increases in reactive oxygen species (ROS) production and pro-apoptotic protein Cleaved-caspase3, synchronized with the decline in anti-apoptotic protein Bcl-2. Moreover, accumulation of lead in CTX cells showed a dose-dependent increase, and meanwhile, decrements in cholesterol content occurred along with increase in lead exposure, in which expressions of cholesterol metabolism related proteins and transcriptions of its genes (SREBP2, LDLR, and HMGCR) were diminished. Furthermore, BDNF signaling pathway was obviously blocked after lead exposure, down-regulating expressions of proteins BDNF and TrkB. However, pretreatment with CS detoxified the negative impacts of lead-invoked CTX cell damage, acting as an effective remedy for apoptosis, imbalance of cholesterol metabolism and inhibition of BDNF signaling pathway. In addition, the relationship between BDNF signaling pathway and cholesterol metabolism was further verified, in which cholesterol metabolism related proteins and genes were promoted significantly after the activation of BDNF/TrkB signaling pathway using 7,8-Dihydroxyflavone (7,8-DHF), thereby detoxifying lead-induced CTX cell injury. However, the pretreatment of TrkB inhibitor ANA-12 offset the promotion of 7,8-DHF and ultimately inhibit cholesterol metabolism. Overall, our study demonstrated that CS could initiate the BDNF/TrkB signaling pathway, regulating the cholesterol metabolism against CTX cell apoptosis invoked by lead.


Assuntos
Fator Neurotrófico Derivado do Encéfalo , Chumbo , Animais , Ratos , Fator Neurotrófico Derivado do Encéfalo/genética , Chumbo/toxicidade , Apoptose , Transdução de Sinais
8.
Proc Natl Acad Sci U S A ; 112(48): E6663-72, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26627257

RESUMO

Recent studies have identified molecular pathways driving forgetting and supported the notion that forgetting is a biologically active process. The circuit mechanisms of forgetting, however, remain largely unknown. Here we report two sets of Drosophila neurons that account for the rapid forgetting of early olfactory aversive memory. We show that inactivating these neurons inhibits memory decay without altering learning, whereas activating them promotes forgetting. These neurons, including a cluster of dopaminergic neurons (PAM-ß'1) and a pair of glutamatergic neurons (MBON-γ4>γ1γ2), terminate in distinct subdomains in the mushroom body and represent parallel neural pathways for regulating forgetting. Interestingly, although activity of these neurons is required for memory decay over time, they are not required for acute forgetting during reversal learning. Our results thus not only establish the presence of multiple neural pathways for forgetting in Drosophila but also suggest the existence of diverse circuit mechanisms of forgetting in different contexts.


Assuntos
Drosophila melanogaster/fisiologia , Memória/fisiologia , Condutos Olfatórios/fisiologia , Animais , Comportamento Animal , Encéfalo/fisiologia , Dopamina/metabolismo , Neurônios Dopaminérgicos/fisiologia , Proteínas de Drosophila/fisiologia , Feminino , Glutamina/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Imageamento Tridimensional , Aprendizagem , Masculino , Vias Neurais/fisiologia , Odorantes , Fenótipo , Conformação Proteica , Olfato/fisiologia , Transgenes
9.
J Neurosci ; 36(12): 3414-21, 2016 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-27013671

RESUMO

Circadian clocks enable organisms to anticipate and adapt to fluctuating environmental conditions. Despite substantial knowledge of central clock machineries, we have less understanding of how the central clock's behavioral outputs are regulated. Here, we identify Drosophila miR-124 as a critical regulator of diurnal activity. During normal light/dark cycles, mir-124 mutants exhibit profoundly abnormal locomotor activity profiles, including loss of anticipatory capacities at morning and evening transitions. Moreover,mir-124 mutants exhibited striking behavioral alterations in constant darkness (DD), including a temporal advance in peak activity. Nevertheless, anatomical and functional tests demonstrate a normal circadian pacemaker in mir-124 mutants, indicating this miRNA regulates clock output. Among the extensive miR-124 target network, heterozygosity for targets in the BMP pathway substantially corrected the evening activity phase shift in DD. Thus, excess BMP signaling drives specific circadian behavioral output defects in mir-124 knock-outs. SIGNIFICANCE STATEMENT: Circadian clocks control rhythmic behaviors of most life-forms. Despite extensive knowledge of the central clock, there is less understanding of how its behavioral outputs are regulated. Here, we identify a conserved neural microRNA as a critical regulator of diurnal behavior. We find Drosophila mir-124 mutants exhibit robust activity abnormalities during normal light/dark cycles and during constant darkness. Nevertheless, as the central pacemaker is functional in these mutants, miR-124 regulates clock output. We provide mechanistic insight by showing deregulation of miR-124 targets in BMP signaling drives specific mir-124 defects. In summary,Drosophila mir-124 mutants reveal post-transcriptional control of circadian activities, and impact of BMP signaling in behavioral output.


Assuntos
Relógios Biológicos/fisiologia , Encéfalo/fisiologia , Geradores de Padrão Central/fisiologia , Ritmo Circadiano/fisiologia , Drosophila/fisiologia , Locomoção/fisiologia , MicroRNAs/fisiologia , Animais , Comportamento Animal/fisiologia , Masculino
10.
J Neurosci ; 33(13): 5821-33, 2013 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-23536094

RESUMO

MicroRNA (miRNA)-mediated gene regulation plays a key role in brain development and function. But there are few cases in which the roles of individual miRNAs have been elucidated in behaving animals. We report a miR-276a::DopR regulatory module in Drosophila that functions in distinct circuits for naive odor responses and conditioned odor memory. Drosophila olfactory aversive memory involves convergence of the odors (conditioned stimulus) and the electric shock (unconditioned stimulus) in mushroom body (MB) neurons. Dopamine receptor DopR mediates the unconditioned stimulus inputs onto MB. Distinct dopaminergic neurons also innervate ellipsoid body (EB), where DopR function modulates arousal to external stimuli. We demonstrate that miR-276a is required in MB neurons for memory formation and in EB for naive responses to odors. Both roles of miR-276a are mediated by tuning DopR expression. The dual role of this miR-276a::DopR genetic module in these two neural circuits highlights the importance of miRNA-mediated gene regulation within distinct circuits underlying both naive behavioral responses and memory.


Assuntos
Aprendizagem da Esquiva/fisiologia , MicroRNAs/metabolismo , Corpos Pedunculados/citologia , Neurônios/fisiologia , Condutos Olfatórios/citologia , Condutos Olfatórios/fisiologia , Análise de Variância , Animais , Animais Geneticamente Modificados , Drosophila , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Eletrochoque/efeitos adversos , Embrião não Mamífero/fisiologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Fluorescência Verde/genética , Temperatura Alta , Masculino , MicroRNAs/genética , Mutação/genética , Odorantes , Receptores Dopaminérgicos/genética , Receptores Dopaminérgicos/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
11.
J Neurosci ; 33(25): 10568-81, 2013 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-23785169

RESUMO

The brain represents sensory information in the coordinated activity of neuronal ensembles. Although the microcircuits underlying olfactory processing are well characterized in Drosophila, no studies to date have examined the encoding of odor identity by populations of neurons and related it to the odor specificity of olfactory behavior. Here we used two-photon Ca(2+) imaging to record odor-evoked responses from >100 neurons simultaneously in the Drosophila mushroom body (MB). For the first time, we demonstrate quantitatively that MB population responses contain substantial information on odor identity. Using a series of increasingly similar odor blends, we identified conditions in which odor discrimination is difficult behaviorally. We found that MB ensemble responses accounted well for olfactory acuity in this task. Kenyon cell ensembles with as few as 25 cells were sufficient to match behavioral discrimination accuracy. Using a generalization task, we demonstrated that the MB population code could predict the flies' responses to novel odors. The degree to which flies generalized a learned aversive association to unfamiliar test odors depended upon the relative similarity between the odors' evoked MB activity patterns. Discrimination and generalization place different demands on the animal, yet the flies' choices in these tasks were reliably predicted based on the amount of overlap between MB activity patterns. Therefore, these different behaviors can be understood in the context of a single physiological framework.


Assuntos
Drosophila/fisiologia , Corpos Pedunculados/fisiologia , Corpos Pedunculados/ultraestrutura , Percepção Olfatória/fisiologia , Animais , Cálcio/fisiologia , Discriminação Psicológica/fisiologia , Generalização Psicológica/fisiologia , Processamento de Imagem Assistida por Computador , Aprendizagem/fisiologia , Modelos Lineares , Corpos Pedunculados/citologia , Neuroimagem/métodos , Odorantes , Condutos Olfatórios , Desempenho Psicomotor/fisiologia , Transmissão Sináptica/fisiologia
12.
Carbohydr Polym ; 333: 121982, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38494234

RESUMO

The production of high-performance starch-based packaging films by extrusion blowing is challenging, ascribed to poor processability of the blend precursors. In this study, a new strategy of mechanical activation (MA)-enhanced metal-organic coordination was proposed to improve the processability of starch (St)/polyvinyl alcohol (PVA) blend precursor, with calcium acetate (CA) as a chelating agent and glycerol as a plasticizer. MA pretreatment activated the hydroxyl groups of starch and PVA for constructing strong metal-organic coordination between CA and St/PVA during reactive extrusion, which effectively enhanced the melt processing properties of the blend precursor, contributing to the fabrication of high-performance St/PVA films by the extrusion-blowing method. The as-prepared St/PVA films exhibited excellent mechanical properties (tensile strength of 34.5 MPa; elongation at break of 271.8 %), water vapor barrier performance (water vapor permeability of 0.704 × 10-12 g·cm-1·s-1·Pa-1), and oxygen barrier performance (oxygen transmission rate of 0.7 cm3/(m2·day·bar)), along with high transmittance and good uniformity. These outstanding characteristics and performances can be attributed to the improved interfacial interaction and compatibility between the two matrix phases. This study uncovers the mechanism of MA-enhanced metal-organic coordination for improving the properties of starch-based films, which provides a convenient and eco-friendly technology for the preparation of high-performance biodegradable films.

13.
Nat Commun ; 15(1): 5047, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38871750

RESUMO

Direct solar-to-hydrogen conversion from pure water using all-organic heterogeneous catalysts remains elusive. The challenges are twofold: (i) full-band low-frequent photons in the solar spectrum cannot be harnessed into a unified S1 excited state for water-splitting based on the common Kasha-allowed S0 → S1 excitation; (ii) the H+ → H2 evolution suffers the high overpotential on pristine organic surfaces. Here, we report an organic molecular crystal nanobelt through the self-assembly of spin-one open-shell perylene diimide diradical anions (:PDI2-) and their tautomeric spin-zero closed-shell quinoid isomers (PDI2-). The self-assembled :PDI2-/PDI2- crystal nanobelt alters the spin-dependent excitation evolution, leading to spin-allowed S0S1 → 1(TT) → T1 + T1 singlet fission under visible-light (420 nm~700 nm) and a spin-forbidden S0 → T1 transition under near-infrared (700 nm~1100 nm) within spin-hybrid chromophores. With a triplet-triplet annihilation upconversion, a newly formed S1 excited state on the diradical-quinoid hybrid induces the H+ reduction through a favorable hydrophilic diradical-mediated electron transfer, which enables simultaneous H2 and O2 production from pure water with an average apparent quantum yield over 1.5% under the visible to near-infrared solar spectrum.

14.
Artigo em Inglês | MEDLINE | ID: mdl-38963922

RESUMO

Efficient photocatalytic solar CO2 reduction presents a challenge because visible-to-near-infrared (NIR) low-energy photons account for over 50% of solar energy. Consequently, they are unable to instigate the high-energy reaction necessary for dissociating C═O bonds in CO2. In this study, we present a novel methodology leveraging the often-underutilized photo-to-thermal (PTT) conversion. Our unique two-dimensional (2D) carbon layer-embedded Mo2C (Mo2C-Cx) MXene catalyst in black color showcases superior near-infrared (NIR) light absorption. This enables the efficient utilization of low-energy photons via the PTT conversion mechanism, thereby dramatically enhancing the rate of CO2 photoreduction. Under concentrated sunlight, the optimal Mo2C-C0.5 catalyst achieves CO2 reduction reaction rates of 12000-15000 µmol·g-1·h-1 to CO and 1000-3200 µmol·g-1·h-1 to CH4. Notably, the catalyst delivers solar-to-carbon fuel (STF) conversion efficiencies between 0.0108% to 0.0143% and the STFavg = 0.0123%, the highest recorded values under natural sunlight conditions. This innovative approach accentuates the exploitation of low-frequency, low-energy photons for the enhancement of photocatalytic CO2 reduction.

15.
Front Psychol ; 14: 1233434, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37854133

RESUMO

Emerging evidence suggests that the Impostor Phenomenon (IP) among doctoral students is a serious problem worldwide academic. Although previous studies demonstrate that IP can endanger doctoral students' academic advancement and psychological well-being, limited studies systematically and comprehensively explore the IP among those population. Thus, the fundamental goal of this study is to conduct a scoping review of IP among doctoral students so as to clarify the reality of their situation. Systematic searches were conducted using 5 databases: Springer, Google Scholar, Web of Science, PubMed, and JSTOR for empirical studies published from 1978 to 2023. Two reviewers independently carried out the literature search, study selection, data extraction and assessment of study; disagreements were resolved by a third reviewer. Thirty empirical studies covering four specific domains were include in current research, including the characteristics of IP among doctoral students, factors contributing to IP among doctoral students, correlation of IP with doctoral students' mental illness, and measurement of IP. The findings of this study may provide insight to improving the comprehension of IP among doctoral students and establishing the groundwork for future research in this field.

16.
Sci Total Environ ; 903: 166627, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-37647968

RESUMO

The continuous spread of microplastics in aquatic environments poses a growing concern and a potential risk to human health. To address this concern, this paper presents a novel approach using magnetic Janus microparticles (MJMs) synthesized via a modified Pickering emulsion method with aminated Fe3O4@SiO2 as the raw material. The effectiveness of these MJMs in removing polystyrene (PS) and polyethylene (PE) microplastics from water was investigated. Paraffin was employed as the masking agent, while N-Octadecylphosphosphonic acid (PAC18) was used as the graft material for MJM preparation. The resulting particles exhibited a distinctive asymmetric flower-shaped structure on the surface, which was confirmed through various analytical techniques including FTIR, TGA, SEM, and water phase contact angle analysis. The MJMs demonstrated exceptional efficiency in adsorbing microplastics. With a microplastic suspension concentration of 2 mg/mL and an adsorbent dosage of 1 mg/mL, the MJMs can attain removal efficiencies of 92.08 % for PS and 60.67 % for PE in just 20 min of contact time. The effectiveness of the adsorption process was attributed to several factors, including hydrophobic interactions, cation-π interactions, electrostatic attraction, and the efficient dispersion of particles in water, as revealed by size distribution and zeta potential analysis. Additionally, kinetic and thermodynamic studies confirmed the remarkable adsorption rate and capacity of the MJMs (0.759 min-1 and 2.72 mg/mg for PS, 0.539 min-1 and 2.42 mg/mg for PE), highlighting their potential as a promising method for rapidly removing microplastics from water. This work provides valuable insights into the development of effective strategies for addressing microplastic pollution in aquatic environments.

17.
ACS Appl Mater Interfaces ; 15(31): 37966-37975, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37503816

RESUMO

It has been widely accepted that sustainable polymers derived from renewable resources are able to replace the short-turnover petroleum-based materials and reduce environmental impact in the future. However, their hydrophilic chemical structures rich with oxygen groups could lead to easy growth of bacteria, which greatly limit their applications in packaging materials. Here, we present an intelligent food-packaging material with sustained-release antibacterial and real-time monitoring ability based on totally biobased contents. In detail, sodium alginate with Artemisia argyi emission oil (encapsulated in gelatin-Arabic gum microcapsules) and citric acid-sourced pH-responsive carbon quantum dots (CQDs) are coated on bamboo cellulose papers. The obtained biobased composite material (almost 100% biocarbon content) with antibacterial ability is able to extend the shelf life of fresh shrimps and can be biodegraded. Moreover, owing to the introduction of CQDs, the composite can rapidly (within 1 s) detect slight pH variations (response pH ∼5, 10-9 mol/L of OH-) through an obvious color change (hue value from 305 to 355°). The developed strategy may open up new opportunities in the design of multifunctional biobased composites for intelligent applications.


Assuntos
Celulose , Polímeros , Preparações de Ação Retardada/farmacologia , Polímeros/química , Celulose/química , Antibacterianos/farmacologia , Embalagem de Alimentos
18.
Front Physiol ; 13: 1048751, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36467698

RESUMO

Genome-wide profiling of rhythmic gene expression has offered new avenues for studying the contribution of circadian clock to diverse biological processes. Sleep has been considered one of the most important physiological processes that are regulated by the circadian clock, however, the effects of chronic sleep loss on rhythmic gene expression remain poorly understood. In the present study, we exploited Drosophila sleep mutants insomniac 1 (inc 1 ) and wide awake D2 (wake D2 ) as models for chronic sleep loss. We profiled the transcriptomes of head tissues collected from 4-week-old wild type flies, inc 1 and wake D2 at timepoints around the clock. Analysis of gene oscillation revealed a substantial loss of rhythmicity in inc 1 and wake D2 compared to wild type flies, with most of the affected genes common to both mutants. The disruption of gene oscillation was not due to changes in average gene expression levels. We also identified a subset of genes whose loss of rhythmicity was shared among animals with chronic sleep loss and old flies, suggesting a contribution of aging to chronic, sleep-loss-induced disruption of gene oscillation.

19.
J Biol Rhythms ; 36(3): 203-220, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33641476

RESUMO

Circadian clocks are biochemical time-keeping machines that synchronize animal behavior and physiology with planetary rhythms. In Drosophila, the core components of the clock comprise a transcription/translation feedback loop and are expressed in seven neuronal clusters in the brain. Although it is increasingly evident that the clocks in each of the neuronal clusters are regulated differently, how these clocks communicate with each other across the circadian neuronal network is less clear. Here, we review the latest evidence that describes the physical connectivity of the circadian neuronal network . Using small ventral lateral neurons as a starting point, we summarize how one clock may communicate with another, highlighting the signaling pathways that are both upstream and downstream of these clocks. We propose that additional efforts are required to understand how temporal information generated in each circadian neuron is integrated across a neuronal circuit to regulate rhythmic behavior.


Assuntos
Relógios Circadianos , Animais , Ritmo Circadiano , Proteínas de Drosophila , Drosophila melanogaster , Rede Nervosa , Neurônios
20.
Food Chem ; 363: 130344, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34147895

RESUMO

This study focused on constructing a high-solid reaction system to prepare type 3 resistant starch (RS3) with high-amylose maize starch as raw material by mechanical activation (MA) pretreatment combined with thermal and freeze-thaw treatments. MA pretreatment effectively destroyed the crystal structure and molecular structure of native starch. MA damaged starch with a certain viscosity could form dough with a small amount of water to construct a starch continuous phase system. RS content increased with the damage levels of starch as the formation of double helix structure, attributed to that the molecules of MA damaged starch could be easy to move and form recrystallization structure. Thermal and freeze-thaw treatments contributed to strong interaction of starch-water and the re-formation of internal crystal structure of MA damaged starch to form RS3. This study provides insight into the development of a highly effective approach for large scale production of resistant starch.


Assuntos
Amilose , Zea mays , Amido Resistente , Amido , Viscosidade
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