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1.
Nat Commun ; 15(1): 7834, 2024 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-39244565

RESUMO

Water structures at electrolyte/electrode interfaces play a crucial role in determining the selectivity and kinetics of electrochemical reactions. Despite extensive experimental and theoretical efforts, atomic-level details of ion-specific water structures on metal surfaces remain unclear. Here we show, using scanning tunneling microscopy and noncontact atomic force microscopy, that we can visualize water layers containing alkali metal cations on a charged Au(111) surface with atomic resolution. Our results reveal that Li+ cations are elevated from the surface, facilitating the formation of an ice-like water layer between the Li+ cations and the surface. In contrast, K+ and Cs+ cations are in direct contact with the surface. We observe that the water network structure transitions from a hexagonal arrangement with Li+ to a distorted hydrogen-bonding configuration with Cs+. These observations are consistent with surface-enhanced infrared absorption spectroscopy data and suggest that alkali metal cations significantly impact hydrogen evolution reaction kinetics and efficiency. Our findings provide insights into ion-specific water structures on metal surfaces and underscore the critical role of spectator ions in electrochemical processes.

2.
Neuroscience ; 559: 303-315, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39276842

RESUMO

N-methyl-D-aspartate receptors (NMDARs) play a crucial role in mediating Amyloid-ß (Aß) synaptotoxicity. Our previous studies have demonstrated an opposite (neuroprotection and neurotoxicity) effect of activating astrocytic and neuronal NMDARs with higher dose (10 µM) of NMDA, an agonist of NMDARs. By contrast, activating neuronal or astrocyitc NMDARs with lower dose (1 µM) of NMDA both exerts neuroprotective effect in Aß-induced neurotoxicity. However, the underlying mechanism of activating astrocytic NMDARs with lower dose of NMDA to protect against Aß neurotoxicity remains unclear. Based on our previous related work, in this study, using a co-cultured cell model of primary hippocampal neurons and astrocytes, we further investigated the possible factors involved in 1 µM of NMDA activating astrocytic NMDARs to oppose Aß-induced synaptotoxicity. Our results showed that activation of astrocytic NMDARs by 1 µM NMDA rescued Aß-induced reduction of brain-derived neurotrophic factor (BDNF), and inhibited Aß-induced increase of GFAP, complement 3 (C3) and activation of NF-κB. Furthermore, blockade of astrocytic GluN2A with TCN201 abrogated the ability of 1 µM NMDA to counteract the effects of Aß decreasing BDNF, and increasing GFAP, C3 and activation of NF-κB. These findings suggest that activation of astrocytic NMDARs protect against Aß-induced synaptotoxicity probably through elevating BDNF and suppressing GFAP and C3. Our present research provides valuable insights for elucidating the underlying mechanism of astrocytic NMDARs activation resisting the toxic effects of Aß.

3.
Immunol Lett ; 270: 106902, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39181335

RESUMO

Urushiol-induced allergic contact dermatitis (ACD) is a chronic inflammatory skin disease in which skin barrier dysfunction leads to pruritus and eczematous lesions. ACD is triggered by immune imbalance. Aloe emodin is an anthraquinone derivative extracted from rhubarb, aloe and other traditional Chinese medicines. It has a wide range of pharmacological effects, including anti-inflammatory, anti-tumor, and anti-allergic effects. The purpose of our study was to demonstrate the effectiveness of aloe-emodin on urushiol-induced acute pruritus and allergic contact dermatitis. The results showed that urushiol could stimulate keratinocytes to release chemokines CXCL1, CXCL2, CCL2, TSLP, and TNF-α, which recruit or activate mast cells. Aloe-emodin treatment inhibited inflammatory-response-induced mast cell degranulation in skin lesions and suppressed the expression of inflammatory cytokines, such as interleukin-4, and interleukin-6. Therefore, the results indicate that aloe-emodin can improve urushiol-induced acute pruritus and allergic contact dermatitis in mice by inhibiting mast cell degranulation.

4.
Talanta ; 277: 126354, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38850804

RESUMO

Facing the rapid spread of antimicrobial resistance, methods based on single-cell Raman spectroscopy have proven their advances in reducing the turn-around time (TAT) of antimicrobial susceptibility tests (AST). However, the Raman-based methods are still hindered by the prolonged centrifugal cell washing procedure, which may require complex labor operation and induce high mechanical stress, resulting in a pretreatment time of over 1 h as well as a high cell-loss probability. In this study, we developed a micro-flow cell washing device and corresponding Raman-compatible washing chips, which were able to automatically remove the impurities in the samples, retain the bacterial cell and perform Raman spectra acquisition in situ. Results of washing the 5- and 10-µm polymethyl methacrylate (PMMA) microspheres showed that the novel technique achieved a successful removal of 99 % impurity and an 80 % particle retention rate after 6 to 10 cycles of washing. The micro-flow cell washing technique could complete the pretreatment for urine samples in a 96-well plate within 10 min, only taking 15 % of the handling time required by centrifugation. The AST profiles of urine sample spiked with E. coli 25922, E. faecalis 29212, and S. aureus 29213 obtained by the proposed Raman-based approach were found to be 100 % consistent with the results from broth micro-dilution while reducing the TAT to 3 h from several days which is required by the latter. Our study has demonstrated the micro-flow cell washing technique is a reliable, fast and compatible approach to replace centrifuge washing for sample pretreatment of Raman-AST and could be readily applied in clinical scenarios.


Assuntos
Escherichia coli , Testes de Sensibilidade Microbiana , Análise de Célula Única , Análise Espectral Raman , Staphylococcus aureus , Análise Espectral Raman/métodos , Humanos , Staphylococcus aureus/isolamento & purificação , Escherichia coli/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Análise de Célula Única/métodos , Antibacterianos/urina , Antibacterianos/farmacologia , Antibacterianos/análise , Enterococcus faecalis/isolamento & purificação , Automação , Polimetil Metacrilato/química
5.
Science ; 384(6701): 1254-1259, 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38870285

RESUMO

Low-dimensional water transport can be drastically enhanced under atomic-scale confinement. However, its microscopic origin is still under debate. In this work, we directly imaged the atomic structure and transport of two-dimensional water islands on graphene and hexagonal boron nitride surfaces using qPlus-based atomic force microscopy. The lattice of the water island was incommensurate with the graphene surface but commensurate with the boron nitride surface owing to different surface electrostatics. The area-normalized static friction on the graphene diminished as the island area was increased by a power of ~-0.58, suggesting superlubricity behavior. By contrast, the friction on the boron nitride appeared insensitive to the area. Molecular dynamic simulations further showed that the friction coefficient of the water islands on the graphene could reduce to <0.01.

6.
Nature ; 630(8016): 375-380, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38778112

RESUMO

Ice surfaces are closely relevant to many physical and chemical properties, such as melting, freezing, friction, gas uptake and atmospheric reaction1-8. Despite extensive experimental and theoretical investigations9-17, the exact atomic structures of ice interfaces remain elusive owing to the vulnerable hydrogen-bonding network and the complicated premelting process. Here we realize atomic-resolution imaging of the basal (0001) surface structure of hexagonal water ice (ice Ih) by using qPlus-based cryogenic atomic force microscopy with a carbon monoxide-functionalized tip. We find that the crystalline ice-Ih surface consists of mixed Ih- and cubic (Ic)-stacking nanodomains, forming 19 × 19 periodic superstructures. Density functional theory reveals that this reconstructed surface is stabilized over the ideal ice surface mainly by minimizing the electrostatic repulsion between dangling OH bonds. Moreover, we observe that the ice surface gradually becomes disordered with increasing temperature (above 120 Kelvin), indicating the onset of the premelting process. The surface premelting occurs from the defective boundaries between the Ih and Ic domains and can be promoted by the formation of a planar local structure. These results put an end to the longstanding debate on ice surface structures and shed light on the molecular origin of ice premelting, which may lead to a paradigm shift in the understanding of ice physics and chemistry.

7.
Arch Microbiol ; 206(5): 231, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38652321

RESUMO

The CRISPR-Cas system consists of Cas proteins and single-stranded RNAs that recruit Cas proteins and specifically target the nucleic acid. Some Cas proteins can accurately cleave the target nucleic acid under the guidance of the single-stranded RNAs. Due to its exceptionally high specificity, the CRISPR-Cas system is now widely used in various fields such as gene editing, transcription regulation, and molecular diagnosis. However, the huge size of the most frequently utilized Cas proteins (Cas9, Cas12a, and Cas13, which contain 950-1,400 amino acids) can limit their applicability, especially in eukaryotic gene editing, where larger Cas proteins are difficult to deliver into the target cells. Recently discovered miniature CRISPR-Cas proteins, consisting of only 400 to 800 amino acids, offer the possibility of overcoming this limitation. This article systematically reviews the latest research progress of several miniature CRISPR-Cas proteins (Cas12f, Cas12j, Cas12k, and Cas12m) and their practical applications in the field of gene editing.


Assuntos
Proteínas Associadas a CRISPR , Edição de Genes , Proteínas Associadas a CRISPR/química , Sistemas CRISPR-Cas , Edição de Genes/métodos , Células Eucarióticas
8.
Biosensors (Basel) ; 14(4)2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38667164

RESUMO

Raman flow cytometry (RFC) uniquely integrates the "label-free" capability of Raman spectroscopy with the "high-throughput" attribute of traditional flow cytometry (FCM), offering exceptional performance in cell characterization and sorting. Unlike conventional FCM, RFC stands out for its elimination of the dependency on fluorescent labels, thereby reducing interference with the natural state of cells. Furthermore, it significantly enhances the detection information, providing a more comprehensive chemical fingerprint of cells. This review thoroughly discusses the fundamental principles and technological advantages of RFC and elaborates on its various applications in the biomedical field, from identifying and characterizing cancer cells for in vivo cancer detection and surveillance to sorting stem cells, paving the way for cell therapy, and identifying metabolic products of microbial cells, enabling the differentiation of microbial subgroups. Moreover, we delve into the current challenges and future directions regarding the improvement in sensitivity and throughput. This holds significant implications for the field of cell analysis, especially for the advancement of metabolomics.


Assuntos
Citometria de Fluxo , Análise Espectral Raman , Humanos , Neoplasias , Animais
9.
Phytomedicine ; 125: 155266, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38241917

RESUMO

BACKGROUND: Increasing evidence highlights the involvement of metabolic disorder and calcium influx mediated by transient receptor potential channels in migraine; however, the relationship between these factors in the pathophysiology of migraine remains unknown. Gastrodin is the major component of the traditional Chinese medicine Tianma, which is extensively used in migraine therapy. PURPOSE: Our work aimed to explore the analgesic action of gastrodin and its regulatory mechanisms from a metabolic perspective. METHODS/RESULTS: After being treated with gastrodin, the mice were given nitroglycerin (NTG) to induce migraine. Gastrodin treatment significantly raised the threshold of sensitivity in response to both mechanical and thermal stimulus evidenced by von Frey and hot plate tests, respectively, and decreased total contact numbers in orofacial operant behavioral assessment. We found that the expression of transient receptor potential melastatin 2 (TRPM2) channel was increased in the trigeminal ganglion (TG) of NTG-induced mice, resulting in a sustained Ca2+ influx to trigger migraine pain. The content of succinate, a metabolic biomarker, was elevated in blood samples of migraineurs, as well as in the serum and TG tissue from NTG-induced migraine mice. Calcium imaging assay indicated that succinate insult elevated TRPM2-mediated calcium flux signal in TG neurons. Mechanistically, accumulated succinate upregulated hypoxia inducible factor-1α (HIF-1α) expression and promoted its translocation into nucleus, where HIF-1α enhanced TRPM2 expression through transcriptional induction in TG neurons, evidenced by luciferase reporter measurement. Gastrodin treatment inhibited TRPM2 expression and TRPM2-dependent Ca2+ influx by attenuating succinate accumulation and downstream HIF-1α signaling, and thereby exhibited analgesic effect. CONCLUSION: This work revealed that succinate was a critical metabolic signaling molecule and the key mediator of migraine pain through triggering TRPM2-mediated calcium overload. Gastrodin alleviated NTG-induced migraine-like pain via inhibiting succinate/HIF-1α/TRPM2 signaling pathway in TG neurons. These findings uncovered the anti-migraine effect of gastrodin and its regulatory mechanisms from a metabolic perspective and provided a novel theoretical basis for the analgesic action of gastrodin.


Assuntos
Álcoois Benzílicos , Glucosídeos , Transtornos de Enxaqueca , Canais de Cátion TRPM , Camundongos , Animais , Nitroglicerina/efeitos adversos , Nitroglicerina/metabolismo , Ácido Succínico/efeitos adversos , Ácido Succínico/metabolismo , Cálcio/metabolismo , Canais de Cátion TRPM/efeitos adversos , Canais de Cátion TRPM/metabolismo , Gânglio Trigeminal/metabolismo , Dor/tratamento farmacológico , Transtornos de Enxaqueca/induzido quimicamente , Transtornos de Enxaqueca/tratamento farmacológico , Transdução de Sinais , Analgésicos/farmacologia
10.
Faraday Discuss ; 249(0): 38-49, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-37786316

RESUMO

Condensation and arrangement of ions at water-solid interfaces are of great importance in the formation of electrical double layers (EDL) and the transport of ions under a confined geometry. So far, the microscopic understanding of interfacial ion configurations is still far from complete, especially when the local ion concentration is high and ion-ion interactions become prominent. In this study, we directly visualized alkali metal cations within the hydrogen-bonding network of water on graphite and Cu(111)-supported graphene surfaces, using qPlus-based noncontact atomic force microscopy (NC-AFM). We found that the codeposition of the alkali cations and water molecules on the hydrophobic graphite surface leads to the formation of an ion-doped bilayer hexagonal ice (BHI) structure, where the ions are repelled from each other and scattered in a disordered distribution. In contrast, the hydrated alkali cations aggregate in one dimension on the more hydrophilic graphene/Cu(111) surface, forming a nematic state with a long-range order. Such a nematic state arises from the delicate interplay between water-ion and water-water interactions under surface confinement. These results reveal the high sensitivity of ion-ion interactions and ionic ordering to the surface hydrophobicity and hydrophilicity.

11.
Nat Nanotechnol ; 19(4): 479-484, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38049594

RESUMO

The permeability and selectivity of biological and artificial ion channels correlate with the specific hydration structure of single ions. However, fundamental understanding of the effect of ion-ion interaction remains elusive. Here, via non-contact atomic force microscopy measurements, we demonstrate that hydrated alkali metal cations (Na+ and K+) at charged surfaces could come into close contact with each other through partial dehydration and water rearrangement processes, forming one-dimensional chain structures. We prove that the interplay at the nanoscale between the water-ion and water-water interaction can lead to an effective ion-ion attraction overcoming the ionic Coulomb repulsion. The tendency for different ions to become closely packed follows the sequence K+ > Na+ > Li+, which is attributed to their different dehydration energies and charge densities. This work highlights the key role of water molecules in prompting close packing and concerted movement of ions at charged surfaces, which may provide new insights into the mechanism of ion transport under atomic confinement.

12.
Spectrochim Acta A Mol Biomol Spectrosc ; 308: 123699, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38043297

RESUMO

The Raman microspectroscopy technology has been successfully applied to evaluate the molecular composition of living cells for identifying cell types and states, but the rationale behind it was not well investigated. In this study, we acquired single-cell Raman spectra (SCRS) of three Klebsiella pneumoniae (K. pneumoniae) strains with different Carbapenem resistant mechanisms and analyzed them with machine learning algorithm. Two carbapenem resistant Klebsiella pneumoniae (CRKP) strains can be successfully distinguished from susceptible strain and CRKP with KPC or IMP carbapenemases can be classified with an overall accuracy achieving 100 %. Furthermore, we performed a correlation analysis between transcriptome and Raman spectra, and found that Raman shifts such as 752 and 1039 cm-1 highly correlated with drug resistance genes expression and could be regarded as Raman biomarkers for CRKP with different mechanisms. The findings of the study provide a theoretical basis for identifying the relationship between Raman spectra and transcriptome of bacteria, as well as a novel method for rapid identification of CRKP and their carbapenemases types.


Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos , Infecções por Klebsiella , Humanos , Antibacterianos/farmacologia , Klebsiella pneumoniae/genética , Transcriptoma , Infecções por Klebsiella/microbiologia , Carbapenêmicos/farmacologia , Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Perfilação da Expressão Gênica , Testes de Sensibilidade Microbiana
13.
Geroscience ; 46(2): 2295-2315, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37940789

RESUMO

Sleep disturbance is a recognized risk factor for Alzheimer's disease (AD), but the underlying micro-pathological evidence remains limited. To bridge this gap, we established an amyloid-ß oligomers (AßO)-induced rat model of AD and subjected it to intermittent sleep deprivation (SD). Diffusion tensor imaging (DTI) and transmission electron microscopy were employed to assess white matter (WM) integrity and ultrastructural changes in myelin sheaths. Our findings demonstrated that SD exacerbated AßO-induced cognitive decline. Furthermore, we found SD aggravated AßO-induced asymmetrical impairments in WM, presenting with reductions in tract integrity observed in commissural fibers and association fasciculi, particularly the right anterior commissure, right corpus callosum, and left cingulum. Ultrastructural changes in myelin sheaths within the hippocampus and corpus callosum further confirmed a lateralized effect. Moreover, SD worsened AßO-induced lateralized disruption of the brain structural network, with impairments in critical nodes of the left hemisphere strongly correlated with cognitive dysfunction. This work represents the first identification of a lateralized impact of SD on the mesoscopic network and cognitive deficits in an AD rat model. These findings could deepen our understanding of the complex interplay between sleep disturbance and AD pathology, providing valuable insights into the early progression of the disease, as well as the development of neuroimaging biomarkers for screening early AD patients with self-reported sleep disturbances. Enhanced understanding of these mechanisms may pave the way for targeted interventions to alleviate cognitive decline and improve the quality of life for individuals at risk of or affected by AD.


Assuntos
Doença de Alzheimer , Substância Branca , Humanos , Ratos , Animais , Substância Branca/diagnóstico por imagem , Imagem de Tensor de Difusão/métodos , Privação do Sono/complicações , Privação do Sono/patologia , Qualidade de Vida
14.
Eur J Neurosci ; 58(7): 3605-3617, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37671643

RESUMO

Xanthotoxin (XAT) is a natural furanocoumarin clinically used in the treatment of skin diseases such as vitiligo and psoriasis. Recent studies have also investigated its effects on anti-inflammatory, anti-cognitive dysfunction, and anti-amnesia as a guideline for clinic application. However, little is known about its effects on pain relief. Here, we tested the analgesic effects of XAT in serious acute pain and chronic pain models. For acute pain, we used hot-, capsaicin- and formalin-induced paw licking. Nociceptive threshold was measured by mechanical stimuli with von Frey filaments. For chronic pain, we injected complete Freund's adjuvant (CFA) into the mice's plantar surface of the hind paw to induce inflammatory pain. Heat and mechanical hyperalgesia were evaluated by radiant heat and von Frey filament tests, respectively. To investigate the mechanisms underlying the analgesic effect of XAT, we used calcium imaging and western blot to assess transient receptor potential vanilloid 1 (TRPV1) activity and expression in isolated L4-L6 dorsal root ganglion (DRG) neurons. Haematoxylin and eosin (HE) staining, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were used to examine immune cell recruitment and proinflammatory factor release from skin tissue from paw injection sites. Our results demonstrated that XAT not only reduced acute pain behaviors generated by hot, capsaicin, and formalin but also attenuated CFA-induced heat and mechanical hyperalgesia. The analgesic activity of XAT may be achieved by controlling peripheral inflammation, lowering immune cell infiltration at the site of inflammatory tissue, reducing inflammatory factor production, and therefore inhibiting TRPV1 channel sensitization and expression.


Assuntos
Dor Aguda , Dor Crônica , Camundongos , Animais , Hiperalgesia/metabolismo , Metoxaleno/efeitos adversos , Capsaicina/farmacologia , Analgésicos/farmacologia , Analgésicos/uso terapêutico , Anti-Inflamatórios/efeitos adversos , Inflamação/metabolismo , Formaldeído/efeitos adversos , Gânglios Espinais/metabolismo
15.
Aging Brain ; 4: 100091, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37600754

RESUMO

For quite a long time, researches on Alzheimer's disease (AD) primarily focused on the cortex and hippocampus, while the cerebellum has been ignored because of its abnormalities considered to appear in the late stage of AD. In recent years, increasing evidence suggest that the cerebellar pathological changes possibly occur in the preclinical phase of AD, which is also associated with sleep disorder. Sleep disturbance is a high risk factor of AD. However, the changes and roles of cerebellum has rarely been reported under conditions of AD accompanied with sleep disorders. In this study, using an amyloid-ß oligomers (AßO)-induced rat model of AD subjected to sleep deprivation, combining with a 7.0 T animals structural magnetic resonance imaging (MRI), we assessed structural changes of cerebellum in MRI. Our results showed that sleep deprivation combined with AßO led to an increased FA value in the anterior lobe of cerebellum, decreased ADC value in the cerebellar lobes and cerebellar nuclei, and increased cerebellum volume. Besides that, sleep deprivation exacerbated the damage of AßO to the cerebellar structural network. This study demonstrated that sleep deprivation could aggravate the damage to cerebellum induced by AßO. The present findings provide supporting evidence for the involvement of cerebellum in the early pathology of AD and sleep loss. Our data would contribute to advancing the understanding of the mysterious role of cerebellum in AD and sleep disorders, as well as would be helpful for developing non-invasive MRI biomarkers for screening early AD patients with self-reported sleep disturbances.

16.
17.
Sci Total Environ ; 896: 165292, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37414179

RESUMO

The bioavailability and ecotoxicity of pollutants are important for urban ecological systems and human health, particularly at contaminated urban sites. Therefore, whole-cell bioreporters are used in many studies to assess the risks of priority chemicals; however, their application is restricted by low throughput for specific compounds and complicated operations for field tests. In this study, an assembly technology for manufacturing Acinetobacter-based biosensor arrays using magnetic nanoparticle functionalization was developed to solve this problem. The bioreporter cells maintained high viability, sensitivity, and specificity in sensing 28 priority chemicals, seven heavy metals, and seven inorganic compounds in a high-throughput manner, and their performance remained acceptable for at least 20 d. We also tested the performance by assessing 22 real environmental soil samples from urban areas in China, and our results showed positive correlations between the biosensor estimation and chemical analysis. Our findings prove the feasibility of the magnetic nanoparticle-functionalized biosensor array to recognize the types and toxicities of multiple contaminants for online environmental monitoring at contaminated sites.


Assuntos
Técnicas Biossensoriais , Poluentes Ambientais , Metais Pesados , Poluentes do Solo , Humanos , Disponibilidade Biológica , Metais Pesados/análise , Poluentes Ambientais/análise , Técnicas Biossensoriais/métodos , Monitoramento Ambiental/métodos , Fenômenos Magnéticos , Poluentes do Solo/toxicidade , Poluentes do Solo/análise
18.
Natl Sci Rev ; 10(7): nwac282, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37266561

RESUMO

Relevant to broad applied fields and natural processes, interfacial ionic hydrates have been widely studied by using ultrahigh-resolution atomic force microscopy (AFM). However, the complex relationship between the AFM signal and the investigated system makes it difficult to determine the atomic structure of such a complex system from AFM images alone. Using machine learning, we achieved precise identification of the atomic structures of interfacial water/ionic hydrates based on AFM images, including the position of each atom and the orientations of water molecules. Furthermore, it was found that structure prediction of ionic hydrates can be achieved cost-effectively by transfer learning using neural network trained with easily available interfacial water data. Thus, this work provides an efficient and economical methodology that not only opens up avenues to determine atomic structures of more complex systems from AFM images, but may also help to interpret other scientific studies involving sophisticated experimental results.

19.
Prog Neurobiol ; 228: 102489, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37355221

RESUMO

Alzheimer's disease (AD) seriously influences human health, and there is no effective treatment to prevent or cure AD. Recent studies have shown that angiotensin II type 1 receptor (AT1R) blockers significantly reduce the prevalence of AD, while the precise role and mechanism of AT1R in AD remain obscure. In this study, for the first time, we identified that astrocytic but not neuronal AT1R levels were significantly increased in AD model rats and found that astrocyte-specific knockout of AT1R significantly ameliorated amyloid ß (Aß)-induced cognitive deficits and synaptotoxicity. Pretreating astrocytes with an AT1R blocker also alleviated Aß-induced synaptotoxicity in the coculture system of hippocampal neurons and astrocytes. Moreover, AT1R could directly bind to Aß1-42 and activate the astrocytic ß-arrestin2 pathway in a biased manner, and biased inhibition of the astrocytic AT1R/ß-arrestin2 pathway relieved Aß-induced neurotoxicity. Furthermore, we demonstrated that astrocytic AT1R/ß-arrestin2 pathway-mediated synaptotoxicity was associated with the aggregation of autophagosomes, which triggered the disordered degradation of Aß. Our findings reveal a novel molecular mechanism of astrocytic AT1R in Aß-induced neurodegeneration and might contribute to establishing new targets for AD prevention and therapy.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Animais , Humanos , Ratos , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Astrócitos/metabolismo , beta-Arrestina 2/metabolismo , beta-Arrestina 2/farmacologia , Cognição , Receptor Tipo 1 de Angiotensina/metabolismo
20.
Front Microbiol ; 14: 1125676, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37032865

RESUMO

Integrating artificial intelligence and new diagnostic platforms into routine clinical microbiology laboratory procedures has grown increasingly intriguing, holding promises of reducing turnaround time and cost and maximizing efficiency. At least one billion people are suffering from fungal infections, leading to over 1.6 million mortality every year. Despite the increasing demand for fungal diagnosis, current approaches suffer from manual bias, long cultivation time (from days to months), and low sensitivity (only 50% produce positive fungal cultures). Delayed and inaccurate treatments consequently lead to higher hospital costs, mobility and mortality rates. Here, we developed single-cell Raman spectroscopy and artificial intelligence to achieve rapid identification of infectious fungi. The classification between fungi and bacteria infections was initially achieved with 100% sensitivity and specificity using single-cell Raman spectra (SCRS). Then, we constructed a Raman dataset from clinical fungal isolates obtained from 94 patients, consisting of 115,129 SCRS. By training a classification model with an optimized clinical feedback loop, just 5 cells per patient (acquisition time 2 s per cell) made the most accurate classification. This protocol has achieved 100% accuracies for fungal identification at the species level. This protocol was transformed to assessing clinical samples of urinary tract infection, obtaining the correct diagnosis from raw sample-to-result within 1 h.

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