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Understanding the neural basis of speech perception requires that we study the human brain both at the scale of the fundamental computational unit of neurons and in their organization across the depth of cortex. Here we used high-density Neuropixels arrays1-3 to record from 685 neurons across cortical layers at nine sites in a high-level auditory region that is critical for speech, the superior temporal gyrus4,5, while participants listened to spoken sentences. Single neurons encoded a wide range of speech sound cues, including features of consonants and vowels, relative vocal pitch, onsets, amplitude envelope and sequence statistics. Neurons at each cross-laminar recording exhibited dominant tuning to a primary speech feature while also containing a substantial proportion of neurons that encoded other features contributing to heterogeneous selectivity. Spatially, neurons at similar cortical depths tended to encode similar speech features. Activity across all cortical layers was predictive of high-frequency field potentials (electrocorticography), providing a neuronal origin for macroelectrode recordings from the cortical surface. Together, these results establish single-neuron tuning across the cortical laminae as an important dimension of speech encoding in human superior temporal gyrus.
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Córtex Auditivo , Neurônios , Percepção da Fala , Lobo Temporal , Humanos , Estimulação Acústica , Córtex Auditivo/citologia , Córtex Auditivo/fisiologia , Neurônios/fisiologia , Fonética , Fala , Percepção da Fala/fisiologia , Lobo Temporal/citologia , Lobo Temporal/fisiologia , Sinais (Psicologia) , EletrodosRESUMO
Taurine is a conditionally essential micronutrient and one of the most abundant amino acids in humans1-3. In endogenous taurine metabolism, dedicated enzymes are involved in the biosynthesis of taurine from cysteine and in the downstream metabolism of secondary taurine metabolites4,5. One taurine metabolite is N-acetyltaurine6. Levels of N-acetyltaurine are dynamically regulated by stimuli that alter taurine or acetate flux, including endurance exercise7, dietary taurine supplementation8 and alcohol consumption6,9. So far, the identities of the enzymes involved in N-acetyltaurine metabolism, and the potential functions of N-acetyltaurine itself, have remained unknown. Here we show that the body mass index associated orphan enzyme phosphotriesterase-related (PTER)10 is a physiological N-acetyltaurine hydrolase. In vitro, PTER catalyses the hydrolysis of N-acetyltaurine to taurine and acetate. In mice, PTER is expressed in the kidney, liver and brainstem. Genetic ablation of Pter in mice results in complete loss of tissue N-acetyltaurine hydrolysis activity and a systemic increase in N-acetyltaurine levels. After stimuli that increase taurine levels, Pter knockout mice exhibit reduced food intake, resistance to diet-induced obesity and improved glucose homeostasis. Administration of N-acetyltaurine to obese wild-type mice also reduces food intake and body weight in a GFRAL-dependent manner. These data place PTER into a central enzymatic node of secondary taurine metabolism and uncover a role for PTER and N-acetyltaurine in body weight control and energy balance.
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The brain generates complex sequences of movements that can be flexibly configured based on behavioural context or real-time sensory feedback1, but how this occurs is not fully understood. Here we developed a 'sequence licking' task in which mice directed their tongue to a target that moved through a series of locations. Mice could rapidly branch the sequence online based on tactile feedback. Closed-loop optogenetics and electrophysiology revealed that the tongue and jaw regions of the primary somatosensory (S1TJ) and motor (M1TJ) cortices2 encoded and controlled tongue kinematics at the level of individual licks. By contrast, the tongue 'premotor' (anterolateral motor) cortex3-10 encoded latent variables including intended lick angle, sequence identity and progress towards the reward that marked successful sequence execution. Movement-nonspecific sequence branching signals occurred in the anterolateral motor cortex and M1TJ. Our results reveal a set of key cortical areas for flexible and context-informed sequence generation.
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Córtex Motor , Movimento , Animais , Camundongos , Córtex Motor/fisiologia , Movimento/fisiologia , Optogenética , Córtex Somatossensorial/fisiologia , Língua/fisiologia , TatoRESUMO
The Ebola virus causes hemorrhagic fever in humans and poses a significant threat to global public health. Although two viral vector vaccines have been approved to prevent Ebola virus disease, they are distributed in the limited ring vaccination setting and only indicated for prevention of infection from orthoebolavirus zairense (EBOV)-one of three orthoebolavirus species that have caused previous outbreaks. Ebola virus glycoprotein GP mediates viral infection and serves as the primary target of neutralizing antibodies. Here, we describe a universal Ebola virus vaccine approach using a structure-guided design of candidates with hyperglycosylation that aims to direct antibody responses away from variable regions and toward conserved epitopes of GP. We first determined the hyperglycosylation landscape on Ebola virus GP and used that to generate hyperglycosylated GP variants with two to four additional glycosylation sites to mask the highly variable glycan cap region. We then created vaccine candidates by displaying wild-type or hyperglycosylated GP variants on ferritin nanoparticles (Fer). Immunization with these antigens elicited potent neutralizing antisera against EBOV in mice. Importantly, we observed consistent cross-neutralizing activity against Bundibugyo virus and Sudan virus from hyperglycosylated GP-Fer with two or three additional glycans. In comparison, elicitation of cross-neutralizing antisera was rare in mice immunized with wild-type GP-Fer. These results demonstrate a potential strategy to develop universal Ebola virus vaccines that confer cross-protective immunity against existing and emerging filovirus species.
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Vacinas contra Ebola , Ebolavirus , Doença pelo Vírus Ebola , Vacinas Virais , Humanos , Animais , Camundongos , Anticorpos Antivirais , Anticorpos Neutralizantes , Soros ImunesRESUMO
A major challenge in creating universal influenza vaccines is to focus immune responses away from the immunodominant, variable head region of hemagglutinin (HA-head) and toward the evolutionarily conserved stem region (HA-stem). Here we introduce an approach to control antigen orientation via site-specific insertion of aspartate residues that facilitates antigen binding to alum. We demonstrate the generalizability of this approach with antigens from Ebola, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses and observe enhanced neutralizing antibody responses in all cases. We then reorient an H2 HA in an 'upside-down' configuration to increase the exposure and immunogenicity of HA-stem. The reoriented H2 HA (reoH2HA) on alum induced stem-directed antibodies that cross-react with both group 1 and group 2 influenza A subtypes. Electron microscopy polyclonal epitope mapping (EMPEM) revealed that reoH2HA (group 1) elicits cross-reactive antibodies targeting group 2 HA-stems. Our results highlight antigen reorientation as a generalizable approach for designing epitope-focused vaccines.
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Vacinas contra Influenza , SARS-CoV-2 , Vacinas contra Influenza/imunologia , Vacinas contra Influenza/química , Humanos , SARS-CoV-2/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Antígenos Virais/imunologia , Antígenos Virais/química , Reações Cruzadas/imunologia , Camundongos , Epitopos/imunologia , Epitopos/química , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , Ebolavirus/imunologia , Vírus da Influenza A/imunologia , Compostos de Alúmen/química , Mapeamento de Epitopos , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/químicaRESUMO
Flexible electronics have recently gained considerable attention due to their potential to provide new and innovative solutions to a wide range of challenges in various electronic fields. These electronics require specific material properties and performance because they need to be integrated into a variety of surfaces or folded and rolled for newly formatted electronics. Two-dimensional (2D) materials have emerged as promising candidates for flexible electronics due to their unique mechanical, electrical, and optical properties, as well as their compatibility with other materials, enabling the creation of various flexible electronic devices. This article provides a comprehensive review of the progress made in developing flexible electronic devices using 2D materials. In addition, it highlights the key aspects of materials, scalable material production, and device fabrication processes for flexible applications, along with important examples of demonstrations that achieved breakthroughs in various flexible and wearable electronic applications. Finally, we discuss the opportunities, current challenges, potential solutions, and future investigative directions about this field.
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In pandemic scenarios involving novel human pathogenic viruses, it is highly desirable that vaccines induce strong neutralizing antibodies as quickly as possible. However, current vaccine strategies require multiple immunization doses to produce high titers of neutralizing antibodies and are poorly protective after a single vaccination. We therefore wished to design a vaccine candidate that would induce increased protective immune responses following the first vaccine dose. We hypothesized that antibodies against the receptor-binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein could be increased by drawing upon immunity to a previous infection. We generated a fusion protein containing the influenza H1N1 PR8 virus nucleoprotein (NP) and the SARS-CoV-2 spike RBD. Mice with or without preexisting immunity to PR8 were then vaccinated with NP/RBD. We observed significantly increased SARS-CoV-2 neutralizing antibodies in mice with PR8 immunity compared to mice without preexisting PR8 immunity. Vaccination with NP/RBD protected mice from SARS-CoV-2-induced morbidity and mortality after a single dose. Additionally, we compared SARS-CoV-2 virus titers in the lungs and nasal turbinates 4 days post-challenge of mice vaccinated with NP/RBD. SARS-CoV-2 virus was detectable in the lungs and nasal turbinate of mice without preexisting PR8 immunity, while SARS-CoV-2 virus was completely undetectable in mice with preexisting PR8 immunity. We also found that CD4-positive T cells in mice with preexisting immunity to PR8 play an essential role in producing the increased antibody response against RBD. This vaccine strategy potentially can be modified to target other pathogens of concern and offers extra value in future pandemic scenarios.IMPORTANCEIncreased globalization and changes in human interactions with wild animals has increased the likelihood of the emergence of novel viruses with pandemic potential. Vaccines can be effective in preventing severe disease caused by pandemic viruses. However, it takes time to develop protective immunity via prime-boost vaccination. More effective vaccine designs should quickly induce protective immunity. We propose leveraging preexisting immunity to a different pathogen to boost protection against emerging viruses. We targeted SARS-CoV-2 as a representative pandemic virus and generated a fusion protein vaccine that combines the nucleoprotein from influenza A virus and the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. Our vaccine design significantly increased the production of RBD-specific antibodies in mice that had previously been exposed to influenza virus, compared to those without previous exposure. This enhanced immunity reduced SARS-CoV-2 replication in mice. Our results offer a vaccine design that could be valuable in a future pandemic setting.
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Vacinas contra COVID-19 , Vacinas contra Influenza , Animais , Humanos , Camundongos , Anticorpos Neutralizantes , Anticorpos Antivirais , Formação de Anticorpos , COVID-19/imunologia , COVID-19/prevenção & controle , Vírus da Influenza A Subtipo H1N1/fisiologia , Vacinas contra Influenza/imunologia , Nucleoproteínas , SARS-CoV-2/fisiologia , Glicoproteína da Espícula de Coronavírus/química , Vacinas contra COVID-19/imunologia , Influenza Humana/imunologia , Influenza Humana/prevenção & controleRESUMO
Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus consisting of both latent and lytic life cycles. Primary effusion lymphoma (PEL) is an aggressive B-cell lineage lymphoma, dominantly latently infected by KSHV. The latent infection of KSHV is persistent and poses an obstacle to killing tumor cells. Like the "shock and kill" strategy designed to eliminate latent HIV reservoir, methods that induce viral lytic reactivation in tumor latently infected by viruses represent a unique antineoplastic strategy, as it could potentially increase the specificity of cytotoxicity in cancer. Inspired by this conception, we proposed that the induction of KSHV lytic reactivation from latency could be a potential therapeutic stratagem for KSHV-associated cancers. Oxidative stress, the clinical hallmark of PEL, is one of the most prominent inducers for KSHV reactivation. Paradoxically, we found that hydrogen peroxide (H2O2) triggers robust cytotoxic effects on KSHV-negative rather than KSHV-positive B lymphoma cells in a dose-dependent manner. Mechanistically, we identified forkhead box protein O1 (FoxO1) and FoxO3 as irrevocable antioxidant defense genes and both of them are upregulated by KSHV latent infection, which is essential for the promoted ROS scavenging in KSHV-positive B lymphoma cells. Pharmacological inhibition or functional knockdown of either FoxO1 or FoxO3 is sufficient to ablate the antioxidant ability and therefore increases the intracellular ROS level that further reverses KSHV from latency to active lytic replication in PEL cells, resulting in tremendous cell death both in vitro and in vivo. Additionally, the elevated level of ROS by inhibiting FoxO proteins further sensitizes PEL cells to ROS-induced apoptosis. Our study therefore demonstrated that the lytic reactivation of KSHV by inhibiting FoxO proteins is a promising therapeutic approach for PEL, which could be further extended to other virus-associated diseases.
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Síndrome da Imunodeficiência Adquirida , Infecções por HIV , HIV-1 , Herpesviridae , Herpesvirus Humano 8 , Linfoma de Efusão Primária , Humanos , Antioxidantes , Peróxido de Hidrogênio , Espécies Reativas de Oxigênio , Latência ViralRESUMO
Sustainable, durable, and diverse photochromic smart textiles based on bacterial cellulose (BC) have emerged as attractive candidates in UV-sensing applications due to the green and easy functionalization of BC. However, existing BC-based photochromic textiles lack photochromic efficiency and combining fastness. In this study, a green strategy for in situ fermentation is developed to achieve the directional distribution of functional particles and remarkable photochromism in photochromic bacterial cellulose (PBC). The unique functional design obtained by regulating the photochromic dye distribution in 3D nanonetworks of PBCs during in situ growth affords a more uniform distribution and high fastness. Benefiting from the uniform distribution of photochromic dyes and adequate utilization of the 3D network structure, more surface area is provided to receive and utilize the photon energy from the UV rays, making the photochromic process more effective. The as-prepared PBCs exhibited rapid (within 1 min) and stable (30 cycles) discoloration and multicolor selectivity. Their simple preparation process and exceptional wearability, e.g., their flexibility, lightweight, and air permeability, make them suitable for various applications, including tunable color switching systems, photopatterning, and daily sunlight UV monitoring. This study provides empirical value for the biofabrication of photochromic textiles and wearable flexible UV sensors.
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Celulose , Luz Solar , Raios Ultravioleta , Celulose/química , Bactérias , Têxteis , CorRESUMO
BACKGROUND: Dysbiosis of the gut microbiota is pivotal in Crohn's disease (CD) and modulated by host physiological conditions. Hyperbaric oxygen therapy (HBOT) is a promising treatment for CD that can regulate gut microbiota. The relationship between HBOT and the gut microbiota in CD remains unknown. METHODS: CD patients were divided into an HBOT group (n = 10) and a control group (n = 10) in this open-label prospective interventional study. The fecal samples before and after HBOT were used for 16 S rRNA gene sequencing and fecal microbiota transplantation (FMT). A colitis mouse model was constructed using dextran sulfate sodium, and intestinal and systematic inflammation was evaluated. The safety and long-term effect of HBOT were observed. RESULTS: HBOT significantly reduced the level of C-reactive protein (CRP) (80.79 ± 42.05 mg/L vs. 33.32 ± 18.31 mg/L, P = 0.004) and the Crohn's Disease Activity Index (CDAI) (274.87 ± 65.54 vs. 221.54 ± 41.89, P = 0.044). HBOT elevated the declined microbial diversity and ameliorated the altered composition of gut microbiota in patients with CD. The relative abundance of Escherichia decreased, and that of Bifidobacterium and Clostridium XIVa increased after HBOT. Mice receiving FMT from donors after HBOT had significantly less intestinal inflammation and serum CRP than the group before HBOT. HBOT was safe and well-tolerated by patients with CD. Combined with ustekinumab, more patients treated with HBOT achieved clinical response (30%vs.70%, P = 0.089) and remission (20%vs.50%, P = 0.160) at week 4. CONCLUSIONS: HBOT modulates the dysbiosis of gut microbiota in CD and ameliorates intestinal and systematic inflammation. HBOT is a safe option for CD and exhibits a promising auxiliary effect to ustekinumab. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2200061193. Registered 15 June 2022, https://www.chictr.org.cn/showproj.html?proj=171605 .
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Doença de Crohn , Disbiose , Microbioma Gastrointestinal , Oxigenoterapia Hiperbárica , Inflamação , Doença de Crohn/terapia , Doença de Crohn/microbiologia , Humanos , Disbiose/terapia , Disbiose/microbiologia , Animais , Feminino , Masculino , Inflamação/terapia , Adulto , Intestinos/microbiologia , Pessoa de Meia-Idade , Transplante de Microbiota Fecal , Camundongos , Camundongos Endogâmicos C57BL , Adulto JovemRESUMO
PURPOSE: To optimize chemotherapy regimens and improve the effectiveness of chemotherapy combined with immunotherapy, a PET tracer specifically targeting the stimulator of interferon genes (STING), denoted as [18F]FBTA was used to monitor the early changes in tumor immunogenicity after chemotherapy in colorectal cancer (CRC) mice. METHODS: The toluene sulfonate precursor was labeled with 18F to produce the STING targeted probe-[18F]FBTA. [18F]FBTA-PET imaging and biodistribution were performed using CRC mice treated with oxaliplatin (OXA) or cisplatin (CDDP). CRC mice were also treated with low (CDDP-LD: 1 mg/kg) or medium (CDDP-MD: 2.5 mg/kg) doses of CDDP, and subjected to PET imaging and biodistribution. The effects of different chemotherapeutic agents and different doses of CDDP on tumor innate immunity were verified by flow cytometry and immunohistochemistry. RESULTS: PET imaging of CRC mice exhibited notably enhanced tumor uptake in the early phase of chemotherapy with treatment with OXA (3.09 ± 0.25%ID/g) and CDDP (4.01 ± 0.18%ID/g), especially in the CDDP group. The PET-derived tumor uptake values have strong correlations with STING immunohistochemical score. Flow cytometry showed both agents led to DCs and macrophages infiltration in tumors. Compared with OXA, CDDP treatment recruits more DCs and macrophages in CRC tumors. Both CDDP-LD and CDDP-MD treatment elevated uptake in CRC tumors, especially in CDDP-MD group. Immunohistochemistry and flow cytometry confirmed CDDP-MD treatment recruits more DCs and macrophages than CDDP-LD treatment. CONCLUSION: Overall, the STING-targeted tracer-[18F]FBTA was demonstrated to monitor early changes in tumor immunogenicity in CRC mice after chemotherapy. Besides, the STING-targeted strategy may help to select the appropriate chemotherapy regimen, including chemotherapeutic agents and doses, which further improve clinical decision making for combination immunotherapy after chemotherapy for CRC.
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Neoplasias Colorretais , Tomografia por Emissão de Pósitrons , Camundongos , Animais , Distribuição Tecidual , Tomografia por Emissão de Pósitrons/métodos , Neoplasias Colorretais/diagnóstico por imagem , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Linhagem Celular TumoralRESUMO
Imaging strategies for the specific detection and therapeutic monitoring of myocarditis are still lacking. Stimulator of interferon genes (STING) is a signal transduction molecule involved in an innate immune response. Here, we evaluated the feasibility of the recently developed STING-targeted radiotracer [18F]FBTA for positron emission tomography (PET) imaging to detect myocardial inflammation and monitor treatment in myocarditis mice. [18F]FBTA-PET imaging was performed in myocarditis mice and normal mice to verify the specificity of [18F]FBTA for the diagnosis of myocarditis. We also performed PET imaging in mice with myocarditis treated to verify the ability of [18F]FBTA in therapeutic monitoring. The expression of STING and inflammatory cell types was confirmed by flow cytometry and immunohistochemistry. [18F]FDG-PET imaging of myocarditis was used as a contrast. [18F]FBTA-PET imaging showed that the average radioactive uptake was significantly higher in the hearts of the myocarditis group than in the control group. STING was highly overexpressed in cardiac inflammatory cells, including macrophages, dendritic cells (DCs), and T cells. However, there was no significant difference in cardiac radiotracer uptake of [18F]FDG between the myocarditis group and the control group. Moreover, cardiac uptake of [18F]FBTA was significantly reduced in cyclosporin A-treated myocarditis mice and myocardial STING expression was also significantly reduced after the treatment. Overall, we showed that a STING-targeted PET tracer [18F]FBTA can be used to monitor changes in the inflammatory microenvironment in myocarditis. Besides, [18F]FBTA-PET is also suitable for real-time monitoring of myocarditis treatment, representing a promising diagnostic and therapeutic monitoring approach for myocarditis.
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Proteínas de Membrana , Miocardite , Tomografia por Emissão de Pósitrons , Miocardite/diagnóstico por imagem , Miocardite/tratamento farmacológico , Miocardite/metabolismo , Animais , Camundongos , Tomografia por Emissão de Pósitrons/métodos , Proteínas de Membrana/metabolismo , Masculino , Compostos Radiofarmacêuticos , Fluordesoxiglucose F18 , Camundongos Endogâmicos BALB C , Modelos Animais de Doenças , Miocárdio/metabolismo , Miocárdio/patologia , Células Dendríticas/metabolismo , CiclosporinaRESUMO
BACKGROUND: This study examined the relationship between loneliness and bedtime procrastination among Chinese university students, the mediating effects of COVID-19 risk perception and self-regulatory fatigue, and connectedness to nature's protective role, post pandemic. METHODS: We recruited 855 students to complete the Loneliness, Perceived Risk of COVID-19 Pandemic, Self-Regulatory Fatigue, Bedtime Procrastination, and Connectedness to Nature Scales. Data for descriptive statistics, correlation analysis, and moderated chain mediation effects were analyzed using SPSS 24.0 and process 3.5 macros. RESULTS: Loneliness positively correlated with bedtime procrastination, COVID-19 risk perception mediated the impact of loneliness on bedtime procrastination, self-regulatory fatigue mediated the effect of loneliness on bedtime procrastination, and COVID-19 risk perception and self-regulatory fatigue mediated the effect between loneliness and bedtime procrastination. Furthermore, connectedness to nature mediated the impact of COVID-19 risk perception on self-regulatory fatigue. CONCLUSIONS: The results indicate the effects and potential mechanisms of loneliness on bedtime procrastination after the relaxation of the pandemic prevention and control policy in China from the perspective of self-regulatory resources and provide insights into improving university students' sleep routine and mental health post pandemic.
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COVID-19 , Procrastinação , Humanos , Solidão , Pandemias , Universidades , COVID-19/epidemiologia , Fadiga , EstudantesRESUMO
BACKGROUND: N6-methyladenosine (m6A) methylation is considered to induce tumor cell proliferation, migration, and apoptosis. Understanding the mechanism of m6A-related lncRNAs in the development of lung adenocarcinoma (LUAD) may help predict prognosis. METHODS: m6A-related lncRNAs related to lung cancer were identified and combined with the MeRIP-Seq dataset. The consensus clustering method was utilized to divide LUAD patients, and prognostic model was constructed using the Lasso Cox algorithm. The cluster profiler package was used for gene ontology and KEGG enrichment. The proportion of immune infiltration was estimated using the CIBERSORT algorithm. The decision tree was constructed by the rpart package, and nomograms were built by the rms package. The Connectivity Map database was analyzed for the therapeutic effects of small molecule drugs for LUAD. In addition, qPCR, colony formation and transwell assays were performed to validate functions of m6A-associated lncRNAs. RESULTS: Nineteen m6A-modified lncRNAs in LUAD were identified. LUAD patients were divided into two categories based on the expression of 19 m6A-related lncRNAs. Cluster 2 patients had better antigen production and expression, while naive B cells, plasma cells, and activated NK cells were lower in cluster 1. Nine m6A-related lncRNAs were selected to establish a risk model for evaluating the prognosis of LUAD patients. The high-risk group had higher tumor mutational burden and lower TIDE scores with more gamma delta T cells and neutrophils. Nomograms showed that the prognostic model had predominant predictive ability for LUAD patients based on the risk score analyzed by the decision tree model. Benzo(a)pyrene and neurodazine might improve the prognosis of LUAD patients. The qRT-PCR results confirmed the reliability of the analytical results. CONCLUSION: The establishment of a prognostic model of m6A-related lncRNAs can independently predict overall survival in LUAD and may help to develop personalized immunotherapy strategies.
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Adenina/análogos & derivados , Adenocarcinoma , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , Reprodutibilidade dos Testes , Biomarcadores , PulmãoRESUMO
Self-assembly of various building blocks has been considered as a powerful approach to generate novel materials with tailorable structures and optimal properties. Understanding physicochemical interactions and mechanisms related to structural formation and transitions is of essential importance for this approach. Although it is well-known that diverse forces and energies can significantly contribute to the structures and properties of self-assembling systems, the potential entropic contribution remains less well understood. The past few years have witnessed rapid progress in addressing the entropic effects on the structures, responses, and functions in the self-assembling systems, and many breakthroughs have been achieved. This review provides a framework regarding the entropy-controlled strategy of self-assembly, through which the structures and properties can be tailored by effectively tuning the entropic contribution and its interplay with the enthalpic counterpart. First, we focus on the fundamentals of entropy in thermodynamics and the entropy types that can be explored for self-assembly. Second, we discuss the rules of entropy in regulating the structural organization in self-assembly and delineate the entropic force and superentropic effect. Third, we introduce the basic principles, significance and approaches of the entropy-controlled strategy in self-assembly. Finally, we present the applications where this strategy has been employed in fields like colloids, macromolecular systems and nonequilibrium assembly. This review concludes with a discussion on future directions and future research opportunities for developing and applying the entropy-controlled strategy in complex self-assembling systems.
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A staggered vane-shaped slot-line slow-wave structure (SV-SL SWS) for application in W-band traveling wave tubes (TWTs) is proposed in this article. In contrast to the conventional slot-line SWSs with dielectric substrates, the proposed SWS consists only of a thin metal sheet inscribed with periodic grooves and two half-metal enclosures, which means it can be easily manufactured and assembled and has the potential for mass production. This SWS not only solves the problem of the dielectric loading effect but also improves the heat dissipation capability of such structures. Meanwhile, the SWS design presented here covers a -15 dB S11 frequency range from 87.5 to 95 GHz. The 3-D simulation for a TWT based on the suggested SWS is also investigated. Under dual-electron injection conditions with a total voltage of 17.2 kV and a total current of 0.3 A, the maximum output power at 90 GHz is 200 W, with a 3 dB bandwidth up to 4 GHz. With a good potential for fabrication using microfabrication techniques, this structure can be a good candidate for millimeter-wave TWT applications.
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Understanding physicochemical interactions and mechanisms related to the cell membranes of lives under extreme conditions is of essential importance but remains scarcely explored. Here, using a combination of computer simulations and experiments, we demonstrate that the structural integrity and controllable permeability of cell membranes at high temperatures are predominantly directed by configurational entropy emerging from distorted intermolecular organization of bipolar tethered lipids peculiar to the extremophiles. Detailed simulations across multiple scalesâfrom an all-atom exploration of molecular mechanism to a mesoscale examination of its universal natureâsuggest that this configurational entropy effect can be generalized to diverse systems, such as block copolymers. This offers biomimetic inspiration for designing heat-tolerant materials based on entropy, as validated by our experiments of synthetic polymers. The findings provide new insight into the basic nature of the mechanism underlying the adaptation of organisms to extreme conditions and might open paths for designed materials inspired by entropic effects in biological systems.
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Extremófilos , Entropia , Simulação por Computador , Membrana CelularRESUMO
Nowadays, NPS abuse are continuing to expand in terms of harm and scope, due to its cheap and easy to manufacture anywhere in the world. This study reviewed articles related to seven heavily abused NPS to analyze the structure and trends of NPS abuse. A total of 2476 articles were retrieved based on the search strategy for bibliometric analysis. A significant trend of research in recent years was the increasing number of research on synthetic opioids and designer benzodiazepines, but synthetic cannabinoid and synthetic cathinone still dominate, which were mainly concerned with the development of metabolic models and determining methods as well as their abuse characteristics and reasons. However, with the introduction of class-wide ban on synthetic cannabinoid in China and a series of enhancements in other countries, the abuse of it might decrease to some extent, but more than 20 kinds of synthetic cannabinoid beyond the scope of ban in China still reminded researchers of their potential threats. As for synthetic cathinone, an important phenomenon was some of the drugs first identified during certain period might be more widely distributed in the future. Besides, several problems such as the regulation and prevention mode of emerging NPS, development of testing technologies as well as the interpretation and identification of multiple NPS combinations were also worth paying attention to. This study could help entrants better understand the structure of NPS abuse and provided direction for future research in forensic toxicology.
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Electricity generation triggered by the ubiquitous water evaporation process provides an intriguing way to harvest energy from water. Meanwhile, natural water evaporation is also a fundamental way to obtain fresh water for human beings. Here, a wafer-scale nanostructured silicon-based device that takes advantage of its well-aligned configuration that simultaneously realizes solar steam generation (SSG) for freshwater collection and hydrovoltaic effect generation for electricity output is developed. An ingenious porous, black carbon nanotube fabric (CNF) electrode endows the device with sustainable water self-pumping capability, excellent durable conductivity, and intense solar spectrum harvesting. A combined device based on the CNF electrode integrated with nanostructured silicon nanowire arrays (SiNWs) provided an aligned numerous surface-to-volume water evaporation interface that enables a recorded continuous short-circuit current 8.65 mA and a water evaporation rate of 1.31 kg m-2 h-1 under one sun illumination. Such wafer-scale SiNWs-based SSG and hydrovoltaic integration devices would unchain the bottleneck of the weak and discontinuous electrical output of hydrovoltaic devices, which inspires other sorts of semiconductor-based hydrovoltaic device designs to target superior performance.
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Respiratory syncytial virus (RSV) is the most important virus that causes lower respiratory tract disease in children; efficient viral identification is an important component of disease prevention and treatment. Here, we developed and evaluated a ready-to-use (RTU) nucleic acid extraction-free direct reagent for identification of RSV (RTU-Direct test) in clinical samples. The limit of detection (LOD) of the RSV RTU-Direct test was consistent with the LOD of the standard test using extracted nucleic acids. The virus inactivation ability of RTU-Direct reagent was confirmed by viral infectivity assays involving RTU-Direct-treated samples containing RSV and human coronavirus OC43. RSV RNA stability was significantly better in RTU-Direct reagent than in conventional virus transport medium (VTM) at room temperature and 4°C (p < 0.05). The clinical performance of the RTU-Direct test was evaluated using 155 respiratory specimens from patients with suspected RSV infection. Positive agreement between the RTU-Direct test and the VTM standard test was 100% (42/42); negative agreement was 99.1% (112/113), and the kappa statistic was 0.968 (p < 0.001). The distributions of Ct values did not significantly differ between the RTU-Direct test and the standard test (p > 0.05). Overall, the RTU-Direct reagent can improve the efficiency and biosafety of RSV detection, while reducing the cost of detection.