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The deficit in social interaction skills among individuals with autism spectrum disorder (ASD) is strongly influenced by personal experiences and social environments. Neuroimaging studies have previously highlighted the link between social impairment and brain activity in ASD. This study aims to develop a method for assessing and identifying ASD using a social cognitive game-based paradigm combined with electroencephalo-graphy (EEG) signaling features. Typically developing (TD) participants and autistic preadolescents and teenagers were recruited to participate in a social game while 12-channel EEG signals were recorded. The EEG signals underwent preprocessing to analyze local brain activities, including event-related potentials (ERPs) and time-frequency features. Additionally, the global brain network's functional connectivity between brain regions was evaluated using phase-lag indices (PLIs). Subsequently, machine learning models were employed to assess the neurophysiological features. Results indicated pronounced ERP components, particularly the late positive potential (LPP), in parietal regions during social training. Autistic preadolescents and teenagers exhibited lower LPP amplitudes and larger P200 amplitudes compared to TD participants. Reduced theta synchronization was also observed in the ASD group. Aberrant functional connectivity within certain time intervals was noted in the ASD group. Machine learning analysis revealed that support-vector machines achieved a sensitivity of 100%, specificity of 91.7%, and accuracy of 95.8% as part of the performance evaluation when utilizing ERP and brain oscillation features for ASD characterization. These findings suggest that social interaction difficulties in autism are linked to specific brain activation patterns. Traditional behavioral assessments face challenges of subjectivity and accuracy, indicating the potential use of social training interfaces and EEG features for cognitive assessment in ASD.
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Transtorno do Espectro Autista , Eletroencefalografia , Potenciais Evocados , Aprendizado de Máquina , Humanos , Transtorno do Espectro Autista/fisiopatologia , Adolescente , Eletroencefalografia/métodos , Criança , Masculino , Feminino , Potenciais Evocados/fisiologia , Córtex Cerebral/fisiopatologia , Córtex Cerebral/diagnóstico por imagem , Jogos de Vídeo , Algoritmos , Smartphone , Interação SocialRESUMO
Companion animals such as cats and dogs harbor diverse microbial communities that can potentially impact human health due to close and frequent contact. To better characterize their total infectomes and assess zoonotic risks, we characterized the overall infectomes of companion animals (cats and dogs) and evaluated their potential zoonotic risks. Meta-transcriptomic analyses were performed on 239 samples from cats and dogs collected across China, identifying 24 viral species, 270 bacterial genera, and two fungal genera. Differences in the overall microbiome and infectome composition were compared across different animal species (cats or dogs), sampling sites (rectal or oropharyngeal), and health status (healthy or diseased). Diversity analyses revealed that viral abundance was generally higher in diseased animals compared to healthy ones, while differences in microbial composition were mainly driven by sampling site, followed by animal species and health status. Disease association analyses validated the pathogenicity of known pathogens and suggested potential pathogenic roles of previously undescribed bacteria and newly discovered viruses. Cross-species transmission analyses identified seven pathogens shared between cats and dogs, such as alphacoronavirus 1, which was detected in both oropharyngeal and rectal swabs albeit with differential pathogenicity. Further analyses showed that some viruses, like alphacoronavirus 1, harbored multiple lineages exhibiting distinct pathogenicity, tissue, or host preferences. Ultimately, a systematic evolutionary screening identified 27 potential zoonotic pathogens in this sample set, with far more bacterial than viral species, implying potential health threats to humans. Overall, our meta-transcriptomic analysis reveals a landscape of actively transcribing microorganisms in major companion animals, highlighting key pathogens, those with the potential for cross-species transmission, and possible zoonotic threats. IMPORTANCE: This study provides a comprehensive characterization of the entire community of infectious microbes (viruses, bacteria, and fungi) in companion animals like cats and dogs, termed the "infectome." By analyzing hundreds of samples from across China, the researchers identified numerous known and novel pathogens, including 27 potential zoonotic agents that could pose health risks to both animals and humans. Notably, some of these zoonotic pathogens were detected even in apparently healthy pets, highlighting the importance of surveillance. The study also revealed key microbial factors associated with respiratory and gastrointestinal diseases in pets, as well as potential cross-species transmission events between cats and dogs. Overall, this work sheds light on the complex microbial landscapes of companion animals and their potential impacts on animal and human health, underscoring the need for monitoring and management of these infectious agents.
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Bactérias , Doenças do Gato , Doenças do Cão , Animais de Estimação , Zoonoses , Animais , Gatos , Cães , Animais de Estimação/virologia , Animais de Estimação/microbiologia , Humanos , Doenças do Cão/microbiologia , Doenças do Cão/virologia , Doenças do Cão/transmissão , Zoonoses/microbiologia , Zoonoses/virologia , Zoonoses/transmissão , Doenças do Gato/virologia , Doenças do Gato/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Microbiota/genética , China , Vírus/classificação , Vírus/genética , Vírus/isolamento & purificação , Vírus/patogenicidade , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/patogenicidade , Perfilação da Expressão Gênica , TranscriptomaRESUMO
Mosquito transmitted viruses are responsible for an increasing burden of human disease. Despite this, little is known about the diversity and ecology of viruses within individual mosquito hosts. Here, using a meta-transcriptomic approach, we determined the viromes of 2,438 individual mosquitoes (81 species), spanning ~4,000 km along latitudes and longitudes in China. From these data we identified 393 viral species associated with mosquitoes, including 7 (putative) species of arthropod-borne viruses (that is, arboviruses). We identified potential mosquito species and geographic hotspots of viral diversity and arbovirus occurrence, and demonstrated that the composition of individual mosquito viromes was strongly associated with host phylogeny. Our data revealed a large number of viruses shared among mosquito species or genera, enhancing our understanding of the host specificity of insect-associated viruses. We also detected multiple virus species that were widespread throughout the country, perhaps reflecting long-distance mosquito dispersal. Together, these results greatly expand the known mosquito virome, linked viral diversity at the scale of individual insects to that at a country-wide scale, and offered unique insights into the biogeography and diversity of viruses in insect vectors.
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Culicidae , Mosquitos Vetores , Viroma , Animais , Culicidae/virologia , China , Mosquitos Vetores/virologia , Metagenômica , Arbovírus/genética , Arbovírus/classificação , Filogenia , BiodiversidadeRESUMO
Between 7 December 2022 and 28 February 2023, China experienced a new wave of COVID-19 that swept across the entire country and resulted in an increasing amount of respiratory infections and hospitalizations. The purpose of this study is to reveal the intensity and composition of coinfecting microbial agents. In total, 196 inpatients were recruited from The Third People's Hospital of Shenzhen, and 169 respiratory and 73 blood samples were collected for metagenomic next-generation sequencing. The total "Infectome" was characterized and compared across different groups defined by the SARS-CoV-2 detection status, age groups, and severity of disease. Our results revealed a total of 22 species of pathogenic microbes (4 viruses, 13 bacteria, and 5 fungi), and more were discovered in the respiratory tract than in blood. The diversity of the total infectome was highly distinguished between respiratory and blood samples, and it was generally higher in patients that were SARS-CoV-2-positive, older in age, and with more severe disease. At the individual pathogen level, HSV-1 seemed to be the major contributor to these differences observed in the overall comparisons. Collectively, this study reveals the highly complex respiratory infectome and high-intensity coinfection in patients admitted to the hospital during the period of the 2023 COVID-19 pandemic in China.
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OBJECTIVES: The respiratory tract is the portal of entry for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although a variety of respiratory pathogens other than SARS-CoV-2 have been associated with severe cases of COVID-19 disease, the dynamics of the upper respiratory microbiota during disease the course of disease, and how they impact disease manifestation, remain uncertain. METHODS: We collected 349 longitudinal upper respiratory samples from a cohort of 65 COVID-19 patients (cohort 1), 28 samples from 28 recovered COVID-19 patients (cohort 2), and 59 samples from 59 healthy controls (cohort 3). All COVID-19 patients originated from the earliest stage of the epidemic in Wuhan. Based on a modified clinical scale, the disease course was divided into five clinical disease phases (pseudotimes): "Healthy" (pseudotime 0), "Incremental" (pseudotime 1), "Critical" (pseudotime 2), "Complicated" (pseudotime 3), "Convalescent" (pseudotime 4), and "Long-term follow-up" (pseudotime 5). Using meta-transcriptomics, we investigated the features and dynamics of transcriptionally active microbes in the upper respiratory tract (URT) over the course of COVID-19 disease, as well as its association with disease progression and clinical outcomes. RESULTS: Our results revealed that the URT microbiome exhibits substantial heterogeneity during disease course. Two clusters of microbial communities characterized by low alpha diversity and enrichment for multiple pathogens or potential pathobionts (including Acinetobacter and Candida) were associated with disease progression and a worse clinical outcome. We also identified a series of microbial indicators that classified disease progression into more severe stages. Longitudinal analysis revealed that although the microbiome exhibited complex and changing patterns during COVID-19, a restoration of URT microbiomes from early dysbiosis toward more diverse status in later disease stages was observed in most patients. In addition, a group of potential pathobionts were strongly associated with the concentration of inflammatory indicators and mortality. CONCLUSION: This study revealed strong links between URT microbiome dynamics and disease progression and clinical outcomes in COVID-19, implying that the treatment of severe disease should consider the full spectrum of microbial pathogens present.
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COVID-19 , Microbiota , Humanos , SARS-CoV-2 , Nariz , Progressão da DoençaRESUMO
Mosquito transmitted viruses are responsible for an increasing burden of human disease. Despite this, little is known about the diversity and ecology of viruses within individual mosquito hosts. Using a meta-transcriptomic approach, we analysed the virome of 2,438 individual mosquitos (79 species), spanning ~4000 km along latitudes and longitudes in China. From these data we identified 393 core viral species associated with mosquitos, including seven (putative) arbovirus species. We identified potential species and geographic hotspots of viral richness and arbovirus occurrence, and demonstrated that host phylogeny had a strong impact on the composition of individual mosquito viromes. Our data revealed a large number of viruses shared among mosquito species or genera, expanding our knowledge of host specificity of insect-associated viruses. We also detected multiple virus species that were widespread throughout the country, possibly facilitated by long-distance mosquito migrations. Together, our results greatly expand the known mosquito virome, linked the viral diversity at the scale of individual insects to that at a country-wide scale, and offered unique insights into the ecology of viruses of insect vectors.
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Bats are reservoir hosts for many zoonotic viruses. Despite this, relatively little is known about the diversity and abundance of viruses within individual bats, and hence the frequency of virus co-infection and spillover among them. We characterize the mammal-associated viruses in 149 individual bats sampled from Yunnan province, China, using an unbiased meta-transcriptomics approach. This reveals a high frequency of virus co-infection (simultaneous infection of bat individuals by multiple viral species) and spillover among the animals studied, which may in turn facilitate virus recombination and reassortment. Of note, we identify five viral species that are likely to be pathogenic to humans or livestock, based on phylogenetic relatedness to known pathogens or in vitro receptor binding assays. This includes a novel recombinant SARS-like coronavirus that is closely related to both SARS-CoV and SARS-CoV-2. In vitro assays indicate that this recombinant virus can utilize the human ACE2 receptor such that it is likely to be of increased emergence risk. Our study highlights the common occurrence of co-infection and spillover of bat viruses and their implications for virus emergence.
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COVID-19 , Quirópteros , Coinfecção , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave , Animais , Humanos , Filogenia , SARS-CoV-2 , Viroma , China/epidemiologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/genéticaRESUMO
Cats harbor many important viral pathogens, and the knowledge of their diversity has been greatly expanded thanks to increasingly popular molecular sequencing techniques. While the diversity is mostly described in numerous regionally defined studies, there lacks a global overview of the diversity for the majority of cat viruses, and therefore our understanding of the evolution and epidemiology of these viruses was generally inadequate. In this study, we analyzed 12,377 genetic sequences from 25 cat virus species and conducted comprehensive phylodynamic analyses. It revealed, for the first time, the global diversity for all cat viruses known to date, taking into account highly virulent strains and vaccine strains. From there, we further characterized and compared the geographic expansion patterns, temporal dynamics and recombination frequencies of these viruses. While respiratory pathogens such as feline calicivirus showed some degree of geographical panmixes, the other viral species are more geographically defined. Furthermore, recombination rates were much higher in feline parvovirus, feline coronavirus, feline calicivirus and feline foamy virus than the other feline virus species. Collectively, our findings deepen the understanding of the evolutionary and epidemiological features of cat viruses, which in turn provide important insight into the prevention and control of cat pathogens.
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Calicivirus Felino , Doenças do Gato , Animais , Gatos , Calicivirus Felino/genética , Doenças do Gato/epidemiologia , Vírus da Panleucopenia Felina , Variação GenéticaRESUMO
Bats are reservoir hosts for many zoonotic viruses. Despite this, relatively little is known about the diversity and abundance of viruses within bats at the level of individual animals, and hence the frequency of virus co-infection and inter-species transmission. Using an unbiased meta-transcriptomics approach we characterised the mammalian associated viruses present in 149 individual bats sampled from Yunnan province, China. This revealed a high frequency of virus co-infection and species spillover among the animals studied, with 12 viruses shared among different bat species, which in turn facilitates virus recombination and reassortment. Of note, we identified five viral species that are likely to be pathogenic to humans or livestock, including a novel recombinant SARS-like coronavirus that is closely related to both SARS-CoV-2 and SARS-CoV, with only five amino acid differences between its receptor-binding domain sequence and that of the earliest sequences of SARS-CoV-2. Functional analysis predicts that this recombinant coronavirus can utilize the human ACE2 receptor such that it is likely to be of high zoonotic risk. Our study highlights the common occurrence of inter-species transmission and co-infection of bat viruses, as well as their implications for virus emergence.
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Pangolins are the most trafficked wild animal in the world according to the World Wildlife Fund. The discovery of SARS-CoV-2-related coronaviruses in Malayan pangolins has piqued interest in the viromes of these wild, scaly-skinned mammals. We sequenced the viromes of 161 pangolins that were smuggled into China and assembled 28 vertebrate-associated viruses, 21 of which have not been previously reported in vertebrates. We named 16 members of Hunnivirus, Pestivirus and Copiparvovirus pangolin-associated viruses. We report that the L-protein has been lost from all hunniviruses identified in pangolins. Sequences of four human-associated viruses were detected in pangolin viromes, including respiratory syncytial virus, Orthopneumovirus, Rotavirus A and Mammalian orthoreovirus. The genomic sequences of five mammal-associated and three tick-associated viruses were also present. Notably, a coronavirus related to HKU4-CoV, which was originally found in bats, was identified. The presence of these viruses in smuggled pangolins identifies these mammals as a potential source of emergent pathogenic viruses.
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COVID-19 , Quirópteros , Animais , Humanos , Mamíferos , Pangolins , SARS-CoV-2/genéticaRESUMO
BACKGROUND: COVID-19 is an ongoing global pandemic caused by SARS-CoV-2. As of June 2021, 5 emergency vaccines were available for COVID-19 prevention, and with the improvement of vaccination rates and the resumption of activities in each country, verification of vaccination has become an important issue. Currently, in most areas, vaccination and reverse transcription polymerase chain reaction (RT-PCR) test results are certified and validated on paper. This leads to the problem of counterfeit documents. Therefore, a global vaccination record is needed. OBJECTIVE: The main objective of this study is to design a vaccine passport (VP) validation system based on a general blockchain architecture for international use in a simulated environment. With decentralized characteristics, the system is expected to have the advantages of low cost, high interoperability, effectiveness, security, and verifiability through blockchain architecture. METHODS: The blockchain decentralized mechanism was used to build an open and anticounterfeiting information platform for VPs. The contents of a vaccination card are recorded according to international Fast Healthcare Interoperability Resource (FHIR) standards, and blockchain smart contracts (SCs) are used for authorization and authentication to achieve hierarchical management of various international hospitals and people receiving injections. The blockchain stores an encrypted vaccination path managed by the user who manages the private key. The blockchain uses the proof-of-authority (PoA) public chain and can access all information through the specified chain. This will achieve the goal of keeping development costs low and streamlining vaccine transit management so that countries in different economies can use them. RESULTS: The openness of the blockchain helps to create transparency and data accuracy. This blockchain architecture contains a total of 3 entities. All approvals are published on Open Ledger. Smart certificates enable authorization and authentication, and encryption and decryption mechanisms guarantee data protection. This proof of concept demonstrates the design of blockchain architecture, which can achieve accurate global VP verification at an affordable price. In this study, an actual VP case was established and demonstrated. An open blockchain, an individually approved certification mechanism, and an international standard vaccination record were introduced. CONCLUSIONS: Blockchain architecture can be used to build a viable international VP authentication process with the advantages of low cost, high interoperability, effectiveness, security, and verifiability.
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Blockchain , COVID-19 , Vacinas , COVID-19/epidemiologia , COVID-19/prevenção & controle , Segurança Computacional , Humanos , SARS-CoV-2RESUMO
The p53 family has the following three members: p53, p63 and p73. p53 is a tumor suppressor gene that frequently exhibits mutation in head and neck cancer. Most p53 mutants are loss-of-function (LoF) mutants, but some acquire some oncogenic function, such as gain of function (GoF). It is known that the aggregation of mutant p53 can induce p53 GoF. The p73 activators RETRA and NSC59984 have an anti-cancer effect in p53 mutation cells, but we found that p73 activators were not effective in all head and neck squamous cell carcinoma (HNSCC) cell lines, with different p53 mutants. A comparison of the gene expression profiles of several regulator(s) in mutant HNSCC cells with or without aggregation of p53 revealed that nicotinamide phosphoribosyltransferase (NAMPT) is a key regulator of mutant p53 aggregation. An NAMPT inhibitor, to reduce abnormal aggregation of mutant p53, used in combination with a p73 activator, was able to effectively repress growth in HNSCC cells with p53 GoF mutants. This study, therefore, suggests a potential combination therapy approach for HNSCC with a p53 GoF mutation.
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Neoplasias de Cabeça e Pescoço , Proteína Supressora de Tumor p53 , Proliferação de Células , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/genética , Humanos , Nicotinamida Fosforribosiltransferase/genética , Nicotinamida Fosforribosiltransferase/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Proteína Tumoral p73/genética , Proteína Tumoral p73/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Although metagenomic sequencing has revealed high numbers of viruses in mosquitoes sampled globally, our understanding of how their diversity and abundance varies in time and space as well as by host species and gender remains unclear. To address this, we collected 23,109 mosquitoes over the course of 12 months from a bat-dwelling cave and a nearby village in Yunnan province, China. These samples were organized by mosquito species, mosquito gender, and sampling time for meta-transcriptomic sequencing. A total of 162 eukaryotic virus species were identified, of which 101 were novel, including representatives of seventeen RNA virus multi-family supergroups and four species of DNA virus from the families Parvoviridae, Circoviridae, and Nudiviridae. In addition, two known vector-borne viruses-Japanese encephalitis virus and Banna virus-were found. Analyses of the entire virome revealed strikingly different viral compositions and abundance levels in warmer compared to colder months, a strong host structure at the level of mosquito species, and no substantial differences between those viruses harbored by male and female mosquitoes. At the scale of individual viruses, some were found to be ubiquitous throughout the year and across four mosquito species, while most of the other viruses were season and/or host specific. Collectively, this study reveals the diversity, dynamics, and evolution of the mosquito virome at a single location and sheds new lights on the ecology of these important vector animals.
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At the end of 2019 Wuhan witnessed an outbreak of "atypical pneumonia" that later developed into a global pandemic. Metagenomic sequencing rapidly revealed the causative agent of this outbreak to be a novel coronavirus denoted SARS-CoV-2. To provide a snapshot of the pathogens in pneumonia-associated respiratory samples from Wuhan prior to the emergence of SARS-CoV-2, we collected bronchoalveolar lavage fluid samples from 408 patients presenting with pneumonia and acute respiratory infections at the Central Hospital of Wuhan between 2016 and 2017. Unbiased total RNA sequencing was performed to reveal their "total infectome", including viruses, bacteria and fungi. We identified 35 pathogen species, comprising 13 RNA viruses, 3 DNA viruses, 16 bacteria and 3 fungi, often at high abundance and including multiple co-infections (13.5%). SARS-CoV-2 was not present. These data depict a stable core infectome comprising common respiratory pathogens such as rhinoviruses and influenza viruses, an atypical respiratory virus (EV-D68), and a single case of a sporadic zoonotic pathogen-Chlamydia psittaci. Samples from patients experiencing respiratory disease on average had higher pathogen abundance than healthy controls. Phylogenetic analyses of individual pathogens revealed multiple origins and global transmission histories, highlighting the connectedness of the Wuhan population. This study provides a comprehensive overview of the pathogens associated with acute respiratory infections and pneumonia, which were more diverse and complex than obtained using targeted PCR or qPCR approaches. These data also suggest that SARS-CoV-2 or closely related viruses were absent from Wuhan in 2016-2017.
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COVID-19/epidemiologia , Surtos de Doenças , Pneumonia/epidemiologia , Infecções Respiratórias/epidemiologia , SARS-CoV-2/isolamento & purificação , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Líquido da Lavagem Broncoalveolar/microbiologia , COVID-19/virologia , China/epidemiologia , Estudos de Coortes , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Metagenômica , Pessoa de Meia-Idade , Filogenia , Pneumonia/microbiologia , Infecções Respiratórias/microbiologia , Adulto JovemRESUMO
In a previous study, a metatranscriptomics survey of RNA viruses in several important lower vertebrate host groups revealed huge viral diversity, transforming the understanding of the evolution of vertebrate-associated RNA virus groups. However, the diversity of the DNA and retro-transcribing viruses in these host groups was left uncharacterized. Given that RNA sequencing is capable of revealing viruses undergoing active transcription and replication, we collected previously generated datasets associated with lower vertebrate hosts, and searched them for DNA and retro-transcribing viruses. Our results revealed the complete genome, or "core gene sets", of 18 vertebrate-associated DNA and retro-transcribing viruses in cartilaginous fishes, ray-finned fishes, and amphibians, many of which had high abundance levels, and some of which showed systemic infections in multiple organs, suggesting active transcription or acute infection within the host. Furthermore, these new findings recharacterized the evolutionary history in the families Hepadnaviridae, Papillomaviridae, and Alloherpesviridae, confirming long-term virus-host codivergence relationships for these virus groups. Collectively, our results revealed reliable and sufficient information within metatranscriptomics sequencing to characterize not only RNA viruses, but also DNA and retro-transcribing viruses, and therefore established a key methodology that will help us to understand the composition and evolution of the total "infectome" within a diverse range of vertebrate hosts.
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Replicação do DNA , Vírus de DNA/genética , Vírus de RNA/genética , Transcrição Reversa , Vertebrados/virologia , Animais , Biologia Computacional , Vírus de DNA/classificação , Evolução Molecular , Perfilação da Expressão Gênica , Regulação Viral da Expressão Gênica , Genoma Viral , Sequenciamento de Nucleotídeos em Larga Escala , Interações Hospedeiro-Patógeno , Metagenoma , Metagenômica/métodos , Filogenia , Vírus de RNA/classificação , Retroviridae/classificação , Retroviridae/genética , Análise de Sequência de RNA , TranscriptomaRESUMO
SARS-CoV-2 causes the pandemic of COVID-19 and no effective drugs for this disease are available thus far. Due to the high infectivity and pathogenicity of this virus, all studies on the live virus are strictly confined in the biosafety level 3 (BSL3) laboratory but this would hinder the basic research and antiviral drug development of SARS-CoV-2 because the BSL3 facility is not commonly available and the work in the containment is costly and laborious. In this study, we constructed a reverse genetics system of SARS-CoV-2 by assembling the viral cDNA in a bacterial artificial chromosome (BAC) vector with deletion of the spike (S) gene. Transfection of the cDNA into cells results in the production of an RNA replicon that keeps the capability of genome or subgenome replication but is deficient in virion assembly and infection due to the absence of S protein. Therefore, such a replicon system is not infectious and can be used in ordinary biological laboratories. We confirmed the efficient replication of the replicon by demonstrating the expression of the subgenomic RNAs which have similar profiles to the wild-type virus. By mutational analysis of nsp12 and nsp14, we showed that the RNA polymerase, exonuclease, and cap N7 methyltransferase play essential roles in genome replication and sgRNA production. We also created a SARS-CoV-2 replicon carrying a luciferase reporter gene and this system was validated by the inhibition assays with known anti-SARS-CoV-2 inhibitors. Thus, such a one-plasmid system is biosafe and convenient to use, which will benefit both fundamental research and development of antiviral drugs.
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Antivirais , COVID-19 , Antivirais/farmacologia , Contenção de Riscos Biológicos , Humanos , Replicon , SARS-CoV-2 , Replicação ViralRESUMO
Despite a substantial increase in our knowledge of the biodiversity and evolution of vertebrate RNA viruses, far less is known about the diversity, evolution and origin of RNA viruses across the diverse phylogenetic range of viruses, and particularly in healthy animals that are often only rarely utilized for virological sampling. Fortunately, recent advances in virus discovery using metagenomic approaches are beginning to reveal a multitude of RNA viruses in vertebrates other than birds and mammals. In particular, fish harbor a remarkable array of RNA viruses, including the relatives of important pathogens. In addition, despite frequent cross-species transmission, the RNA viruses in vertebrates generally follow the evolutionary history of their hosts, which began in the oceans and then moved to terrestrial habitats over timescales covering hundreds of millions of years.
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Evolução Biológica , Variação Genética , Interações entre Hospedeiro e Microrganismos , Vírus de RNA/genética , Vertebrados/virologia , Animais , Biodiversidade , Aves/virologia , Peixes/virologia , Genoma Viral , Humanos , FilogeniaRESUMO
Anisotropically-shaped metal nanoparticles act as nanoscale heaters via excitation of a localized surface plasmon resonance, utilizing a photothermal effect which converts the optical energy into local heat. Steady-state temperatures within a polymer matrix embedded with gold nanorods undergoing photothermal heating using continuous-wave excitation are measured in the immediate spatial vicinity of the nanoparticle (referred to as the local temperature) from observing the rate of physical rotation of the asymmetric nanoparticles within the locally created polymer melt. Average temperatures across the entire (mostly solid) sample (referred to as the global temperature) are simultaneously observed using a fluorescence method from randomly dispersed molecular emitters. Comparing these two independent measurements in films having varying concentrations of nanorods reveals the interplay between the local and global temperatures, clearly demonstrating the capability of these material samples to sustain large steady-state spatial temperature gradients when experiencing continuous-wave excitation photothermal heating. These results are discussed quantitatively. Illustrative imaging studies of nanofibers under photothermal heating also support the presence of a large temperature gradient. Photothermal heating in this manner has potential utility in creating unique thermal processing conditions for outcomes such as driving chemical reactions, inducing crystallinity changes, or enhancing degradation processes in a manner unachievable by conventional heating methods.
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Gold nanorods (GNRs) overcoated with SiO2 are of interest for enhancing the shape stability of GNRs during photo-thermal heating, for further functionalization with silanes, and for biomedical applications. While methods have recently been developed for synthesizing GNRs on a large scale, SiO2 overcoating of GNRs is still conducted on a small reaction scale. Here, we report a method for large-scale synthesis of SiO2-overcoated GNRs (SiO2-GNRs), which gives ~190 mg of SiO2-GNRs. SiO2 is deposited onto and encapsulates the cetyltrimethylammonium bromide (CTAB) coatings that stabilize GNRs by adding tetraethoxysilane (TEOS) via syringe pump. Control over the CTAB concentration is critically important for obtaining uniform overcoatings. Optical absorbance spectra of SiO2-GNRs closely resemble uncoated GNRs, which indicates overcoating of single rather than multiple GNRs and confirms that they remain well dispersed. By adjusting the reaction conditions, shells as thick as ~20 nm can be obtained. For thin shells (< 10 nm), addition of poly(ethylene glycol) silane (PEG-silane) at different times during the overcoating reaction allows facile control over the shell thickness, giving shells as thin as ~2 nm. The bulky PEG chain terminates further crosslinking and deposition of SiO2.
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ZnS quantum dots were synthetized at room temperature using a simple photochemical process involving ketyl radicals. Through the simple adjustment of reagent concentration, the method allows the control of nanoparticle size. Transmission electron microscopy confirmed that the nanomaterial adopts the hexagonal structure.