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1.
Cell ; 2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35777355

RESUMO

The host-seeking activity of hematophagous arthropods is essential for arboviral transmission. Here, we demonstrate that mosquito-transmitted flaviviruses can manipulate host skin microbiota to produce a scent that attracts mosquitoes. We observed that Aedes mosquitoes preferred to seek and feed on mice infected by dengue and Zika viruses. Acetophenone, a volatile compound that is predominantly produced by the skin microbiota, was enriched in the volatiles from the infected hosts to potently stimulate mosquito olfaction for attractiveness. Of note, acetophenone emission was higher in dengue patients than in healthy people. Mechanistically, flaviviruses infection suppressed the expression of RELMα, an essential antimicrobial protein on host skin, thereby leading to the expansion of acetophenone-producing commensal bacteria and, consequently, a high acetophenone level. Given that RELMα can be specifically induced by a vitamin A derivative, the dietary administration of isotretinoin to flavivirus-infected animals interrupted flavivirus life cycle by reducing mosquito host-seeking activity, thus providing a strategy of arboviral control.

2.
Nat Immunol ; 19(4): 342-353, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29507355

RESUMO

Pathogens have co-evolved with mosquitoes to optimize transmission to hosts. Mosquito salivary-gland extract is known to modulate host immune responses and facilitate pathogen transmission, but the underlying molecular mechanisms of this have remained unknown. In this study, we identified and characterized a prominent 15-kilodalton protein, LTRIN, obtained from the salivary glands of the mosquito Aedes aegypti. LTRIN expression was upregulated in blood-fed mosquitoes, and LTRIN facilitated the transmission of Zika virus (ZIKV) and exacerbated its pathogenicity by interfering with signaling through the lymphotoxin-ß receptor (LTßR). Mechanically, LTRIN bound to LTßR and 'preferentially' inhibited signaling via the transcription factor NF-κB and the production of inflammatory cytokines by interfering with the dimerization of LTßR during infection with ZIKV. Furthermore, treatment with antibody to LTRIN inhibited mosquito-mediated infection with ZIKV, and abolishing LTßR potentiated the infectivity of ZIKV both in vitro and in vivo. This study provides deeper insight into the transmission of mosquito-borne diseases in nature and supports the therapeutic potential of inhibiting the action of LTRIN to disrupt ZIKV transmission.


Assuntos
Aedes/virologia , Proteínas de Insetos/metabolismo , Saliva/metabolismo , Infecção por Zika virus/transmissão , Zika virus/patogenicidade , Animais , Humanos , Receptor beta de Linfotoxina/imunologia , Receptor beta de Linfotoxina/metabolismo , Camundongos , Mosquitos Vetores/química , Mosquitos Vetores/imunologia , Mosquitos Vetores/metabolismo , Saliva/química
3.
EMBO J ; 43(9): 1690-1721, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38378891

RESUMO

Mosquitoes transmit many disease-relevant flaviviruses. Efficient viral transmission to mammalian hosts requires mosquito salivary factors. However, the specific salivary components facilitating viral transmission and their mechanisms of action remain largely unknown. Here, we show that a female mosquito salivary gland-specific protein, here named A. aegypti Neutrophil Recruitment Protein (AaNRP), facilitates the transmission of Zika and dengue viruses. AaNRP promotes a rapid influx of neutrophils, followed by virus-susceptible myeloid cells toward mosquito bite sites, which facilitates establishment of local infection and systemic dissemination. Mechanistically, AaNRP engages TLR1 and TLR4 of skin-resident macrophages and activates MyD88-dependent NF-κB signaling to induce the expression of neutrophil chemoattractants. Inhibition of MyD88-NF-κB signaling with the dietary phytochemical resveratrol reduces AaNRP-mediated enhancement of flavivirus transmission by mosquitoes. These findings exemplify how salivary components can aid viral transmission, and suggest a potential prophylactic target.


Assuntos
Aedes , Zika virus , Animais , Aedes/virologia , Aedes/metabolismo , Feminino , Zika virus/fisiologia , Camundongos , Vírus da Dengue/fisiologia , Proteínas e Peptídeos Salivares/metabolismo , Mosquitos Vetores/virologia , Proteínas de Insetos/metabolismo , Células Mieloides/virologia , Células Mieloides/metabolismo , Infecção por Zika virus/transmissão , Infecção por Zika virus/virologia , Infecção por Zika virus/metabolismo , Dengue/transmissão , Dengue/virologia , Dengue/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais , Fator 88 de Diferenciação Mieloide/metabolismo , Fator 88 de Diferenciação Mieloide/genética
4.
Proc Natl Acad Sci U S A ; 121(16): e2317978121, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38593069

RESUMO

Mosquito-borne flaviviruses such as dengue (DENV) and Zika (ZIKV) cause hundreds of millions of infections annually. The single-stranded RNA genome of flaviviruses is translated into a polyprotein, which is cleaved equally into individual functional proteins. While structural proteins are packaged into progeny virions and released, most of the nonstructural proteins remain intracellular and could become cytotoxic if accumulated over time. However, the mechanism by which nonstructural proteins are maintained at the levels optimal for cellular fitness and viral replication remains unknown. Here, we identified that the ubiquitin E3 ligase HRD1 is essential for flaviviruses infections in both mammalian hosts and mosquitoes. HRD1 directly interacts with flavivirus NS4A and ubiquitylates a conserved lysine residue for ER-associated degradation. This mechanism avoids excessive accumulation of NS4A, which otherwise interrupts the expression of processed flavivirus proteins in the ER. Furthermore, a small-molecule inhibitor of HRD1 named LS-102 effectively interrupts DENV2 infection in both mice and Aedes aegypti mosquitoes, and significantly disturbs DENV transmission from the infected hosts to mosquitoes owing to reduced viremia. Taken together, this study demonstrates that flaviviruses have evolved a sophisticated mechanism to exploit the ubiquitination system to balance the homeostasis of viral proteins for their own advantage and provides a potential therapeutic target to interrupt flavivirus infection and transmission.


Assuntos
Aedes , Infecções por Flavivirus , Flavivirus , Infecção por Zika virus , Zika virus , Animais , Camundongos , Flavivirus/genética , Zika virus/genética , Ubiquitina/metabolismo , Ligases/metabolismo , Proteínas Virais/metabolismo , Mamíferos
5.
EMBO Rep ; 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39048750

RESUMO

Viruses have developed various strategies to ensure their survival and transmission. One intriguing strategy involves manipulating the behavior of infected arthropod vectors and hosts. Through intricate interactions, viruses can modify vector behavior, aiding in crossing barriers and improving transmission to new hosts. This manipulation may include altering vector feeding preferences, thus promoting virus transmission to susceptible individuals. In addition, viruses employ diverse dissemination methods, including cell-to-cell and intercellular transmission via extracellular vesicles. These strategies allow viruses to establish themselves in favorable environments, optimize replication, and increase the likelihood of spreading to other individuals. Understanding these complex viral strategies offers valuable insights into their biology, transmission dynamics, and potential interventions for controlling infections. Unraveling interactions between viruses, hosts, and vectors enables the development of targeted approaches to effectively mitigate viral diseases and prevent transmission.

6.
J Virol ; 98(5): e0157323, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38572974

RESUMO

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and characterized by dysregulated immune response. Studies have shown that the SARS-CoV-2 accessory protein ORF7b induces host cell apoptosis through the tumor necrosis factor alpha (TNF-α) pathway and blocks the production of interferon beta (IFN-ß). The underlying mechanism remains to be investigated. In this study, we found that ORF7b facilitated viral infection and production, and inhibited the RIG-I-like receptor (RLR) signaling pathway through selectively interacting with mitochondrial antiviral-signaling protein (MAVS). MAVS439-466 region and MAVS Lys461 were essential for the physical association between MAVS and ORF7b, and the inhibition of the RLR signaling pathway by ORF7b. MAVSK461/K63 ubiquitination was essential for the RLR signaling regulated by the MAVS-ORF7b complex. ORF7b interfered with the recruitment of tumor necrosis factor receptor-related factor 6 (TRAF6) and the activation of the RLR signaling pathway by MAVS. Furthermore, interfering peptides targeting the ORF7b complex reversed the ORF7b-suppressed MAVS-RLR signaling pathway. The most potent interfering peptide V disrupts the formation of ORF7b tetramers, reverses the levels of the ORF7b-inhibited physical association between MAVS and TRAF6, leading to the suppression of viral growth and infection. Overall, this study provides a mechanism for the suppression of innate immunity by SARS-CoV-2 infection and the mechanism-based approach via interfering peptides to potentially prevent SARS-CoV-2 infection.IMPORTANCEThe pandemic coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and continues to be a threat to public health. It is imperative to understand the biology of SARS-CoV-2 infection and find approaches to prevent SARS-CoV-2 infection and ameliorate COVID-19. Multiple SARS-CoV-2 proteins are known to function on the innate immune response, but the underlying mechanism remains unknown. This study shows that ORF7b inhibits the RIG-I-like receptor (RLR) signaling pathway through the physical association between ORF7b and mitochondrial antiviral-signaling protein (MAVS), impairing the K63-linked MAVS polyubiquitination and its recruitment of tumor necrosis factor receptor-related factor 6 (TRAF6) to MAVS. The most potent interfering peptide V targeting the ORF7b-MAVS complex may reverse the suppression of the MAVS-mediated RLR signaling pathway by ORF7b and prevent viral infection and production. This study may provide new insights into the pathogenic mechanism of SARS-CoV-2 and a strategy to develop new drugs to prevent SARS-CoV-2 infection.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , COVID-19 , SARS-CoV-2 , Transdução de Sinais , Animais , Humanos , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Apoptose , COVID-19/virologia , COVID-19/imunologia , COVID-19/metabolismo , Proteína DEAD-box 58/metabolismo , Células HEK293 , Imunidade Inata , Interferon beta/metabolismo , Receptores Imunológicos/metabolismo , SARS-CoV-2/imunologia , SARS-CoV-2/metabolismo , Fator 6 Associado a Receptor de TNF/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Ubiquitinação , Proteínas Virais Reguladoras e Acessórias/metabolismo , Proteínas Virais Reguladoras e Acessórias/genética
7.
Cell ; 142(5): 714-25, 2010 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-20797779

RESUMO

West Nile virus (WNV) is the most common arthropod-borne flavivirus in the United States; however, the vector ligand(s) that participate in infection are not known. We now show that an Aedes aegypti C-type lectin, mosGCTL-1, is induced by WNV, interacts with WNV in a calcium-dependent manner, and facilitates infection in vivo and in vitro. A mosquito homolog of human CD45 in A. aegypti, designated mosPTP-1, recruits mosGCTL-1 to enable viral attachment to cells and to enhance viral entry. In vivo experiments show that mosGCTL-1 and mosPTP-1 function as part of the same pathway and are critical for WNV infection of mosquitoes. A similar phenomenon was also observed in Culex quinquefasciatus, a natural vector of WNV, further demonstrating that these genes participate in WNV infection. During the mosquito blood-feeding process, WNV infection was blocked in vivo with mosGCTL-1 antibodies. A molecular understanding of flaviviral-arthropod interactions may lead to strategies to control viral dissemination in nature.


Assuntos
Aedes/virologia , Culex/virologia , Proteínas de Insetos/metabolismo , Lectinas Tipo C/metabolismo , Antígenos Comuns de Leucócito/metabolismo , Internalização do Vírus , Vírus do Nilo Ocidental/fisiologia , Animais , Humanos , Antígenos Comuns de Leucócito/química
8.
Genomics ; 116(2): 110817, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38431031

RESUMO

Perilipin-2 (PLIN2) can anchor to lipid droplets (LDs) and play a crucial role in regulating nascent LDs formation. Bimolecular fluorescence complementation (BiFC) and flow cytometry were examined to verify the PLIN2-CGI-58 interaction efficiency in bovine adipocytes. GST-Pulldown assay was used to detect the key site arginine315 function in PLIN2-CGI-58 interaction. Experiments were also examined to research these mutations function of PLIN2 in LDs formation during adipocytes differentiation, LDs were measured after staining by BODIPY, lipogenesis-related genes were also detected. Results showed that Leucine (L371A, L311A) and glycine (G369A, G376A) mutations reduced interaction efficiencies. Serine (S367A) mutations enhanced the interaction efficiency. Arginine (R315A) mutations resulted in loss of fluorescence in the cytoplasm and disrupted the interaction with CGI-58, as verified by pulldown assay. R315W mutations resulted in a significant increase in the number of LDs compared with wild-type (WT) PLIN2 or the R315A mutations. Lipogenesis-related genes were either up- or downregulated when mutated PLIN2 interacted with CGI-58. Arginine315 in PLIN2 is required for the PLIN2-CGI-58 interface and could regulate nascent LD formation and lipogenesis. This study is the first to study amino acids on the PLIN2 interface during interaction with CGI-58 in bovine and highlight the role played by PLIN2 in the regulation of bovine adipocyte lipogenesis.


Assuntos
Arginina , Gotículas Lipídicas , Animais , Bovinos , Perilipina-2/genética , Perilipina-2/química , Perilipina-2/metabolismo , Arginina/genética , Arginina/metabolismo , Gotículas Lipídicas/metabolismo , Mutação , Adipócitos/metabolismo , Metabolismo dos Lipídeos
9.
Nano Lett ; 24(26): 8098-8106, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38913786

RESUMO

The development of multifunctional MXene-based fabrics for smart textiles and portable devices has garnered significant attention. However, very limited studies have focused on their structure design and associated mechanical properties. Here, the supertough MXene fiber felts composed of MXene/sodium alginate (SA) fibers were fabricated. The fracture strength and bending stiffness of felts can be up to 97.8 MPa and 1.04 N mm2, respectively. Besides, the fracture toughness of felts was evaluated using the classic Griffith theory, yielding to a critical stress intensity factor of 1.79 MPam. In addition, this kind of felt presents outstanding electrothermal conversion performance (up to 119 °C at a voltage of 2.5 V), high cryogenic and high-temperature tolerance of photothermal conversion performance (-196 to 160 °C), and excellent electromagnetic interference (EMI) shielding effectiveness (54.4 dB in the X-band). This work provides new structural design concepts for high-performance MXene-based textiles, broadening their future applications.

10.
Nano Lett ; 24(14): 4248-4255, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38557042

RESUMO

Grain boundaries (GBs) in two-dimensional (2D) covalent organic frameworks (COFs) unavoidably form during the fabrication process, playing pivotal roles in the physical characteristics of COFs. Herein, molecular dynamics simulations were employed to elucidate the fracture failure and thermal transport mechanisms of polycrystalline COFs (p-COFs). The results revealed that the tilt angle of GBs significantly influences out-of-plane wrinkles and residual stress in monolayer p-COFs. The tensile strength of p-COFs can be enhanced and weakened with the tilt angle, which exhibits an inverse relationship with the defect density. The crack always originates from weaker heptagon rings during uniaxial tension. Notably, the thermal transport in p-COFs is insensitive to the GBs due to the variation of minor polymer chain length at defects, which is abnormal for other 2D crystalline materials. This study contributes insights into the impact of GBs in p-COFs and offers theoretical guidance for structural design and practical applications of advanced COFs.

11.
BMC Genomics ; 25(1): 558, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38834950

RESUMO

BACKGROUND: Indigenous Chinese cattle have abundant genetic diversity and a long history of artificial selection, giving local breeds advantages in adaptability, forage tolerance and resistance. The detection of selective sweeps and comparative genome analysis of selected breeds and ancestral populations provide a basis for understanding differences among breeds and for the identification and utilization of candidate genes. We investigated genetic diversity, population structure, and signatures of selection using genome-wide sequencing data for a new breed of Qinchuan cattle (QNC, n = 21), ancestral Qinchuan cattle (QCC, n = 20), and Zaosheng cattle (ZSC, n = 19). RESULTS: A population structure analysis showed that the ancestry components of QNC and ZSC were similar. In addition, the QNC and ZSC groups showed higher proportions of European taurine ancestry than that of QCC, and this may explain the larger body size of QNC, approaching that of European cattle under long-term domestication and selection. A neighbor-joining tree revealed that QCC individuals were closely related, whereas QNC formed a distinct group. To search for signatures of selection in the QNC genome, we evaluated nucleotide diversity (θπ), the fixation index (FST) and Tajima's D. Overlapping selective sweeps were enriched for one KEGG pathway, the apelin signaling pathway, and included five candidate genes (MEF2A, SMAD2, CAMK4, RPS6, and PIK3CG). We performed a comprehensive review of genomic variants in QNC, QCC, and ZSC using whole-genome sequencing data. QCC was rich in novel genetic diversity, while diversity in QNC and ZSC cattle was reduced due to strong artificial selection, with divergence from the original cattle. CONCLUSIONS: We identified candidate genes associated with production traits. These results support the success of selective breeding and can guide further breeding and resource conservation of Qinchuan cattle.


Assuntos
Variação Genética , Seleção Genética , Animais , Bovinos/genética , Genômica/métodos , Polimorfismo de Nucleotídeo Único , Genética Populacional , Estudo de Associação Genômica Ampla , Genoma , Cruzamento
12.
Small ; : e2401635, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38607950

RESUMO

Vapor-driven smart Janus materials have made significant advancements in intelligent monitoring, control, and interaction, etc. Nevertheless, the development of ultrafast response single-layer Janus membrane, along with a deep exploration of the smart response mechanisms, remains a long-term endeavor. Here, the successful synthesis of a high-crystallinity single-layer Covalent organic framework (COF) Janus membrane is reported by morphology control. This kind of membrane displays superior mechanical properties and specific surface area, along with excellent responsiveness to CH2Cl2 vapor. The analysis of the underlying mechanisms reveals that the vapor-induced breathing effect of the COF and the stress mismatch of the Janus structure play a crucial role in its smart deformation performance. It is believed that this COF Janus membrane holds promise for complex tasks in various fields.

13.
J Transl Med ; 22(1): 366, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38632662

RESUMO

BACKGROUND: Early-onset prostate cancer (EOPC, ≤ 55 years) has a unique clinical entity harboring high genetic risk, but the majority of EOPC patients still substantial opportunity to be early-detected thus suffering an unfavorable prognosis. A refined understanding of age-based polygenic risk score (PRS) for prostate cancer (PCa) would be essential for personalized risk stratification. METHODS: We included 167,517 male participants [4882 cases including 205 EOPC and 4677 late-onset PCa (LOPC)] from UK Biobank. A General-, an EOPC- and an LOPC-PRS were derived from age-specific genome-wide association studies. Weighted Cox proportional hazard models were applied to estimate the risk of PCa associated with PRSs. The discriminatory capability of PRSs were validated using time-dependent receiver operating characteristic (ROC) curves with additional 4238 males from PLCO and TCGA. Phenome-wide association studies underlying Mendelian Randomization were conducted to discover EOPC linking phenotypes. RESULTS: The 269-PRS calculated via well-established risk variants was more strongly associated with risk of EOPC [hazard ratio (HR) = 2.35, 95% confidence interval (CI) 1.99-2.78] than LOPC (HR = 1.95, 95% CI 1.89-2.01; I2 = 79%). EOPC-PRS was dramatically related to EOPC risk (HR = 4.70, 95% CI 3.98-5.54) but not to LOPC (HR = 0.98, 95% CI 0.96-1.01), while LOPC-PRS had similar risk estimates for EOPC and LOPC (I2 = 0%). Particularly, EOPC-PRS performed optimal discriminatory capability for EOPC (area under the ROC = 0.613). Among the phenomic factors to PCa deposited in the platform of ProAP (Prostate cancer Age-based PheWAS; https://mulongdu.shinyapps.io/proap ), EOPC was preferentially associated with PCa family history while LOPC was prone to environmental and lifestyles exposures. CONCLUSIONS: This study comprehensively profiled the distinct genetic and phenotypic architecture of EOPC. The EOPC-PRS may optimize risk estimate of PCa in young males, particularly those without family history, thus providing guidance for precision population stratification.


Assuntos
Estratificação de Risco Genético , Neoplasias da Próstata , Humanos , Masculino , Estudo de Associação Genômica Ampla , Estudos de Coortes , Fatores de Risco , Predisposição Genética para Doença
14.
PLoS Pathog ; 18(6): e1010552, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35679229

RESUMO

Arboviruses are etiological agents of various severe human diseases that place a tremendous burden on global public health and the economy; compounding this issue is the fact that effective prophylactics and therapeutics are lacking for most arboviruses. Herein, we identified 2 bacterial lipases secreted by a Chromobacterium bacterium isolated from Aedes aegypti midgut, Chromobacterium antiviral effector-1 (CbAE-1) and CbAE-2, with broad-spectrum virucidal activity against mosquito-borne viruses, such as dengue virus (DENV), Zika virus (ZIKV), Japanese encephalitis virus (JEV), yellow fever virus (YFV) and Sindbis virus (SINV). The CbAEs potently blocked viral infection in the extracellular milieu through their lipase activity. Mechanistic studies showed that this lipase activity directly disrupted the viral envelope structure, thus inactivating infectivity. A mutation in the lipase motif of CbAE-1 fully abrogated the virucidal ability. Furthermore, CbAEs also exert lipase-dependent entomopathogenic activity in mosquitoes. The anti-arboviral and entomopathogenic properties of CbAEs render them potential candidates for the development of novel transmission control strategies against vector-borne diseases.


Assuntos
Aedes , Arbovírus , Vírus da Dengue , Infecção por Zika virus , Zika virus , Animais , Arbovírus/genética , Humanos , Lipase , Mosquitos Vetores
15.
Opt Express ; 32(8): 14892-14903, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38859423

RESUMO

This work presents a theoretical design and experimental demonstration of a transmissive microwave metasurface for generating dual-vector vortex beams (VVBs). The proposed metasurface consists of an array of pixelated dartboard discretization meta-atoms. By rotating the meta-atoms from 0° to 180°, a Pancharatnam-Barry (P-B) phase covering the full 360° range is achieved, with a transmittance exceeding 90% over the frequency range from 9.7 to 10.2 GHz. The measured results demonstrate that when a linearly polarized microwave normally impinges on the metasurface, the transmitted beams correspond to the dual VVBs with different directions. A good agreement among Poincaré sphere theory, full-wave simulation, and experimental measurement is observed. This proposed transmissive microwave metasurface for VVBs may offer promising applications in communications and radar detection.

16.
EMBO Rep ; 23(11): e55671, 2022 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-36197120

RESUMO

Frequent turnover of dengue virus (DENV) clades is one of the major forces driving DENV persistence and prevalence. In this study, we assess the fitness advantage of nine stable substitutions within the envelope (E) protein of DENV serotypes. Two tandem neighboring substitutions, threonine to lysine at the 226th (T226K) and glycine to glutamic acid at the 228th (G228E) residues in the DENV2 Asian I genotype, enhance virus infectivity in either mosquitoes or mammalian hosts, thereby promoting clades turnover and dengue epidemics. Mechanistic studies indicate that the substitution-mediated polarity changes in these two residues increase the binding affinity of E for host C-type lectins. Accordingly, we predict that a G228E substitution could potentially result in a forthcoming epidemic of the DENV2 Cosmopolitan genotype. Investigations into the substitutions associated with DENV fitness in hosts may offer mechanistic insights into dengue prevalence, thus providing a warning of potential epidemics in the future.


Assuntos
Vírus da Dengue , Dengue , Animais , Vírus da Dengue/genética , Dengue/epidemiologia , Filogenia , Sorogrupo , Genótipo , Mutação , Mamíferos
17.
Phys Chem Chem Phys ; 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39036842

RESUMO

The combustion processes and catalytic after-treatment of ammonia/hydrogen-fueled engines, including NOx storage and reduction (NSR) and noble-metal selective catalytic reduction (SCR), can produce the byproduct N2O, a potent greenhouse gas that weakens the zero-carbon attribute of these fuels. Currently, the mechanism of N2O formation on DeNOx catalysts remains unclear due to limited research on catalytic after-treatment for such engines and the complexity of surface catalytic reactions. To elucidate the formation of N2O on the DeNOx catalysts of ammonia/hydrogen fuel engines, the impact factors on N2O formation on platinum catalysts (typical catalysts in NSR and noble-metal SCR) were investigated using first-principles molecular dynamics (FPMD). By employing the blue-moon ensemble enhanced sampling method and the slow-growth approach for free energy surface exploration, together with density functional theory (DFT) for electronic structure analysis, a linear relationship between the spin splitting of the d states of Pt clusters and N2O formation energy barriers was revealed, along with the increased structural sensitivity of Pt clusters with fewer atoms. It is highlighted that the energy barrier for N2O formation is determined by the matching degree of energy levels between molecules and surfaces. These findings provide atomic-scale insights into N2O formation on DeNOx catalysts for ammonia/hydrogen-fueled engines, facilitating N2O emission control for carbon-free engines.

18.
Appl Opt ; 63(11): 2863-2867, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38856382

RESUMO

Using the self-developed fused indium wetting technology and planar waveguide, the uniform heat dissipation of the slab crystal and uniform pumping of the pump light were achieved, respectively. Based on the master oscillator power amplification (MOPA) scheme, the power was then amplified when the seed light source passed through the Nd:YAG slab crystal three times. Additionally, the image transfer system that we added to the amplified optical path achieved high beam quality. Finally, we obtained a rectangular pulsed laser with an output average power of 4461 W, a repetition frequency of 20 kHz, a pulse width of 62 ns, an optical-to-optical conversion efficiency of 26.8%, and a beam quality of ß x=7.0 and ß y=7.7.

19.
Proc Natl Acad Sci U S A ; 118(42)2021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34620704

RESUMO

Zika virus (ZIKV) caused millions of infections during its rapid and expansive spread from Asia to the Americas from 2015 to 2017. Here, we compared the infectivity of ZIKV mutants with individual stable substitutions which emerged throughout the Asian ZIKV lineage and were responsible for the explosive outbreaks in the Americas. A threonine (T) to alanine (A) mutation at the 106th residue of the ZIKV capsid (C) protein facilitated the transmission by its mosquito vector, as well as infection in both human cells and immunodeficient mice. A mechanistic study showed that the T106A substitution rendered the C a preferred substrate for the NS2B-NS3 protease, thereby facilitating the maturation of structural proteins and the formation of infectious viral particles. Over a complete "mosquito-mouse-mosquito" cycle, the ZIKV C-T106A mutant showed a higher prevalence of mosquito infection than did the preepidemic strain, thus promoting ZIKV dissemination. Our results support the contribution of this evolutionary adaptation to the occasional widespread reemergence of ZIKV in nature.


Assuntos
Evolução Molecular , Mosquitos Vetores/genética , Mutação , Zika virus/genética , Animais , Genoma Viral , Humanos , Camundongos , Filogenia
20.
BMC Med Inform Decis Mak ; 24(1): 18, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38243204

RESUMO

OBJECTIVE: To develop a Chinese Diabetes Mellitus Ontology (CDMO) and explore methods for constructing high-quality Chinese biomedical ontologies. MATERIALS AND METHODS: We used various data sources, including Chinese clinical practice guidelines, expert consensus, literature, and hospital information system database schema, to build the CDMO. We combined top-down and bottom-up strategies and integrated text mining and cross-lingual ontology mapping. The ontology was validated by clinical experts and ontology development tools, and its application was validated through clinical decision support and Chinese natural language medical question answering. RESULTS: The current CDMO consists of 3,752 classes, 182 fine-grained object properties with hierarchical relationships, 108 annotation properties, and over 12,000 mappings to other well-known medical ontologies in English. Based on the CDMO and clinical practice guidelines, we developed 200 rules for diabetes diagnosis, treatment, diet, and medication recommendations using the Semantic Web Rule Language. By injecting ontology knowledge, CDMO enhances the performance of the T5 model on a real-world Chinese medical question answering dataset related to diabetes. CONCLUSION: CDMO has fine-grained semantic relationships and extensive annotation information, providing a foundation for medical artificial intelligence applications in Chinese contexts, including the construction of medical knowledge graphs, clinical decision support systems, and automated medical question answering. Furthermore, the development process incorporated natural language processing and cross-lingual ontology mapping to improve the quality of the ontology and improved development efficiency. This workflow offers a methodological reference for the efficient development of other high-quality Chinese as well as non-English medical ontologies.


Assuntos
Ontologias Biológicas , Diabetes Mellitus , Humanos , Inteligência Artificial , Idioma , Semântica , Diabetes Mellitus/diagnóstico
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