We present second-order expressions for the free-surface elevation, velocity potential and pressure resulting from the interaction of surface waves in water of arbitrary depth. When the surface waves have nearly equal...We present second-order expressions for the free-surface elevation, velocity potential and pressure resulting from the interaction of surface waves in water of arbitrary depth. When the surface waves have nearly equal frequencies and nearly opposite directions, a second-order pressure can be felt all the way to the sea bottom. There are at least two areas of applications： reflective structures and microseisms. Microseisms generated by water waves in the ocean are small vibrations of the ground resulting from pressure oscillations associated with the coupling of ocean surface gravity waves and the sea floor. They are recorded on land-based seismic stations throughout the world and they are divided into primary and secondary types, as a function of spectral content. Secondary microseisms are generated by the interaction of surface waves with nearly equal frequencies and nearly opposite directions. The efficiency of microseism generation thus depends in part on ocean wave frequency and direction. Based on the second-order expressions for the dynamic pressure, a simple theoretical analysis that quantifies the degree of nearness in amplitude, frequency, and incidence angle, which must be reached to observe the phenomenon, is presented.展开更多
DNA methylation is an essential epigenetic modification, and found to be dynamically changed due to the ob- servation of active DNA demethylation. During active demethylation, 5-methylcytosine （5mC） was oxidized ste...DNA methylation is an essential epigenetic modification, and found to be dynamically changed due to the ob- servation of active DNA demethylation. During active demethylation, 5-methylcytosine （5mC） was oxidized step- wise by ten-eleven translocation （TET） enzymes into 5-hydroxymethylcytosine （5hmc）, 5-formylcytosine （5fC）, and 5-carboxylcytosine （5caC）. Then, the subsequent excision of 5fC and 5caC combined with base excision repair further restored cytosine, which completes the demethylation process. Here, we report that 5-formylcytosine and 5-carboxylcytosine significantly reduce the activity of HhaI DNA methyltransferase to methylate target cytosines when present on the hemi-modified sequence of the complementary DNA. This finding demonstrates that 5fC and 5caC function as more than intermediates for active DNA demethylation.展开更多
Respiratory syncytial virus(RSV)is the major cause of bronchiolitis and pneumonia in young children and the elderly.There are currently no approved RSV-specific therapeutic small molecules available.Using high-through...Respiratory syncytial virus(RSV)is the major cause of bronchiolitis and pneumonia in young children and the elderly.There are currently no approved RSV-specific therapeutic small molecules available.Using high-throughput antiviral screening,we identified an oral drug,the prenylation inhibitor lonafarnib,which showed potent inhibition of the RSV fusion process.Lonafarnib exhibited antiviral activity against both the RSV A and B genotypes and showed low cytotoxicity in HEp-2 and human primary bronchial epithelial cells(HBEC).Time-of-addition and pseudovirus assays demonstrated that lonafarnib inhibits RSV entry,but has farnesyltransferase-independent antiviral efficacy.Cryo-electron microscopy revealed that lonafarnib binds to a triple-symmetric pocket within the central cavity of the RSV F metastable pre-fusion conformation.Mutants at the RSV F sites interacting with lonafarnib showed resistance to lonafarnib but remained fully sensitive to the neutralizing monoclonal antibody palivizumab.Furthermore,lonafarnib dose-dependently reduced the replication of RSV in BALB/c mice.Collectively,lonafarnib could be a potential fusion inhibitor for RSV infection.展开更多
In this paper we first compute the out-of-time-order correlators （OTOC） for both a phenomenological model and a random-field XXZ model in the many-body localized phase. We show that the OTOC decreases in power law i...In this paper we first compute the out-of-time-order correlators （OTOC） for both a phenomenological model and a random-field XXZ model in the many-body localized phase. We show that the OTOC decreases in power law in a many-body localized system at the scrambling time. We also find that the OTOC can also be used to distinguish a many-body localized phase from an Anderson localized phase, while a normal correlator cannot. Furthermore, we prove an exact theorem that relates the growth of the second Renyi entropy in the quench dynamics to the decay of the OTOC in equilibrium. This theorem works for a generic quantum system. We discuss various implications of this theorem.展开更多
基金partly supported by the Science Foundation Ireland(SFI)under the research project "High-end computational modeling for wave energy systems"(SFI/10/IN.1/12996)in collaboration with Marine Renewable Energy Ireland(MaREI)the SFI Centre for Marine Renewable Energy Research(SFI/12/RC/2302)
文摘We present second-order expressions for the free-surface elevation, velocity potential and pressure resulting from the interaction of surface waves in water of arbitrary depth. When the surface waves have nearly equal frequencies and nearly opposite directions, a second-order pressure can be felt all the way to the sea bottom. There are at least two areas of applications： reflective structures and microseisms. Microseisms generated by water waves in the ocean are small vibrations of the ground resulting from pressure oscillations associated with the coupling of ocean surface gravity waves and the sea floor. They are recorded on land-based seismic stations throughout the world and they are divided into primary and secondary types, as a function of spectral content. Secondary microseisms are generated by the interaction of surface waves with nearly equal frequencies and nearly opposite directions. The efficiency of microseism generation thus depends in part on ocean wave frequency and direction. Based on the second-order expressions for the dynamic pressure, a simple theoretical analysis that quantifies the degree of nearness in amplitude, frequency, and incidence angle, which must be reached to observe the phenomenon, is presented.
文摘DNA methylation is an essential epigenetic modification, and found to be dynamically changed due to the ob- servation of active DNA demethylation. During active demethylation, 5-methylcytosine （5mC） was oxidized step- wise by ten-eleven translocation （TET） enzymes into 5-hydroxymethylcytosine （5hmc）, 5-formylcytosine （5fC）, and 5-carboxylcytosine （5caC）. Then, the subsequent excision of 5fC and 5caC combined with base excision repair further restored cytosine, which completes the demethylation process. Here, we report that 5-formylcytosine and 5-carboxylcytosine significantly reduce the activity of HhaI DNA methyltransferase to methylate target cytosines when present on the hemi-modified sequence of the complementary DNA. This finding demonstrates that 5fC and 5caC function as more than intermediates for active DNA demethylation.
基金supported by the Natural Science Foundation of Guangdong province(Grant no.2024A1515011589 to Q.Y.)the National Natural Science Foundation of China(Grant no.32000111 to Q.Y.,82170473 to J.S.)+3 种基金the Pearl River Talent Recruitment Program(Grant no.2019CX01Y422 to X.C.)the Guangzhou Laboratory(Grant no.SRPG22-002 to J.S.and X.C.,No.SRPG22-011 to W.P.and Q.Y.)the Basic and Applied Basic Research Projects of Guangzhou Basic Research Program(2023A04J0161 to Q.Y.,2021QN020451 to J.S.)the Young Elite Scientists Sponsorship Program by CAST(Grant no.2023QNRC001 to F.L.).
文摘Respiratory syncytial virus(RSV)is the major cause of bronchiolitis and pneumonia in young children and the elderly.There are currently no approved RSV-specific therapeutic small molecules available.Using high-throughput antiviral screening,we identified an oral drug,the prenylation inhibitor lonafarnib,which showed potent inhibition of the RSV fusion process.Lonafarnib exhibited antiviral activity against both the RSV A and B genotypes and showed low cytotoxicity in HEp-2 and human primary bronchial epithelial cells(HBEC).Time-of-addition and pseudovirus assays demonstrated that lonafarnib inhibits RSV entry,but has farnesyltransferase-independent antiviral efficacy.Cryo-electron microscopy revealed that lonafarnib binds to a triple-symmetric pocket within the central cavity of the RSV F metastable pre-fusion conformation.Mutants at the RSV F sites interacting with lonafarnib showed resistance to lonafarnib but remained fully sensitive to the neutralizing monoclonal antibody palivizumab.Furthermore,lonafarnib dose-dependently reduced the replication of RSV in BALB/c mice.Collectively,lonafarnib could be a potential fusion inhibitor for RSV infection.
基金supported by the National Key Research and Development Plan (2016YFA0301600)the National Natural Science Foundation of China (11325418)Tsinghua University Initiative Scientific Research Program
文摘In this paper we first compute the out-of-time-order correlators （OTOC） for both a phenomenological model and a random-field XXZ model in the many-body localized phase. We show that the OTOC decreases in power law in a many-body localized system at the scrambling time. We also find that the OTOC can also be used to distinguish a many-body localized phase from an Anderson localized phase, while a normal correlator cannot. Furthermore, we prove an exact theorem that relates the growth of the second Renyi entropy in the quench dynamics to the decay of the OTOC in equilibrium. This theorem works for a generic quantum system. We discuss various implications of this theorem.
