The performance of a damper in controlling large-amplitude vibrations of a stay cable in a bridge... more The performance of a damper in controlling large-amplitude vibrations of a stay cable in a bridge is influenced by essential parameters such as the amount of sag and flexural rigidity of the cable, and the stiffness of the damper support. In this paper, accurate asymptotic formulas ...
The effects of bending on the modal properties of a stay cable with a transverse damper are analy... more The effects of bending on the modal properties of a stay cable with a transverse damper are analytically studied. Considering that the value of the flexural rigidity in the stay cable is small in practice, an explicit asymptotic formula for the modal damping of a cable with a general ...
The combined effect of two dampers, either on the same end or opposite ends of a stay cable, is a... more The combined effect of two dampers, either on the same end or opposite ends of a stay cable, is analytically studied in this paper. By considering small distances of the dampers from the anchorages, an asymptotic formula for the modal damping ratio of the cable is derived ...
In seismic retrofit of a long-span truss bridge in Japan, a new retrofit scheme was applied in wh... more In seismic retrofit of a long-span truss bridge in Japan, a new retrofit scheme was applied in which the existing bearings of the bridge were replaced by a new floor deck isolation system. The floor decks and isolation system together can be viewed as a giant tuned ...
During DNA replication or repair, the DNA polymerase cofactor, proliferating cell nuclear antigen... more During DNA replication or repair, the DNA polymerase cofactor, proliferating cell nuclear antigen (PCNA), homotrimerizes and encircles the replicating DNA, thereby acting as a DNA clamp that promotes DNA polymerase processivity. The formation of the PCNA trimer is also essential for targeting the replication- licensing protein, chromatin-licensing and DNA replication factor 1 (CDT1), for ubiquitin-dependent proteolysis to prevent chromosomal DNA re-replication. CDT1 uses its PCNA-interacting peptide box (PIP box) to interact with PCNA, and the CRL4 E3 ubiquitin ligase subunit CDT2 is recruited through the formation of PCNA-CDT1 complexes. However, it remains unclear how CDT1 and many other PIP box-containing proteins are marked for degradation by the CRL4CDT2 ubiquitin ligase during DNA replication or damage. Here, using recombinant protein expression coupled with site-directed mutagenesis, we report that CDT2 and PCNA directly interact and this interaction depends on the presence o...
Many non-histone proteins are lysine methylated and a novel function of this modification is to t... more Many non-histone proteins are lysine methylated and a novel function of this modification is to trigger the proteolysis of methylated proteins. Here, we report that the methylated lysine 142 of DNMT1, a major DNA methyltransferase that preserves epigenetic inheritance of DNA methylation patterns during DNA replication, is demethylated by LSD1. A novel methyl-binding protein, L3MBTL3, binds the K142-methylated DNMT1 and recruits a novel CRL4 ubiquitin ligase to degrade DNMT1. Both LSD1 and PHF20L1 act primarily in S phase to prevent DNMT1 degradation by L3MBTL3-CRL4. Mouse L3MBTL3/MBT-1 deletion causes accumulation of DNMT1 protein, increased genomic DNA methylation, and late embryonic lethality. DNMT1 contains a consensus methylation motif shared by many non-histone proteins including E2F1, a key transcription factor for S phase. We show that the methylation-dependent E2F1 degradation is also controlled by L3MBTL3-CRL4. Our studies elucidate for the first time a novel mechanism by w...
The performance of a damper in controlling large-amplitude vibrations of a stay cable in a bridge... more The performance of a damper in controlling large-amplitude vibrations of a stay cable in a bridge is influenced by essential parameters such as the amount of sag and flexural rigidity of the cable, and the stiffness of the damper support. In this paper, accurate asymptotic formulas ...
The effects of bending on the modal properties of a stay cable with a transverse damper are analy... more The effects of bending on the modal properties of a stay cable with a transverse damper are analytically studied. Considering that the value of the flexural rigidity in the stay cable is small in practice, an explicit asymptotic formula for the modal damping of a cable with a general ...
The combined effect of two dampers, either on the same end or opposite ends of a stay cable, is a... more The combined effect of two dampers, either on the same end or opposite ends of a stay cable, is analytically studied in this paper. By considering small distances of the dampers from the anchorages, an asymptotic formula for the modal damping ratio of the cable is derived ...
In seismic retrofit of a long-span truss bridge in Japan, a new retrofit scheme was applied in wh... more In seismic retrofit of a long-span truss bridge in Japan, a new retrofit scheme was applied in which the existing bearings of the bridge were replaced by a new floor deck isolation system. The floor decks and isolation system together can be viewed as a giant tuned ...
During DNA replication or repair, the DNA polymerase cofactor, proliferating cell nuclear antigen... more During DNA replication or repair, the DNA polymerase cofactor, proliferating cell nuclear antigen (PCNA), homotrimerizes and encircles the replicating DNA, thereby acting as a DNA clamp that promotes DNA polymerase processivity. The formation of the PCNA trimer is also essential for targeting the replication- licensing protein, chromatin-licensing and DNA replication factor 1 (CDT1), for ubiquitin-dependent proteolysis to prevent chromosomal DNA re-replication. CDT1 uses its PCNA-interacting peptide box (PIP box) to interact with PCNA, and the CRL4 E3 ubiquitin ligase subunit CDT2 is recruited through the formation of PCNA-CDT1 complexes. However, it remains unclear how CDT1 and many other PIP box-containing proteins are marked for degradation by the CRL4CDT2 ubiquitin ligase during DNA replication or damage. Here, using recombinant protein expression coupled with site-directed mutagenesis, we report that CDT2 and PCNA directly interact and this interaction depends on the presence o...
Many non-histone proteins are lysine methylated and a novel function of this modification is to t... more Many non-histone proteins are lysine methylated and a novel function of this modification is to trigger the proteolysis of methylated proteins. Here, we report that the methylated lysine 142 of DNMT1, a major DNA methyltransferase that preserves epigenetic inheritance of DNA methylation patterns during DNA replication, is demethylated by LSD1. A novel methyl-binding protein, L3MBTL3, binds the K142-methylated DNMT1 and recruits a novel CRL4 ubiquitin ligase to degrade DNMT1. Both LSD1 and PHF20L1 act primarily in S phase to prevent DNMT1 degradation by L3MBTL3-CRL4. Mouse L3MBTL3/MBT-1 deletion causes accumulation of DNMT1 protein, increased genomic DNA methylation, and late embryonic lethality. DNMT1 contains a consensus methylation motif shared by many non-histone proteins including E2F1, a key transcription factor for S phase. We show that the methylation-dependent E2F1 degradation is also controlled by L3MBTL3-CRL4. Our studies elucidate for the first time a novel mechanism by w...
Uploads
Papers by Nam Anh Nguyen Hoang