Menghang Xia - Academia.edu (original) (raw)

Papers by Menghang Xia

Research paper thumbnail of Chemical treatment of the intra-canal dentin surface: a new approach to modify dentin hydrophobicity

Journal of Applied Oral Science, Feb 1, 2013

O bjective: This study evaluated the hydrophobicity of dentin surfaces that were modified through... more O bjective: This study evaluated the hydrophobicity of dentin surfaces that were modified through chemical silanization with octadecyltrichlorosilane (OTS). Material and Methods: An in vitro experimental study was performed using 40 human permanent incisors that were divided into the following two groups: non-silanized and silanized. The specimens were pretreated and chemically modified with OTS. After the chemical modification, the dentin hydrophobicity was examined using a water contact angle measurement (WCA). The effectiveness of the modification of hydrophobicity was verified by the fluid permeability test (FPT). Results and Conclusions: Statistically significant differences were found in the values of WCA and FPT between the two groups. After silanization, the hydrophobic intraradicular dentin surface exhibited in vitro properties that limit fluid penetration into the sealed root canal. This chemical treatment is a new approach for improving the sealing of the root canal system.

Research paper thumbnail of Identification of novel PARP inhibitors using a cell-based TDP1 inhibitory assay in a quantitative high-throughput screening platform

DNA Repair, 2014

Please cite this article in press as: J. Murai, et al., Identification of novel PARP inhibitors u... more Please cite this article in press as: J. Murai, et al., Identification of novel PARP inhibitors using a cell-based TDP1 inhibitory assay in a quantitative high-throughput screening platform, DNA Repair (2014), http://dx.

Research paper thumbnail of Exploration and optimization of substituted triazolothiadiazines and triazolopyridazines as PDE4 inhibitors

Bioorganic & Medicinal Chemistry Letters, 2009

PDE4 inhibitor Triazolothiadiazines Triazolopyridazines Asthma COPD a b s t r a c t An expansion ... more PDE4 inhibitor Triazolothiadiazines Triazolopyridazines Asthma COPD a b s t r a c t An expansion of structure-activity studies on a series of substituted 7H- triazolo [3,4-b] thiadiazine PDE4 inhibitors and the introduction of a related triazolo [4,3-b]pyridazine based inhibitor of PDE4 is presented. The development of SAR included strategic incorporation of known substituents on the critical catachol diether moiety of the 6-phenyl appendage on each heterocyclic core. From these studies, (R)-3-(2,5-dimethoxyphenyl)-6-(4-methoxy-3-(tetrahydrofuran-3-yloxy)phenyl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine (10) and (R)-3-(2,5-dimethoxyphenyl)-6-(4-methoxy-3-(tetrahydrofuran-3-yloxy)phenyl)-[1,2,4]triazolo[4,3-b]pyridazine (18) were identified as highly potent PDE4A inhibitors. Each of these analogues was submitted across a panel of 21 PDE family members and was shown to be highly selective for PDE4 isoforms (PDE4A, PDE4B, PDE4C, PDE4D). Both 10 and 18 were then evaluated in divergent cell-based assays to assess their relevant use as probes of PDE4 activity. Finally, docking studies with selective ligands (including 10 and 18) were undertaken to better understand this chemotypes ability to bind and inhibit PDE4 selectively.

Research paper thumbnail of Chemical treatment of the intra-canal dentin surface: a new approach to modify dentin hydrophobicity

Journal of Applied Oral Science, Feb 1, 2013

O bjective: This study evaluated the hydrophobicity of dentin surfaces that were modified through... more O bjective: This study evaluated the hydrophobicity of dentin surfaces that were modified through chemical silanization with octadecyltrichlorosilane (OTS). Material and Methods: An in vitro experimental study was performed using 40 human permanent incisors that were divided into the following two groups: non-silanized and silanized. The specimens were pretreated and chemically modified with OTS. After the chemical modification, the dentin hydrophobicity was examined using a water contact angle measurement (WCA). The effectiveness of the modification of hydrophobicity was verified by the fluid permeability test (FPT). Results and Conclusions: Statistically significant differences were found in the values of WCA and FPT between the two groups. After silanization, the hydrophobic intraradicular dentin surface exhibited in vitro properties that limit fluid penetration into the sealed root canal. This chemical treatment is a new approach for improving the sealing of the root canal system.

Research paper thumbnail of Identification of novel PARP inhibitors using a cell-based TDP1 inhibitory assay in a quantitative high-throughput screening platform

DNA Repair, 2014

Please cite this article in press as: J. Murai, et al., Identification of novel PARP inhibitors u... more Please cite this article in press as: J. Murai, et al., Identification of novel PARP inhibitors using a cell-based TDP1 inhibitory assay in a quantitative high-throughput screening platform, DNA Repair (2014), http://dx.

Research paper thumbnail of Exploration and optimization of substituted triazolothiadiazines and triazolopyridazines as PDE4 inhibitors

Bioorganic & Medicinal Chemistry Letters, 2009

PDE4 inhibitor Triazolothiadiazines Triazolopyridazines Asthma COPD a b s t r a c t An expansion ... more PDE4 inhibitor Triazolothiadiazines Triazolopyridazines Asthma COPD a b s t r a c t An expansion of structure-activity studies on a series of substituted 7H- triazolo [3,4-b] thiadiazine PDE4 inhibitors and the introduction of a related triazolo [4,3-b]pyridazine based inhibitor of PDE4 is presented. The development of SAR included strategic incorporation of known substituents on the critical catachol diether moiety of the 6-phenyl appendage on each heterocyclic core. From these studies, (R)-3-(2,5-dimethoxyphenyl)-6-(4-methoxy-3-(tetrahydrofuran-3-yloxy)phenyl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine (10) and (R)-3-(2,5-dimethoxyphenyl)-6-(4-methoxy-3-(tetrahydrofuran-3-yloxy)phenyl)-[1,2,4]triazolo[4,3-b]pyridazine (18) were identified as highly potent PDE4A inhibitors. Each of these analogues was submitted across a panel of 21 PDE family members and was shown to be highly selective for PDE4 isoforms (PDE4A, PDE4B, PDE4C, PDE4D). Both 10 and 18 were then evaluated in divergent cell-based assays to assess their relevant use as probes of PDE4 activity. Finally, docking studies with selective ligands (including 10 and 18) were undertaken to better understand this chemotypes ability to bind and inhibit PDE4 selectively.