Monosaccharide as a Central Scaffold Toward the Construction of Salicylate-Based Bidentate PTP1B Inhibitors via Click Chemistry

Tang, Yan-Hui,Hu, Min,He, Xiao-Peng,Fahnbulleh, Sando,Li, Cui,Gao, Li-Xin,Sheng, Li,Tang, Yun,Li, Jia,Chen, Guo-Rong Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.3

The discovery of carbohydrate-based bioactive compounds has recently received considerable interest in the drug development. This paper stresses on the application of 1-methoxy-O-glucoside as the central scaffold, whereas salicylic pharmacophores were introduced with diverse spatial orientations probing into the structural preference of an enzymatic target, i.e. protein tyrosine phosphatase 1B (PTP1B). By employing regioselective protection and deprotection strategy, 2,6-, 3,4-, 4,6- and 2,3-di-O-propynyl 1-methoxy-O-glucosides were previously synthesized and then coupled with azido salicylate via click chemistry in forming the desired bidentate salicylic glucosides with high yields. The inhibitory assay of the obtained triazolyl derivatives leads to the identification of the 2,3-disubstituted salicylic 1-methoxy-O-glucoside as the structurally privileged PTP1B inhibitor among this bidentate compound series with micromole-ranged $IC_{50}$ value and reasonable selectivity over other homologous PTPs tested. In addition, docking simulation was conducted to propose a plausible binding mode of this authorized inhibitor with PTP1B. This research might furnish new insight toward the construction of structurally different bioactive compounds based on the monosaccharide scaffold.

An Unreliable Opportunistic Spectrum Sharing System with Sensitive Secondary Users

Shensheng Tang,Rong Yu,Xiaojiang Chen,Chenghua Tang,Yi Xie 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.3

The focus of this paper is on the modeling and performance analysis of an unreliable opportunistic spectrum sharing (OSS) system at the call level with sensitive secondary users. Unreliable spectrum sensing is modeled by type I and type II false alarm events and class-A and class-B misdetection events, which brings more flexibility for the purpose of performance evaluation. Spectrum sensing errors negatively impact the performance of primary users and secondary users, particularly when a call collision happens. To maximize the protection of primary users under call collisions, it is required in the system design that secondary users be sensitive to the call collisions, to protect primary users. We model the unreliable OSS system through a two-dimensional Markov process and develop the steady-state probabilities of the system as well as several performance metrics of interest.

Bond Distortion and Electron States in Charged $C_{60}{^2-}$

Fu, Rong-Tang,Fu, Rou-Li,Lee, Kee-Hag,Sun, Xin,Ye, Hong-Juan Korean Chemical Society 1993 Bulletin of the Korean Chemical Society Vol.14 No.6

By considering both electron-electron and electron-lattice interactions, the effect of charge transfer on the bond structure and electronic states of $C_{60}$ is studied without configuration limitation. The results show that the electron-electron interaction does not eliminate the layer structure of the bond distortion and the self-trapping of transferred electrons. For charged ${C_{60}}^{2-}$, there exist two localized electronic states, which possess laminar wave functions, and four nonequivalent groups of carbon atoms, which induce a fine-structure in the NMR spectrum line.

Monosaccharide as a Central Scaffold Toward the Construction of Salicylate-Based Bidentate PTP1B Inhibitors via Click Chemistry

Yan-Hui Tang,Min Hu,Xiao-Peng He,Sando Fahnbulleh,Cui Li,Li-Xin Gao,Li Sheng,Yun Tang,Jia Li,Guo-Rong Chen 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.3

The discovery of carbohydrate-based bioactive compounds has recently received considerable interest in the drug development. This paper stresses on the application of 1-methoxy-O-glucoside as the central scaffold,whereas salicylic pharmacophores were introduced with diverse spatial orientations probing into the structural preference of an enzymatic target, i.e. protein tyrosine phosphatase 1B (PTP1B). By employing regioselective protection and deprotection strategy, 2,6-, 3,4-, 4,6- and 2,3-di-O-propynyl 1-methoxy-O-glucosides were previously synthesized and then coupled with azido salicylate via click chemistry in forming the desired bidentate salicylic glucosides with high yields. The inhibitory assay of the obtained triazolyl derivatives leads to the identification of the 2,3-disubstituted salicylic 1-methoxy-O-glucoside as the structurally privileged PTP1B inhibitor among this bidentate compound series with micromole-ranged IC50 value and reasonable selectivity over other homologous PTPs tested. In addition, docking simulation was conducted to propose a plausible binding mode of this authorized inhibitor with PTP1B. This research might furnish new insight toward the construction of structurally different bioactive compounds based on the monosaccharide scaffold.

Coffin-Siris syndrome in two chinese patients with novel pathogenic variants of ARID1A and SMARCA4

Liu Mingjie,Wan Linlin,Wang Chunrong,Yuan Hongyu,Peng Yun,Wan Na,Tang Zhichao,Yuan Xinrong,Chen Daji,Long Zhe,Shi Yuting,Qiu Rong,Tang Beisha,Tang Beisha,Chen Zhao 한국유전학회 2022 Genes & Genomics Vol.44 No.9

Background: Coffin-Siris syndrome (CSS) is a rare congenital syndrome characterized by developmental delay, intellectual disability, microcephaly, coarse face and hypoplastic nail of the fifth digits. Heterozygous variants of different BAF complex-related genes were reported to cause CSS, including ARID1A and SMARCA4. So far, no CSS patients with ARID1A and SMARCA4 variants have been reported in China. Objective: The aim of the current study was to identify the causes of two Chinese patients with congenital growth deficiency and intellectual disability. Methods: Genomic DNA was extracted from the peripheral venous blood of patients and their family members. Genetic analysis included whole-exome and Sanger sequencing. Pathogenicity assessments of variants were performed according to the guideline of the American College of Medical Genetics and Genomics. The phenotypic characteristics of all CSS subtypes were summarized through literature review. Results: We identified two Chinese CSS patients carrying novel variants of ARID1A and SMARCA4 respectively. The cases presented most core symptoms of CSS except for the digits involvement. Additionally, we performed a review of the phenotypic characteristics in CSS, highlighting phenotypic varieties and related potential causes. Conclusions: We reported the first Chinese CSS2 and CSS4 patients with novel variants of ARID1A and SMARCA4. Our study expanded the genetic and phenotypic spectrum of CSS, providing a comprehensive overview of genotype-phenotype correlations of CSS.

Electrical Characteristics of Charge Trap Flash Memory with a Composition Modulated (ZrO₂)_x(Al₂O₃)_1-x Film

Tang, Zhenjie,Zhang, Jing,Jiang, Yunhong,Wang, Guixia,Li, Rong,Zhu, Xinhua The Korean Institute of Electrical and Electronic 2015 Transactions on Electrical and Electronic Material Vol.16 No.3

This research proposes the use of a composition modulated (ZrO₂)_x(Al₂O₃)_1-x film as a charge trapping layer for charge trap flash memory; this is possible when the Zr (Al) atomic percent is controlled to form a variable bandgap as identified by the valence band offsets and electron energy loss spectrum measurements. Compared to memory devices with uniform compositional (ZrO₂)_0.1(Al₂O₃)_0.9 or a (ZrO₂)_0.92(Al₂O₃)_0.08 trapping layer, the memory device using the composition modulated (ZrO₂)_x(Al₂O₃)_1-x as the charge trapping layer exhibits a larger memory window (6.0 V) at the gate sweeping voltage of ±8 V, improved data retention, and significantly faster program/erase speed. Improvements of the memory characteristics are attributed to the special energy band alignments resulting from non-uniform distribution of elemental composition. These results indicate that the composition modulated (ZrO₂)_x(Al₂O₃)_1-x film is a promising candidate for future nonvolatile memory device applications.

Traffic-load-induced dynamic stress accumulation in subgrade and subsoil using small scale model tests

Tang, Lian Sheng,Chen, Hao Kun,Sun, Yin Lei,Zhang, Qing Hua,Liao, Hua Rong Techno-Press 2018 Geomechanics & engineering Vol.16 No.2

Under repeated loading, the residual stresses within the subgrade and subsoil can accelerate the deformation of the road structures. In this paper, a series of laboratory cyclic loading model tests and small-scale model tests were conducted to investigate the dynamic stress response within soils under different loading conditions. The experimental results showed that a dynamic stress accumulation effect occurred if the soil showed cumulative deformation: (1) the residual stress increased and accumulated with an increasing number of loading cycles, and (2) the residual stress was superimposed on the stress response of the subsequent loading cycles, inducing a greater peak stress response. There are two conditions that must be met for the dynamic stress accumulation effect to occur. A threshold state exists only if the external load exceeds the cyclic threshold stress. Then, the stress accumulation effect occurs. A higher loading frequency results in a higher rate of increase for the residual stress. In addition to the superposition of the increasing residual stress, soil densification might contribute to the increasing peak stress during cyclic loading. An increase in soil stiffness and a decrease in dissipative energy induce a greater stress transmission within the material.

KNOWLEDGE-BASED PLANNING IN A SIMULATED ROBOT WORLD

Tang Shuo Fei,Li Ming Shu,Hong Bing Rong 대한전자공학회 1992 대한전자공학회 Conference Vol.1992 No.2

Expression of the CXCL12/SDF-1 Chemokine Receptor CXCR7 in Human Brain Tumours

Tang, Tian,Xia, Qing-Jie,Chen, Jian-Bin,Xi, Ming-Rong,Lei, Ding Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.10

Purpose: Receptor 7 (CXCR7) has recently been characterized as a novel receptor for CXCL12/SDF-1 (stromal cell derived factor-1). Given the demonstrated importance of CXCL12/SDF-1 in angiogenesis and tumour metastasis, we hypothesized that CXCR7 may also play a role in tumour pathogenesis. Located in the limited space of the intracranial cavity, any brain tumours can be inherently serious and life-threatening. However, the expression of CXCR7 in pituitary adenoma, neurilemmoma or hemangioblastoma remains to be elucidated. Therefore, we aimed to determine the potential contribution of CXCR7 in the development of brain tumours. Methods: In this study we examined and quantified the mRNA expression of CXCR7 in four different human brain tumours - 27 patients with neurilemmoma (8 patients), pituitary adenoma (7 patients), hemangioblastoma (6 patients), or meningioma (6 patients) undergoing surgical resection in the West China Hospital of Sichuan University. There were 15 females and 12 males aged from 28 to 70 years old. Total RNA was isolated and mRNA was measured by quantitative real-time RT-PCR. One-way analysis of variance (ANOVA) was performed using SPSS 11.0 statistical software to compare the mRNA levels of CXCR7 among four groups. Results: We found that CXCR7 mRNA was detected in all tumour samples. Quantitative results showed that the levels of CXCR7 mRNA in brain tissues from patients with neurilemmoma or meningioma were significantly higher than those with pituitary adenoma or hemangioblastoma. Conclusions: The results suggest that the CXCR7 may play a role in progression, metastasis and angiogenesis of brain tumours.

Effect of Annealing Atmosphere on the La₂O₃ Nanocrystallite Based Charge Trap Memory

Tang, Zhenjie,Zhao, Dongqiu,Hu, Huiping,Li, Rong,Yin, Jiang The Korean Institute of Electrical and Electronic 2014 Transactions on Electrical and Electronic Material Vol.15 No.2

$Pt/Al_2O_3/La_2Si_5O_x/SiO_2/Si$ charge trap memory capacitors were prepared, in which the $La_2Si_5O_x$ film was used as the charge trapping layer, and the effects of post annealing atmospheres ($NH_3$ and $N_2$) on their memory characteristics were investigated. $La_2O_3$ nanocrystallites, as the storage nodes, precipitated from the amorphous $La_2Si_5O_x$ film during rapid thermal annealing. The $NH_3$ annealed memory capacitor showed higher charge storage performances than either the capacitor without annealing or the capacitor annealed in $N_2$. The memory characteristics were enhanced because more nitrogen was incorporated at the $La_2Si_5O_x/SiO_2$ interface and interfacial reaction was suppressed after the $NH_3$ annealing treatment.