Preparation of Silver Nanocap Arrays and Their Surface-enhanced Raman Scattering Activity

Chunxu Wang,Duo Xu,Yuhai Wang,Li Wang,Lei Chen,Xiangxin Xue,Zhengkun Qin 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.10

In this article, a surface-enhanced Raman scattering (SERS) substrate of silver nanocap arrays was reported. With increasing the size of nanocaps, the localized surface plasmon resonance (LSPR) of the arrays exhibited tunable ability in the visible spectral region. The optical response of the nanocap arrays stimulated their use in SERS experiments. The assessment of SERS activity of the nanocap arrays was performed by using the 514.5 nm excitation line, and different average enhancement factor (EF) values were obtained. The good tunability of LSPR, relatively high average EF values and long-range order of these substrates suggest that the silver nanocap arrays have promising applications as functional components in spectroscopy, immunoassay, biosensors, and biochips.

Salivary Pepsin as an Intrinsic Marker for Diagnosis of Sub-types of Gastroesophageal Reflux Disease and Gastroesophageal Reflux Disease-related Disorders

( Yan-jun Wang ),( Xiu-qiong Lang ),( Dan Wu ),( Yu-qin He ),( Chun-hui Lan ),( Xiao-xiao ),( Bin Wang ),( Duo-wu Zou ),( Ji-min Wu ),( Yong-bin Zhao ),( Peter W Dettmar ),( Dong-feng Chen ),( Min Yan 대한소화기 기능성질환·운동학회 2020 Journal of Neurogastroenterology and Motility (JNM Vol.26 No.1

Background/Aims To determine the value of salivary pepsin in discriminating sub-types of gastroesophageal reflux disease (GERD) and GERD-related disorders. Methods Overall, 322 patients with different sub-types of GERD and 45 healthy controls (HC) were studied. All patients took Gastroesophageal Reflux Disease Questionnaire (GerdQ) and underwent endoscopy and 24-hour esophageal pH monitoring and manometry. Salivary pepsin concentration (SPC) was detected by using colloidal gold double-antibody immunological sandwich assay. Oral esomeprazole treatment was administrated in the patients with non-erosive reflux disease (NERD) and extra-esophageal symptoms (EES). Results Compared to HC, patients with erosive esophagitis, NERD, EES, EES plus typical GERD symptoms, or Barrett’s esophagus had a higher prevalence of saliva and SPC (all P < 0.001). There was no significant difference in the positive rate for pepsin in patients with functional heartburn or GERD with anxiety and depression, compared to HC. After esomeprazole treatment, the positive rate and SPC were significantly reduced in NERD (both P < 0.001) and in EES (P = 0.001 and P = 0.002, respectively). Of the 64 NERD patients, 71.9% (n = 46) were positive for salivary pepsin, which was significantly higher than the rate (43.8%, n = 28) of pathological acid reflux as detected by 24-hour esophageal pH monitoring (P = 0.002). Conclusions Salivary pepsin has an important significance for the diagnosis of GERD and GERD-related disorders. Salivary pepsin and 24-hour esophageal pH monitoring may complement with each other to improve the diagnostic efficiency.

A novel, reversible, Chinese text information hiding scheme based on lookalike traditional and simplified Chinese characters

( Bin Feng ),( Zhi-hui Wang ),( Duo Wang ),( Ching-yun Chang ),( Ming-chu Li ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.1

Compared to hiding information into digital image, hiding information into digital text file requires less storage space and smaller bandwidth for data transmission, and it has obvious universality and extensiveness. However, text files have low redundancy, so it is more difficult to hide information in text files. To overcome this difficulty, Wang et al. proposed a reversible information hiding scheme using left-right and up-down representations of Chinese characters, but, when the scheme is implemented, it does not provide good visual steganographic effectiveness, and the embedding and extracting processes are too complicated to be done with reasonable effort and cost. We observed that a lot of traditional and simplified Chinese characters look somewhat the same (also called lookalike), so we utilize this feature to propose a novel information hiding scheme for hiding secret data in lookalike Chinese characters. Comparing to Wang et al.`s scheme, the proposed scheme simplifies the embedding and extracting procedures significantly and improves the effectiveness of visual steganographic images. The experimental results demonstrated the advantages of our proposed scheme.

The Regulation of LexA on UV-Induced SOS Response in Myxococcus xanthus Based on Transcriptome Analysis

( Duo-hong Sheng ),( Ye Wang ),( Shu-ge Wu ),( Rui-qin Duan ),( Yue-zhong Li ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.7

SOS response is a conserved response to DNA damage in prokaryotes and is negatively regulated by LexA protein, which recognizes specifically an “SOS-box” motif present in the promoter region of SOS genes. Myxococcus xanthus DK1622 possesses a lexA gene, and while the deletion of lexA had no significant effect on either bacterial morphology, UV-C resistance, or sporulation, it did delay growth. UV-C radiation resulted in 651 upregulated genes in M. xanthus, including the typical SOS genes lexA, recA, uvrA, recN and so on, mostly enriched in the pathways of DNA replication and repair, secondary metabolism, and signal transduction. The UV-irradiated lexA mutant also showed the induced expression of SOS genes and these SOS genes enriched into a similar pathway profile to that of wild-type strain. Without irradiation treatment, the absence of LexA enhanced the expression of 122 genes that were not enriched in any pathway. Further analysis of the promoter sequence revealed that in the 122 genes, only the promoters of recA2, lexA and an operon composed of three genes (pafB, pafC and cyaA) had SOS box sequence to which the LexA protein is bound directly. These results update our current understanding of SOS response in M. xanthus and show that UV induces more genes involved in secondary metabolism and signal transduction in addition to DNA replication and repair; and while the canonical LexA-dependent regulation on SOS response has shrunk, only 5 SOS genes are directly repressed by LexA.

A new SDOF method of one-way reinforced concrete slab under non-uniform blast loading

Wang, Wei,Zhang, Duo,Lu, Fangyun,Liu, Ruichao Techno-Press 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.46 No.5

A new effective model for calculation of the equivalent uniform blast load for non-uniform blast load such as close-in explosion of a one-way square and rectangle reinforced concrete slab is proposed in this paper. The model is then validated using single degree of freedom (SDOF) system with the experiments and blast tests for square slabs and rectangle slabs. Test results showed that the model is accurate in predicting the damage level on the tested RC slabs under the given explosive charge weight and stand-off distance especially for close-in blast load. The results are also compared with those obtained by conventional SDOF analysis and finite element (FE) analysis using solid elements. It is shown that the new model is more accurate than the conventional SDOF analysis and is running faster than the FE analysis.

The influence of load pulse shape on pressure-impulse diagrams of one-way RC slabs

Wang, Wei,Zhang, Duo,Lu, Fangyun Techno-Press 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.42 No.3

This study is aimed at providing an efficient analytical model to obtain pressure- impulse diagram of one-way reinforced concrete slabs subjected to different shapes of air blast loading using single degree of freedom method (SDOF). A tri-linear elastic perfectly plastic SDOF model has been used to obtain the pressure-impulse diagram to correlate the blast pressure and the corresponding concrete flexural damage. In order to capture the response history for the slab, a new approximately SDOF method based on the conventional SDOF method is proposed and validated using published test data. The influences of pulse loading shape on the pressure-impulse diagram are studied. Based on the results, a pressure-impulse diagram generation method using SDOF and an analytical equation for the pressure-impulse diagram is proposed to different damage levels and different blast loading shapes.

Transcriptomic analysis reveals that cell wall- and hypersensitive response (HR)-related genes are involved in the responses of apple to Valsa mali

Wang Chao,Mao Xia,Zhao Dan,Yu Hongqiang,Duo Hu,Sun E.,Lu Yuan,Zuo Cunwu 한국식물생명공학회 2022 Plant biotechnology reports Vol.16 No.5

The necrotrophic pathogen Valsa mali (Vm) resulting Valsa canker of apple is considered one of the most destructing fungal diseases. To study the resistance mechanism, we investigated gene expression profiles of suspension cells from resistant varieties ‘Dongbeishanjingzi’ (DS, Malus baccata) and susceptible varieties ‘Gala’ (GL, Malus × domestica) in response to Vm metabolism (VmM) using RNA sequencing (RNA-seq). Functional enrichment showed that differentially expressed genes (DEGs) were widely involved in multiple metabolisms or signals, such as “Lipid metabolic process”, “plant hormone signal transduction” and “plant-pathogen interaction”. Further expressional patterns exhibited that induction of genes related to ‘‘xyloglucan biosynthetic process’’ and ‘‘cell wall biogenesis’’ was beneficial for cell wall integrity and tolerance of DS cells. In brassinosteroid signaling, we identified that TCH4 gene MbTCH4-1 positively regulated Vm resistance of ‘Fuji’ fruit, but BSK gene MdBSK1 negatively regulated the resistance. In contrast, cell death associated with hypersensitive response caused by up-regulation of CNGCs and CDPK genes is an important cause of weakened tolerance in GL cells. Our results provide a new insight direction for the molecular mechanism of apple against Valsa canker.

Two‑vector predictive current control strategy based on maximum torque per ampere control for PMSMs

Duo Jin,Housheng Zhang,Shengjie Zhu,Ao Wang,Junjie Jiang 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.8

In permanent magnet synchronous motor systems with double closed-loop maximum torque current ratio control, a PI adjuster is used as the current inner ring. Unfortunately, the current may not be tracked effectively due to controller saturation when the load suddenly changes. To counteract this effect, a novel two-vector predictive current control strategy based on maximum torque current ratio control is proposed in this paper. The control strategy introduces the model predictive current control of two voltage vectors based on maximum torque per ampere control, which is acted upon by two voltage vectors in one control period. The second selected vector is no longer limited to the null vector. The orientation and amplitude of the synthesized virtual voltage vector are adjustable. Simulation results indicate that the proposed control method has the advantages of maximum torque per ampere control and model predictive control. It optimizes the stability of the system and reduces the fluctuation of the stator current.

Predictive direct torque control of permanent magnet synchronous motors using deadbeat torque and flux control

Ao Wang,Housheng Zhang,Junjie Jiang,Duo Jin,Shengjie Zhu 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.2

In consideration of the shortcomings of the large torque and flux ripples in direct torque control (DTC), and the insufficient utilization of the duty cycle module in traditional DTC based on the duty cycle modulation of PMSMs, a DTC method based on deadbeat control of the torque and flux is proposed in this paper. In the synchronous rotation, coordinate system positioned with the stator flux vector, the reference voltage vector is calculated in accordance to the deadbeat control method. Six virtual voltages are constructed in such a manner that two adjacent basic voltage vectors are evenly divided in one control cycle. The effective voltage vectors are expanded to 12. The effective voltage vector closest to the phase angle of the reference voltage vector is determined to be the optimal voltage vector. Then, the duty cycle is introduced to further reduce the error between the final output voltage vector and the voltage vector required by the system. Simulation comparisons are carried out for DTC, traditional DTC based on duty cycle modulation, and the proposed DTC. The obtained simulation results demonstrate that the proposed DTC can effectively suppress both torque ripple and flux ripple, improve the utilization rate of the duty cycle module, and reduce the stator current distortion rate.

Impact of feeding regimens on the composition of gut microbiota and metabolite profiles of plasma and feces from Mongolian sheep

Bohui Wang,Yulong Luo,Rina Su,Duo Yao,Yanru Hou,Chang Liu,Rui Du,Ye Jin 한국미생물학회 2020 The journal of microbiology Vol.58 No.6

Mongolian sheep are an indigenous ruminant raised for wool and meat production in China. The gut microbial community plays an important role in animal performance and metabolism. The objective of this study was to investigate the effects of two feeding regimens on the diversity and composition of gut microbiota and metabolite profiles of feces and plasma from Mongolian sheep. A total of 20 Mongolian sheep were assigned to one of two feeding regimens: free grazing (FG) and barn confinement (BC). When samples were collected, the average live weights of the sheep were 31.28 ± 1.56 kg and 34.18 ± 1.87 kg for the FG and BC groups, respectively. At the genus level, the FG group showed higher levels of Bacteroides, RC9_gut_group, Alistipes, Phocaeicola, Barnesiella, and Oscillibacter, and lower levels of Succinivibrio, Treponema, and Prevotella, compared to the BC group. The butyric acid content in feces was lower in the FG group (P < 0.05). Higher levels of palmitic acid, oleic acid, alpha-linolenic acid, L-carnitine, L-citrulline, and L-histidine, and lower levels of L-tyrosine, L-phenylalanine, and L-kynurenine were found in the plasma of the FG sheep. Moreover, there were substantial associations between several gut microbiota genera and alterations in feces and plasma metabolites especially those involved in the metabolism of butyric acid, linolenic acid, and L-tyrosine. Feeding regimens can not only influence the composition of gut microbiota, but also alter metabolic homeostasis in sheep.