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 Robust Method for Speech Replay Attack Detection

( Lang Lin ),( Rangding Wang ),( Diqun Yan ),( Li Dong ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.1

Spoofing attacks, especially replay attacks, pose great security challenges to automatic speaker verification (ASV) systems. Current works on replay attacks detection primarily focused on either developing new features or improving classifier performance, ignoring the effects of feature variability, e.g., the channel variability. In this paper, we first establish a mathematical model for replay speech and introduce a method for eliminating the negative interference of the channel. Then a novel feature is proposed to detect the replay attacks. To further boost the detection performance, four post-processing methods using normalization techniques are investigated. We evaluate our proposed method on the ASVspoof 2017 dataset. The experimental results show that our approach outperforms the competing methods in terms of detection accuracy. More interestingly, we find that the proposed normalization strategy could also improve the performance of the existing algorithms.

Analysis of Stress-strain Characteristics of Geogrid Reinforced Crushed Gravel

Ruiqing Lang,Aiwu Yang,Shuwang Yan 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.2

To study the stress-strain characteristics of reinforced cushion with multi-layer geogrids, a new calculation method was proposed. Based on hyperbolic model, the reinforced cushion was regard as a nonlinear elastomer. The effect of reinforcing geogrids was considered as an equivalent additional pressure and included into the gravel skeleton. Considering the friction effect between geogrids and crushed gravel, the calculation method of stress-strain relationship and shear strength of the reinforced crushed gravel was deduced through definite integral. The proposed method was verified by triaxial tests and the calculated results were in good agreement with the measured data. Furthermore, the key parameters influencing the shear strength, such as the total number of geogrids, the geogrids spacing and the corresponding position, were quantified through sensitivity analysis. The effects of the key parameters on the stress-strain relationship of reinforced cushion were determined. It is shown that the ability of reinforced body to resist bulging deformation is great improved by geogrids. The key parameters are the confining pressure and the total number of geogrids. With the increase of the total number and the confining pressure, the shear strength of the reinforced body increases; but the shear strength is less affected by its location. The research results can provide reference for practical projects.

Interactive Image Segmentation Based on Gaussian Mixture Models with Spatial Prior

Mo Yan,Peng-Lang Shui 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.7

In this paper, an interactive color natural image segmentation method is proposed. The method extends the Gaussian Mixture Model (GMM) by taking into account user markers as useful spatial prior. In this way, a distribution combining with color and spatial location is obtained. The distribution is incorporated in a Bayesian MAP approach. The approach is formalized as an iterative energy minimization problem. A direct global minimization technique based on variational method is employed to get binary solution. After each iteration, the largest connected region from foreground is used to update foreground GMMs and achieve more superior performance than original GrabCut method. Extensive experiments are performed on public benchmark datasets such as GrabCut benchmark, Berkeley segmentation database and Graz benchmark. The results show that the proposed method can extract the object region from the complex background accurately.

NiO Nanocrystalline/Reduced Graphene Oxide Composite Film with Enhanced Electrochromic Properties

Fengpei Lang,Jingbing Liu,Hao Wang,Hui Yan 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.5

The NiO nanocrystalline/reduced graphene oxide (rGO) composite film was successfully synthesized using a simple hot-injection and dip coating method. The as-prepared samples were characterized using X-ray diffraction (XRD), Raman, scanning electron microscope (SEM), ultraviolet and visible spectrophotometer (UV). Compared to the NiO film, the NiO nanocrystalline/rGO composite film exhibits enhanced electrochromic properties and large ΔT (40.7% at 550 nm), fast switching speed (tc = 4.3 s and tb = 3.9 s), high coloration efficiency (12.85 cm2 C -1) and better cycling performance (1000 cycles). The improvement of the electrochromic properties was attributed to the large specific surface area and good conductivity of the rGO.

Molecular Engineering of Metal-Organic Cycles/Cages for Drug Delivery

Nicola Judge,Lang Wang,Yannis Yan Lum Ho,Yufeng Wang 한국고분자학회 2018 Macromolecular Research Vol.26 No.12

The assembly of nanoscale materials with well-defined size and shape is an intriguing approach to aid in drug design and delivery. Of the various nano-structures that have been synthesised, metal-organic cycles and cages (MOCs), featuring great structural versatility, have emerged as promising components in cancer chemotherapeutics. We review the recent progress of exploiting self-assembled MOCs as anticancer drugs as well as drug carriers. Particularly molecular engineering designs allow MOCs to carry drugs with specificity, and interface with biological systems whilst possessing the desired stability, cytotoxicity, and compatibility. A special focus is given to the functionalization method of integrating MOCs with polymers, leading to the synthesis of colloidal nanoparticles-micelles and vesicles-that possess combined properties and extended system tunability.

The Influence of Epoxy Functionalized Acrylate Particles on the Properties of Plasticized PLA Blown Films

Ye Zhang,Yan Zhao,Hongwei Pan,Xianzhong Lang,Huili Yang,Huiliang Zhang,Huixuan Zhang,Lisong Dong 한국고분자학회 2016 폴리머 Vol.40 No.3

Polylactide (PLA) was plasticized with poly(diethylene glycol adipate) (PDEGA). The plasticized PLA was further blended with core-shell structured particles of glycidyl methacrylate-functionalized methyl methacrylate-butyl acrylate copolymer (GACR) using a twin-screw extruder, and the extruded samples were blown using the blown thin film technique. Both PDEGA and GACR significantly influenced the physical properties of the films. Compared to neat PLA, the elongation at break and tear strength of the films were significantly improved. The shear yielding induced by cavitation of GACR particles was the major tearing mechanism. GACR could act as a tear resistance modifier for PLA blown films. The spherulite size of the PLA/PDEGA/GACR films decreased with the addition of GACR. The biodegradability of the PLA/PDEGA/GACR films decreased slightly. These findings contributed new knowledge to the additive area and gave important implications for designing and manufacturing polymer packaging materials.

Dry hob with heat transfer enhancement based on field synergy and its temperature field distribution

Xiao Yang,Lang He,Peng Chen,Benjie Li,Yan-bin Du 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.7

Excessive heat accumulation is an essential factor in dry hob wear. Given this problem, this research is conducted on a dry hob with heat transfer enhancement by field synergy (FS-HTE dry hob). Firstly, through the combination of simulation and thermal image reconstruction, the heat accumulation behavior and thermal-induced wear mechanism are investigated for traditional dry hob. Then, using field synergy theory, a three-dimensional solid model is established for FS-HTE dry hob based on the structure of traditional dry hob. Finally, a process experiment by fluid-solid coupling simulation is executed to explore the temperature field distribution law of the FS-HTE dry hob as well as the temperature control mechanism. Results show that the minimum average temperature can be reached for the FS-HTE dry hob characterized by 0° synergy angle. It is also beneficial to suppress the thermal-induced wear benefiting from the characteristics of value and distribution law for the high-temperature region. The research demonstrates a potential method for the thermal-induced wear suppression of dry hob in green dry hobbing.

Synthesis and Self-Assembly Behavior of Six-Armed Block Copolymers with pH- and Thermo-Responsive Properties

Xiujuan Huang,Yan Xiao,Meidong Lang 한국고분자학회 2011 Macromolecular Research Vol.19 No.2

A series of amphiphilic six-armed copolymers, containing poly(ε-caprolactone) (PCL) and poly(2-(diethylamino)ethyl methacrylate) (PDEAEMA or PDEA) as the arm and cyclotriphosphazene as the core, were obtained by a combination of ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). The star block S(PCL-b-PDEAEMA) copolymers were characterized by ^1H NMR spectroscopy and size exclusive chromatography (SEC). These copolymers could self-assembly into micelles in an aqueous solution at low pH with a low critical aggregation concentration (CAC) in the range of 2 to 10 mg/L, which depend on the composition of the copolymers. The original aggregates could further form larger micelles and/or vesicles by adjusting the external stimulus, which was examined by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The lower critical solution temperature (LCST) of the star copolymers were determined to be 49.7 and 26.3 ℃ at pH 6.5and 7.4, respectively, demonstrating a pH-dependent thermo-response.

Cloning, Expression, and Characterization of a Highly Active Alkaline Pectate Lyase from Alkaliphilic Bacillus sp. N16-5

( Gang Li ),( Lang Rao ),( Yan Fen Xue ),( Cheng Zhou ),( Yun Zhang ),( Yan He Ma ) 한국미생물 · 생명공학회 2010 Journal of microbiology and biotechnology Vol.20 No.4