Solidification Structure Evolution and Grain Refinement Mechanism of a Deeply Undercooled Ni65Cu35 Alloy

Xiaolong Xu,Yukang An,Hua Hou,Yuhong Zhao 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

The maximum 320 K undercooling of Ni65Cu35 alloy was obtained by means of cyclic superheating in the state of moltenglass. The solidification structuresat different undercoolings were systematically studied. There are two grain refinementsatlow and high undercoolings. It was generally believed that the grain refinement atlowundercooling was caused by dendritesuperheat remelting. Electron backscattering diffraction was used to characterize the solidification structure athighundercooling,and obvious random orientation, high-angle grain boundaries and twin boundaries were found, indicating grainrefinement was caused by recrystallization under highundercooling. There were almost no visible dislocation defects in theTEM bright-field images at high undercooling, and the microstructure hardness decreased obviously after grain refinement. This further illustrated the rapid accumulation of stress and defects in recalescenceare completely abreacted in recrystallizationduring post-recalescence period, at the same time as the driving force to promote the second grain refinement inthe microstructure.

The Secure IEEE 11073:20601 Protocol and Agent Structure for Protecting PHD

Xiaolong Xu,Zhonghe Gao,Lijuan Han 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.12

In this paper, we suggest improvements of security in IEEE 11073:20601 protocol and the structure of its agent for protecting user’s healthcare information safely. Current IEEE 11073:20601 standard does not provide any method to ensure security of data exchange, and it assumes that data exchange is secured by other means. The suggested improvements include mechanism to enhance security in exchanging and storing data in PHD. While providing those advantages, it also satisfies availability by effective encoding rules and data protecting algorithm.

CDH17 nanobodies facilitate rapid imaging of gastric cancer and efficient delivery of immunotoxin

Jingbo Ma,Xiaolong Xu,Chunjin Fu,Peng Xia,Ming Tian,Liuhai Zheng,Kun Chen,Xiaolian Liu,Yilei Li,Le Yu,Qinchang Zhu,Yangyang Yu,Rongrong Fan,Haibo Jiang,Zhifen Li,Chuanbin Yang,Chengchao Xu,Ying Long,J 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Background: It is highly desirable to develop new therapeutic strategies for gastric cancer given the low survival rate despite improvement in the past decades. Cadherin 17 (CDH17) is a membrane protein highly expressed in cancers of digestive system. Nanobody represents a novel antibody format for cancer targeted imaging and drug delivery. Nanobody targeting CHD17 as an imaging probe and a delivery vehicle of toxin remains to be explored for its theragnostic potential in gastric cancer. Methods: Naïve nanobody phage library was screened against CDH17 Domain 1-3 and identified nanobodies were extensively characterized with various assays. Nanobodies labeled with imaging probe were tested in vitro and in vivo for gastric cancer detection. A CDH17 Nanobody fused with toxin PE38 was evaluated for gastric cancer inhibition in vitro and in vivo. Results: Two nanobodies (A1 and E8) against human CDH17 with high affinity and high specificity were successfully obtained. These nanobodies could specifically bind to CDH17 protein and CDH17-positive gastric cancer cells. E8 nanobody as a lead was extensively determined for tumor imaging and drug delivery. It could efficiently co-localize with CDH17-positive gastric cancer cells in zebrafish embryos and rapidly visualize the tumor mass in mice within 3 h when conjugated with imaging dyes. E8 nanobody fused with toxin PE38 showed excellent anti-tumor effect and remarkably improved the mice survival in cell-derived (CDX) and patient-derived xenograft (PDX) models. The immunotoxin also enhanced the anti-tumor effect of clinical drug 5-Fluorouracil. Conclusions: The study presents a novel imaging and drug delivery strategy by targeting CDH17. CDH17 nanobodybased immunotoxin is potentially a promising therapeutic modality for clinical translation against gastric cancer.

Bacterial Community Structure and Function Shift in Rhizosphere Soil of Tobacco Plants Infected by Meloidogyne incognita

Wenjie Tong(Wenjie Tong),Junying Li(Junying Li),Wenfeng Cong(Wenfeng Cong),Cuiping Zhang(Cuiping Zhang),Zhaoli Xu(Zhaoli Xu),Xiaolong Chen(Xiaolong Chen),Min Yang(Min Yang),Jiani Liu(Jiani Liu),Lei Yu 한국식물병리학회 2022 Plant Pathology Journal Vol.38 No.6

Root-knot nematode disease is a widespread and catastrophic disease of tobacco. However, little is known about the relationship between rhizosphere bacterial community and root-knot nematode disease. This study used 16S rRNA gene sequencing and PICRUSt to assess bacterial community structure and function changes in rhizosphere soil from Meloidogyne incognita-infected tobacco plants. We studied the rhizosphere bacterial community structure of M. incognita-infected and uninfected tobacco plants through a paired comparison design in two regions of tobacco planting area, Yuxi and Jiuxiang of Yunnan Province, southwest China. According to the findings, M. incognita infection can alter the bacterial population in the soil. Uninfested soil has more operational taxonomic unit numbers and richness than infested soil. Principal Coordinate Analysis revealed clear separations between bacterial communities from infested and uninfested soil, indicating that different infection conditions resulted in significantly different bacterial community structures in soils. Firmicutes was prevalent in infested soil, but Chloroflexi and Acidobacteria were prevalent in uninfested soil. Sphingomonas, Streptomyces, and Bradyrhizobium were the dominant bacteria genera, and their abundance were higher in infested soil. By PICRUSt analysis, some metabolism-related functions and signal transduction functions of the rhizosphere bacterial community in the M. incognita infection-tobacco plants had a higher relative abundance than those uninfected. As a result, rhizosphere soils from tobacco plants infected with M. incognita showed considerable bacterial community structure and function alterations.

Surgical Options for Appropriate Length of J-Pouch Construction for Better Outcomes and Long-term Quality of Life in Patients with Ulcerative Colitis after Ileal Pouch-Anal Anastomosis

Xu Weimin,Tang Wenbo,Ding Wenjun,Hua Zhebin,Wang Yaosheng,Ge Xiaolong,Cui Long,Wu Xiaojian,Zhou Wei,Ding Zhao,Du Peng 거트앤리버 소화기연관학회협의회 2024 Gut and Liver Vol.18 No.1

Background/Aims: Total proctocolectomy with ileal pouch-anal anastomosis (IPAA) is widely accepted as a radical surgery for refractory ulcerative colitis (UC). Definite results on the appropriate pouch length for an evaluation of the risk-to-benefit ratio regarding technical complications and long-term quality of life (QOL) are still scarce. Methods: Data on UC patients who underwent IPAA from 2008 to 2022 in four well-established pouch centers affiliated to China UC Pouch Center Union were collected. Results: A total of 208 patients with a median follow-up time of 6.0 years (interquartile range, 2.3 to 9.0 years) were enrolled. The median lengths of the patients’ short and long pouches were 14.0 cm (interquartile range, 14.0 to 15.0 cm) and 22.0 cm (interquartile range, 20.0 to 24.0 cm), respectively. Patients with a short J pouch configuration were less likely to achieve significantly improved long-term QOL (p=0.015) and were prone to develop late postoperative complications (p=0.042), such as increased defecation frequency (p=0.003) and pouchitis (p=0.035). A short ileal pouch was an independent risk factor for the development of late postoperative complications (odds ratio, 3.100; 95% confidence interval, 1.519 to 6.329; p=0.002) and impaired long-term QOL improvement (odds ratio, 2.221; 95% confidence interval, 1.218 to 4.050, p=0.009). Conclusions: The length of the J pouch was associated with the improvement in long-term QOL and the development of late post-IPAA complications. A long J pouch configuration could be a considerable surgical option for pouch construction.

Fluctuation Power Control Strategy for MMC-based SST to Reduce the Submodule Capacitor Voltage Oscillation

Xiaolong Cai,Jianwen Zhang,Gang Shi,Xu Cai,Jianqiao Zhou,Zhuyong Li,Jiacheng Wang,Jiajie Zang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

In the future AC-DC hybrid distribution system, solid state transformer (SST) will take place of conventional transformer, as it could reduce the weight and volume of transformer, and achieve voltage and current regulation, power flow control, power quality enhancement. MMC-based SST is a novel SST topology, which could provide the MVDC port. However, the excessive bulky submodule capacitors limits this topology into practical application. This paper proposes a fluctuation power control strategy for MMC-based SST to reduce the submodule capacitor voltage oscillation, which could optimize the capacitance and reduce the volume and cost of capacitor. The feasibility of this proposed method is verified by MATLAB simulation.

Vortex-Induced Vibration Characteristics and Equivalent Static Force Calculation Method of Circular Steel Hangers on Arch Bridge

Xinyu Xu,Yingliang Wang,Xingyu Chen,Xiaolong Zheng,Yongping Zeng 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.4

In order to study the vortex-induced vibration (VIV) characteristics and equivalent static force calculation method of circular steel hangers on the arch bridge, a numerical simulation model of VIV was established using FLUENT software, and the reliability of the model was verified by wind tunnel tests. Effects of wind speed, damping ratio, initial tension and slenderness ratio on the VIV characteristics of circular steel hanger were investigated. Furthermore, the equivalent static force calculation formula and loading range of hanger considering VIV were presented. The results show that with the hanger’s damping ratio decreasing, the maximum amplitude and the lock-in wind speed range increases gradually, while the wind speed and frequency of VIV at the maximum amplitude were not significantly affected. As the initial tension increases or the slenderness ratio decreases, the frequency of VIV increases, and the wind speed corresponding to the maximum amplitude increases, however the maximum vibration amplitude has few changes. Based on a number of numerical analyses on VIV characteristics of hangers, the equivalent static force calculation method is put forward. The equivalent static force calculation method could provide a reference for the design and static analysis of the circular steel hangers.

Stress sensitivity in naturally fractured reservoirs: a case study of the Lower Cretaceous Xiagou Formation, Qingxi Oilfield, Jiuxi Basin, northwestern China

Wei Ju,Xiaolong Fu,Weifeng Sun,Haoran Xu,Shengyu Wang 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.3

Stress sensitivity is the variation of rock petrophysical parameters resulting from changes in effective stress. In fractured reservoirs, experimental methods exhibit a certain amount of error in the quantitative analysis of reservoir rock stress sensitivity. In addition, fracture-bearing experimental rock samples are difficult to obtain and prepare. Therefore, in the present study, reservoir rock stress sensitivity in naturally fractured reservoirs was investigated based on geomechanical modeling using a case study of the Lower Cretaceous Xiagou Formation in the Qingxi Oilfield. The results indicate that the Xiagou fractured reservoir experiences strong stress sensitivity with a fracture permeability damage rate reaching 94.38%. Natural fractures influence reservoir rock stress sensitivity. The degree of filling and type of filled minerals within natural fractures have great effects on the permeability damage rate. A higher permeability damage rate suggests stronger rock stress sensitivity. Generally, I) for reservoir rocks with unfilled natural fractures, the permeability damage rate is extremely high; II) for reservoir rocks with partially filled natural fractures, the permeability damage rate is high, and if the minerals within the natural fractures are insoluble, the permeability damage rate is slightly higher than if the materials are soluble; III) for reservoir rocks with completely filled natural fractures, the permeability damage rate is extremely low if the minerals within the natural fractures are insoluble; however, if the materials are soluble, the permeability becomes slightly higher with the increase of effective stress. Most importantly, this study provides a practical method for analyzing stress sensitivity in naturally fractured reservoirs.

Increased Wall Enhancement Extent Representing Higher Rupture Risk of Unruptured Intracranial Aneurysms

Jiang, Yeqing,Xu, Feng,Huang, Lei,Lu, Gang,Ge, Liang,Wan, Hailin,Geng, Daoying,Zhang, Xiaolong The Korean Neurosurgical Society 2021 Journal of Korean neurosurgical society Vol.64 No.2

Objective : This study aims to investigate the relationship between aneurysm wall enhancement and clinical rupture risks based on the magnetic resonance vessel wall imaging (MR-VWI) quantitative methods. Methods : One hundred and eight patients with 127 unruptured aneurysms were prospectively enrolled from Feburary 2016 to October 2017. Aneurysms were divided into high risk (≥10) and intermediate-low risk group (<10) according to the PHASES (Population, Hypertension, Age, Size of aneurysm, Earlier SAH history from another aneurysm, Site of aneurysm) scores. Clinical risk factors, aneurysm morphology, and wall enhancement index (WEI) calculated using 3D MR-VWI were analyzed and compared. Results : In comparison of high-risk and intermediated-low risk groups, univariate analysis showed that neck width (4.5±3.3 mm vs. 3.4±1.7 mm, p=0.002), the presence of wall enhancement (100.0% vs. 62.9%, p<0.001), and WEI (1.6±0.6 vs. 0.8±0.8, p<0.001) were significantly associated with high rupture risk. Multivariate regression analysis revealed that WEI was the most important factor in predicting high rupture risk (odds ratio, 2.6; 95% confidence interval, 1.4-4.9; p=0.002). The receiver operating characteristic (ROC) curve analysis can efficiently differentiate higher risk aneurysms (area under the curve, 0.780; p<0.001) which have a reliable WEI cutoff value (1.04; sensitivity, 0.833; specificity, 0.67) predictive of high rupture risk. Conclusion : Aneurysms with higher rupture risk based on PHASES score demonstrate increased neck width, wall enhancement, and the enhancement intensity. Higher WEI in unruptured aneurysms has a predictive value for increased rupture risk.

Preparation and Self-Healing Behaviors of Poly(acrylic acid)/Cerium Ions Double Network Hydrogels

Hongwei Zhou,Guohe Xu,Jie Li,Shihao Zeng,Xiaolong Zhang,Zhaohui Zheng,Xiaobin Ding,Weixing Chen,Qiguan Wang,Wenzhi Zhang 한국고분자학회 2015 Macromolecular Research Vol.23 No.12

This work aims at developing an approach to poly(acrylic acid)/cerium ions (PAA/cerium ions) double network hydrogels and exploring the self-healing properties of the hydrogels, with expectation to provide some clues for constructing new healable gel actuators and enrich the family of self-healable hydrogels. The hydrogel is covalently crosslinked by a traditional crosslinking agent N,N'-methylene bis-acrylamide to form the first network and further physically crosslinked by the ionic interaction between cerium ions and the carboxyl groups in the hydrogel network. The preparation method and self-healing behaviors of the hydrogels are investigated.