Equine hyperimmune serum protects mice against Clostridium difficile spore challenge

Weiwei Yan,Kang-Soon Shin,Shih-Jon Wang,Hua Xiang,Thomas Divers,Sean McDonough,James Bowman,Anne Rowlands,Bruce Akey,Hussni Mohamed,Yung-Fu Chang 대한수의학회 2014 Journal of Veterinary Science Vol.15 No.2

Clostridium (C.) difficile is a common cause of nosocomialdiarrhea in horses. Vancomycin and metronidazole havebeen used as standard treatments but are only moderatelyeffective, which highlights the need for a novel alternativetherapy. In the current study, we prepared antiserum ofequine origin against both C. difficile toxins A and B as wellas whole-cell bacteria. The toxin-neutralizing activities of theantibodies were evaluated in vitro and the prophylacticeffects of in vivo passive immunotherapy were demonstratedusing a conventional mouse model. The data demonstratedthat immunized horses generated antibodies against bothtoxins A and B that possessed toxin-neutralizing activity. Additionally, mice treated with the antiserum lost less weightwithout any sign of illness and regained weight back to anormal range more rapidly compared to the control groupwhen challenged orally with 107 C. difficile spores 1 day afterserum injection. These results indicate that intravenousdelivery of hyperimmune serum can protect animals from C. difficile challenge in a dose-dependent manner. Hence,immunotherapy may be a promising prophylactic strategyfor preventing C. difficile infection in horses.

Covalent bonding of ZnO nanostructures with dispersible carbon nanotubes for self-assembly photocatalytic heterostructures

Tie, Weiwei,Jin, Jiaming,Bhattacharyya, Surjya Sarathi,Yue, Hongwei,Lei, Yan,Zheng, Zhi,He, Weiwei,Lee, Seung Hee Elsevier BV * North-Holland 2019 Applied Surface Science Vol.492 No.-

<P><B>Abstract</B></P> <P>This work demonstrates the fabrication of zinc oxide‑carbon nanotube (ZnO/CNT) heterostructures with tunable photocatalytic activity via microstructure modulation. The ZnO/CNT heterostructures are constructed in one-step hydrothermal procedure consisting of in situ anchoring of ZnO nanostructures with dispersible CNTs in an aqueous alkali solution containing bile salts as a dispersant. Observation via scanning (SEM) and transmission (TEM) electron microscopy reveals self-assembled heterostructures of monodispersible CNTs tightly surrounding ZnO nanostructures with multimorphology. The XRD, FT-IR, Raman and XPS analysis confirm that the CNTs were successfully incorporated into the ZnO nanostructures with strong interfacial contact of covalent bonding rather than simple mixing. A series of ZnO/CNT heterostructures, which varies according to their degree of doping with dispersible CNTs, exhibit distinct sunlight-induced photocatalytic activity onto the degradation of Rhodamine B (RhB). The superior photocatalytic performance of ZnO/CNT heterostructures originates from synergistic effects of sufficient interfacial bonding, self-assembly microstructures, and continuous conducting pathways between ZnO nanostructures and CNTs, which acquires better sunlight utilization and more efficient separation of electron-hole pair, confirmed by UV–Visible diffuse reflectance spectra as well as photocurrent and photovoltage analysis. This study also proposes a photocatalytic degradation mechanism of RhB dyes through detection of active species confirmed by electron-spin-resonance analysis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> ZnO nanostructures covalently linking with dispersible carbon nanotubes for self-assembly heterostructures are synthesized. </LI> <LI> This sunlight-driven self-assembly heterostructures possess tunable photocatalytic activity via microstructure modulation. </LI> <LI> The charge separation and transfer process are monitored by transient photovoltaic and photocurrent measurement. </LI> </UL> </P>

Asocial: Adaptive Task Re-Allocation in Distributed Computing Systems with Node Failures

Yanli Shen,Taoshun Xiao,Weiwei Zheng 한국통신학회 2020 한국통신학회 APNOMS Vol.2020 No.09

Task allocation-the problem of efficiently allocating a set of M tasks to a set of N nodes-is a fundamental issue in distributed computing systems (DCSs). The problem is particularly challenging in the presence of fail-prone nodes. In this work, we design an adaptive task (re-)allocation mechanism, named Asocial. The Asocial allows us to optimize the utilization of system resources (including computing resources and network resources) while increasing service-level fault tolerance as well as failure resilience. In addition, we propose a cooperative game model based task (re-)allocation approach for cooperation among Physical Nodes (PNs). We consider both the performance states and reliability levels of candidate PNs when deploying tasks. Specifically, we exploit failure prediction techniques to evaluate PNs’ reliability levels. As a result, we can utilize the resources efficiently and thus improve the service reliability (i.e., the probability of serving all the tasks before their delivery time). We show by means of numerical evaluations that the proposed Asocial can significantly improve service reliability, system availability as well as resource utilization. In particular, by using failure prediction result (F-measure is around 0.8), the application completion rate (ACR), the task completion rate (TCR) and the computing resource utilization (CRU) reach 85.20%, 85.67% and 78.34%, respectively. Compared with 67.30%, 70.07% and 65.79% of the initial allocation scheme, the performance achieves a significant improvement (26.60%, 22.26% and 19.08%, respectively).

Enhancement of Thermal Stability and Bending Ductility of Fe–Si–B Amorphous Ribbons with Minor Y Addition

Weiwei Dong,Xiaowei Wu,Mi Yan 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.10

The influences of minor Y addition on the thermal stability, crystallization behavior, magnetic property and bending ductilityof Fe–Si–B amorphous ribbons have been systematically investigated. The results show that all the ribbons with Y additionare fully amorphous structure, and the introduction of Y can enhance the glass forming ability of Fe–Si–B amorphous alloy. With Y addition, crystallization temperature of the first and second phase shift to high temperature side, the temperatureinterval between the two crystallization peaks are enlarged, the third phase transitions process of Fe–Si–B amorphous alloywith Y addition corresponds to the precipitation of Fe3Bphase. The activation energy of the first and second phase calculatedby Kissinger’s formula increased with Y addition. Appropriate Y addition is beneficial for Ms. The measured coercivity Hcgradually decreased with the Y addition increased. The amorphous alloys exhibit good bending ductility in the quenchedstate. The ductile to brittle temperature increase to 300 °C with 1 at% Y addition. Furthermore, the mechanism of ductile tobrittle for amorphous alloy was discussed.

The durability and rehabilitation technologies of concrete sewerage pipes: A state-of-the-art review

Zhuge Yan,Fan Wei,Duan Weiwei,Liu Yue 아시아콘크리트학회 2021 Journal of Asian Concrete Federation Vol.7 No.2

This paper reviews the literature available on the subject of the durability of concrete sewer pipes and the corresponding rehabilitation technologies. An introduction related to the importance of the sewer system in urban life and its durability issues was first discussed as most people did not recognise the scale and complexity of the underground sewer system. Then the recent development of alternative binder materials or filler materials to improve the acid resistance of concrete was specified. For instance, the effects of alternative binders on the hydration products and the mechanism of biogenic corrosion were discussed in detail. The paper ends with the current rehabilitation technologies and the structural performance of rehabilitated sewer pipes. Also, some suggestions associated with future research were made.

肥胖青少年健康素养研究进展

严雪琴(Xueqin Yan),刘薇薇(Weiwei Liu),雷迅(Xun Lei),吴成斌(Chengbin Wu) 아시아사회과학학회 2023 International Science Research Vol.3 No.1

The incidence of obesity has risen rapidly in the world, and the occurrence and development of obesity is closely related to the “three high” problem of adolescents after adulthood, which has become one of the most serious public health problems. China's teenagers are not only facing the problem of obesity, but also lack understanding of health-related knowledge, and their health literacy needs to be improved. Based on the analysis of the epidemic trend of adolescent obesity, this paper focuses on the relevant factors affecting the health literacy of obese adolescents, and puts forward countermeasures from the four levels of the country, school, family and individual, in order to improve and enhance their health literacy level, and provide theoretical basis for achieving the overall goal of national health.

Computational Bio-Fluid Mechanics

Yang Liu,Weiwei Yan,Mingzhen Lu,Bingmei Fu 한국전산유체공학회 2014 한국전산유체공학회 학술대회논문집 Vol.2014 No.10

It has been found that both circulating blood cells and tumor cells are more easily adherent to curved microvessels than straight ones. In this paper, the hypothesis that tumor cells prefer to adhere at the microvessels with localized shear stresses and their gradients, such as in the curved microvessels, was examined both experimentally and computationally. The fluid dynamics was carried out by the lattice Boltzmann method (LBM), and the cell dynamics was governed by the Newton’s law of translation and rotation. The adhesive dynamics model is involved the effect of receptor-ligand bonds between circulating cells and endothelial cells (ECs). It was found that the wall shear stress/gradient, over a threshold, had significant contribution to tumor cell adhesion by activating or inactivating cell adhesion molecules. Our results elucidated why the tumor cell adhesion prefers to occur at the positive curvature of curved microvessels with very low Reynolds number (in the order of 10<SUP>-2</SUP>) laminar flow. Obstructive sleep apnea (OSA) is a common disorder characterized by partial or complete narrowing of the pharyngeal airway during sleep. The success rate of OSA surgery is very low, CFD is a good alternative tool to understand OSA pathophysiology. We have carried out both LES simulation and experimental measurement in real OSA upper airways for both before and after surgery, and a good agreement is achieved.

Biosynthesis of Three Chalcone β-D-glucosides by Glycosyltransferase from Bacillus subtilis ATCC 6633

( Yinuo Fei ),( Yan Shao ),( Weiwei Wang ),( Yatian Cheng ),( Boyang Yu ),( Xiaorong He ),( Jian Zhang ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 한국미생물·생명공학회지 Vol.49 No.2

Chalcones exhibit multiple biological activities. Various studies have attempted to modify the structure of chalcones with a special focus on the addition of substituents to the benzene rings. However, these chemical modifications did not improve the water solubility and bioavailability of chalcones. Glycosylation can markedly affect the physical and chemical properties of hydrophobic compounds. Here, we evaluated the ability of a highly promiscuous glycosyltransferase (GT) BsGT1 from Bacillus subtilis ATCC 6633 to biosynthesize chalcone glucosides. Purified BsGT1 catalyzed the conversion of 4'-hydroxychalcone (compound 1), 4'-hydroxy-4-methylchalcone (compound 2), and 4-hydroxy-4'-methoxychalcone (compound 3), into chalcone 4'-O-β-D-glucoside (compound 1a), 4-methylchalcone 4'-O-β-D-glucoside (compound 2a), and 4'- methoxychalcone 4-O-β-D-glucoside (compound 3a), respectively. To avoid the addition of expensive uridine diphosphate glucose (UDP-Glc), a whole-cell biotransformation system was employed to provide a natural intracellular environment for in situ co-factor regeneration. The yields of compounds 1a, 2a, and 3a were as high as 90.38%, 100% and 74.79%, respectively. The successful co-expression of BsGT1 with phosphoglucomutase (PGM) and UDP-Glc pyrophosphorylase (GalU), which are involved in the biosynthetic pathway of UDP-Glc, further improved the conversion rates of chalcones (the yields of compounds 1a and 3a increased by approximately 10%). In conclusion, we demonstrated an effective whole-cell biocatalytic system for the enzymatic biosynthesis of chalcone β-D-glucoside derivatives.

Effectiveness of Chinese medicine formula Huashibaidu granule on mild COVID-19 patients: A prospective, non-randomized, controlled trial

Bowu Chen,Yan Xue,Hua Jing,Xiaodong Wang,Peimin Zhu,Weiwei Hao,Man Li,Yueqiu Gao 한국한의학연구원 2023 Integrative Medicine Research Vol.12 No.2

Background: The effectiveness and safety of herbal medicine Huashibaidu granule (HSBD) in treating mild Coronavirus Disease 2019 (COVID-19) patients infected with SARS-CoV-2 remain to be identified. We aimed to evaluate the effectiveness of HSBD in mild COVID-19 patients. Methods: A prospective, non-randomized, controlled study in mild COVID-19 patients was conducted in Shanghai, China, from April 8 to May 6, 2022. Finally, 360 mild COVID-19 patients received HSBD (orally 20 g twice daily for 7 days), and 368 patients received herbal medicine placebo (orally 20 g twice daily for 7 days). The primary endpoints were the negative conversion rate of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and the negative conversion time. Secondary endpoints included the hospitalized days and the improvement in the clinical condition. Results: The negative conversion rate of SARS-CoV-2 at 7 days posttreatment in the HSBD group was higher than that in the control group (95.28% vs. 82.61%, P < 0.001). The median negative conversion time in the HSBD group was markedly decreased by 2 days compared with the control group (3 [3–6] vs. 5 [4–7], P < 0.001). In addition, the median hospitalized day was shortened in the HSBD group by 1 day compared with the control group (6 [4–7] vs. 7 [5–9], P < 0.001). The clinical improvement rate (275/360 [76.39%]) in the HSBD group within 7 days was significantly higher than that (203/368 [55.16%]) in the control group (P < 0.001). The improvement of symptom scores in the HSBD group was higher than that in the control group (2 [1–4] vs. 1 [1–2], P < 0.001). No severe adverse events occurred. Conclusions: Our study suggested that HSBD effectively increased the negative conversion rate of SARS-CoV-2 and shortened the negative conversion time and hospitalized days in mild COVID-19 patients. Clinical trial registration: The trial was registered at Chinese Clinical Trial Registry, ChiCTR2200058668.

Synthesis and characterization of novel Ti-containing mesoporous silicas support

Peihong Yao,Weiwei Hu,Yan Bao,Cuiling Zhang,Bochao Zhu,Wenxia Liu,Yongxiao Bai 한양대학교 세라믹연구소 2011 Journal of Ceramic Processing Research Vol.12 No.3

Titanium-containing novel mesoporous silicas have been synthesized at ambient temperature by a sol-gel method using amines with alkyl chains of 10-16 carbon atoms as a templating surfactant. An identical synthesis procedure was followed together with the addition of different amounts of titanium (IV) source in the synthesis gels to obtain its titanium-containing silicate gels. Following this synthesis route, it was possible to prepare materials without forming extrawall TiO2. The transparent gel formed as a precursor resulted in a relatively high titanium incorporation in the silicate framework of up to 0.4% Ti. The characterization results show that most Ti4+ are isolated and tetrahedrally incorporated into the framework of the silicate gel. Raman spectra and UV-vis spectra indicated that most Ti atoms were incorporated as isolated Ti sites into the silicate framework, and materials with a higher wt% Ti using relatively more coordination agent to prevent TiO2 forming anatase.