Effect of MoS2 on Iron‑Based Friction Material Prepared Directly from Vanadium‑Bearing Titanomagnetite Concentrates

Yanyan Zhang,Keqin Feng,Yue Shui 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.7

The iron-based friction material was prepared directly from vanadium-bearing titanomagnetite concentrates by in situ selectivecarbothermic reactions and sintering process. This paper studies the effects of MoS2addition (1–4 wt%) on the microstructureand properties of iron-based friction material. The results show that the addition of MoS2greatly improves themicrostructure and properties of the material. During the sintering process, MoS2reacts with Fe to produce new lubricatingphase FeS and Mo which is dissolved in the Fe matrix. Appropriate amounts of FeS and Mo promote the sintering densification,which improves the microstructure by reducing the number of pores, as well as making the hard particles and graphitedistribute evenly. In addition, Mo could facilitate the formation of lamellar pearlite. As a result, the relative density, hardnessand tribological properties are significantly enhanced. Particularly, the friction coefficient decreases from 0.55 to 0.36–0.48and the wear rate decreases from 1.899 × 10−7 to 0.673 × 10−7–1.653 × 10−7 cm3/J when MoS2is added. However, excessiveMoS2deteriorates both the microstructure and properties of the material. The material containing 2 wt% MoS2representsthe optimum properties.

Working Conditions on the Afterglow Characteristics of Rare-earth Luminous Fibers

Xuefeng Guo,Keqin Zhang,Hongwei Zhang,Mingqiao Ge 한국섬유공학회 2018 Fibers and polymers Vol.19 No.3

To test and clarify the stability of afterglow performance of luminescent fibers can accelerate the step of the commercialized application on luminescent textiles. This work investigated the possible effects of a number of working conditions on the afterglow characteristics of luminous fibers. The fibers in our studies did not show any significant change in their afterglow brightness and duration after storage for 12 months under conditions of constant temperature and humidity, after 5 hours of light exposure, or soaking in water for 4 hours. The insignificant decay appears to follow the same mechanism. Thermal perturbation seemed to cause some changes to the initial brightness and decay time with the best performance being observed at about 80 oC. Moreover, contact with acid or base for 5 minutes only resulted in slight reduction of the afterglow brightness. Our studies thus indicate a high degree of stability of the afterglow performance of the luminous fibers used.

Antibacterial metabolites from the Actinomycete Streptomyces sp. P294

Huining Su,Hongwei Shao,Keqin Zhang,Guohong Li 한국미생물학회 2016 The journal of microbiology Vol.54 No.2

The Actinomycete strain P294 was isolated from soil and identified as Streptomyces sp. based upon the results of 16S rRNA sequence analysis. Three compounds obtained from the solid fermentation products of this strain have been determined by 1D, 2D NMR and HRMS experiments. These compounds include two new compounds angumycinones C (1) and D (2), and the known compound X-14881 E (3). All compounds were assayed for antibacterial and nematicidal activity. The results showed the three compounds had different degrees of inhibitory activity against several target bacteria but no significant toxicity against the nematode Caenorhabditis elegans.

Recommendations on management of gynecological malignancies during the COVID-19 pandemic: perspectives from Chinese gynecological oncologists

Yingmei Wang,Shiqian Zhang,Lihui Wei,Zhongqiu Lin,Xinyu Wang,Jianliu Wang,Keqin Hua,Manhua Cu,Jiandong Wang,Shixuan Wang,Wen Di,Yudong Wang,Ruifang An,Mingrong Xi,Ruixia Guo,Qi Zhou,Xing Xie,Fengxia X 대한부인종양학회 2020 Journal of Gynecologic Oncology Vol.31 No.4

The outbreak of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratorysyndrome coronavirus 2 has rapidly spread globally. Cancer patients are at a higher risk ofbeing infected with the coronavirus and are more likely to develop severe complications, ascompared to the general population. The increasing spread of COVID-19 presents challengesfor the clinical care of patients with gynecological malignancies. Concerted efforts should beput into managing gynecological malignancies in an orderly manner by strictly implementingthe measures that are specifically developed for controlling the spread of COVID-19. We havedrafted Recommendations on Management of Gynecological Malignancies during the COVID-19 Pandemicbased on our experience on controlling COVID-19 pandemic in China. We recommendthat patients with gynecological malignancies should be managed in hierarchical andindividualized manners in combination with local conditions related to COVID-19. Medicalcare decision should be balanced between controlling COVID-19 pandemic spread and timelydiagnosis and treatment for gynecologic oncology patients.

Genetic Relationships Among Panicle Characteristics of Rice (Oryza sativa L.) Using Unconditional and Conditional QTL Analyses

Zihong Ye,Junmin Wang,Qian Liu,Minzhou Zhang,Keqin Zou,Xianshu Fu 한국식물학회 2009 Journal of Plant Biology Vol.52 No.3

Using mixed-model-based composite interval mapping and conditional statistical methods, we studied quantitative trait loci (QTLs) with epistatic effects and QTLs by environment interaction effects for rice seed set percent (SSP), filled grain number per plant (FGP), and panicle length (PL). A population of 241 recombinant inbred lines was used which was derived from a cross between “Zhenshan 97” and “Minghui 63.” Its linkage map included 221 molecular markers. Our QTL analysis detected 28, 25, and 32 QTLs for SSP, FGP, and PL, respectively. Each QTL explained 1.37%∼13.19% of the mean phenotypic variation. A comparison of conventional and conditional mapping provided information about the genetic control system involved in the synthetic process of SSP, FGP, and PL at the level of individual QTLs. Conditional QTLs with reduced (or increased) effects were identified for SSP, which were significantly influenced by FGP or PL. Some QTLs could express independently for the given traits, thereby providing possibilities for simultaneous improvement of SSR and PL, and SSR and FGP. Epistasis was more sensitive to environmental conditions than were additive effects.

Phylogenetic Analysis on the Bacteria Producing Non-Volatile Fungistatic Substances

ZhiFang Li,ChangSong Zou,YueQiu He,MingHe Mo,KeQin Zhang 한국미생물학회 2008 The journal of microbiology Vol.46 No.3

This study characterized the soil bacteria producing non-volatile fungistatic substances. Among the 2,100 colonies of soil bacteria randomly isolated from seven agricultural soil samples, 518 isolates (24.67% of total) showed fungistatic activity toward nematophagous fungi Paecilomyces lilacinus and Trichoderma viride by producing non-volatile substances. A phylogenetic analysis based on amplified ribosomal DNA restriction analysis (ARDRA) and 16S rDNA sequence placed the 518 bacteria in three groups of the domain Bacteria: Actinomycetales, Bacillales, and Gammaproteobacteria. Three genera, Arthrobacter, Bacillus, and Pseudomonas, were the most frequently encountered groups.

Association of CDKN2B-AS1 rs1333049 with Brain Diseases: A Case-control Study and a Meta-analysis

Jikuang Zhao,Xizheng Wu,Sheng Nie,Xiang Gao,Jie Sun,Keqin Li,Tiefeng Zhang,Yi Huang 대한정신약물학회 2017 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.15 No.1

Objective: CDKN2B-AS1 polymorphisms were shown to associate with the risk of stroke in European. The goal of this study was to evaluate the contribution of CDKN2B-AS1 rs1333049 to the risk of hemorrhagic stroke (HS) and brain tumor (BT) in Han Chinese. Methods: A total of 142 HSs, 115 BTs, and 494 controls were included in the current association study. The genotyping test was performed using the melting temperature shift method. Results: We failed to validate the association of CDKN2B-AS1 rs1333049 with the risk of brain disease. Significantly higher levels of low-density lipoprotein cholesterol (LDL-C) (p=0.027), high-density lipoprotein cholesterol (HDL-C) (p<0.001) and total cholesterol (TC) (p<0.001) were found in HSs in the genotype GG/GC carriers, but not the genotype CC carriers (p>0.05). The meta-analysis of 10 studies among 133,993 individuals concluded that rs1333049 of CDKN2B-AS1 gene was likely to increase a 16% incidence rate of cerebrovascular disease (CD) among various populations (odds ratio 1.16, 95% confidence interval 1.08-1.25; p<0.0001, random-effect method). Conclusion: Our case-control study identified rs1333049 genotypes showed different association with the concentration of the LDL-C, HDL-C and TC in the HS patients. Meta-analysis supported the association between rs1333049 and CD risk in various populations, although we were unable to observe association between rs1333049 and the risk of HSs in Han Chinese.

Intraoperative frozen pathology exam of Common iliac lymph nodes and Para-Aortic lymphadenectomy on the prognosis and quality of life for patients with IB2-IIA2 Cervical Cancer: trial protocol for a randomized controlled trial (C-PACC trial)

Xinyu Qu,Junjun Qiu,Lili Jiang,Xiaorong Qi,Guonan Zhang,Weiwei Feng,Yudong Wang,Yincheng Teng,Xipeng Wang,Xiaoqing Guo,Keqin Hua 대한부인종양학회 2023 Journal of Gynecologic Oncology Vol.34 No.2

Background: The impact of para-aortic lymphadenectomy (PALD) on prognosis and quality of life (QoL) for IB2-IIA2 cervical cancer patients remain controversial. And whether intraoperative frozen pathology exam on common iliac lymph nodes could help predict para-aortic lymph node (PALN) metastasis was unanswered with high-level evidence. Methods: A multi-center, randomized controlled study is intended to investigate the effect of PALD on the prognosis and QoL in cervical cancer patients and to assess the value of intraoperative frozen pathological evaluation of common iliac nodes metastasis for the prediction of PALN metastasis. After choosing whether to receive intraoperative frozen pathological examination of bilateral common iliac lymph nodes, eligible patients will be randomly assigned (1:1) to receive PALD or not. The primary end point is 2-year progression-free survival (PFS). The secondary end points include 5-year PFS, 2-year overall survival (OS), 5-year OS, adverse events (AEs) caused by PALD, AEs caused by radiotherapy and QoL. A total of 728 patients will be enrolled from 8 hospitals in China within 3-year period and followed up for 5 years.