Preparation and Study on Thermal Conductive Composites of Chlorinated Polyethylene Rubber Reinforced by Boron Nitride Particles

Junjie Shu,Ru Xia,Jiasheng Qian,JIBIN MIAO,LIFEN SU,Ming Cao,Hongyun Lin,Peng Chen,Jinyang Chen 한국고분자학회 2016 Macromolecular Research Vol.24 No.7

The composites of chlorinated polyethylene rubber (CM) filled with boron nitride (BN) were prepared and examined systematically. Scanning electron microscopy (SEM) was used to observe microscopic morphology of composites. Mechanical properties of composites were analyzed by a rubber process analyzer (RPA) and dynamic mechanical thermal analyzer (DMTA). Thermal conductivity as well as thermo stability of composites was improved by adding BN particles into the CM rubber. It was found that BN particles can reinforce the rubber matrix while they also break down the network of polymer chains and ruin the physical properties of the rubber matrix. During the dynamic compressing process, BN particles can transfer heat from the matrix and alleviate the heat build-up phenomenon. The BN/CM composites (volume content CBN=18%) with thermal conductivity 1.179 W/(m·K) and good flexibility (Elongation at break=320%) were prepared, which may be used as thermal interface materials in a dynamic compressing process.

Non-cardiac Chest Pain in Japan: Prevalence, Impact, and Consultation Behavior - A Population-based Study

Junji Chen,Tadayuki Oshima,Takashi Kondo,Toshihiko Tomita,Hirokazu Fukui,Shinichiro Shinzaki,Hiroto Miwa 대한소화기 기능성질환∙운동학회 2023 Journal of Neurogastroenterology and Motility (JNM Vol.29 No.4

Background/AimsNon-cardiac chest pain (NCCP) is defined as recurring angina-like retrosternal chest pain of non-cardiac origin. Information about the epidemiology of NCCP in Japan is lacking. We aim to determine the prevalence and characteristics of NCCP in the Japanese general population. MethodsTwo internet-based surveys were conducted among the general population in March 2017. Questions investigated the characteristics of symptoms associated with chest pain and consultation behavior. Quality of life, anxiety, depression, and gastroesophageal reflux disease were analyzed. ResultsFive percent of the survey respondents reported chest pain. Subjects with chest pain showed higher frequencies of anxiety and depression and lower quality of life. Among subjects with chest pain, approximately 30% had sought medical attention for their symptoms. Among all consulters, 70% were diagnosed with NCCP. Females were less likely to seek consultations for chest pain than males. Further, severity and frequency of chest pain, lower physical health component summary score, and more frequent gastroesophageal reflux disease were associated with consultation behavior. Subjects with NCCP and cardiac chest pain experienced similar impacts on quality of life, anxiety, and depression. Among subjects with NCCP, 82% visited a primary-care physician and 15% were diagnosed with reflux esophagitis. ConclusionsThe prevalence of chest pain in this sample of a Japanese general population was 5%. Among all subjects with chest pain, less than one-third consulted physicians, approximately 70% of whom were diagnosed with NCCP. Sex and both the severity and frequency of chest pain were associated with consultation behavior.

Comparison of oxide layers formed on the low-cycle fatigue crack surfaces of Alloy 690 and 316 SS tested in a simulated PWR environment

Junjie Chen,Andrieanto Nurrochman,홍종대,김태순,장창희,이용선 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.2

Low-cycle fatigue (LCF) tests were performed for Alloy 690 and 316 SS in a simulated pressurized waterreactor (PWR) environment. Alloy 690 showed about twice longer LCF life than 316 SS at the test conditionof 0.4% amplitude at strain rate of 0.004%/s. Observation of the oxide layers formed on the fatiguecrack surface showed that Cr and Ni rich oxide was formed for Alloy 690, while Fe and Cr rich oxide for316 SS as an inner layer. Electrochemical analysis revealed that the oxide layers formed on the LCF cracksurface of Alloy 690 had higher impedance and less defect density than those of 316 SS, which resulted inlonger LCF life of Alloy 690 than 316 SS in a simulated PWR environment

One-Pot Synthesis of Magnetic Cationic Adsorbent Modified with PDDA for Organic Phosphonates Removal

Junjie Chen,Yonggan Ju,Hongling Chen 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.2

Fe3O4 nanoparticles coating with poly dimethyl diallyl ammonium chloride (Fe3O4/PDDA) as novel magnetic adsorbents were synthesized with chemical co-precipitation method to study the removal capacity of organic phosphonates from aqueous solution. The as-prepared magnetic absorbents were characterized for the morphology, material structure and surface properties by SEM, TEM, FT-IR, XRD, TGA and BET. HEDP was employed as a common organic phosphonate to investigate the adsorption performance. Substantial quaternary ammonium groups existing on the surface of Fe3O4/PDDA could enhance the absorption of HEDP with electrostatic attraction. In the optimum condition (4 mg adsorbent dosage, 11.0 pH, 36 mg/L HEDP solution and 120 min adsorption time), the maximum adsorption capacity (qm) for HEDP could reach 254.86 mg/g. The kinetic study revealed that the adsorption process followed the pseudo-second-order model. The adsorption isotherm fitted closely to the Freundlich model. The as-prepared magnetic adsorbents exhibited notable reusability in some cycles and were easily separated from the solution with the external magnetic field. These as-prepared Fe3O4/PDDA nanoparticles have the potential as an environmental-friendly adsorbent for organic phosphonates removal from waste-water.

Mechanical overload-induced release of extracellular mitochondrial particles from tendon cells leads to inflammation in tendinopathy

Chen Ziming,Li Mengyuan,Chen Peilin,Tai Andrew,Li Jiayue,Bassonga Euphemie Landao,Gao Junjie,Liu Delin,Wood David,Kennedy Brendan F.,Zheng Qiujian,Zheng Ming H. 생화학분자생물학회 2024 Experimental and molecular medicine Vol.56 No.-

Tendinopathy is one of the most common musculoskeletal diseases, and mechanical overload is considered its primary cause. However, the underlying mechanism through which mechanical overload induces tendinopathy has not been determined. In this study, we identified for the first time that tendon cells can release extracellular mitochondria (ExtraMito) particles, a subtype of medium extracellular particles (mEPs), into the environment through a process regulated by mechanical loading. RNA sequencing systematically revealed that oxygen-related reactions, extracellular particles, and inflammation were present in diseased human tendons, suggesting that these factors play a role in the pathogenesis of tendinopathy. We simulated the disease condition by imposing a 9% strain overload on three-dimensional mouse tendon constructs in our cyclic uniaxial stretching bioreactor. The three-dimensional mouse tendon constructs under normal loading with 6% strain exhibited an extended mitochondrial network, as observed through live-cell confocal laser scanning microscopy. In contrast, mechanical overload led to a fragmented mitochondrial network. Our microscopic and immunoblot results demonstrated that mechanical loading induced tendon cells to release ExtraMito particles. Furthermore, we showed that mEPs released from tendon cells overloaded with a 9% strain (mEP9%) induced macrophage chemotaxis and increased the production of proinflammatory cytokines, including IL-6, CXCL1, and IL-18, from macrophages compared to mEP0%, mEP3%, and mEP6%. Partial depletion of the ExtraMito particles from mEP9% by magnetic-activated cell sorting significantly reduced macrophage chemotaxis. N-acetyl-L-cysteine treatment preserved the mitochondrial network in overloaded tendon cells, diminishing overload-induced macrophage chemotaxis toward mEP9%. These findings revealed a novel mechanism of tendinopathy; in an overloaded environment, ExtraMito particles convey mechanical response signals from tendon cells to the immune microenvironment, culminating in tendinopathy.

Regulatory T cells Are Increased and Correlate With Mast Cells in Eosinophilic Esophagitis

Junji Chen,Tadayuki Oshima,Toshihiko Tomita,Hirokazu Fukui,Shinichiro Shinzaki 대한소화기 기능성질환∙운동학회 2024 Journal of Neurogastroenterology and Motility (JNM Vol.30 No.1

ackground/AimsThe incidence of eosinophilic esophagitis (EoE) has been increasing recently. The role of regulatory T cells (Tregs) and correlations with other inflammatory cells in EoE remain unknown. We aim to clarify the role of Tregs and their correlations with inflammatory cells in EoE patients. MethodsBiopsies from controls and EoE patients before and after treatments were analyzed. Eosinophil infiltration was evaluated by hematoxylin and eosin staining. Immunohistochemical staining was performed to examine infiltration of T cells, Tregs, and mast cells. Gene expressions of chemokines were evaluated by reverse transcription-quantitative polymerase chain reaction. ResultsTregs and mast cells were increased in the esophageal epithelial layers of EoE patients. After treatments, Tregs and mast cells were decreased when histologic remission was achieved. Infiltration of Tregs correlated significantly with numbers of eosinophils and mast cells. Filaggrin mRNA was decreased in patients with EoE before treatment and upregulated after treatment, even when histologic remission was not achieved. ConclusionsTregs were increased in esophageal epithelium of patients with EoE, and correlated with mast cell infiltration.

The corrosion behaviour of alloy 690 tube in simulated PWR secondary water with the effect of solid diffusing hydrogen

Chen, Junjie,Lu, Zhanpeng,Meng, Fanjiang,Xu, Xuelian,Xiao, Qian,Kim, Ho-Sub,Jang, Changheui Elsevier 2019 JOURNAL OF NUCLEAR MATERIALS Vol.517 No.-

<P><B>Abstract</B></P> <P>High-temperature water corrosion tests were performed to investigate the corrosion behaviors of Alloy 690 TT in simulated PWR secondary water with gaseous hydrogen permeation condition. Double-layer oxide films formed on hydrogen-free and hydrogen-permeating specimens. The thickness of a Cr-rich inner oxide film on the hydrogen-free specimens has no obvious difference from the hydrogen-permeating ones. For hydrogen-free specimens, the outer oxide films were Fe and Ni enriched spinel-type oxide particles. For hydrogen-permeating specimens, outer oxide films were sheet-like or needle-like Cr-rich chromia-type oxides. In summary, the solid diffusing hydrogen affected the morphology and composition of outer oxides.</P> <P><B>Highlights</B></P> <P> <UL> <LI> High temperature water corrosion test was performed in hydrogen permeation condition. </LI> <LI> The thickness of Cr-rich inner films has no obvious change by hydrogen permeation. </LI> <LI> Sheet-like outer oxides on hydrogen-permeating samples unlike hydrogen-free ones. </LI> <LI> Fe and Ni-rich spinel-type outer oxide films formed on hydrogen-free specimens. </LI> <LI> Cr-rich chromia-type outer oxide films formed on hydrogen-permeating specimens. </LI> </UL> </P>

Isoperistaltic side-to-side anastomosis for the surgical treatment of Crohn disease

Wenhao Chen,Junjie Zhou,Min Chen,Congqing Jiang,Qun Qian,Zhao Ding 대한외과학회 2022 Annals of Surgical Treatment and Research(ASRT) Vol.103 No.1

Purpose: Increasing evidence has shown an association of surgical technique, particularly anastomotic configuration, with postoperative recurrence of CD. This pilot study aimed to evaluate short-term outcomes of isoperistaltic side-to-side anastomosis (ISSA) employed on Crohn disease (CD) patients. Methods: Data were retrieved from a prospectively maintained database. Postoperatively, all patients were followed up with close endoscopic (ileocolonoscopy) surveillance. Results: From January 2017 to May 2021, 30 patients diagnosed with CD who underwent ISSA were compared with 45 CD patients who underwent antiperistaltic side-to-side anastomosis (ASSA). The 2 groups were comparable in baseline demographics and clinical characteristics. No significant differences were observed between groups regarding postoperative safety issues, including anastomotic leak, abdominal/pelvic abscess, length of hospital stay, readmission rate within 30 days, etc. At postoperative 24th month, reduced endoscopic recurrence was observed in the ISSA group compared with that in the ASSA group (18 of 24, 75.0%, . 36 of 38, 94.7%; P = 0.024). Regarding surgical recurrence, there was 0% in the ISSA group . 4.4% (2 of 45) in the ASSA group (P = 0.510). Conclusion: In this study, we aimed to explore the influence of ISSA on postoperative recurrence in CD patients, and the preliminary results show that ISSA was technically safe and feasible, and appears to be effective in reducing postoperative recurrence in CD patients. However, our conclusion was underpowered due to small sample size and inadequate follow- up. We proposed ISSA be considered as another alternative option in the toolbox of inflammatory bowel disease surgeons when performing anastomosis on CD patients.

New Players in the BRCA1-mediated DNA Damage Responsive Pathway

김홍태,Junjie Chen 한국분자세포생물학회 2008 Molecules and cells Vol.25 No.4

DNA damage checkpoint is an important self-defense mechanism for the maintenance of genome stability. Defects in DNA damage signaling and repair lead to various disorders and increase tumor incidence in humans. In the past 10 years, we have identified many components involved in the DNA damage-signaling pathway, including the product of breast cancer susceptibility gene 1 (BRCA1). Mutations in BRCA1 are associated with increased risk of breast and ovarian cancers, highlighting the importance of this DNA damagesignaling pathway in tumor suppression. While it becomes clear that BRCA1 plays a crucial role in the DNA damage responsive pathway, exactly how BRCA1 receives DNA damage signals and exerts its checkpoint function has not been fully addressed. A series of recent studies reported the discovery of many novel components involved in DNA damage-signaling pathway. These newly identified checkpoint proteins, including RNF8, RAP80 and CCDC98, work in concern in recruiting BRCA1 to DNA damage sites and thus regulate BRCA1 function in G2/M checkpoint control. This review will summarize these recent findings and provide an updated view of the regulation of BRCA1 in response to DNA damage.

Vacuum infiltration transformation of non-heading Chinese cabbage (Brassica rapa L. ssp. chinensis) with the pinII gene and bioassay for diamondback moth resistance

Zhang, Junjie,Liu, Fan,Yao, Lei,Luo, Chen,Zhao, Qing,Huang, Yubi The Korean Society of Plant Biotechnology 2011 Plant biotechnology reports Vol.5 No.3

Non-heading Chinese cabbage (Brassica rapa L. ssp. chinensis) is a popular vegetable in Asian countries. The diamondback moth (DBM), Plutella xylostella (L.), an insect with worldwide distribution, is a main pest of Brassicaceae crops and causes enormous crop losses. Transfer of the anti-insect gene into the plant genome by transgenic technology and subsequent breeding of insect-resistant varieties will be an effective approach to reducing the damage caused by this pest. We have produced transgenic non-heading Chinese cabbage plants expressing the potato proteinase inhibitor II gene (pinII) and tested the pest resistance of these transgenic plants. Non-heading Chinese cabbages grown for 45 days on which buds had formed were used as experimental materials for Agrobacterium-mediated vacuum infiltration transformation. Forty-one resistant plants were selected from 1166 g of seed harvested from the infiltrated plants based on the resistance of the young seedlings to the herbicide Basta. The transgenic traits were further confirmed by the Chlorophenol red test, PCR, and genomic Southern blotting. The results showed that the bar and pinII genes were co-integrated into the resistant plant genome. A bioassay of insect resistance in the second generation of individual lines of the transgenic plants showed that DBM larvae fed on transgenic leaves were severely stunted and had a higher mortality than those fed on the wild-type leaves.