In-pile tritium release behavior and the post-irradiation experiments of Li4SiO4 fabricated by melting process

Zhao Linjie,Yang Mao,Xiao Chengjian,Gong Yu,Ran Guangming,Chen Xiaojun,Li Jiamao,Yue Lei,Chen Chao,Hou Jingwei,Wang Heyi,Long Xinggui,Peng Shuming 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.1

Understanding the tritium release and retention behavior of candidate tritium breeder materials is crucial for breeder blanket design. Recently, a melt spraying process was developed to prepare Li4SiO4 pebbles, which were subsequently subjected to the in-pile tritium production and extraction platform in China Mianyang Research Reactor (CMRR) to investigate their in-situ tritium release behavior and irradiation performance. The results demonstrate that HT is the main tritium release form, and adding hydrogen to the purge gas reduces tritium retention while increasing the HT percent in the purge gas. Post-irradiation experiments reveal that the irradiated pebbles darken in color and their grains swell, but the mechanical properties remain largely unchanged. It is concluded that the tritium residence time of Li4SiO4 made by melt spraying method at 467 ◦C is approximately 23.34 h. High-density Li4SiO4 pebbles exhibit tritium release at relatively low temperatures (<600 ◦C) that is mainly controlled by bulk diffusion. The diffusion coefficient at 525 ◦C and 550 ◦C is 1.19 × 10 11 cm2/s and 5.34 × 10 11 cm2/s, respectively, with corresponding tritium residence times of 21.3 hours and 4.7 hours.

Cloning and Characterization of a Na+/H+ Antiporter Gene of the Moderately Halophilic Bacterium Halobacillus aidingensis AD-6T

Ya Jie Zou,Li Fu Yang,Lei Wang,Su Sheng Yang 한국미생물학회 2008 The journal of microbiology Vol.46 No.4

A gene encoding a Na+/H+ antiporter was obtained from the genome of Halobacillus aidingensis AD-6T, which was sequenced and designated as nhaH. The deduced amino acid sequence of the gene was 91% identical to the NhaH of H. dabanensis, and shared 54% identity with the NhaG of Bacillus subtilis. The cloned gene enable the Escherichia coli KNabc cell, which lack all of the major Na+/H+ antiporters, to grow in medium containing 0.2 M NaCl or 10 mM LiCl. The nhaH gene was predicted to encode a 43.5 kDa protein (403 amino acid residues) with 11 putative transmembrane regions. Everted membrane vesicles prepared from E. coli KNabc cells carrying NhaH exhibited Na+/H+ as well as Li+/H+ antiporter activity, which was pH-dependent with the highest activity at pH 8.0, and no K+ /H+ antiporter activity was detected. The deletion of hydrophilic C-terminal amino acid residues showed that the short C-terminal tail was vital for Na+/H+ antiporter activity.

Removal of chlorinated organic solvents from hydraulic fracturing wastewater by bare and entrapped nanoscale zero-valent iron

Lei, Cheng,Sun, Yuqing,Khan, Eakalak,Chen, Season S.,Tsang, Daniel C.W.,Graham, Nigel J.D.,Ok, Yong Sik,Yang, Xin,Lin, Daohui,Feng, Yujie,Li, Xiang-Dong Elsevier 2018 CHEMOSPHERE - Vol.196 No.-

<P><B>Abstract</B></P> <P>With the increasing application of hydraulic fracturing, it is urgent to develop an effective and economically feasible method to treat the large volumes of fracturing wastewater. In this study, bare and entrapped nanoscale zero-valent iron (nZVI) were introduced for the removal of carbon tetrachloride (CT) and 1,1,2-trichloroethane (TCA) in model high-salinity fracturing wastewater. With increasing ionic strength (<I>I</I>) from Day-1 (<I>I</I> = 0.35 M) to Day-90 (<I>I</I> = 4.10 M) wastewaters, bare nZVI presented significantly lower removal efficiency of CT (from 53.5% to 38.7%) and 1,1,2-TCA (from 71.1% to 21.7%) and underwent more serious Fe dissolution from 1.31 ± 1.19% in Day-1 to 5.79 ± 0.32% in Day-90 wastewater. Particle aggregation induced by high ionic strength was primarily responsible for the lowered performance of nZVI due to less available reactive sites on nZVI surface. The immobilization of nZVI in alginate with/without polyvinyl alcohol provided resistance to particle aggregation and contributed to the superior performance of entrapped nZVI in Day-90 wastewater for 1,1,2-TCA removal (62.6–72.3%), which also mitigated Fe dissolution (4.00–4.69%). Both adsorption (by polymer matrix) and reduction (by immobilized nZVI) were involved in the 1,1,2-TCA removal by entrapped nZVI. However, after 1-month immersion in synthetic fracturing wastewater, a marked drop in the reactivity of entrapped nZVI for 1,1,2-TCA removal from Day-90 wastewater was observed with significant release of Na and total organic carbon. In summary, bare nZVI was sensitive to the nature of the fracturing wastewater, while the use of environmentally benign entrapped nZVI was more promising for wastewater treatment.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Increasing ionic strength decreased nZVI reactivity and increased Fe dissolution. </LI> <LI> Entrapping nZVI in polymer matrix improved reactivity and limited Fe dissolution. </LI> <LI> Entrapped nZVI removed model chlorinated organic via both adsorption and reduction. </LI> <LI> Aging process was mitigated by polymer matrix but still inhibited nZVI reactivity. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Flame Retardancy of Epoxy Resin Improved by Graphene Hybrid Containing Phosphorous, Boron, Nitrogen and Silicon Elements

Li Li,Huan Wang,Fenglin Hua,Mingming Wang,Yuanshuo Zhang,Hui Xi,Jing Yang,Zhiwang Yang,Ziqiang Lei 한국고분자학회 2021 Macromolecular Research Vol.29 No.9

An effective ternary organic-inorganic composite flame retardant of reduced graphene oxide-poly-dopamine@graphitic carbon nitride@10-(2,5-dihydroxyphenyl)- 10-H-9-oxa-10-phosphaphenanthrene-10-oxide (RGO-PDA@g-C3N4@ODOPB) was successfully fabricated by co-precipitation method. Its property concerning the intrinsic flame retardancy and the mechanical performance was well studied when it was used as co-additives in combination with ammonium polyphosphate (APP) in epoxy resin (EP) samples. The surface morphology and the structure of RGO-PDA@g-C3N4 @ODOPB were characterized by SEM, and the molecular structure and compositions were investigated by FT-IR, powder XRD and 1H NMR. TGA, limit oxygen index (LOI), vertical burning test (UL-94), cone calorimeter test, and SEM were also used to investigate the thermal properties and flame retardancy of materials. As expected, the flame retardancy of EP was significantly heightened after adding of RGOPDA@ g-C3N4@ODOPB composites. It showed that with the 20% adding of RGO-PDA@g-C3N4@ODOPB/APP into EP led to the decreasing of the peak heat release rate and the total heat release at 78% and 62.5%, respectively. Meanwhile, the LOI value of the EP composites was as high as 29% and reached UL-94 V-0 rate. It was deemed that the excellent flame retardancy was attributed to the forming of compact and stable carbon layer, which was being catalytic carbonization by APP existed in the RGO-PDA@g-C3N4@ODOPB/APP composites. At the same time, the non-combustible gas released from thermal cracking of g-C3N4 during the combustion also benefited the flame retardant performance of EP.

Chronic Hepatitis B Virus Infection and Risk of Pancreatic Cancer: A Meta-analysis

Li, Lei,Wu, Bo,Yang, Li-Bo,Yin, Guan-Cheng,Liu, Ji-Yong Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

Objectives: A number of studies have shown that chronic hepatitis B virus infection is implicated in susceptibility to pancreatic cancer. However, the results are still controversial. This meta-analysis aimed to quantitatively assess the relationship between chronic hepatitis B virus infection and incidence of pancreatic cancer of cohort and case-control studies. Methods: A literature search was performed for entries from 1990 to 2012 using PUBMED and EMBASE. Studies were included if they reported odds ratios (ORs) and corresponding 95% CIs of pancreatic cancer with respect to the infection of hepatitis B virus. Results: Eight studies met the inclusion criteria, which included five case-control studies and three cohort studies. Compared with individuals who have not infection of hepatitis B virus, the pooled OR of pancreatic cancer was 1.403 (95%CI: 1.139-1.729, P=0.001) for patients with hepatitis B virus infection. Sub-group analysis by study design showed that the summary OR was 1.43 (95%CI: 1.06-1.94, P=0.021) when pooling case-control studies and 1.31 (95%CI: 1.00-1.72, P=0.05) when pooling cohort studies. Conclusion: Findings from this meta-analysis suggest that chronic hepatitis B virus infection may increase the risk of pancreatic cancer. This relationship needs to be confirmed by further follow-up studies.

Fibulin2: a negative regulator of BMSC osteogenic differentiation in infected bone fracture healing

Li Shi-Dan,Xing Wei,Wang Shao-Chuan,Li You-Bin,Jiang Hao,Zheng Han-Xuan,Li Xiao-Ming,Yang Jing,Guo De-Bin,Xie Xiao-Yu,Jiang Ren-Qing,Fan Chao,Li Lei,Xu Xiang,Fei Jun 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Bone fracture remains a common occurrence, with a population-weighted incidence of approximately 3.21 per 1000. In addition, approximately 2% to 50% of patients with skeletal fractures will develop an infection, one of the causes of disordered bone healing. Dysfunction of bone marrow mesenchymal stem cells (BMSCs) plays a key role in disordered bone repair. However, the specific mechanisms underlying BMSC dysfunction caused by bone infection are largely unknown. In this study, we discovered that Fibulin2 expression was upregulated in infected bone tissues and that BMSCs were the source of infection-induced Fibulin2. Importantly, Fibulin2 knockout accelerated mineralized bone formation during skeletal development and inhibited inflammatory bone resorption. We demonstrated that Fibulin2 suppressed BMSC osteogenic differentiation by binding to Notch2 and inactivating the Notch2 signaling pathway. Moreover, Fibulin2 knockdown restored Notch2 pathway activation and promoted BMSC osteogenesis; these outcomes were abolished by DAPT, a Notch inhibitor. Furthermore, transplanted Fibulin2 knockdown BMSCs displayed better bone repair potential in vivo. Altogether, Fibulin2 is a negative regulator of BMSC osteogenic differentiation that inhibits osteogenesis by inactivating the Notch2 signaling pathway in infected bone.

Oxymatrine Causes Hepatotoxicity by Promoting the Phosphorylation of JNK and Induction of Endoplasmic Reticulum Stress Mediated by ROS in LO2 Cells

Li-li Gu,Zhe-lun Shen,Yang-Lei Li,Yi-Qi Bao,Hong Lu 한국분자세포생물학회 2018 Molecules and cells Vol.41 No.5

Oxymatrine (OMT) often used in treatment for chronic hepatitis B virus infection in clinic. However, OMT–induced liver injury has been reported. In this study, we aim to investigate the possible mechanism of OMT-induced hepatotoxicity in human normal liver cells (L02). Exposed cells to OMT, the cell viability was decreased and apoptosis rate increased, the intracellular markers of oxidative stress were changed. Simultaneously, OMT altered apoptotic related proteins levels, including Bcl-2, Bax and pro-caspase-8/-9/-3. In addition, OMT enhanced the protein levels of endoplasmic reticulum (ER) stress makers (GRP78/Bip, CHOP, and cleaved-Caspase-4) and phosphorylation of c-Jun N-terminal kinase (p-JNK), as well as the mRNA levels of GRP78/Bip, CHOP, caspase-4, and ER stress sensors (IREI, ATF6, and PERK). Pre-treatment with Z-VAD-fmk, JNK inhibitor SP600125 and N-acetyl-l-cysteine (NAC), a ROS scavenger, partly improved the survival rates and restored OMT-induced cellular damage, and reduced caspase-3 cleavage. SP600125 or NAC reduced OMT-induced p-JNK and NAC significantly lowered caspase-4. Furthermore, 4-PBA, the ER stress inhibitor, weakened inhibitory effect of OMT on cells, on the contrary, TM worsen. 4-PBA also reduced the levels of p-JNK and cleaved-caspase-3 proteins. Therefore, OMT-induced injury in L02 cells was related to ROS mediated p-JNK and ER stress induction. Antioxidant, by inhibition of p-JNK or ER stress, may be a feasible method to alleviate OMT-induced liver injury.

Estimation of Dynamic Behaviors of Bedrock Foundation Subjected to Seismic Loads Based on FEM and DEM Simulations

Lei Yang,Yujing Jiang,Bo Li,Shucai Li,Gang Wang 대한토목학회 2013 KSCE JOURNAL OF CIVIL ENGINEERING Vol.17 No.2

Seismic behavior of bedrock foundation remains as one of the most fundamental and important problems concerning the stability and safety of nuclear power plants. The dynamic FEM (Finite Element Method) is commonly utilized in analyzing the seismic responses of bedrock; while in recent decades, the DEM (Distinct Element Method) has attracted more and more attentions, which has a better capability of simulating the sliding and separation of discontinuities in dynamic simulations. In this study, the FEM and DEM were adopted to investigate the seismic behavior of the bedrock of a nuclear power plant located in Japan, and the differences between the two methods in dynamic simulations were illuminated. Simulation results using FEM and DEM models without discontinuities agree well with each other, exhibiting an amplification effect of intact bedrock on the seismic wave propagation. Numerical simulation results obtained from the models containing faults give similar responses of bedrock to the input seismic waves; however, the FEM model underestimates the weakening effect of discontinuities on the propagation of seismic waves due to that it cannot represent well the large deformational behavior of discontinuities. When large deformation happens due to large seismic loads, the DEM can be regarded as a better method in seismic response evaluations of bedrock with discontinuities.

Risk Factors for Surgical Site Infections after Liver Resec-tion (A Multivariate Analysis of 6,132 Patients)

( Li-yang Sun ),( Jiong-jie Yu ),( Ju-dong Li ),( Xin-fei Xu ),( Jia-he Wang ),( Bing Quan ),( Wen-tao Yan ),( Feng Shen ),( Chao Li ),( Lei Liang ),( Tian Yang ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Surgical site infection (SSI) is a common postoperative complication and associated with an increased morbidity, hospital stay, and overall cost. The aim of the present study was to identify risk factors for SSIs after hepatic resection based on a large single-center cohort. Methods: A retrospective study was conducted of 6,132 patients who underwent liver resection without concomitant biliary reconstruction or gastrointestinal procedures between 2014 and 2016 at the largest hepatic center in China. The occurrences of SSI, classified as incisional SSI and organ/space SSI within 30 days after operation were investigated. Patient- and surgical-related risk variables were collected using standardized data collection form. A likelihood ratio forward regression model was used to assess the independent association of risk factors with SSI. Results: SSI developed in 587 patients (9.6%), including superficial/deep incisional SSI in 357 patients (5.8 %), and organ/ space SSI in 304 patients (5.0 %). Multivariate logistic regression analysis showed that obesity, diabetes mellitus, ASA score ≥ 2, liver cirrhosis, re-hepatectomy, hepatoliathiasis, and intraoperative blood transfusion were independent risk factors of overall SSI. However, incisional and organ/space SSI differed from each other with respect to risk factors. Among a variety of risk factors, hepatolithiasis, liver cirrhosis, and intraoperative blood transfusion were consistently associated with both incisional and organ/space SSI. Conclusions: SSI is a common complication after liver resection, and more caution should be taken in patients with hepatolithiasis or liver cirrhosis. Prevention strategies focusing on factors associated with SSI is necessary in order to reduce SSI after liver resection.

Synthesis of Phosphorous Phenanthrene/L-Tryptophan Flame Retardant for Enhanced Flame Retardancy of Epoxy Resins

Li Li,Fenglin Hua,Hui Xi,Jing Yang,Ting Xiao,Rui Zuo,Xueqing Xu,Zhiwang Yang,Ziqiang Lei 한국고분자학회 2022 Macromolecular Research Vol.30 No.12

A new type of phosphorus-containing intrinsic flame retardant was prepared with L-tryptophan (L-Trp) and 9,10-dihydro-9-oxa-10-phosphorbenzophenanthrene- 10-oxide (DOPO) as the main components. The Schiff base from the reaction of 1,4-terephthalaldehyde and L-tryptophan provides active sites, and then the phosphorous compound, DOPO, is successfully introduced into the Schiff base to synthesize L-Trp-DOPO flame retardant. The intrinsic flame retardant property of LTrp- DOPO comes from the reaction of carbonyl groups and the epoxy groups in epoxy resin (EP) matrix. The prepared L-Trp-DOPO flame retardant can efficiently improve the flame retardancy and smoke suppression of the base material of EP. Cone calorimetric test (CCT) of EP/L-Trp-DOPO composite material was carried out. The data showed that the peak heat release rate (pk-HRR) value was reduced by 50.8% (from 1459 kW/m2 to 717 kW/m2), the THR value reduced by 78.3%, and the limiting oxygen index (LOI) value was increased by 24%. The addition of new flame retardant greatly reduced the release of toxic CO gas. The flame retardant mechanism was explored, and it can be found that after thermal decomposition of L-Trp- DOPO a dense carbon layer can be produced to isolate the fire source. In addition, during the combustion process, L-Trp-DOPO will produce phosphorus-containing free radicals which will quench the active free radicals in the gas phase and dilute the combustible gas. The prepared L-Trp-DOPO flame retardant has a flame retardant effect in both the condensed phase and the gas phase during the combustion process.