Magnetocaloric effect in La_1-xSr_xCoO₃ undergoing a second-order phase transition

Long, Phan The,Manh, T.V.,Ho, T.A.,Dongquoc, Viet,Zhang, P.,Yu, S.C. Elsevier 2018 CERAMICS INTERNATIONAL Vol.44 No.13

<P><B>Abstract</B></P> <P>We have prepared rhombohedral La<SUB>1-x</SUB>Sr<SUB>x</SUB>CoO<SUB>3-δ</SUB> (<I>x</I> = 0.2–0.5) compounds with a mass density <I>ρ</I> ≈ 5.5 g/cm<SUP>3</SUP>. Their magnetocaloric (MC) effect is studied via the magnetic-entropy change (Δ<I>S</I> <SUB>m</SUB>) and relative cooling power (<I>RCP</I>), which are calculated from initial magnetization data recorded at different temperatures. Results reveal that the Δ<I>S</I> <SUB>m</SUB> magnitude is maximum (Δ<I>S</I> <SUB>max</SUB>) around the ferromagnetic-paramagnetic phase transition and dependent on both the applied-field (<I>H</I>) magnitude and Sr content (<I>x</I>). For <I>H</I> = 50 kOe, |Δ<I>S</I> <SUB>max</SUB>| can be tuned in the range of 1.6–2.7 J/kg K, corresponding to <I>RCP</I> values of 89–141 J/kg. Among the studied La<SUB>1-x</SUB>Sr<SUB>x</SUB>CoO<SUB>3-δ</SUB> samples, the samples with <I>x</I> = 0.3–0.5 have the largest |Δ<I>S</I> <SUB>max</SUB>| values. If combining these samples as MC blocks in refrigeration application, the working temperature range of a cooling device could range from 204 to ~280 K, with |Δ<I>S</I> <SUB>max</SUB>| stable at ~2.6 J/kg K and <I>RCP</I> ≈ 198 J/kg. We have also assessed the phase-transition type and magnetic order and found La<SUB>1-x</SUB>Sr<SUB>x</SUB>CoO<SUB>3-δ</SUB> undergoing a second-order phase transition. Magnetic order tends to change from the long-range type to the short-range one when <I>x</I> varies from 0.2 to 0.5. This is in good agreement with the results obtained from the analysis of critical behavior.</P>

Targeting treatment of bladder cancer using PTK7 aptamer-gemcitabine conjugate

Xiang Wei,Peng Yongbo,Zeng Hongliang,Yu Chunping,Zhang Qun,Liu Biao,Liu Jiahao,Hu Xing,Wei Wensu,Deng Minhua,Wang Ning,Liu Xuewen,Xie Jianfei,Hou Weibin,Tang Jin,Long Zhi,Wang Long,Liu Jianye 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Gemcitabine (GEM) is one of the first-line chemotherapies for bladder cancer (BC), but the GEMs cannot recognize cancer cells and have a low long-term response rate and high recurrence rate with side effects during the treatment of BC. Targeted transport of GEMs to mediate cytotoxicity to tumor and avoid the systemic side effects remains a challenge in the treatment of BC.Based on a firstly confirmed biomarker in BC-protein tyrosine kinase 7 (PTK7), which is overexpressed on the cell membrane surface in BC cells, a novel targeting system protein tyrosine kinase 7 aptamer-Gemcitabine conjugate (PTK7-GEMs) was designed and synthesized using a specific PTK7 aptamer and GEM through auto-synthesis method to deliver GEM against BC. In addition, the antitumor effects and safety evaluation of PTK7-GEMs was assessed with a series of in vitro and in vivo assays.PTK7-GEMs can specifically bind and enter to BC cells dependent on the expression levels of PTK7 and via the macropinocytosis pathway, which induced cytotoxicity after GEM cleavage from PTK7-GEMs respond to the intracellular phosphatase. Moreover, PTK7-GEMs showed stronger anti-tumor efficacy and excellent biosafety in three types of tumor xenograft mice models.These results demonstrated that PTK7-GEMs is a successful targeted aptamer-drug conjugates strategy (APDCs) to treat BC, which will provide new directions for the precision treatment of BC in the field of biomarker-oriented tumor targeted therapy.

Comparative Study on the Supramolecular Nanocarriers Derived from the Assembly of Gemini and Conventional Surfactants onto Hyperbranched Polyethylenimine

Zhan-Long Yu,Fa Cheng,Shao-Jing Zhao,Jian-Wei Zhang,Zu-Cheng Cai,Yu Chen 한국고분자학회 2011 Macromolecular Research Vol.19 No.2

Conventional surfactant dodecylbenzenesulfonic acid (DBSA) and its corresponding Gemini surfactant acid (GSA) were simply mixed with a solution of hyperbranched polyethylenimine (HPEI) in chloroform. This resulted in the novel supramolecular complexes, HPEI-DBSA and HPEI-GSA, through a neutralization reaction between the amino groups of HPEI and the sulfonic-acid groups of DBSA and GSA. The formed supramolecular complexes and their precursors were characterized by FTIR, 1H NMR, and dynamic light scattering. HPEI-DBSA and HPEI-GSA exhibited inverted-micelle properties that could accommodate the water-soluble guest molecules in an apolar solvent. With the anionic dye methyl orange (MO) as the model guest, both HPEI-DBSA and HPEI-GSA showed superior guest-encapsulation performance than the supramolecular nanocarrier derived from the assembly of aliphatic acid onto HPEI. For example, HPEI-DBSA and HPEI-GSA nanocarriers could encapsulate more MO molecules, and a much smaller amount of the surfactant molecules was required to achieve the maximum MO encapsulation. These results highlight the importance of strong-acid groups of the surfactants in raising the guest-encapsulation efficiency of this type of supramolecular nanocarrier. HPEI-DBSA and HPEI-GSA had different guestencapsulation mechanisms. This indicates that HPEI-GSA can encapsulate basic guests more than HPEI-DBSA,such as MO and fluorescein sodium (FS), but fewer relatively acidic guests, such as Alizarin Yellow R sodium salt and bromophenol blue.

Magnetite-based Biochar Coupled with Binary Oxidants for the Effective Removal of Mixed Dye from Wastewater

Mingxia Yu,Huosheng Li,Keke Li,Yuting Li,Fengli Liu,Gaosheng Zhang,Tangfu Xiao,Ping Zhang,Hongguo Zhang,Jianyou Long 한국섬유공학회 2022 Fibers and polymers Vol.23 No.2

Decolorization and organic degradation of wastewater containing multiple dyes are still challenging inwastewater treatment. Magnetic biochar coupled with advanced oxidation is a potential solution to this issue. In this study,a series of magnetite-based biochar composites (Fe3O4@C) was prepared and compared for the removal of mixed dyes,including methyl orange (MO), rhodamine B (RhB), methylene blue (MB), and an organic macromolecule, humic acid(HA). The pyrolysis of watermelon rinds followed by precipitation of Fe3O4 onto the biochar was selected as the optimummethod to prepare an adsorbent and catalyst to couple binary oxidants (hypochlorite and persulfate) for color and totalorganic carbon removal. Persulfate was prone to degrade HA and MB, while hypochlorite was inclined to oxidize MO andRhB. Fe3O4@C exhibited better dye removal performance in coupling with binary oxidants than with a single oxidant. Formixed dye solutions with an initial concentration of 50 mg/l for each dye, the highest TOC (57.24±3.17 %) and the colorremoval efficiencies (94.13±1.68 %) for the mixed dye solution were achieved at a sorbent dosage of 1 g/l and an oxidantdosage of 5 mmol/l for both hypochlorite and persulfate. Multiple free radicals, including hydroxyl radicals, sulfateradicals, and hypochlorite-induced radicals, play critical roles in the degradation of mixed dyes and color removal. Theregeneratibility and reutilization of the magnetic Fe3O4@C composite were effective and stable. The results obtained inthis study show that the combined Fe3O4@C and binary oxidants technique is promising for the treatment of multi-dyewastewater.

Treatment of bladder cancer by geoinspired synthetic chrysotile nanocarrier-delivered circPRMT5 siRNA

Chunping Yu,Yi Zhang,Ning Wang,Wensu Wei,Ke Cao,Qun Zhang,Peiying Ma,Dan Xie,Pei Wu,Biao Liu,Jiahao Liu,Wei Xiang,Xing Hu,Xuewen Liu,Jianfei Xie,Jin Tang,Zhi Long,Long Wang,Hongliang Zeng,Jianye Liu 한국생체재료학회 2022 생체재료학회지 Vol.26 No.1

Background: Circular RNAs (circRNAs) have important functions in many fields of cancer biology. In particular, we previously reported that the oncogenic circRNA, circPRMT5, has a major role in bladder cancer progression. Therapy based on circRNAs have good prospects as anticancer strategies. While anti-circRNAs are emerging as therapeutics, the specific in vivo delivery of anti-circRNAs into cancer cells has not been reported and remains challenging. Methods: Synthesized chrysotile nanotubes (SCNTs) with a relatively uniform length (~ 200 nm) have been designed to deliver an siRNA against the oncogenic circPRMT5 (si-circPRMT5) inhibit circPRMT5. In addition, the antitumor effects and safety evaluation of SCNTs/si-circPRMT5 was assessed with a series of in vitro and in vivo assays. Results: The results showed that SCNTs/si-circPRMT5 nanomaterials prolong si-circPRMT5’s half-life in circulation, enhance its specific uptake by tumor cells, and maximize the silencing efficiency of circPRMT5. In vitro, SCNTs encapsulating si-circPRMT5 could inhibit bladder cancer cell growth and progression. In vivo, SCNTs/si-circPRMT5 inhibited growth and metastasis in three bladder tumor models (a subcutaneous model, a tail vein injection lung metastatic model, and an in situ model) without obvious toxicities. Mechanistic study showed that SCNTs/sicircPRMT5 regulated the miR-30c/SNAIL1/E-adherin axis, inhibiting bladder cancer growth and progression. Conclusion: The results highlight the potential therapeutic utility of SCNTs/si-circPRMT5 to deliver si-circPRMT5 to treat bladder cancer.

Mucin2 is Required for Probiotic Agents-Mediated Blocking Effects on Meningitic E. coli-Induced Pathogenicities

Jing Yi Yu,Xiao Long He,Santhosh Puthiyakunnon,Liang Peng,Yan Li,Li Sha Wu,Wen Ling Peng,Ya Zhang,Jie Gao,Yao Yuan Zhang,Swapna Boddu,Min Long,Hong Cao,Sheng He Huang 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.10

β-elemene Induces Caspase-dependent Apoptosis in Human Glioma Cells in vitro through the Upregulation of Bax and Fas/FasL and Downregulation of Bcl-2

Li, Chen-Long,Chang, Liang,Guo, Lin,Zhao, Dan,Liu, Hui-Bin,Wang, Qiu-Shi,Zhang, Ping,Du, Wen-Zhong,Liu, Xing,Zhang, Hai-Tao,Liu, Yang,Zhang, Yao,Xie, Jing-Hong,Ming, Jian-Guang,Cui, Yu-Qiong,Sun, Ying Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Background: ${\beta}$-elemene, extracted from herb medicine Curcuma wenyujin has potent anti-tumor effects in various cancer cell lines. However, the activity of ${\beta}$-elemene against glioma cells remains unclear. In the present study, we assessed effects of ${\beta}$-elemene on human glioma cells and explored the underlying mechanism. Materials and Methods: Human glioma U87 cells were used. Cell proliferation was determined with MTT assay and colony formation assay to detect the effect of ${\beta}$-elemene at different doses and times. Fluorescence microscopy was used to observe cell apoptosis with Hoechst 33258 staining and change of glioma apoptosis and cell cycling were analyzed by flow cytometry. Real-time quantitative PCR and Western-blotting assay were performed to investigated the influence of ${\beta}$-elemene on expression levels of Fas/FasL, caspase-3, Bcl-2 and Bax. The experiment was divided into two groups: the blank control group and ${\beta}$-elemne treatment group. Results: With increase in the concentration of ${\beta}$-elemene, cytotoxic effects were enhanced in the glioma cell line and the concentration of inhibited cell viability ($IC_{50}$) was $48.5{\mu}g/mL$ for 24h. ${\beta}$-elemene could induce cell cycle arrest in the G0/G1 phase. With Hoechst 33258 staining, apoptotic nuclear morphological changes were observed. Activation of caspase-3,-8 and -9 was increased and the pro-apoptotic factors Fas/FasL and Bax were upregulated, while the anti-apoptotic Bcl-2 was downregulated after treatment with ${\beta}$-elemene at both mRNA and protein levels. Furthermore, proliferation and colony formation by U87 cells were inhibited by ${\beta}$-elemene in a time and does-dependent manner. Conclusions: Our results indicate that ${\beta}$-elemene inhibits growth and induces apoptosis of human glioma cells in vitro. The induction of apoptosis appears to be related with the upregulation of Fas/FasL and Bax, activation of caspase-3,-8 and -9 and downregulation of Bcl-2, which then trigger major apoptotic cascades.

Diversity and geographic variation of endosymbiotic bacteria in natural populations of the pea aphid (Acyrthosiphon pisum) in China

Zhang Li,Cao Ya,Zhang Li-Jun,Wang Meng-Yao,Wang Xiao-Tong,Yang Xing-Zhuo,Duan Ting-Yu,Yuan Ming-Long 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.3

Bacterial symbionts in aphids are known to benefit the insect host and associated with aphid’s ecological adaptation. The pea aphid (Acyrthosiphon pisum), an important legume pest worldwide, carries at least eight endosymbionts, providing a model system to study insect–bacteria interactions. However, species diversity and geographic variations of endosymbionts are unknown in Chinese populations; therefore, we characterized symbiont communities and diversity of 27 pea aphid samples from 13 geographic populations of China. Via amplicon high-throughput sequencing and diagnostic PCR, we found that bacterial communities of Chinese populations were dominated by Proteobacteria and Firmicutes. Among eight known endosymbionts, five (Buchnera, Serratia, Hamiltonella, Regiella, and Rickettsia) were detected by both methods, with a specific geographical distribution. The obligate symbiont, Buchnera, was present in all aphid samples, while the four facultative symbionts showed a significant geographic variation. Each population was randomly infected with distinct endosymbionts, ranging from three to five species. Serratia and Rickettsia showed relatively higher abundance in central regions of China, Regiella was predominant in eastern and western China, whereas Ham iltonella showed an extremely low abundance and was absent in four populations. Samples grouped by altitudes showed a significant diversity difference, whereas there was no significant difference between red and green body colors. Bacterial community structures of the Chinese pea aphid populations were mainly influenced by environmental factors, other than body colors. These data can guide the development of potential biocontrol techniques against this aphid.

Impact of Platelet Function Test on Platelet Responsiveness and Clinical Outcome After Coronary Stent Implantation: Platelet Responsiveness and Clinical Outcome

Long Hao Yu,김무현,Hong Zhe Zhang,박종성,박태호,김영대,차광수,한진영 대한심장학회 2012 Korean Circulation Journal Vol.42 No.6

Background and Objectives: The aim of this study was to confirm the predictive cut-off values for P2Y12 reaction units (PRU) and aspirin reaction units (ARU) and to evaluate the clinical impact of VerifyNow® assays. Subjects and Methods: From November 2007 to October 2009, 186 eligible patients were prospectively recruited. Post-treatment platelet reactivity was measured by VerifyNow® assays within 12 to 24 hours after intervention, followed by standard dual maintenance dose therapy for 1 year. All patients had scheduled clinical follow-ups at 1, 3, 6, and 12 months. Results: The rate of low responders to clopidogrel, aspirin, and both drugs were 41.4%, 10.2%, and 3.8%, respectively. The predictive fac-tors for low responsiveness to clopidogrel (PRU ≥240) were female sex, age, and non-use of cilostazol medication in our univariate analysis and age ≥65 years and non-use cilostazol in the multivariate analysis. The predictors of low responsiveness to aspirin (ARU ≥550) were male sex and age in both univariate and multivariate analyses. There was no significant difference in the clinical event rate with a cut-off value of PRU ≥240 or ARU ≥550 for 30 days and 1-year (p>0.05). Conclusion: Hyporesponsiveness to antiplatelet agents (namely aspirin and clopidogrel) was identified in about half of the patients. The cut-off point of PRU ≥240 or ARU ≥550 did not confer predictive value for 30-day or 1-year clinical event rates in patients who had un-dergone coronary intervention with drug-eluting stents.

Demand Response Based on Kalman-Filtering for the Frequency Control

Yu-Qing Bao,Cheng Shen,Qi Wang,Jin-Long Zhang 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.3

DR control can be incorporated with traditional frequency control methods to achieve better performance. However, in the frequency measurement process, disturbances may infl uence the precision of measured frequency, and further infl uence the control performance. In this paper, a hierarchical DR control strategy is considered for the frequency control. In order to reduce the infl uence of detection error, a Kalman-fi ltering based method is proposed. At last, the eff ectiveness of the proposed method is verifi ed by the testing results.