Effects of the Zr concentration on transparent Y2O3 ceramics fabricated by vacuum pre-sintering and a subsequent HIP treatment

Zhu, L. L.,Park, Y. J.,Gan, L.,Go, S. I.,Kim, H. N.,Kim, J. M.,Ko, J. W. Chapman and Hall 2017 Journal of materials science Materials in electron Vol. No.

<P>Highly transparent Y2O3 ceramics doped with different Zr concentrations were successfully fabricated by vacuum pre-sintering at temperatures ranging from 1600 to 1800 degrees C combined with a subsequent hot-isostatic pressing (HIP) treatment using commercial powders as the starting materials. All of the 1 mol% Zr-doped Y2O3 ceramics exhibit very good optical quality. The sample with the highest transparency level was realized by vacuum sintering at 1650 degrees C for 4 h followed by a post-HIP treatment at 1450 degrees C lasting 5 h. It has a fine microstructure and the grain size is 1.48 mu m. Furthermore, the in-line transmittance reaches 83.3% at 1100 nm (1.2 mm thickness). It was found that a relatively low vacuum sintering temperature (1650 degrees C) and relatively low Zr doping concentration (1 mol%) are more appropriate to achieve optimally transparent Y2O3 ceramics with a subsequent HIP treatment.</P>

Porcine satellite cells are restricted to a phenotype resembling their muscle origin

Zhu, H.,Park, S.,Scheffler, J. M.,Kuang, S.,Grant, A. L.,Gerrard, D. E. American Society of Animal Science 2013 Journal of animal science Vol.91 No.10

<P>Muscles in most domestic animals differ in function and growth potential based largely on muscle fiber type composition. Though much is known about satellite cells (SC), information is limited regarding how populations of SC differ with muscle fiber type, especially in pigs. Therefore, the objective of this study was to isolate and culture SC from red (RST) and white (WST) portions of the semitendinosus muscle of neonatal and adult pigs and determine their capacity to proliferate, differentiate, and express various myosin heavy chain (MyHC) isoforms in vitro. Porcine satellite cells were isolated from RST and WST muscles of 6-wk-old and adult (>6-mo-old) pigs and cultured under standard conditions. Muscle from neonatal pigs yielded nearly 10 times more (<I>P</I> < 0.001) presumptive satellite cells as those from adult pigs, with fusion percentages close to 60% for the former. The RST yielded more (<I>P</I> < 0.001) SC per gram muscle compared to WST, 8.1 ± 0.2 × 10<SUP>4</SUP> cells versus 6.7 ± 0.1 × 10<SUP>4</SUP> cells/gram muscle in young pigs, and 9.7 ± 0.4 × 10<SUP>3</SUP> cells versus 5.5 ± 0.4 × 10<SUP>3</SUP> cells/gram muscle in adult pigs, respectively. Likewise, satellite cells from RST proliferated faster (<I>P</I> < 0.001) than those from WST across both ages, as indicated by a shorter cell doubling time, 18.6 ± 0.8 h versus 21.3 ± 0.9 h in young pigs, and 23.2 ± 0.7 h versus 26.7 ± 0.9 h in adult pigs, respectively. As a result of shorter times to confluence, satellite cells from RST also formed myotubes earlier than those SC originating from WST. Once induced, however, SC from WST differentiated and fused faster (<I>P</I> < 0.05) as evidenced by fusion percentage within the first 24 h, 41.6% versus 34.3%, respectively; but reached similar ultimate fusion percentages similar to WST by 48 h. Over 90% of MyHC expressed in maximally fused SC cultures from both RST and WST was restricted to the embryonic isoform. Type IIX MyHC mRNA was not detected in any culture. Myotube cultures from RST expressed more (<I>P</I> < 0.01) Type I MyHC isoform mRNA than those from WST, whereas those cultures from WST expressed more (<I>P</I> < 0.05) Type II (including Types IIA and IIB) MyHC transcripts. These data show SC cultures from porcine fast and slow muscles express MyHC profiles largely reflective of their muscle of origin and suggest satellite cells are partially restricted to a particular muscle phenotype in which they are juxtapositioned. Understanding the molecular nature of these intrinsic control mechanisms may lead to improved strategies for augmenting meat animal growth or muscle regeneration.</P>

Deoxynivalenol exposure induces autophagy/apoptosis and epigenetic modification changes during porcine oocyte maturation

Han, J.,Wang, Q.C.,Zhu, C.C.,Liu, J.,Zhang, Y.,Cui, X.S.,Kim, N.H.,Sun, S.C. Academic Press 2016 Toxicology and applied pharmacology Vol.300 No.-

Deoxynivalenol (DON) is a widespread trichothecene mycotoxin which contaminates agricultural staples and elicits a complex spectrum of toxic effects on humans and animals. It has been shown that DON impairs oocyte maturation, reproductive function and causes abnormal fetal development in mammals; however, the mechanisms remain unclear. In the present study, we investigate the possible reasons of the toxic effects of DON on porcine oocytes. Our results showed that DON significantly inhibited porcine oocyte maturation and disrupted meiotic spindle by reducing p-MAPK protein level, which caused retardation of cell cycle progression. In addition, up-regulated LC3 protein expression and aberrant Lamp2, LC3 and mTOR mRNA levels were observed with DON exposure, together with Annexin V-FITC staining assay analysis, these results indicated that DON treatment induced autophagy/apoptosis in porcine oocytes. We also showed that DON exposure increased DNA methylation level in porcine oocytes through altering DNMT3A mRNA levels. Histone methylation levels were also changed showing with increased H3K27me3 and H3K4me2 protein levels, and mRNA levels of their relative methyltransferase genes, indicating that epigenetic modifications were affected. Taken together, our results suggested that DON exposure reduced porcine oocytes maturation capability through affecting cytoskeletal dynamics, cell cycle, autophagy/apoptosis and epigenetic modifications.

A facile sol-gel method for synthesis of porous Nd-doped TiO₂ monolith with enhanced photocatalytic activity under UV-Vis irradiation

Du, J.,Chen, H.,Yang, H.,Sang, R.,Qian, Y.,Li, Y.,Zhu, G.,Mao, Y.,He, W.,Kang, D.J. Elsevier 2013 Microporous and mesoporous materials Vol.182 No.-

A porous Nd-doped TiO<SUB>2</SUB> monolith was successfully synthesized with polystyrene spheres as a template using a sol-gel method followed by calcination at high temperature. The porous Nd-doped TiO<SUB>2</SUB> monolith was characterized by X-ray diffractometry, scanning electron microscopy and Brunauer-Emmett-Teller measurements. Nd doping can increase the TiO<SUB>2</SUB> surface area by hindering the growth of large TiO<SUB>2</SUB> particles, and suppressing the recombination of photo-produced hole/electron (h<SUP>+</SUP>/e<SUP>-</SUP>) pairs. Moreover, its porous structure can provide a large surface area, facilitating enhanced adsorption and fast transfer of pollutants. To evaluate the photocatalytic activity of the porous Nd-doped TiO<SUB>2</SUB> monolith, the photo-degradation for methyl orange was investigated under UV-Vis irradiation. The porous 0.5% Nd-doped TiO<SUB>2</SUB> monolith showed better behavior than the other as-prepared samples and Degussa P25 due to its narrow band gap, high efficiency for h<SUP>+</SUP>/e<SUP>-</SUP> pair separation, and large surface area. The synergistic combination of Nd doping and the porous structure is a promising material design strategy for use in the degradation of organic pollutants.

Cowpea bruchid midgut transcriptome response to a soybean cystatin – costs and benefits of counter-defence

Chi, Y. H.,Salzman, R. A.,Balfe, S.,Ahn, J.-E.,Sun, W.,Moon, J.,Yun, D.-J.,Lee, S. Y.,Higgins, T. J. V.,Pittendrigh, B.,Murdock, L. L.,Zhu-Salzman, K. Blackwell Publishing Ltd 2009 INSECT MOLECULAR BIOLOGY Vol.18 No.1

<P>Abstract</P><P>The insect digestive system is the first line of defence protecting cells and tissues of the body from a broad spectrum of toxins and antinutritional factors in its food. To gain insight into the nature and breadth of genes involved in adaptation to dietary challenge, a collection of 20 352 cDNAs was prepared from the midgut tissue of cowpea bruchid larvae (<I>Callosobruchus maculatus</I>) fed on regular diet and diets containing antinutritional compounds. Transcript responses of the larvae to dietary soybean cystatin (scN) were analysed using cDNA microarrays, followed by quantitative real-time PCR (RT-PCR) confirmation with selected genes. The midgut transcript profile of insects fed a sustained sublethal scN dose over the larval life was compared with that of insects treated with an acute high dose of scN for 24 h. A total of 1756 scN-responsive cDNAs was sequenced; these clustered into 967 contigs, of which 653 were singletons. Many contigs (451) did not show homology with known genes, or had homology only with genes of unknown function in a B<SMALL>LAST</SMALL> search. The identified differentially regulated sequences encoded proteins presumptively involved in metabolism, structure, development, signalling, defence and stress response. Expression patterns of some scN-responsive genes were consistent in each larval stage, whereas others exhibited developmental stage-specificity. Acute (24 h), high level exposure to dietary scN caused altered expression of a set of genes partially overlapping with the transcript profile seen under chronic lower level exposure. Protein and carbohydrate hydrolases were generally up-regulated by scN whereas structural, defence and stress-related genes were largely down-regulated. These results show that insects actively mobilize genomic resources in the alimentary tract to mitigate the impact of a digestive protease inhibitor. The enhanced or restored digestibility that may result is possibly crucial for insect survival, yet may be bought at the cost of weakened response to other stresses.</P>

Charge transfer bands of Mo-O and photoluminescence properties of micro-material Y₂MoO₆:Eu³⁺ red phosphor

Wang, M.,Zhang, H.,Li, L.,Liu, X.,Hong, F.,Li, R.,Song, H.,Gui, M.,Shen, J.,Zhu, W.,Wang, J.,Zhou, L.,Jeong, J.H. Elsevier Sequoia 2014 JOURNAL OF ALLOYS AND COMPOUNDS Vol.585 No.-

Eu<SUP>3+</SUP> activated micrometer Y<SUB>2</SUB>MoO<SUB>6</SUB> phosphors with strong red emission bands, under a broad-band excitation wavelength range of 340-400nm, have been prepared by solid-state reaction and sol-gel technique. The photoluminescence indicates that the materials exhibit a characteristic red emission peak of Eu<SUP>3+</SUP> ions at 612nm. Compared with the material obtained by sol-gel method, the Y<SUB>2</SUB>MoO<SUB>6</SUB>:Eu prepared using solid state method showed much stronger red emission under the n-UV excitation. The broad excitation bands are assigned to charge transfer (CT) bands originating from the ligands (O) to the central ions Mo<SUP>6+</SUP>. About 12nm shift of excitation bands in Y<SUB>2</SUB>MoO<SUB>6</SUB>:Eu was found. With a decrease of the crystalline size, the excitation bands of O-Mo CT shift to the short wavelength. The origin of CT shift in macromaterial Y<SUB>2</SUB>MoO<SUB>6</SUB>:Eu was investigated quantitatively from the chemical bond viewpoint. All constituent chemical bonds in the crystal with or without oxygen vacancy were considered. The changes of average energy gap of the chemical bond Mo-O and the environmental factor (h<SUB>e</SUB>) surrounding Mo<SUP>6+</SUP> ions in the crystals were discussed quantitatively. Calculated results from two different methods analysis specifications showed that the origin of CT blue-shifts mainly come from the vacancies of O6 sites within the crystals.

The Magnetic Filtering Vacuum Arc Film Deposition System and Its Applications

Wang, G.F.,Zhang, H.X.,Zhang, H.J.,Zhu, H. The Korean Vacuum Society 1997 Applied Science and Convergence Technology Vol.6 No.1

A cathodic arc with beam filter is employed for the deposition of metallic and hydrogen-free amorphous carbon films. A solenoid filter is used to prevent macropaticles and nonionized atoms from reaching the substrate. The detail transport characters of the filter are presented in the paper. With an optmum filter arrangement we are able to obtain a filter output of 18.4% of the total number of ions produced by the vacuum arc discharge. The deposited amorphous cabon thin film contains no hydrogen and a high fraction of $sp^3$ is determined by XPS. A dense Ti film deposited on H13 steel improves the corrosion resistance of the H13 steel and significant improvements of corrosion resistance were observed by implanting Ti, C in the film.

Induction of leukemic-cell-specific cytotoxic T lymphocytes by autologous monocyte-derived dendritic cells presenting leukemic cell antigens

Lee, J.-J.,Park, M.-S.,Park, J.-S.,Kang, H.-K.,Kim, S.-K.,Nguyen Pham, T.-N.,Zhu, X.-W.,Cho, D.,Nam, J.-H.,Kim, Y.-J.,Rhee, J.-H.,Chung, I.-J.,Kim, H.-J. Wiley-Liss 2006 JOURNAL OF CLINICAL APHERESIS Vol.21 No.3

<P>Leukemic-dendritic cells (leukemic-DCs) have certain limitations, which include difficult generation in 30–40% of patients, and low levels of expression of several key molecules. Therefore, an alternative approach using monocyte-derived DCs pulsed with tumor antigens is required. We investigated the possibility of immunotherapy for AML using leukemic-cell-specific cytotoxic T lymphocytes that were stimulated in vitro by autologous DCs pulsed with tumor antigens. To generate DCs, CD14+ cells were isolated from peripheral blood mononuclear cells using magnetic-activated cell sorting, and cultured in the presence of GM-CSF and IL-4. On day 6, maturation of DCs was induced by addition of cytokine cocktail (TNF-&agr;, IL-1&bgr;, IL-6, and prostaglandin E<SUB>2</SUB>) for 2 days, and then the mature DCs were pulsed with whole leukemic cell lysates or apoptotic leukemic cells. There were no differences in the phenotypic expressions of mature DCs generated by pulsing with or without leukemic antigens. The mature DCs pulsed with tumor cell lysates or apoptotic leukemic cells showed a higher allostimulatory capacity for allogeneic CD3+ T cells as compared with mature non-pulsed DCs. Autologous CD3+ T cells stimulated by the mature pulsed DCs showed more potent cytotoxic activities against autologous leukemic cells than those stimulated by mature non-pulsed DCs. These results suggest that use of DCs pulsed with leukemic cell lysates or apoptotic leukemic cells is a feasible alternative immunotherapeutic approach to overcome the limitations of leukemic-DCs for the treatment of AML patients. J Clin Apheresis 2006. © 2006 Wiley-Liss, Inc.</P>

Hepatitis B virus reactivation in B-cell lymphoma patients treated with rituximab: Analysis from the Asia Lymphoma Study Group

Kim, S.J.,Hsu, C.,Song, Y.Q.,Tay, K.,Hong, X.N.,Cao, J.,Kim, J.S.,Eom, H.S.,Lee, J.H.,Zhu, J.,Chang, K.M.,Reksodiputro, A.H.,Tan, D.,Goh, Y.T.,Lee, J.,Intragumtornchai, T.,Chng, W.J.,Cheng, A.L.,Lim, Pergamon Press 2013 European journal of cancer Vol.49 No.16

Background: Hepatitis B virus (HBV) reactivation is increasing, as rituximab has become widely used for B-cell lymphoma. Thus, prevention and management of HBV reactivation are important in HBV-endemic areas. Methods: Hepatitis B virus (HBV) reactivation in HBV surface antigen (HBsAg)-positive patients and HBsAg-negative/HBV core antibody (HBcAb)-positive patients who received rituximab-containing chemotherapy was investigated by the Asia Lymphoma Study Group via retrospective (n=340), and the results were compared to cross-sectional analysis with patients who were prospectively monitored in a single institute (n=127). The goal of the study was to define the frequency of HBV reactivation and the efficacy of antiviral prophylaxis. Results: HBV reactivation was found in 27.8% of HBsAg-positive patients (45/162) in the retrospective analysis, being significantly less frequent in patients receiving antiviral prophylaxis than those not (22.9%, 32/140 versus 59.1%, 13/22; p<0.001). Lamivudine was most commonly used (96/162, 59.3%), but more than 20% of HBsAg-positive patients showed breakthrough HBV reactivation. In the cross-sectional analysis, a reduced rate of HBV reactivation occurred for entecavir as compared with lamivudine prophylaxis (6.3% versus 39.3%; p<0.05). HBV DNA monitoring of HBsAg-negative/HBcAb-positive patients in the cross-sectional analysis showed HBV reactivation in only 2.4% of cases. Conclusions: This is the largest study of HBV reactivation in patients receiving rituximab-containing chemotherapy to date, and we defined the probability of HBV reactivation in an HBV-endemic region.

A self-assembled amphiphilic imidazolium-based ATP probe

Zhu, J. H.,Yu, C.,Chen, Y.,Shin, J.,Cao, Q. Y.,Kim, J. unknown 2017 Chemical communications Vol. No.

<P>A novel amphiphilic imidazolium-based probe containing a dansyl fluorophore and a long cetyl chain has been developed for ATP recognition. The probe forms self-assembled micelle-like aggregates at low concentration in its aqueous solution and can selectively recognize ATP among other bioactive anions with a significant enhancement in fluorescence emission.</P>