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991.
992.
Sheng‐Li Hu Jiu‐Quan Zhang Xiang Hu Rong Hu Hai‐Shui Luo Fei Li Yong‐Zhi Xia Jiang‐Tao Li Jiang‐Kai Lin Gang Zhu Hua Feng 《Journal of cellular biochemistry》2009,108(2):529-535
Human umbilical cord mesenchymal stem cells (hUC‐MSCs) transplantation has been shown to promote regeneration and neuroprotection in central nervous system (CNS) injuries and neurodegenerative diseases. To develop this approach into a clinical setting it is important to be able to follow the fates of transplanted cells by noninvasive imaging. Neural precursor cells and hematopoietic stem cells can be efficiently labeled by superparamagnetic iron oxide (SPIO) nanoparticle. The purpose of our study was to prospectively evaluate the influence of SPIO on hUC‐MSCs and the feasibility of tracking for hUC‐MSCs by noninvasive imaging. In vitro studies demonstrated that magnetic resonance imaging (MRI) can efficiently detect low numbers of SPIO‐labeled hUC‐MSCs and that the intensity of the signal was proportional to the number of labeled cells. After transplantation into focal areas in adult rat spinal cord transplanted SPIO‐labeled hUC‐MSCs produced a hypointense signal using T2‐weighted MRI in rats that persisted for up to 2 weeks. This study demonstrated the feasibility of noninvasive imaging of transplanted hUC‐MSCs. J. Cell. Biochem. 108: 529–535, 2009. © 2009 Wiley‐Liss, Inc. 相似文献
993.
Yin-Juan Zhao Yi-Jun Dai Ci-Gang Yu Jun Luo Wen-Ping Xu Jue-Ping Ni Sheng Yuan 《Biodegradation》2009,20(6):761-768
Chloropyridinyl neonicotinoid insecticides play a major role in crop protection and flea control on cats and dogs. Imidacloprid,
thiacloprid and acetamiprid have in common the 6-chloro-3-pyridinylmethyl group but differ in the nitroguanidine or cyanoamidine
substituent on an acyclic or cyclic moiety. Our previous study found that Stenotrophomonas maltophilia CGMCC 1.1788 could hydroxylate imidacloprid to 5-hydroxy imidacloprid, and 5-hydroxy imidacloprid was easily converted to
10–19 times higher insecticidal olefin imidacloprid against aphid or whitefly. Acetamiprid could be transformed by S. maltophilia to form N-demethylation product(IM 2-1). In this paper, we examined S. maltophilia CGMCC 1.1788’s ability of transformation of thiacloprid. S. maltophilia CGMCC 1.1788 can hydroxylate thiacloprid to 4-hydroxy thiacloprid characterized by HPLC-MS/MS and NMR analysis, however 4-hydroxy
thiacloprid could not be converted to olefin thiacloprid under acid conditions like imidacloprid, whereas oxidized and decyonated
simultaneously to form 4-ketone thiacloprid imine in alkaline solution. Bioassays indicated that 4-hydroxy thiacloprid had
156 times lower insecticidal activity than thiacloprid, and the ketone-imine derivative almost had no toxicity towards aphid.
Though both imidacloprid and thiacloprid are hydroxylated by S. maltophilia CGMCC 1.1788 at the same carbon atom position, however the structural difference between in imidacloprid and thiacloprid,
originate the entire discrepancy in bioefficacy of metabolite and its further degrading pathway. These results explain that
why thiacloprid is classified as not relevant grade for soil and seed applications, whereas imidacloprid is recommended and
acetamiprid is limited. 相似文献
994.
Nitrogen transformations were studied in flooded and non-flooded vertical flow columns with and without a rice plant. Influent (average concentration: NH4+-N: 40 mg L?1; NO3?-N: 0.15 mg L?1; and NO2?-N: 4.0 mg L?1) was supplied at 1.25 cm d?1 during stage 1 (20 May–5 August) and at 2.50 cm d?1 at stage 2 (6 August–26 October), which resulted in an average nitrogen loading of 156 g m?2 during the entire experimental period. Total nitrogen (T-N) removal efficiencies exceeded 90% in vertical flow systems with rice plants. Nitrogen assimilated by the rice plants in the flooded column accounted for 60% of the total input nitrogen, while that in the non-flooded column accounted for 36% of the total input. The remaining nitrogen appeared to be removed through biogeochemical pathways. Although some nitrogen flowed out, most input nitrogen was also removed even in the flooded and non-flooded unplanted columns.A high-resolution vertical distribution investigation showed the changes of nitrogen forms in soil water. In the flooded condition, there were high ammonium and high nitrite concentrations in the upper layers. The concentrations of ammonium and nitrite simultaneously decreased with depth increasing, suggesting that anaerobic ammonia oxidation (anammox) may occur in these anaerobic conditions. In contrast, the distributions of nitrogen in the non-flooded columns with elevated water level suggested that nitrification–denitrification route was the major removal mechanism, whether or not rice plants were present. 相似文献
995.
Effects of exogenous B supply on growth, B accumulation and distribution of two navel orange cultivars 总被引:3,自引:0,他引:3
Ou Sheng Shang W. Song Yun J. Chen Shu A. Peng Xiu X. Deng 《Trees - Structure and Function》2009,23(1):59-68
To investigate the effects of boron (B) on growth, B concentration and distribution of two navel orange cultivars, ‘Newhall’
(Citrus sinensis Osbeck) and ‘Skagg’s Bonanza’ (Citrus sinensis Osbeck) grafted on the rootstock trifoliate orange [Poncirus trifoliata (L.) Raf.], B at five levels was exogenously supplied to 1-year-old grafted plants of both cultivars under greenhouse conditions.
Plants were grown in sand:perlite (1:1, v/v) medium and were irrigated every 2 days with half-strength Hoagland’s No. 2 nutrient
solutions containing different B, 0.01, 0.05, 0.10, 0.25 and 2.50 mg l−1 (0.25 and 2.50 mg l−1 were considered as control and excess B treatment, respectively, and the other three B levels were considered as low B treatments).
After treatments for 183 days, leaves (from basal, middle, upper parts of the shoots), stem of scion, stem of rootstock and
root were separately sampled. Our results showed that plant growth (plant height, root volume and dry weights of various parts)
was inhibited in response to low or excess B supplies in both cultivars. It was found that B concentrations in the upper leaves
of both cultivars were substantially higher than those in the basal leaves when low concentrations (≤0.05 mg l−1) of exogenous B were applied, suggesting that B was preferentially translocated to the upper-younger leaves to support their
growth. Analysis of B distribution in different parts indicated that translocation of B from the root to the scion’s shoots
(stems and leaves of scion) may be restricted upon exposure to low B conditions. When B was inadequately supplied, growth
of ‘Skagg’s Bonanza’ was better than ‘Newhall’, implying that the former cultivar was more tolerant to low B status, which
may be due to the higher efficiency of B translocation from the root to the scion’s shoots. However, when the plants were
treated with excess B (2.50 mg l−1), both cultivars showed a similar degree of B toxicity. The probability of scion–rootstock interactions in relation to the
differential responses of growth and different efficiency of B translocation involved in the two orange cultivars following
the long-term low B stress were discussed. 相似文献
996.
997.
Xin Li Yonghui Li Zhikai Zhong Donghai Wang Jo A. Ratto Kuichuan Sheng Xiuzhi Susan Sun 《Bioresource technology》2009,100(14):3556-3562
Soybean protein is a renewable and abundant material that offers an alternative to formaldehyde-based resins. In this study, soybean protein was modified with sodium dodecyl sulfate (SDS) as an adhesive for wood fiber medium density fiberboard (MDF) preparation. Second-order response surface regression models were used to study the effects and interactions of initial moisture content (IMC) of coated wood fiber, press time (PT) and temperature on mechanical and water soaking properties of MDF. Results showed that IMC of coated fiber was the dominant influencing factor. Mechanical and soaking properties improved as IMC increased and reached their highest point at an IMC of 35%. Press time and temperature also had a significant effect on mechanical and water soaking properties of MDF. Second-order regression results showed that there were strong relationships between mechanical and soaking properties of MDF and processing parameters. Properties of MDF made using soybean protein adhesive are similar to those of commercial board. 相似文献
998.
A biochar (BC) generated from straw as a cost-effective substitute for activated carbon (AC) was tested for its adsorptive ability toward reactive brilliant blue (KNR) and rhodamine B (RB). BC and AC had similar surface areas but differed in porosity, surface acidity and point of zero surface charge. The two carbons were highly effective adsorbents for both dyes at pH 3.0 and 6.5. BC was slightly more effective than AC to adsorb RB due to the RB–BC electrostatic interactions and RB protonation at low pH. The two carbons reversed in their effectiveness to adsorb KNR for similar reasons. The π–π interactions between dye molecules and graphene layers of BC, the direct dye-BC electrostatic attraction/repulsion and the intermolecular hydrogen bonding are proposed to be the combined mechanisms for dye adsorption. Rich phenolic hydroxyls on the surface of BC are expected to enhance the π–π interactions. 相似文献
999.
Jing Li Xinyan Li Min Tan Birong Lin Sheng Hou Weizhu Qian Bohua Li Dapeng Zhang Bo Zhou Hao Wang Tongyu Zhu Yajun Guo 《MABS-AUSTIN》2009,1(1):49-55
HuCD25mAb is a humanized anti-CD25 antibody which has the same amino acid sequence as daclizumab (Zenapax, Roche). HuCD25mAb is expressed in Chinese hamster ovary (CHO) cells while daclizumab is expressed in the NSO myeloma cell line. A comparative study was performed to evaluate the pharmacokinetics and pharmacodynamics between huCD25mAb and daclizumab in a two-dose regimen incorporating triple immunosuppressant treatment regimens (MMF, CsA and steroids). Fifteen patients were enrolled and randomized to receive intravenous infusion of either huCD25mAb (n = 10) or daclizumab (n = 5) at a dosage of 1 mg·kg−1 on operation day 0 and post-operation day 14. Serum concentrations of huCD25mAb and daclizumab were measured by a validated competitive ELISA. Subgroups of CD3+, CD25+, CD4+ and CD8+ lymphocytes were monitored periodically by flow cytometry. The concentration-time curves of huCD25mAb and daclizumab were found to fit well to a one-compartment model. A significant decline of proportion (%) of CD3-CD25+ and CD3+CD25+ lymphocytes was observed 30 min after first infusion on day 0 (3.40 ± 1.83 to 0.03 ± 0.07, 3.35 ± 2.02 to 0.37 ± 0.49), and these levels remained low for at least 70 days (0.03 ± 0.05, 0.31 ± 0.47). All pharmacokinetic parameters of huCD25mAb seemed similar to those of daclizumab. The two-dose huCD25mAb regimen was as effective as daclizumab in rapidly achieving high therapeutic concentration in the treated patients, and a significant decrease of CD3−CD25+ and CD3+CD25+ lymphocytes was demonstrated. This suggests that two-dose regimen is feasible in maintaining host immunosuppression and may provide an effective and economical strategy for reducing incidence of acute graft rejection.Key words: CD25, pharmacokinetics, kidney transplantation, enzyme immunoassay, flow cytometry, monoclonal antibody 相似文献
1000.
Tzyy‐Rong Jinn Suey‐Sheng Kao Yin‐Chin Tseng Ying‐Ju Chen Tzong‐Yuan Wu 《Biotechnology progress》2009,25(2):384-389
The baculovirus–insect expression system is a popular tool for recombinant protein production. The standard method for infecting insect larvae with recombinant baculovirus for protein production involves either feeding occlusion bodies or injecting budded virus into the cuticle. In this study, we showed that the recombinant Autographa californica multiple nucleopolyhedrovirus (AcMNPV) at titers >108 pfu/mL efficiently infected Trichoplusia ni (T. ni) larvae through aerosol inoculation of budded virus at a pressure of 5.5 × 104 Pa. The dipping T. ni larvae in virus‐containing solution efficiently infected them. These results indicate that surface contamination, either by aerosol or dipping, lead to infection via spiracles. The aerosol infection route for AcMNPV was restricted to T. ni and Plutella xylostella larvae, whereas Spodoptera litura and Helicoverpa armigera larvae were resistant to this inoculation process. The yields of the reporter proteins DsRed and EGFP from T. ni larvae following aerosol infection were nearly identical to those following oral feeding or injection. This alternative baculovirus infection strategy facilitates recombinant protein and virus production by insect larvae. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 相似文献