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991.
Hongliang Wang Xiaolan Tang Ganghua Tang Tingting Huang Xiang Liang Kongzhen Hu Huaifu Deng Chang Yi Xinchong Shi Kening Wu 《Apoptosis : an international journal on programmed cell death》2013,18(8):1017-1027
The synthetic bis(zinc(II)-dipicolylamine) (DPAZn2) coordination complexes are known to have a high specific and selective affinity to target the exposed phosphatidylserine (PS) on the surface of dead and dying cells. An 18F-labeled DPAZn2 complex (4-18F-Fluoro-benzoyl-bis(zinc(II)-dipicolylamine), 18F-FB-DPAZn2) as positron emission tomography (PET) tracer was developed and evaluated for in vivo imaging of tumor treated with a chemical agent. The in vitro cell stain studies revealed that fluorescent DPAZn2 complexes (Dansyl-DPAZn2) stained the same cells (apoptotic and necrotic cells) as fluorescein isothiocyanate (FITC) labeled Annexin V (FITC-Annexin V). The radiosynthesis of 18F-FB-DPAZn2 was achieved through the amidation the precursor bis(2,2′-dipicolylamine) derivative (DPA2) with the prosthetic group N-succinimidyl-4-[18F]-fluorobenzoate (18F-SFB) and chelation with zinc nitrate. In the biodistribution study, the fast clearance of 18F-FB-DPAZn2 from blood and kidney was observed and high uptake in liver and intestine within 90 min postinjection was also found. For the PET imaging, significantly higher tumor uptake of 18F-FB-DPAZn2 was observed in the adriamycin (ADM)-treated Hepa1-6 hepatocellular carcinoma-bearing mice than that in the untreated tumor-model mice, while a slightly decreased tumor uptake of 18F-FDG was found in the ADM-treated tumor-bearing mice. The results indicate that 18F-FB-DPAZn2 has the similar capability of apoptosis detection as FITC-Annexin V and seems to be a potential PET tracer for noninvasive evaluation and monitoring of anti-tumor chemotherapy. The high uptake of 18F-FB-DPAZn2 in the abdomen needs to optimize the structure for improving its pharmacokinetics characteristics in the future work. 相似文献
992.
993.
Cloud computing is an emerging computing paradigm in which IT resources and capacities are provided as services over the Internet. Promising as it is, this paradigm also brings forth new challenges for security when users want to securely outsource the computation of cryptographic operations to the untrusted cloud servers. As we know, modular exponentiation is one of the basic operations among most of current cryptosystems. In this paper, we present the generic secure outsourcing schemes enabling users to securely outsource the computations of exponentiations to the untrusted cloud servers. With our techniques, a batch of exponentiations (e.g. t exponentiations) can be efficiently computed by the user with only O(n+t) multiplications, where n is the number of bits of the exponent. Compared with the state-of-the-art algorithm, the proposed schemes are superior in both efficiency and verifiability. Furthermore, there are not any complicated pre-computations on the user side. Finally, the schemes are proved to be secure under the Subset Sum Problem. 相似文献
994.
Jaehoon Choi Jee-Hyeok Chung Geun-Yong Kwon Ki-Wan Kim Sukwha Kim Hak Chang 《Cell and tissue banking》2013,14(3):413-422
In cell culture, medium supplemented with fetal bovine serum is commonly used, and it is widely known that fetal bovine serum supplies an adequate environment for culture and differentiation of stem cells. Nevertheless, the use of xenogeneic serum can cause several problems. We compared the effects of four different concentrations of autologous serum (1, 2, 5, and 10 %) on expansion and adipogenic differentiation of adipose-derived stem cells using 10 % fetal bovine serum as a control. The stem cells were grafted on nude mice and the in vivo differentiation capacity was evaluated. The isolation of adipose-derived stem cells was successful irrespective of the culture medium. The proliferation potential was statistically significant at passage 2, as follows: 10 % autologous serum >10 % fetal bovine serum = 5 % autologous serum >2 % autologous serum = 1 % autologous serum. The differentiation capacity appeared statistically significant at passage 4, as follows: 10 % fetal bovine serum >10 % autologous serum = 5 % autologous serum >2 % autologous serum = 1 % autologous serum. Ten percent autologous serum and 10 % fetal bovine serum had greater differentiation capacity than 1 and 2 % autologous serum in vivo, and no significant difference was observed between the groups at ≥5 % concentration at 14 weeks. In conclusion, 10 % autologous serum was at least as effective as 10 % fetal bovine serum with respect to the number of adipose-derived stem cells at the end of both isolation and expansion, whereas 1 and 2 % autologous serum was inferior. 相似文献
995.
Arctic organisms are adapted to the strong seasonality of environmental forcing. A small timing mismatch between biological processes and the environment could potentially have significant consequences for the entire food web. Climate warming causes shrinking ice coverage and earlier ice retreat in the Arctic, which is likely to change the timing of primary production. In this study, we test predictions on the interactions among sea ice phenology and production timing of ice algae and pelagic phytoplankton. We do so using the following (1) a synthesis of available satellite observation data; and (2) the application of a coupled ice‐ocean ecosystem model. The data and model results suggest that, over a large portion of the Arctic marginal seas, the timing variability in ice retreat at a specific location has a strong impact on the timing variability in pelagic phytoplankton peaks, but weak or no impact on the timing of ice‐algae peaks in those regions. The model predicts latitudinal and regional differences in the timing of ice algae biomass peak (varying from April to May) and the time lags between ice algae and pelagic phytoplankton peaks (varying from 45 to 90 days). The correlation between the time lag and ice retreat is significant in areas where ice retreat has no significant impact on ice‐algae peak timing, suggesting that changes in pelagic phytoplankton peak timing control the variability in time lags. Phenological variability in primary production is likely to have consequences for higher trophic levels, particularly for the zooplankton grazers, whose main food source is composed of the dually pulsed algae production of the Arctic. 相似文献
996.
CYP57B3 from Aspergillus oryzae was recently discovered to catalyze the ortho-hydroxylation of the soyisoflavone genistein. In the present study, the gene encoding CYP57B3 was fused with the reductase domain of the CYP102A1 gene (BM3R) from Bacillus megaterium, and recombinant Pichia pastoris harboring the P450 fusion gene was evaluated for its ability to produce ortho-hydroxydaidzein derivatives from daidzein. The results showed that 8-hydroxydaidzein (8-OHDe), 3′-hydroxydaidzein (3′-OHDe), and 6-hydroxydaidzein (6-OHDe) were produced during fermentation with a maximal conversion of 2.4, 0.9, and 36.3%, respectively. The maximal yield of 6-OHDe by the recombinant strain was 9.1 mg/l. To our knowledge, both the maximal yield and the conversion efficiency of 6-OHDe from daidzein in the present study are the highest among those reported in the literatures to date. The present study is also the first to demonstrate production of ortho-hydroxydaidzein derivatives using a fusion fungus cytochrome P450 enzyme. 相似文献
997.
Qingtian Guan Xiaohan Guo Ting Han Mengwei Wei Meiling Jin Fan Zeng Lin Liu Zhe Li Yuhan Wang Gang-Won Cheong Shihong Zhang Baolei Jia 《Process Biochemistry》2013,48(5-6):878-884
Thermostable amylopullulanases can catalyse the hydrolysis of both α-1,4 and α-1,6 glucosidic bonds and are of considerable interest in the starch saccharification industry. In this study, the gene Apu-Tk encoding an extracellular amylopullulanase was cloned from an extremely thermophilic anaerobic archaeon Thermococcus kodakarensis KOD1. Apu-Tk encodes an 1100-amino acid protein with a 27-residue signal peptide, which has a predicted mass of 125 kDa after signal peptide cleavage. Sequence alignments showed that Apu-Tk contains the five regions conserved in all GH57 family proteins. Full-length Apu-Tk was expressed in Escherichia coli and purified to homogeneity. The purified enzyme displayed both pullulanase and amylase activity. The optimal temperature for Apu-Tk to hydrolyse pullulan and soluble starch was >100 °C. Apu-Tk was also active at a broad range of pH (4–7), with an optimum pH of ~5.0–5.5. Apu-Tk also retained >30% of its original activity and partially folded globular structure in the presence of 8% SDS or 10% β-mercaptoethanol. The high yield, broad pH range, and stability of Apu-Tk implicate it as a potential enzyme for industrial applications. 相似文献
998.
Koeun Han Hee-Jin Jeong Joohee Sung Young Soo Keum Myeong-Cheoul Cho Jeong-Han Kim Jin-Kyung Kwon Byung-Dong Kim Byoung-Cheorl Kang 《Molecular breeding : new strategies in plant improvement》2013,31(3):537-548
Pungency in pepper (Capsicum annuum L.) has unique characteristics due to the alkaloid compound group, capsaicinoids, which includes capsaicin. Although capsaicinoids have been proved to have pharmacological and physiological effects on human health, the application of capsaicinoids has been limited because of their pungency. Capsinoids found in non-pungent peppers share closely related structures with capsaicinoids and show similar biological effects. Previous studies demonstrated that mutations in the p-AMT gene were related to the production of capsinoids; however, the pathway of capsinoid synthesis has not yet been fully elucidated. In this study, we performed genetic analysis to determine the mechanism of capsinoid synthesis using a F6 recombinant inbred line population. In this population, the presence/absence of capsinoids co-segregated with the genotype of the Pun1 locus, without exception. In addition, we screened the patterns of capsinoid synthesis and the correlation between the Pun1 locus and capsinoid synthesis in p-AMT mutant accessions. In Capsicum germplasms, we selected amino-acid-substituted mutants in the PLP binding domain of the p-AMT gene. Capsinoids were not synthesized with the recessive pun1 gene, regardless of the p-AMT genotype, and no relationship was found between p-AMT mutant type and capsinoid content. We concluded that the Pun1 gene, which is responsible for capsaicinoid synthesis, also controls capsinoid synthesis. 相似文献
999.
Faming Wang Songmin Zhao Yonghua Han Yutao Shao Zhenying Dong Yang Gao Kunpu Zhang Xin Liu Dawei Li Jinhua Chang Daowen Wang 《Molecular breeding : new strategies in plant improvement》2013,31(4):777-784
Melanaphis sacchari causes serious damage to sorghum (Sorghum bicolor (L.) Moench) growth, development and productivity in many countries. A dominant gene (RMES1) conferring resistance to M. sacchari has been found in the grain sorghum variety Henong 16 (HN16), but fine mapping of the RMES1 locus remains to be reported. In this study, genetic populations segregating for RMES1 were prepared with HN16 and BTx623 as parental lines. The latter had been used for sorghum genome sequencing but was found to be susceptible to M. sacchari in this work. A total of 11 molecular markers were mapped to the short arm of chromosome 6 harboring RMES1. The closest markers flanking the RMES1 locus were Sb6m2650 and Sb6rj2776, which delimited a chromosomal region of about 126 kb containing five predicted genes. The utility of the newly identified DNA markers for tagging RMES1 in molecular breeding of M. sacchari resistance, and further efforts in cloning RMES1, are discussed. 相似文献
1000.
Jae Su Kim Se Jin Lee Margaret Skinner Bruce L. Parker Byung-Taek Oh Kui-Jae Lee 《BioControl》2013,58(5):607-614
Bioassay can be used for analysis of the biological potency of Bacillus thuringiensis (Bt) in fermentation and formulation but requires precise scheduling and several repetitions. Alternatively, this work explored if the endospore counting could be used to predict the potency of Bt technical powder. Analyses of Bt technical powers provided a strong linear relationship (r = 0.971) between the number of viable endospores and the potency of the technical powder against second instar Plutella xylostella (L.) larvae. Next, a Bt wettable powder formulation was stored at 25 and 40 °C for 12 weeks to investigate the influence of storage temperature on the prediction of insecticidal potency based on the counting. At 25 °C storage, the insecticidal potency could be predicted based on the counting, but at 40 °C the predicted insecticidal potency was much lower than the measured potency. These results suggest that the NT0423 endospore viability can be used to predict its potency in production, but the relationship may not be the same following the storage at high temperature. 相似文献