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991.
A novel biodegradable amphiphilic brush-coil block copolymer consisting of poly(epsilon-caprolactone) and PEGylated polyphosphoester was synthesized by ring opening polymerization. The composition and structure of the copolymer were characterized by 1H NMR, 13C NMR, and FT-IR, and the molecular weight and molecular weight distribution were analyzed by gel permeation chromatograph (GPC) measurements to confirm the diblock structure. These amphiphilic copolymers formed micellar structures in water, and the critical micelle concentrations (CMCs) were around 10(-3) mg/mL, which was determined using pyrene as a fluorescence probe. Transmission electron microscopy (TEM) images showed that the micelles took an approximately spherical shape with core-shell structure, which was further demonstrated by laser light scattering (LLS) technique. The degradation behavior of the polymeric micelle was also investigated in the presence of Pseudomonas lipase and characterized by GPC measurement. Such polymer micelles from brush-coil block copolymers are expected to have wide utility in the field of drug delivery. 相似文献
992.
Du C Sato A Watanabe S Ikemoto A Fujii Y Okuyama H 《The Journal of nutritional biochemistry》2001,12(8):474-480
Female mice were fed a conventional diet, shifted at 119 days of age to a diet supplemented with 10 wt % lard (Lar), high-linoleic (n-6) safflower oil (Saf), rapeseed oil (low-erucic, Rap), high-alpha-linolenic (n-3) perilla oil (Per) or a mixture (1:9) of ethyl docosahexaenoate (n-3) and soybean oil (DHA/Soy). Weight gain was less in the Per group than in the other groups at 497 days of age. In the Rap group, proteinuria was more severe than in the Saf, Per and DHA/Soy group, and hepatic triacylglycerol accumulation was greater than in the other groups. The mean survival time of the DHA/Soy group (753 days) was significantly longer than in the Lar group (672 days) and Saf group (689 days); the differences among other groups (e.g., 701 days in the Per group and 712 days in the Rap group) were not statistically significant. Although DHA is more susceptible to auto-oxidation than other major fatty acids in the air, an oil containing DHA was found to increase the survival of mice. Rapeseed oil that decreases the survival time of SHRSP rats was found to be safe in the mouse strain used in this study when survival was an end point. 相似文献
993.
Lacking systematic evaluations in soil quality and microbial community recovery after different amendments addition limits optimization of amendments combination in coal mine soils. We performed a short‐term incubation experiment with a varying temperature over 12 weeks to assess the effects of three amendments (biochar: C; nitrogen fertilizer at three levels: N‐N1~N3; microbial agent at two levels: M‐M1~M2) based on C/N ratio (regulated by biochar and N level: 35:1, 25:1, 12.5:1) on mine soil properties and microbial community in the Qilian Mountains, China. Over the incubation period, soil pH and MBC/MBN were significantly lower than unamended treatment in N addition and C + M + N treatments, respectively. Soil organic carbon (SOC), total nitrogen (TN), available nitrogen (AN), available phosphorus (AP), available potassium (AK), microbial biomass carbon (MBC), and nitrogen (MBN) contents increased significantly in all amended treatments (p < .001). Higher AP, AK, MBC, MBN, and lower MBC/MBN were observed in N2‐treated soil (corresponding to C/N ratio of 25:1). Meanwhile, N2‐treated soil significantly increased species richness and diversity of soil bacterial community (p < .05). Principal coordinate analysis further showed that soil bacterial community compositions were significantly separated by N level. C‐M‐N treatments significantly increased the relative abundance (>1%) of the bacterial phyla Bacteroidetes and Firmicutes, and decreased the relative abundance of fungal phyla Chytridiomycota (p < .05). Redundancy analysis illustrated the importance of soil nutrients in explaining variability in bacterial community composition (74.73%) than fungal composition (35.0%). Our results indicated that N addition based on biochar and M can improve soil quality by neutralizing soil pH and increasing soil nutrient contents in short‐term, and the appropriate C/N ratio (25:1) can better promote microbial mass, richness, and diversity of soil bacterial community. Our study provided a new insight for achieving restoration of damaged habitats by changing microbial structure, diversity, and mass by regulating C/N ratio of amendments. 相似文献
994.
Du Y Yan L Du H Wang L Ding F Quan L Cheng X Song K Liu H 《Journal of cellular biochemistry》2012,113(10):3218-3228
Autoantibodies against the second extracellular loop of β1‐adrenergic receptor (β1‐AA) not only contribute to increased susceptibility to heart failure, but also play a causative role in myocardial remodeling through their catecholamine‐like effects via binding with the β1‐adrenergic receptor. The current study was designed to determine whether β1‐AA isolated from the sera of heart failure patients could cause TNF‐α secretion from the murine macrophage‐like cell line RAW264.7. Blood samples were collected from 40 patients who had suffered heart failure, as well as from 40 healthy subjects. The titer of β1‐AA and the level of TNF‐α were detected using ELISA. The effect of β1‐AA on murine macrophage‐like cell line RAW264.7 proliferation was detected by CCK‐8 kits and CFSE assay. Western blot assay was used to analyze the expression of phospho‐VASP. β1‐AA appeared more frequently in patients with heart failure than in healthy subjects. The β1‐AA isolated from heart failure patients promoted an increase of TNF‐α levels, which could be completely blocked by the selective β1‐adrenergic receptor antagonist metoprolol and the second extracellular loop of β1‐adrenergic receptor (β1‐AR‐ECII), but only partially inhibited by PKA inhibitor H89. Furthermore, the β1‐AA could enhance the proliferation of RAW264.7 cells in vitro. Meanwhile, the expression of phospho‐VASP was markedly increased in the presence of β1‐AA. These results demonstrate for the first time that the β1‐AA isolated from heart failure patients could bind with β1‐AR on the surface of RAW264.7 cells, causing the release of TNF‐α largely in a PKA‐dependent fashion. J. Cell. Biochem. 113: 3218–3228, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
995.
996.
Li D Du X Zhang R Shen B Huang Y Valenzuela RK Wang B Zhao H Liu Z Li J Xu Z Gao L Ma J 《Genomics》2012,99(4):220-226
In this study, through linkage analysis of a four-generation Chinese family with multiple members afflicted with DGI (type II), we identified a novel missense mutation in DSPP. The mutation was located in exon 2 at the second nucleotide position of the last codon and resulted in a substitution of a proline with a leucine residue (c.50C>T, p.P17L, g.50C>T). To assess the potential effects of this novel mutation, we utilized various bioinformatics analysis programs. The results indicate that the mutation likely affects protein cleavage/trafficking. We also analyzed previously reported mutations of DSPP. In summary, our finding supports that the genomic sequence that corresponds to the P17 residue of DSPP is a mutational hotspot and P17 may be critical for the function of DSPP. 相似文献
997.
Feral pigeons are known as reservoirs of pathogenic yeasts that cause opportunistic infections in human. In the outskirts of Beijing, China, pigeons are more frequently raised at homes than are encountered in public areas. Many studies have focused on the presence of pathogenic yeasts in the excreta (fresh or withered) of a variety kinds of birds, pigeon crop and cloacae. One hundred and forty-three samples of fresh droppings were collected from three suburban pigeon-raising homes in an area of northern Beijing, China. The internal transcribed sequences (ITS) of all strains (except for 8 strains of Rhodotorula sp. ) were sequenced and compared with those of the databases of the National Center for Biotechnology Information website ( http://www.ncbi.nlm.nih.gov ) using the Basic Local Alignment Search Tool (BLAST). Yeasts representing 8 genera, Cryptococcus, Filobasidium, Rhodotorula, Candida, Debaryomyces, Saccaromyces, Trichosporon and Sporidiobolus, were identified from 120 isolates. Cryptococcus was the most prolific genera represented by eight species. The populations of yeast species isolated from fresh pigeon droppings were different among homes. Although it is well established that Cryptococcus neoformans exists mainly in old pigeon guano, several C. neoformans strains were still isolated from fresh pigeon excreta, providing a clue that live cryptococcal cells could move through the gastrointestinal tract of the pigeons. Eight genera identified from fresh droppings of domestic pigeons further confirm that pigeons serve as reservoirs, carriers and even spreaders of Cryptococcus species and other medically significant yeasts. The proportion of pathogenic yeasts in all isolates is more than 90 %. 相似文献
998.
Ya-Nan Wang Wei-Hong He Hua He Xun Du Bin Jia Zhi-Peng Zeng Ming-Li An Guo-Can Chen 《Archives of microbiology》2012,194(10):809-813
A Gram-negative, non-mobile, polar single flagellum, rod-shaped bacterium WZBFD3-5A2T was isolated from a wheat soil subjected to herbicides for several years. Cells of strain WZBFD3-5A2T grow optimally on Luria-Bertani agar medium at 30?°C in the presence of 0–4.0?% (w/v) NaCl and pH 8.0. 16S rRNA gene sequence analysis revealed that strain WZBFD3-5A2T belongs to the genus Pseudomonas. Physiological and biochemical tests supported the phylogenetic affiliation. Strain WZBFD3-5A2T is closely related to Pseudomonas nitroreducens IAM1439T, sharing 99.7?% sequence similarity. DNA–DNA hybridization experiments between the two strains showed only moderate reassociation similarity (33.92?±?1.0?%). The DNA G+C content is 62.0?mol%. The predominant respiratory quinine is Q-9. The major cellular fatty acids present are C16:0 (28.55?%), C16:1ω6c or C16:1ω7c (20.94?%), C18:1ω7c (17.21?%) and C18:0 (13.73?%). The isolate is distinguishable from other related members of the genus Pseudomonas on the basis of phenotypic and biochemical characteristics. From the genotypic, chemotaxonomic and phenotypic data, it is evident that strain WZBFD3-5A2T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas nitritereducens sp. nov. is proposed. The type strain is WZBFD3-5A2T (=CGMCC 1.10702T?=?LMG 25966T). 相似文献
999.
1000.