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991.
Gaoxiang Qi Fen Peng Lian Xiong Xiaoqing Lin Chao Huang Hailong Li 《Preparative biochemistry & biotechnology》2017,47(3):276-281
Extraction of high-value products from agricultural wastes is an important component for sustainable bioeconomy development. In this study, wax extraction from sugarcane bagasse was performed and the beneficial effect of dewaxing pretreatment on the enzymatic hydrolysis was investigated. About 1.2% (w/w) of crude sugarcane wax was obtained from the sugarcane bagasse using the mixture of petroleum ether and ethanol (mass ratio of 1:1) as the extraction agent. Results of Fourier-transform infrared characterization and gas chromatography–mass spectrometry qualitative analysis showed that the crude sugarcane wax consisted of fatty fractions (fatty acids, fatty aldehydes, hydrocarbons, and esters) and small amount of lignin derivatives. In addition, the effect of dewaxing pretreatment on the enzymatic hydrolysis of sugarcane bagasse was also investigated. The digestibilities of cellulose and xylan in dewaxed sugarcane bagasse were 18.7 and 10.3%, respectively, compared with those of 13.1 and 8.9% obtained from native sugarcane bagasse. The dewaxed sugarcane bagasse became more accessible to enzyme due to the disruption of the outermost layer of the waxy materials. 相似文献
992.
为了探讨珍稀树种对短期氮素添加的响应,该文研究了氮素添加(0、0.1、0.2、0.4和0.6g·kg~(-1)土)对观光木、棱角山矾和半枫荷幼苗生长和生物量分配的影响。结果表明:3个树种幼苗对外源氮素添加的反应不同,施氮显著促进观光木幼苗株高、基径、冠幅以及全株生物量和各部分生物量的增加,中低氮促进半枫荷幼苗的生长,但高氮抑制其生长;少量施氮对棱角山矾幼苗的形态和生物量参数没有产生显著影响,中量施氮抑制其生长。氮素营养的改变显著影响3种植物幼苗的生物量分配,观光木幼苗的根生物量比和根冠比均随施氮量的增加而显著降低;除高氮处理外,半枫荷幼苗的根生物量比和根冠比均随供氮量的增加而显著升高;棱角山矾的根生物量比和根冠比均随供氮量的增加而显著升高,可能与施氮抑制其茎叶的生长有关。总的来看,观光木幼苗更能耐受高氮条件,半枫荷幼苗次之,而棱角山矾幼苗不耐高氮;但到当年生长季末,各氮处理半枫荷幼苗的株高、基径和总相对生长速率均显著大于其它两种植物。 相似文献
993.
Background
We evaluated the therapeutic effect and fate of high doses of human umbilical cord Wharton jelly cells (hUCWJCs) after IP administration to streptozotocin (STZ)-induced diabetic mice.Methods
Type 1 diabetes (T1D) was induced in Kunming mice via IP injection of STZ. hUCWJCs were labeled with 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI). Diabetic animals with sustained hyperglycemia for at least 2 weeks were administered 1 × 107 Dil-hUCWJCs via intraperitoneal injection. Insulin, glucagon and PDX-1 were detected by immunofluorescence with confocal microscopy. Serum mouse and human C-peptide was assayed in blood collected via intracardiac puncture. Specific β-cell differentiation markers and human DNA were assessed using qPCR performed with 200 ng of target DNA.Results
hUCWJCs migrated to the STZ-damaged organs and contributed to lower blood glucose levels in 30% of the treated mice. Confocal microscopy revealed the presence of resident insulin-positive cells in the liver and kidneys. hUCWJC-treated mice with restored hyperglycemia also showed increased serum mouse C-peptide levels. The qPCR results, particularly in the liver, revealed that after transplantation hUCWJCs upregulated genes of endocrine precursors but failed to express endocrine stage markers. Mice with restored hyperglycemia had reduced urinary volume and lacked glomerular hypertrophy, exhibiting a morphology resembling that of normal glomeruli. Moreover, we also verified that one of the possible mechanisms by which hUCWJCs exert immunosuppressive effects is through down-regulation of the cell surface receptor HLA-1.Conclusions
We confirmed the potential of IP administration of hUCWJCs and the capability of these cells to migrate to damaged tissues and promote insulin secretion from non-pancreatic local cells and to improve renal damage. These findings confer unique therapeutic properties to hUCWJCs, suggesting a promising future in the treatment of diabetes mellitus.994.
Enhanced photoluminescence of the Ca0.8Zn0.2TiO3:0.05% Pr3+ phosphor by optimized hydrothermal conditions 下载免费PDF全文
Mao Xia Guanhua Wang Zhiqiang Gu Zhongxian Qiu Chunying Rong Jilin Zhang Wenli Zhou Liping Yu Shixun Lian 《Luminescence》2017,32(6):999-1008
The red‐emitting phosphor Ca0.8Zn0.2TiO3:Pr3+ was synthesized using an ethylene glycol (EG)‐assisted hydrothermal method. The effects of additional amounts of and order of adding EG, plus hydrothermal temperature, time, and pH on the composition, morphology and optical properties of the titanate phosphors were studied. The crystalline phases of the titanate phosphors were confirmed to be constituted of a series of co‐existing CaTiO3, Zn2TiO4 and Ca2Zn4Ti16O38 compounds in various proportions that were visualized using an X‐ray diffractometer (XRD). The optical properties of the phosphors were studied using photoluminescence spectra and UV–visible spectroscopy. The results show that the impurities Zn2TiO4:Pr3+ and Ca2Zn4Ti16O38:Pr3+ significantly contributed to the enhancement of an absorption band around 380 nm. The optimum Ca0.8Zn0.2TiO3:Pr3+ phosphor consisting of appropriate amounts of CaTiO3, Ca2Zn4Ti16O38 and Zn2TiO4 in three phases was achieved by controlling the hydrothermal conditions, and the obtained red phosphor exhibited the highest red emission (1D2 → 3H4 transition of Pr3+) with an ideal chromaticity coordinate located at (x = 0.667, y = 0.332) under 380 nm excitation. 相似文献
995.
Luyuan Jin Yu Cao Guoxia Yu Jinsong Wang Xiao Lin Lihua Ge Juan Du Liping Wang Shu Diao Xiaomeng Lian Songlin Wang Rui Dong Zhaochen Shan 《Cellular & molecular biology letters》2017,22(1):14
Background
Exploring the molecular mechanisms underlying directed differentiation is helpful in the development of clinical applications of mesenchymal stem cells (MSCs). Our previous study on dental tissue-derived MSCs demonstrated that secreted frizzled-related protein 2 (SFRP2), a Wnt inhibitor, could enhance osteogenic differentiation in stem cells from the apical papilla (SCAPs). However, how SFRP2 promotes osteogenic differentiation of dental tissue-derived MSCs remains unclear. In this study, we used SCAPs to investigate the underlying mechanisms.Methods
SCAPs were isolated from the apical papilla of immature third molars. Western blot and real-time RT-PCR were applied to detect the expression of β-catenin and Wnt target genes. Alizarin Red staining, quantitative calcium analysis, transwell cultures and in vivo transplantation experiments were used to study the osteogenic differentiation potential of SCAPs.Results
SFRP2 inhibited canonical Wnt signaling by enhancing phosphorylation and decreasing the expression of nuclear β-catenin in vitro and in vivo. In addition, the target genes of the Wnt signaling pathway, AXIN2 (axin-related protein 2) and MMP7 (matrix metalloproteinase-7), were downregulated by SFRP2. WNT1 inhibited the osteogenic differentiation potential of SCAPs. SFRP2 could rescue this WNT1-impaired osteogenic differentiation potential.Conclusions
The results suggest that SFRP2 could bind to locally present Wnt ligands and alter the balance of intracellular Wnt signaling to antagonize the canonical Wnt pathway in SCAPs. This elucidates the molecular mechanism underlying the SFRP2-mediated directed differentiation of SCAPs and indicates potential target genes for improving dental tissue regeneration.996.
997.
998.
Betula platyphylla var. japonica is a typical pioneer tree species in the secondary succession in northern Japan. We describe the cloning and characterization of 13 polymorphic, codominant microsatellite loci isolated from this species. These polymorphic loci had 2–8 alleles per locus and a range of expected heterozygosities from 0.050 to 0.808. 相似文献
999.
Regulation of synaptophysin degradation by mammalian homologues of seven in absentia. 总被引:6,自引:0,他引:6
Tiffany C Wheeler Lih-Shen Chin Yankun Li Francine L Roudabush Lian Li 《The Journal of biological chemistry》2002,277(12):10273-10282
Synaptophysin is an integral membrane protein of synaptic vesicles characterized by four transmembrane domains with both termini facing the cytoplasm. Although synaptophysin has been implicated in neurotransmitter release, and decreased synaptophysin levels have been associated with several neurodegenerative diseases, the molecular mechanism that regulates the degradation of synaptophysin remains unsolved. Using the cytoplasmic C terminus of synaptophysin as bait in a yeast two-hybrid screen, we identified two synaptophysin-binding proteins, Siah-1A and Siah-2, which are rat homologues of Drosophila Seven in Absentia. We demonstrated that Siah-1A and Siah-2 associate with synaptophysin both in vitro and in vivo and defined the binding domains of synaptophysin and Siah that mediate their association. Siah proteins exist in both cytosolic and membrane-associated pools and co-localize with synaptophysin on synaptic vesicles and early endosomes. In addition, Siah proteins interact specifically with the brain-enriched E2 ubiquitin-conjugating enzyme UbcH8 and facilitate the ubiquitination of synaptophysin. Furthermore, overexpression of Siah proteins promotes the degradation of synaptophysin via the ubiquitin-proteasome pathway. Our findings indicate that Siah proteins function as E3 ubiquitin-protein ligases to regulate the ubiquitination and degradation of synaptophysin. 相似文献
1000.
类黄酮化合物在植物胁迫反应中作用的研究进展 总被引:15,自引:0,他引:15
植物胁迫发生时,一个明显的特征是在植物器官中积累红色与紫色类黄酮化合物。文章讨论了类黄酮化合物在植物胁迫保护中作用,如类黄酮化合物在抗植物UV—B辐射、抗病性以及铝毒害耐性等多方面的作用,也讨论了植物受胁迫时类黄酮积累的分子基础。 相似文献