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61.
An immunosensor based on the electrochemiluminescence (ECL) of peroxydisulfate was firstly proposed by coupling the cooperation of two enzymes to in situ generate coreactant with palladium nanoparticles (PdNPs) as catalyst for the ECL reaction. PdNPs were previously synthesized, which successfully attached to functional carbon nanotubes (FCNTs), to bind the secondary antibody and bienzyme (horseradish peroxidase and glucose oxidase). Then the prepared bioconjugates were introduced to the electrode via sandwich immunoreactions. Accordingly, a dramatically amplified ECL signal was obtained for that GOD catalyzed glucose to produce H(2)O(2) which was subsequently reduced by HRP to in situ generate O(2), then PdNPs as catalyst for the ECL reaction of peroxydisulfate/O(2). The present immunosensor was used to detect α-1-fetoprotein (AFP) and showed a wide linear range of 1×10(-5)-100ngmL(-1), with a low detection limit of 3.3fgmL(-1)(S/N=3). This new signal amplification strategy for preparation of the ECL immunosensor could be easily realized and has a potential application in ultrasensitive bioassays. 相似文献
62.
Human umbilical cord mesenchymal stem cells (hUCMSCs) are considered to be an ideal replacement for bone marrow MSCs. However, up to date, there is no convenient and efficient method for hUCMSC isolation and culture. The present study was carried out to explore the modified enzyme digestion for hUCMSC in vitro. Conventional enzyme digestion, modified enzyme digestion, and tissue explant were used on hUCMSCs to compare their efficiencies of isolation and culture, to observe primary cell growth and cell subculture. The results show that the cells cultured using the tissue explant method had a longer culture cycle (P < 0.01) and lower yield of primary cells per centimetre of umbilical cord (P < 0.01) compared with the two enzyme digestion methods. Subculture adherence and cell doubling took significantly less time with the tissue explant method (P < 0.05) than with the conventional enzyme digestion method; however, there was no significant difference between the tissue explant method and the modified enzyme digestion method (P > 0.05). Comparing two enzyme digestion methods, the modified method yielded more cells than did the conventional method (P < 0.01), and primary cell adherence took significantly less time with the modified method than with the conventional method (P < 0.05). Cell cycle analysis of the third-generation hUCMSCs cultured by modified enzyme digestion method indicated that most cells were quiescent. Immunofluorescence staining showed that these cells expressed MSC markers CD44 and CD90. And Von Kossa and oil red O staining detection showed that they could be differentiated into osteoblasts and adipocytes with induction medium in vitro. This study suggests that hUCMSC isolation and culture using 0.2 % collagenase II at 37 °C for digestion of 16–20 h is an effective and simple modified enzyme digestion method. 相似文献
63.
The feasibility of composite hydrolysis enzymes in enhanced dewatering of waste-activated sludge (WAS) was verified in this study. A Pearson correlation analysis was conducted to explore the roles of different extracellular polymeric substance (EPS) fractions on WAS dewaterability. The results indicated that tightly bound EPS (TB-EPS) was released into the liquid phase consistently during enzymatic hydrolysis to form soluble EPS (S-EPS) and loosely bound EPS and that the TB-EPS content was positively correlated with the capillary suction time of WAS. A kinetic analysis was carried out to gain further insights into the kinetic variation in TB-EPS removal. It was found that TB-EPS reduction fit a first-order kinetic model and that mild temperature (25–30 °C) and a slightly acidic condition were favorable for the improvement of enzyme activity. Solid phase extraction combined with UV–Vis spectroscopy analysis was used to characterize the processes of migration and transformation of the hydrophobic (HPO), transphilic and hydrophilic (HPI) fractions in EPS during the enzymatic process. The results revealed that HPO and HPI were mainly composed of PN and PS, respectively, and that the enzymatic hydrolysis could enhance the transformation of HPI from TB-EPS to S-EPS, which was the dominant mechanism of improving WAS dewaterability. 相似文献
64.
Yunji Hwang Kyu Eun Lee Elisabete Weiderpass Young Joo Park Young Jun Chai Hyungju Kwon Do Joon Park BeLong Cho Ho-Chun Choi Daehee Kang Sue K. Park 《PloS one》2016,11(3)
Background
This study evaluated the effects of acute high-dose and chronic lifetime exposure to alcohol and exposure patterns on the development of differentiated thyroid cancer (DTC).Methods
The Thyroid Cancer Longitudinal Study (T-CALOS) included 2,258 DTC patients (449 men and 1,809 women) and 22,580 healthy participants (4,490 men and 18,090 women) who were individually matched by age, gender, and enrollment year. In-person interviews were conducted with a structured questionnaire to obtain epidemiologic data. Clinicopathologic features of the patients were obtained by chart reviews. Odds ratios (ORs) and 95% confidence intervals (95%CI) were estimated using conditional regression models.Results
While light or moderate drinking behavior was related to a reduced risk of DTC, acute heavy alcohol consumption (151 g or more per event or on a single occasion) was associated with increased risks in men (OR = 2.22, 95%CI = 1.27–3.87) and women (OR = 3.61, 95%CI = 1.52–8.58) compared with never-drinkers. The consumption of alcohol for 31 or more years was a significant risk factor for DTC for both men (31–40 years: OR = 1.58, 95%CI = 1.10–2.28; 41+ years: OR = 3.46, 95%CI = 2.06–5.80) and women (31–40 years: OR = 2.18, 95%CI = 1.62–2.92; 41+ years: OR = 2.71, 95%CI = 1.36–5.05) compared with never-drinkers. The consumption of a large amount of alcohol on a single occasion was also a significant risk factor, even after restricting DTC outcomes to tumor size, lymph node metastasis, extrathyroidal extension and TNM stage.Conclusion
The findings of this study suggest that the threshold effects of acute high-dose alcohol consumption and long-term alcohol consumption are linked to an increased risk of DTC. 相似文献65.
66.
Anaerobic methane oxidation coupled to nitrite reduction can be a potential methane sink in coastal environments 总被引:1,自引:0,他引:1
67.
Two amino acids near the N‐terminus of Cucumber mosaic virus 2b play critical roles in the suppression of RNA silencing and viral infectivity
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Kai Dong Ying Wang Zhen Zhang Long‐Xiang Chai Xin Tong Jin Xu Dawei Li Xian‐Bing Wang 《Molecular Plant Pathology》2016,17(2):173-183
Cucumber mosaic virus (CMV) 2b suppresses RNA silencing primarily through the binding of double‐stranded RNA (dsRNA) of varying sizes. However, the biologically active form of 2b remains elusive. Here, we demonstrate that the single and double alanine substitution mutants in the N‐terminal 15th leucine and 18th methionine of CMV 2b exhibit drastically attenuated virulence in wild‐type plants, but are efficiently rescued in mutant plants defective in RNA‐dependent RNA polymerase 6 (RDR6) and Dicer‐like 4 (DCL4). Moreover, the transgenic plants of 2b, but not 2blm (L15A/M18A), rescue the high infectivity of CMV‐Δ2b through the suppression of antiviral silencing. L15A, M18A or both weaken 2b suppressor activity on local and systemic transgene silencing. In contrast with the high affinity of 2b to short and long dsRNAs, 2blm is significantly compromised in 21‐bp duplex small interfering RNA (siRNA) binding ability, but maintains a strong affinity for long dsRNAs. In cross‐linking assays, 2b can form dimers, tetramers and oligomers after treatment with glutaraldehyde, whereas 2blm only forms dimers, rather than tetramers and oligomers, in vitro. Together, these findings suggest that L15 and M18 of CMV 2b are required for high affinity to ds‐siRNAs and oligomerization activity, which are essential for the suppression activity of 2b on antiviral silencing. 相似文献
68.
Dong Lin Yubo Chai Reza Izadpanah Stephen E. Braun 《Cell cycle (Georgetown, Tex.)》2016,15(18):2414-2419
Natriuretic peptide receptor 3 (NPR3) is a clearance receptor by binding and internalizing natriuretic peptides (NPs) for ultimate degradation. Patients with cardiac failure show elevated NPs. NPs are linked to poor long-term survival because of their apoptotic effects. However, the underling mechanisms have not been identified yet. Here we report the role of NPR3 in anti-apoptosis via the breast cancer type 1 susceptibility protein (BRCA1) and tumor necrosis factor α (TNF-α ). To demonstrate a role for NPR3 in apoptosis, stable H9C2 cardiomyocyte cell lines using shRNA to knockdown NPR3 were generated. The activities of caspase-3, 8, and 9 were significantly increased in NPR3 knockdown H9C2 cardiomyocytes. Knockdown of NPR3 increased the expression of BRCA1. Also NPR3 knockdown remarkably increased the activity of cAMP response element-binding protein (CREB), a positive regulatory element for BRCA1 expression. BRCA1 showed dispersed nuclear localization in non-cardiomyocytes while predominantly cytoplasmic localization in H9C2 cells. Meanwhile, NPR3 knockdown significantly increased TNF-α gene expression. These data show that NPR3 knockdown in H9C2 cells triggered both extrinsic and intrinsic apoptotic pathways. NPR3 protects cardiomyocytes from apoptosis through inhibition of cytosolic BRCA1 and TNF-α, which are regulators of apoptosis. Our studies demonstrate anti-apoptosis role of NPR3 in protecting cardiomyocytes and establish the first molecular link between NP system and programmed cell death. 相似文献
69.
对蝉棒束孢菌子实体(0.75g/kg)重复灌胃SD雄性大鼠90d及恢复28d的早期肾损伤生物标记物肾损伤分子-1(KIM-1)和中性粒细胞明胶酶相关载脂蛋白(NGAL)进行测定,评估蝉棒束孢菌子实体对肾小管上皮细胞的影响;研究不同剂量蝉棒束孢菌子实体(0.25g/kg、0.5g/kg、1.0g/kg)对肾小管上皮细胞增殖和增生能力的影响。给药30、60、90d及恢复28d时,SD大鼠血清中KIM-1浓度与对照组相比均无显著差异(P>0.05),给药30d、60d时,SD大鼠血清中NGAL浓度与对照组相比均无显著差异(P>0.05),给药90d及恢复28d时,SD大鼠血清中NGAL浓度低于对照组(P<0.05),且给药90d组与对照组相比有显著性差异(P<0.01);免疫组化检测增殖细胞核抗原法(PCNA)及四甲基偶氮唑盐微量酶反应比色法(MTT)表明:与对照组相比,蝉棒束孢菌子实体能使肾小管上皮细胞增生能力增强,未导致肾小管上皮细胞凋亡。 相似文献
70.
Huan Zhang Shanshan Zhu Tianzhen Liu Chunming Wang Zhijun Cheng Xin Zhang Liping Chen Peike Sheng Maohong Cai Chaonan Li Jiachang Wang Zhe Zhang Juntao Chai Liang Zhou Cailin Lei Xiuping Guo Jiulin Wang Jie Wang Ling Jiang Chuanyin Wu Jianmin Wan 《Plant biotechnology journal》2019,17(2):531-539
Heading date is an important agronomic trait affecting crop yield. The GRAS protein family is a plant‐specific super family extensively involved in plant growth and signal transduction. However, GRAS proteins are rarely reported have a role in regulating rice heading date. Here, we report a GRAS protein DHD1 (Delayed Heading Date1) delays heading and enhances yield in rice. Biochemical assays showed DHD1 physically interacts with OsHAP5C/D both in vitro and in vivo. DHD1 and OsHAP5C/D located in the nucleus and showed that rhythmic expression. Both DHD1 and OsHAP5C/D affect heading date by regulating expression of Ehd1. We propose that DHD1 interacts with OsHAP5C/D to delay heading date by inhibiting expression of Ehd1. 相似文献