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61.
Olugbenga Solomon Bello Bukola Morenike Lasisi Olamide Joshua Adigun Vunain Ephraim 《Chemical Speciation and Bioavailability》2017,29(1):120-134
Moringa oliferia seed pod was modified using orthophosphoric acid (H3PO4) and used as adsorbent for sequestering Rhodamine B (Rh-B) dye from aqueous solution. The acid-modified adsorbent (MOSPAC) was characterized using Scanning Electron microscopy (SEM), Fourier Transform Infra Red (FTIR), Energy Dispersive X-ray (EDX), pH point of zero charge (pHpzc) and Boehm Titration (BT) techniques, respectively. Operational parameters such as contact time, initial dye concentration, adsorbent dosage, pH and solution temperature were studied in batch process. Optimum dye adsorption was observed at pH 3.01. Equilibrium adsorption data was tested data using four different isotherm models: Langmuir, Freundlich, Temkin and Dubinin-Radushkevich. Langmuir isotherm model fitted most with maximum monolayer adsorption capacity of 1250 mg g–1. Pseudo-second-order kinetic model provided the best correlation for the experimental data. Thermodynamic study showed that the process is endothermic, spontaneous and feasible. MOSPAC is an effective adsorbent for the removal of RhB dye from aqueous solutions. 相似文献
62.
R Moriggi Jr HS Di Mauro SC Dias JM Matos MB Urtado NF Camar?o IV Sousa Neto DC Nascimento RA Tibana CO Assump??o J Prestes CB Urtado 《Biology of sport / Institute of Sport》2015,32(4):289-294
Low intensity resistance exercise (RE) with blood flow restriction (BFR) has gained attention in the literature due to the beneficial effects on functional and morphological variables, similar to those observed during traditional RE without BFR, while the effects of BFR on post-exercise hypotension remain unclear. The aim of the present study was to compare the blood pressure (BP) response of trained normotensive individuals to RE with and without BFR. In this cross-over randomized trial, eight male subjects (23.8 ± 4 years, 74 ± 3 kg, 174 ± 4 cm) completed two exercise protocols: traditional RE (3 x 10 repetitions at 70% one-repetition maximum [1-RM]) and low intensity RE (3 x 15 repetitions at 20% 1-RM) with BFR. Blood pressure measurements were performed after 15 min of seated rest (0), immediately after and 10 min, 20 min, 30 min, 40 min, 50 min and 60 min after the experimental sessions. Similar hypotensive effects for systolic BP (SBP) were observed for both protocols (P < 0.05) after exercise, with no differences between groups (P > 0.05) and no statistically significant difference for diastolic BP (P > 0.05). These results suggest that in normotensive trained individuals, both traditional RE and RE with BFR induce hypotension for SBP, which is important to prevent cardiovascular disturbances. 相似文献
63.
Summary. The aim of this work was to study the activity of NAD(P)H:(quinone acceptor) oxidoreductase 1 (EC 1.6.99.2) in the regeneration
of lipophilic antioxidants, alpha-tocopherol, and reduced-coenzyme Q analogs. First, we tested whether or not two isoforms
of the NAD(P)H:(quinone acceptor) oxidoreductase 1 designated as “hydrophilic” and “hydrophobic” (H. J. Prochaska and P. Talalay,
Journal of Biological Chemistry 261: 1372–1378, 1986) show differential enzyme activities towards hydrophilic or hydrophobic
ubiquinone homologs. By chromatography on phenyl Sepharose, we purified the two isoforms from pig liver cytosol and measured
their reduction of several ubiquinone homologs of different side chain length. We also studied by electron paramagnetic resonance
the effect of NAD(P)H:(quinone acceptor) oxidoreductase 1 on steady-state levels of chromanoxyl radicals generated by linoleic
acid and lipooxygenase and confirmed the enzyme's ability to protect alpha-tocopherol against oxidation induced with H2O2-Fe2+. Our results demonstrated that the different hydrophobicities of the isoforms do not reflect different reactivities towards
ubiquinones of different side chain length. In addition, electron paramagnetic resonance studies showed that in systems containing
the reductase plus NADH, levels of chromanoxyl radicals were dramatically reduced. Morever, in the presence of oxidants, alpha-tocopherol
was preserved by NAD(P)H:(quinone acceptor) oxidoreductase 1, supporting our hypothesis that regeneration of alpha-tocopherol
may be one of the physiologic functions of this enzyme.
Received May 20, 2002; accepted September 20, 2002; published online May 21, 2003
RID="*"
ID="*" Correspondence and reprints: Departamento de Biología Celular, Fisiología e Inmunología, Facultad de Ciencias, Edificio
Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, 14014 Córdoba, Spain. 相似文献
64.
Cécile H. Albert Francesco de Bello Isabelle Boulangeat Gilles Pellet Sandra Lavorel Wilfried Thuiller 《Oikos》2012,121(1):116-126
Functional diversity (FD) is a key facet of biodiversity used to address central questions in ecology. Despite recent methodological advances, FD remains a complex concept and no consensus has been reached either on how to quantify it, or on how it influences ecological processes. Here we define FD as the distribution of trait values within a community. When and how to account for intraspecific trait variability (ITV) when measuring FD remains one of the main current debates. It remains however unclear to what extent accounting for population‐level ITV would modify FD quantification and associated conclusions. In this paper, we address two critical questions: (1) How sensitive are different components of FD to the inclusion of population‐level ITV? (2) Does the omission of ITV obscure the understanding of ecological patterns? Using a mixture of empirical data and simulation experiments, we conducted a sensitivity analysis of four commonly used FD indices (community weighted mean traits, functional richness, Rao's quadratic entropy, Petchey and Gaston's FD index) and their relationships with environmental gradients and species richness, by varying both the extent (plasticity or not) and the structure (contingency to environmental gradient due to local adaptation) of population‐level ITV. Our results suggest that ITV may strongly alter the quantification of FD and the detection of ecological patterns. Our analysis highlights that 1) species trait values distributions within communities are crucial to the sensitivity to ITV, 2) ITV structure plays a major role in this sensitivity and 3) different indices are not evenly sensitive to ITV, the single‐trait FD from Petchey and Gaston being the most sensitive among the four metrics tested. We conclude that the effects of intraspecific variability in trait values should be more systematically tested before drawing central conclusions on FD, and suggest the use of simulation studies for such sensitivity analyses. 相似文献
65.
We recently performed a molecular epidemiology survey of human immunodeficiency virus type 1 (HIV-1) infection in Miracema, a small city in Southeast Brazil, and found multiple monophyletic clusters, consistent with independent introductions and spread of different viral lineages in the city. Here we apply Bayesian coalescent-based methods to the two largest subtype B clusters and estimate that the most recent common ancestors that gave rise to these two transmission chains were in circulation around 1991-1992. The finding that HIV-1 spread in this Brazilian small city was already taking place at a time Aids was considered a problem restricted to large urban centers may have important public health implications. 相似文献
66.
Functional diversification of the dehydrin gene family in apple and its contribution to cold acclimation during dormancy 下载免费PDF全文
Vítor da Silveira Falavigna Yohanna Evelyn Miotto Henrique Pessoa dos Santos Flávio Bello Fialho Márcia Margis‐Pinheiro Giancarlo Pasquali Luís Fernando Revers 《Physiologia plantarum》2015,155(3):315-329
Dehydrins (DHN) are proteins involved in plant adaptive responses to abiotic stresses, mainly dehydration. Several studies in perennial crops have linked bud dormancy progression, a process characterized by the inability to initiate growth from meristems under favorable conditions, with DHN gene expression. However, an in‐depth characterization of DHNs during bud dormancy progression is still missing. An extensive in silico characterization of the apple DHN gene family was performed. Additionally, we used five different experiments that generated samples with different dormancy status, including genotypes with contrasting dormancy traits, to analyze how DHN genes are being regulated during bud dormancy progression in apple by real‐time quantitative polymerase chain reaction (RT‐qPCR). Duplication events took place in the diversification of apple DHN family. Additionally, MdDHN genes presented tissue‐ and bud dormant‐specific expression patterns. Our results indicate that MdDHN genes are highly divergent in function, with overlapping levels, and that their expressions are fine‐tuned by the environment during the dormancy process in apple. 相似文献
67.
Stephen J. Wood Josef W. Goldufsky Daniella Bello Sara Masood Sasha H. Shafikhani 《The Journal of biological chemistry》2015,290(48):29063-29073
Pseudomonas aeruginosa is the most common cause of hospital-acquired pneumonia and a killer of immunocompromised patients. We and others have demonstrated that the type III secretion system (T3SS) effector protein ExoT plays a pivotal role in facilitating P. aeruginosa pathogenesis. ExoT possesses an N-terminal GTPase-activating protein (GAP) domain and a C-terminal ADP-ribosyltransferase (ADPRT) domain. Because it targets multiple non-overlapping cellular targets, ExoT performs several distinct virulence functions for P. aeruginosa, including induction of apoptosis in a variety of target host cells. Both the ADPRT and the GAP domain activities contribute to ExoT-induced apoptosis. The ADPRT domain of ExoT induces atypical anoikis by transforming an innocuous cellular protein, Crk, into a cytotoxin, which interferes with integrin survival signaling. However, the mechanism underlying the GAP-induced apoptosis remains unknown. In this study, we demonstrate that the GAP domain activity is both necessary and sufficient to induce mitochondrial (intrinsic) apoptosis. We show that intoxication with GAP domain results in: (i) JNK1/2 activation; (ii) substantial increases in the mitochondrial levels of activated pro-apoptotic proteins Bax and Bid, and to a lesser extent Bim; (iii) loss of mitochondrial membrane potential and cytochrome c release; and (iv) activation of initiator caspase-9 and executioner caspase-3. Further, GAP-induced apoptosis is partially mediated by JNK1/2, but it is completely dependent on caspase-9 activity. Together, the ADPRT and the GAP domains make ExoT into a highly versatile and potent cytotoxin, capable of inducing multiple forms of apoptosis in target host cells. 相似文献
68.
69.
Nuclear factor erythroid 2-related factor-2 activity controls 4-hydroxynonenal metabolism and activity in prostate cancer cells 总被引:1,自引:0,他引:1
Pettazzoni P Ciamporcero E Medana C Pizzimenti S Dal Bello F Minero VG Toaldo C Minelli R Uchida K Dianzani MU Pili R Barrera G 《Free radical biology & medicine》2011,51(8):1610-1618
4-Hydroxynonenal (HNE) is an end product of lipoperoxidation with antiproliferative and proapoptotic properties in various tumors. Here we report a greater sensitivity to HNE in PC3 and LNCaP cells compared to DU145 cells. In contrast to PC3 and LNCaP cells, HNE-treated DU145 cells showed a smaller reduction in growth and did not undergo apoptosis. In DU145 cells, HNE did not induce ROS production and DNA damage and generated a lower amount of HNE-protein adducts. DU145 cells had a greater GSH and GST A4 content and GSH/GST-mediated HNE detoxification. Nuclear factor erythroid 2-related factor-2 (Nrf2) is a regulator of the antioxidant response. Nrf2 protein content and nuclear accumulation were higher in DU145 cells compared to PC3 and LNCaP cells, whereas the expression of KEAP1, the main negative regulator of Nrf2 activity, was lower. Inhibition of Nrf2 expression with specific siRNA resulted in a reduction in GST A4 expression and GS-HNE formation, indicating that Nrf2 controls HNE metabolism. In addition, Nrf2 knockdown sensitized DU145 cells to HNE-mediated antiproliferative and proapoptotic activity. In conclusion, we demonstrated that increased Nrf2 activity resulted in a reduction in HNE sensitivity in prostate cancer cells, suggesting a potential mechanism of resistance to pro-oxidant therapy. 相似文献
70.
A highly conserved metalloprotease effector enhances virulence in the maize anthracnose fungus Colletotrichum graminicola 下载免费PDF全文