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991.
Climate change is altering forest dynamics in the tropics, with large potential impacts on forest structure and understory conditions. However, we found that canopy height distribution and openness remained stable over two decades in the western Amazon, and that gap creation rates would need to increase 300% before affecting equilibrium. 相似文献
992.
Martins Renato Tavares Gonçalves José Francisco Campos Claudimir Menezes Lopes Aline Piedade Maria Teresa Fernandez Hamada Neusa 《Limnology》2020,21(2):257-266
Limnology - We grew leaves of Montrichardia arborescens in four microcosm chambers with different temperatures and CO2 concentrations simulating the scenarios of expected climate change. These... 相似文献
993.
Géssica Luana Antunes Josiane Silva Silveira Daniela Benvenutti Kaiber Carolina Luft Mariana Severo da Costa Eduardo Peil Marques Fernanda Silva Ferreira Ricardo Vaz Breda Angela T. S. Wyse Renato Tetelbom Stein Paulo Márcio Pitrez Aline Andrea da Cunha 《Journal of cellular physiology》2020,235(2):1838-1849
Asthma is characterized by the influx of inflammatory cells, especially of eosinophils as well as reactive oxygen species (ROS) production, driven by the release of the T helper 2 (Th2)-cell-associated cytokines. The cholinergic anti-inflammatory pathway (CAP) inhibit cytokines production and controls inflammation. Thus, we investigated the effects of pharmacological activation of CAP by neostigmine on oxidative stress and airway inflammation in an allergic asthma model. After the OVA challenge, mice were treated with neostigmine. We showed that CAP activation by neostigmine reduced the levels of pro-inflammatory cytokines (IL-4, IL-5, IL-13, IL-1β, and TNF-α), which resulted in a decrease of eosinophils influx. Furthermore, neostigmine also conferred airway protection against oxidative stress, attenuating ROS production through the increase of antioxidant defense, evidenced by the catalase (CAT) activity. We propose, for the first time, that pharmacological activation of the CAP can lead to new possibilities in the therapeutic management of allergic asthma. 相似文献
994.
Ana Patrícia C. Silva Auricélio A. Macêdo Luciana F. Costa Cláudia E. Rocha Luize N. N. Garcia Jade R. D. Farias Priscilla P. R. Gomes Gustavo C. Teixeira Kessler W. J. Fonseca Andréa R. F. Maia Gabriela G. Neves Everton L. Rom?o Teane M. A. Silva Juliana P. S. Mol Renata M. Oliveira Márcio S. S. Araújo Ernane F. Nascimento Olindo A. Martins-Filho Humberto M. Brand?o Tatiane A. Paix?o Renato L. Santos 《PloS one》2015,10(8)
This study aimed to evaluate protection induced by the vaccine candidate B. ovis ΔabcBA against experimental challenge with wild type B. ovis in rams. Rams were subcutaneously immunized with B. ovis ΔabcBA encapsulated with sterile alginate or with the non encapsulated vaccine strain. Serum, urine, and semen samples were collected during two months after immunization. The rams were then challenged with wild type B. ovis (ATCC25840), and the results were compared to non immunized and experimentally challenged rams. Immunization, particularly with encapsulated B. ovis ΔabcBA, prevented infection, secretion of wild type B. ovis in the semen and urine, shedding of neutrophils in the semen, and the development of clinical changes, gross and microscopic lesions induced by the wild type B. ovis reference strain. Collectively, our data indicates that the B. ovis ΔabcBA strain is an exceptionally good vaccine strain for preventing brucellosis caused by B. ovis infection in rams. 相似文献
995.
996.
In the setting of an aerobiological study of confined environments and environmental prevention of nosocomial infections,
aerobiological monitoring of 22 areas in Montescano Medical Rehabilitation Centre (Pavia) was performed in three different
months: February, May, and August, 1994. A Lanzoni 3000 spore trap was used for the monitoring. Examination of the results
showed that, in the environments monitored, the indoor presence of fungi increased progresively over the three periods considered.
The behaviour of individual genera of fungi differed. In the winter periodPenicillium andAspergillus were the most commonly encountered genera,Cladosporium was the dominant genus from the spring to the summer while the yeasts had their maximum counts in the spring morning. The
use of air conditioning, combined with the low air exchange between outdoors and andoors in some of the environments certainly
played a part in the low concentrations of these latter aerofungi. 相似文献
997.
Riek U Scholz R Konarev P Rufer A Suter M Nazabal A Ringler P Chami M Müller SA Neumann D Forstner M Hennig M Zenobi R Engel A Svergun D Schlattner U Wallimann T 《The Journal of biological chemistry》2008,283(26):18331-18343
Heterotrimeric AMP-activated protein kinase (AMPK) is crucial for energy homeostasis of eukaryotic cells and organisms. Here we report on (i) bacterial expression of untagged mammalian AMPK isoform combinations, all containing gamma(1), (ii) an automated four-dimensional purification protocol, and (iii) biophysical characterization of AMPK heterotrimers by small angle x-ray scattering in solution (SAXS), transmission and scanning transmission electron microscopy (TEM, STEM), and mass spectrometry (MS). AMPK in solution at low concentrations (~1 mg/ml) largely consisted of individual heterotrimers in TEM analysis, revealed a precise 1:1:1 stoichiometry of the three subunits in MS, and behaved as an ideal solution in SAXS. At higher AMPK concentrations, SAXS revealed concentration-dependent, reversible dimerization of AMPK heterotrimers and formation of higher oligomers, also confirmed by STEM mass measurements. Single particle reconstruction and averaging by SAXS and TEM, respectively, revealed similar elongated, flat AMPK particles with protrusions and an indentation. In the lower AMPK concentration range, addition of AMP resulted in a significant decrease of the radius of gyration by approximately 5% in SAXS, which indicates a conformational switch in AMPK induced by ligand binding. We propose a structural model involving a ligand-induced relative movement of the kinase domain resulting in a more compact heterotrimer and a conformational change in the kinase domain that protects AMPK from dephosphorylation of Thr(172), thus positively affecting AMPK activity. 相似文献
998.
Chen J Capozza F Wu A Deangelis T Sun H Lisanti M Baserga R 《Journal of cellular physiology》2008,217(1):281-289
The insulin receptor substrate-1 (IRS-1), a docking protein of the type 1 insulin-like growth factor receptor (IGF-IR) plays a significant role in cell proliferation and differentiation. The expression of IRS-1 is down-regulated in mouse embryo fibroblasts (MEFs) with a deletion of caveolin-1 (cav1) genes (KO cells). Levels of IRS-1 mRNA are not affected. Re-introduction of cav1 into KO cells rescues IRS-1 expression. Stabilization of protein levels is reciprocal and a strict correlation between IRS-1 and cav1 levels was confirmed in five cell lines, and in mouse tissues. IRS-1 binds through its phosphotyrosine binding (PTB) domain to tyrosine 14 (Y14) of cav1, the residue phosphorylated by IGF-1 stimulation and by v-src. The down-regulation of IRS-1 in cav-/- cells occurs via the proteasome pathway. These results indicate a novel mechanism for the regulation of IRS-1 expression levels, an important finding in view of IRS-1 role in cell proliferation and transformation. 相似文献
999.
Claudia Dragonetti Stefania Righetto Dominique Roberto Renato Ugo Adriana Valore Francesco Demartin Filippo De Angelis Antonio Sgamellotti Simona Fantacci 《Inorganica chimica acta》2008,361(14-15):4070-4076
[Ir(cyclometallated 4,5-diphenyl-2-methyl-thiazole)2(5-R-1,10-phenanthroline)][PF6] (R = CH3, NO2) complexes were prepared and fully characterized, the structure of the complex with 5-CH3-1,10-phenanthroline being also determined by X-ray diffraction. The emission properties of both complexes have been investigated and their second-order nonlinear optical (NLO) response has been determined experimentally by the EFISH technique and found to be similar but slightly lower than that of related [Ir(ppy)2(5-R-1,10-phenanthroline)][PF6] (ppy = cyclometallated 2-phenylpyridine), characterized by one of the highest second-order NLO response ever reported for a metal complex. In the complexes, SOS/TDDFT calculations show that the large and negative sign of the measured hyperpolarizability is mainly due to the significant contribution of rather intense MLCT transitions involving the phenanthroline as acceptor ligand. 相似文献
1000.
Sugiana C Pagliarini DJ McKenzie M Kirby DM Salemi R Abu-Amero KK Dahl HH Hutchison WM Vascotto KA Smith SM Newbold RF Christodoulou J Calvo S Mootha VK Ryan MT Thorburn DR 《American journal of human genetics》2008,83(4):468-478
Complex I (NADH:ubiquinone oxidoreductase) is the first and largest multimeric complex of the mitochondrial respiratory chain. Human complex I comprises seven subunits encoded by mitochondrial DNA and 38 nuclear-encoded subunits that are assembled together in a process that is only partially understood. To date, mutations causing complex I deficiency have been described in all 14 core subunits, five supernumerary subunits, and four assembly factors. We describe complex I deficiency caused by mutation of the putative complex I assembly factor C20orf7. A candidate region for a lethal neonatal form of complex I deficiency was identified by homozygosity mapping of an Egyptian family with one affected child and two affected pregnancies predicted by enzyme-based prenatal diagnosis. The region was confirmed by microcell-mediated chromosome transfer, and 11 candidate genes encoding potential mitochondrial proteins were sequenced. A homozygous missense mutation in C20orf7 segregated with disease in the family. We show that C20orf7 is peripherally associated with the matrix face of the mitochondrial inner membrane and that silencing its expression with RNAi decreases complex I activity. C20orf7 patient fibroblasts showed an almost complete absence of complex I holoenzyme and were defective at an early stage of complex I assembly, but in a manner distinct from the assembly defects caused by mutations in the assembly factor NDUFAF1. Our results indicate that C20orf7 is crucial in the assembly of complex I and that mutations in C20orf7 cause mitochondrial disease. 相似文献