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131.
de Oliveira Hellen Oliveira de Castro Gledson Luiz Salgado Correa Lorena Oliveira Silvestre Walter Vellasco Duarte do Nascimento Sidney Vasconcelos da Silva Valadares Rafael Borges de Oliveira Guilherme Corrêa Santos Rodolfo Inacio Nunes Festucci-Buselli Reginaldo Alves Pinheiro Hugo Alves 《Photosynthesis research》2019,140(2):189-205
Photosynthesis Research - This study examined whether drought sensitivity in açaí (Euterpe oleracea Mart.) is associated with reductions in photosynthesis and increasing oxidative stress... 相似文献
132.
ngel A. del Río‐Chvez Hugo A. García‐Gutirrez Luisa U. Romn‐Marín Lidia Beiza‐Granados Carlos M. Cerda‐García‐Rojas Pedro Joseph‐Nathan Juan D. Hernndez‐Hernndez 《Chirality》2019,31(11):934-946
The epimeric diterpenes (+)‐(1S,3E,7E,11S,12S)‐verticilla‐3,7‐dien‐12‐ol ( 1 ), isolated from Bursera suntui, and (+)‐(1S,3E,7E,11S,12R)‐verticilla‐3,7‐dien‐12‐ol ( 2 ), isolated from Bursera kerberi, gave the same Wagner‐Meerwein rearrangement product (?)‐(1E,4Z,8Z,11S,12R)‐phomacta‐1,(15)4,8‐triene ( 3 ). The Et2O:BF3‐induced transformations evidence that verticillenes and phomactanes, both containing the bicyclo[9.3.1]pentadecane skeleton, are biogenetically related through the verticillen‐12‐yl cation ( A + ), which also is a key intermediate in the biosynthetic pathways to generate antitumor taxanes. Molecular modeling using the Monte Carlo protocol, followed by density functional theory (DFT) geometry optimization employing the hybrid functionals B3LYP and B3PW91, both with the DGDZVP basis set, secured the configuration of 3 as followed from the good agreement between the calculated and experimental vibrational circular dichroism spectra. Similar DFT calculations allowed determining the absolute configuration of (+)‐(1R,4R,5R,8S,9S,11S,12R,15R)‐1,15:4,5:8,9‐triepoxyphomactane ( 9 ), which surprisingly derives from epoxidation of the second minimum energy conformer of 3 . 相似文献
133.
Rodrigo Fortes-Silva Fabiola De Oliveira Paes Leme Túlio Pacheco Boaventura Helena Corrêa Pinto De Mendonça Jane Prado Leite Moreira Pedro Hugo Henriques Cunha 《Chronobiology international》2019,36(2):276-287
The aim of this study was to investigate the daily rhythms of hematological, biochemical and enzymatic parameters of the blood of a nocturnal model of fish (Lophiosilurus alexandri) bred in the laboratory (F1). Thirty-six juveniles were stocked in six tanks of a recirculation aquaculture system for 20 days. The fish were exposed to a light:dark cycle of 12:12 h and were fed 1% of biomass twice a day with commercial diet. The daily rhythms of hematological, biochemical and enzymatic parameters were then measured at six sampling times “zeitgeber time = ZT” at four-hour intervals under light:dark 12:12 h (lights on = ZT0, at 8.00 a.m). No differences were observed to alkaline phosphatase, glucose, cortisol, aspartate aminotransferase, superoxide dismutase, total protein and hematocrit (p > 0.05). However, white blood cell count, Lymphocytes (LYN), Neutrophils (NEU), Eosinophil and Neutrophils to Lymphocytes ratio were significant different between sample times (p < 0.05). Also, a significant difference in alanine transaminase was observed, with a peak of production at nighttime. In contrast, glutathione peroxidase peaked at 8:00. Uric acid, magnesium and Calcium (Ca++) showed statistically significant differences (p < 0.05). A significant difference was observed (p < 0.05), with a peak of albumin at 08:00 and triglycerides at 12:00, while cholesterol was low (p < 0.05) at 08:00 and higher from 12:00 to 04:00. Cosinor analysis revealed also rhythmicity to SOD, UA, Mg and Ca++, ALB and CHO (p < 0.05). In conclusion, the time of day must be considered a key factor when using blood parameters as biomarkers for disease, health and welfare in the L. alexandri aquaculture. 相似文献
134.
135.
Maxence S. Vincent Caterina Comas Hervada Corinne Sebban-Kreuzer Hugo Le Guenno Maïalne Chabalier Artemis Kosta Franoise Guerlesquin Tm Mignot Mark J. McBride Eric Cascales Thierry Doan 《PLoS biology》2022,20(3)
Motile bacteria usually rely on external apparatus like flagella for swimming or pili for twitching. By contrast, gliding bacteria do not rely on obvious surface appendages to move on solid surfaces. Flavobacterium johnsoniae and other bacteria in the Bacteroidetes phylum use adhesins whose movement on the cell surface supports motility. In F. johnsoniae, secretion and helicoidal motion of the main adhesin SprB are intimately linked and depend on the type IX secretion system (T9SS). Both processes necessitate the proton motive force (PMF), which is thought to fuel a molecular motor that comprises the GldL and GldM cytoplasmic membrane proteins. Here, we show that F. johnsoniae gliding motility is powered by the pH gradient component of the PMF. We further delineate the interaction network between the GldLM transmembrane helices (TMHs) and show that conserved glutamate residues in GldL TMH2 are essential for gliding motility, although having distinct roles in SprB secretion and motion. We then demonstrate that the PMF and GldL trigger conformational changes in the GldM periplasmic domain. We finally show that multiple GldLM complexes are distributed in the membrane, suggesting that a network of motors may be present to move SprB along a helical path on the cell surface. Altogether, our results provide evidence that GldL and GldM assemble dynamic membrane channels that use the proton gradient to power both T9SS-dependent secretion of SprB and its motion at the cell surface.Motile bacteria usually rely on external apparatus like flagella or pili, but gliding bacteria do not rely on obvious surface appendages for their movement. This study shows that bacteria in the phylum Bacteroidetes use proton-dependent motors to power protein secretion and gliding motility. 相似文献
136.
Yannik Bollen Joris H. Hageman Petra van Leenen Lucca L. M. Derks Bas Ponsioen Julian R. Buissant des Amorie Ingrid Verlaan-Klink Myrna van den Bos Leon W. M. M. Terstappen Ruben van Boxtel Hugo J. G. Snippert 《PLoS biology》2022,20(1)
CRISPR-associated nucleases are powerful tools for precise genome editing of model systems, including human organoids. Current methods describing fluorescent gene tagging in organoids rely on the generation of DNA double-strand breaks (DSBs) to stimulate homology-directed repair (HDR) or non-homologous end joining (NHEJ)-mediated integration of the desired knock-in. A major downside associated with DSB-mediated genome editing is the required clonal selection and expansion of candidate organoids to verify the genomic integrity of the targeted locus and to confirm the absence of off-target indels. By contrast, concurrent nicking of the genomic locus and targeting vector, known as in-trans paired nicking (ITPN), stimulates efficient HDR-mediated genome editing to generate large knock-ins without introducing DSBs. Here, we show that ITPN allows for fast, highly efficient, and indel-free fluorescent gene tagging in human normal and cancer organoids. Highlighting the ease and efficiency of ITPN, we generate triple fluorescent knock-in organoids where 3 genomic loci were simultaneously modified in a single round of targeting. In addition, we generated model systems with allele-specific readouts by differentially modifying maternal and paternal alleles in one step. ITPN using our palette of targeting vectors, publicly available from Addgene, is ideally suited for generating error-free heterozygous knock-ins in human organoids.A major downside of double-strand break-mediated genome editing is the need to verify the genomic integrity of the targeted locus and confirm the absence of off-target indels. This study shows that in-trans paired nicking is a mutation-free CRISPR strategy to introduce precise knock-ins into human organoids; its genomic fidelity allows all knock-in cells to be pooled, accelerating the establishment of new organoid models. 相似文献
137.
138.
van den Berg HA 《Acta biotheoretica》2001,49(1):1-21
A microbial colony needs several essential nutrients in order to grow. Moreover, the colony requires these nutrients in fixed combinations, which are dictated by the chemical composition of its biomass. Unfortunately, ambient availabilities of the various nutrients vary all the time. This poses the question of how microbes can achieve balanced growth.The present solution to this problem is novel in that the allocation of molecular building blocks among assimilatory machineries within the cell is regarded as dynamic. This paper shows that allocation can be adapted so as to achieve balanced growth, nearly regardless of environmental conditions. Moreover, it is shown that a feedback mechanism, which monitors internal stores, is able to achieve this allocation. 相似文献
139.
140.
Venter T Kock JL Botes PJ Smit MS Hugo A Joseph M 《Systematic and applied microbiology》2004,27(2):135-138
It was discovered that the addition of 10 g/l acetate to a medium containing 30 g/l sunflower oil caused a drastic increase in citric acid production by Yarrowia lipolytica UOFS Y-1701 i.e. from 0.5 g/l in the absence of acetate to 18.7 g/l in the presence of acetate. Similarly, the ratio of citric acid:isocitric acid increased significantly from 1.7:1 in the absence of acetate to 3.7:1 in the presence of acetate after 240 h of growth. 相似文献