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231.
Dilution experiments were performed to estimate phytoplankton growth and microzooplankton grazing rates during two Lagrangian surveys in inner and eastern locations of the Eastern North Atlantic Subtropical Gyre province (NAST-E). Our design included two phytoplankton size fractions (0.2–5 µm and >5 µm) and five depths, allowing us to characterize differences in growth and grazing rates between size fractions and depths, as well as to estimate vertically integrated measurements. Phytoplankton growth rates were high (0.11–1.60 d−1), especially in the case of the large fraction. Grazing rates were also high (0.15–1.29 d−1), suggesting high turnover rates within the phytoplankton community. The integrated balances between phytoplankton growth and grazing losses were close to zero, although deviations were detected at several depths. Also, O2 supersaturation was observed up to 110 m depth during both Lagrangian surveys. These results add up to increased evidence indicating an autotrophic metabolic balance in oceanic subtropical gyres. 相似文献
232.
Edmond Y. Lau Sergio E. Wong Sarah E. Baker Jane P. Bearinger Lucas Koziol Carlos A. Valdez Joseph H. Satcher Jr Roger D. Aines Felice C. Lightstone 《PloS one》2013,8(6)
In nature, the zinc metalloenzyme carbonic anhydrase II (CAII) efficiently catalyzes the conversion of carbon dioxide (CO2) to bicarbonate under physiological conditions. Many research efforts have been directed towards the development of small molecule mimetics that can facilitate this process and thus have a beneficial environmental impact, but these efforts have met very limited success. Herein, we undertook quantum mechanical calculations of four mimetics, 1,5,9-triazacyclododedacane, 1,4,7,10-tetraazacyclododedacane, tris(4,5-dimethyl-2-imidazolyl)phosphine, and tris(2-benzimidazolylmethyl)amine, in their complexed form either with the Zn2+ or the Co2+ ion and studied their reaction coordinate for CO2 hydration. These calculations demonstrated that the ability of the complex to maintain a tetrahedral geometry and bind bicarbonate in a unidentate manner were vital for the hydration reaction to proceed favorably. Furthermore, these calculations show that the catalytic activity of the examined zinc complexes was insensitive to coordination states for zinc, while coordination states above four were found to have an unfavorable effect on product release for the cobalt counterparts. 相似文献
233.
Margarita Fernández García de Castro Carlos J. Martinez-Honduvilla 《Physiologia plantarum》1984,62(4):581-588
The decline of germination observed after storage of Pinus pinea L. seeds up to 35 years at room temperature was accompanied by an increase in their ability to leak reducing sugars, probably as a consequence of membrane alterations due to senescence. Results of studies of the cell ultrastructure of viable and non-viable seeds before and after imbibition indicate that such is the case. Noticeable changes occurred in the ultrastructure of endosperm and embryo cells with germinability loss, even in the unimbibed condition. The main alterations were spherosome coalescence, plasmalemma separation from the cell wall and chromatin aggregation. 相似文献
234.
235.
Verónica Corrales-Sánchez María del Mar Noblejas-López Cristina Nieto-Jiménez Javier Pérez-Peña Juan Carlos Montero Miguel Burgos Eva M. Galán-Moya Atanasio Pandiella Alberto Ocaña 《Journal of cellular and molecular medicine》2020,24(5):3117-3127
Identification of druggable vulnerabilities is a main objective in triple-negative breast cancer (TNBC), where no curative therapies exist. Gene set enrichment analyses (GSEA) and a pharmacological evaluation using a library of compounds were used to select potential druggable combinations. MTT and studies with semi-solid media were performed to explore the activity of the combinations. TNBC cell lines (MDAMB-231, BT549, HS-578T and HCC3153) and an additional panel of 16 cell lines were used to assess the activity of the two compounds. Flow cytometry experiments and biochemical studies were also performed to explore the mechanism of action. GSEA were performed using several data sets (GSE21422, GSE26910, GSE3744, GSE65194 and GSE42568), and more than 35 compounds against the identified functions were evaluated to discover druggable opportunities. Analyses done with the Chou and Talalay algorithm confirmed the synergy of dasatinib and olaparib. The combination of both agents significantly induced apoptosis in a caspase-dependent manner and revealed a pleotropic effect on cell cycle: Dasatinib arrested cells in G0/G1 and olaparib in G2/M. Dasatinib inhibited pChk1 and induced DNA damage measured by pH2AX, and olaparib increased pH3. Finally, the effect of the combination was also evaluated in a panel of 18 cell lines representative of the most frequent solid tumours, observing a particularly synergism in ovarian cancer. Breast cancer, triple negative, dasatinib, olaparib, screening. 相似文献
236.
David García‐Bernal Marta Palomo Carlos M. Martínez Jos E. Milln‐Rivero Ana I. García‐Guilln Miguel Blanquer Maribel Díaz‐Ricart Robert Sackstein Enric Carreras Jose M. Moraleda 《Journal of cellular and molecular medicine》2020,24(14):8031-8044
Allogeneic hematopoietic stem cell transplantation (allo‐HCT) is an effective therapy for the treatment of high‐risk haematological malignant disorders and other life‐threatening haematological and genetic diseases. Acute graft‐versus‐host disease (aGvHD) remains the most frequent cause of non‐relapse mortality following allo‐HCT and limits its extensive clinical application. Current pharmacologic agents used for prophylaxis and treatment of aGvHD are not uniformly successful and have serious secondary side effects. Therefore, more effective and safe prophylaxis and therapy for aGvHD are an unmet clinical need. Defibrotide is a multi‐target drug successfully employed for prophylaxis and treatment of veno‐occlusive disease/sinusoidal obstruction syndrome. Recent preliminary clinical data have suggested some efficacy of defibrotide in the prevention of aGvHD after allo‐HCT. Using a fully MHC‐mismatched murine model of allo‐HCT, we report here that defibrotide, either in prophylaxis or treatment, is effective in preventing T cell and neutrophil infiltration and aGvHD‐associated tissue injury, thus reducing aGvHD incidence and severity, with significantly improved survival after allo‐HCT. Moreover, we performed in vitro mechanistic studies using human cells revealing that defibrotide inhibits leucocyte‐endothelial interactions by down‐regulating expression of key endothelial adhesion molecules involved in leucocyte trafficking. Together, these findings provide evidence that defibrotide may represent an effective and safe clinical alternative for both prophylaxis and treatment of aGvHD after allo‐HCT, paving the way for new therapeutic approaches. 相似文献
237.
Xabier Rodríguez‐Martínez Semih Sevim Xiaofeng Xu Carlos Franco Paula Pamies‐Puig Laura Crcoles‐Guija Romen Rodriguez‐Trujillo Francisco Javier del Campo David Rodriguez San Miguel Andrew J. deMello Salvador Pan David B. Amabilino Olle Ingans Josep Puigmartí‐Luis Mariano Campoy‐Quiles 《Liver Transplantation》2020,10(33)
Microfluidic technologies are highly adept at generating controllable compositional gradients in fluids, a feature that has accelerated the understanding of the importance of chemical gradients in biological processes. That said, the development of versatile methods to generate controllable compositional gradients in the solid‐state has been far more elusive. The ability to produce such gradients would provide access to extensive compositional libraries, thus enabling the high‐throughput exploration of the parametric landscape of functional solids and devices in a resource‐, time‐, and cost‐efficient manner. Herein, the synergic integration of microfluidic technologies is reported with blade coating to enable the controlled formation of compositional lateral gradients in solution. Subsequently, the transformation of liquid‐based compositional gradients into solid‐state thin films using this method is demonstrated. To demonstrate efficacy of the approach, microfluidic‐assisted blade coating is used to optimize blending ratios in organic solar cells. Importantly, this novel technology can be easily extended to other solution processable systems that require the formation of solid‐state compositional lateral gradients. 相似文献
238.
239.
Jaime Carrasco Carlos García-Delgado Rebeca Lavega María L. Tello María De Toro Víctor Barba-Vicente María S. Rodríguez-Cruz María J. Sánchez-Martín Margarita Pérez Gail M. Preston 《Microbial biotechnology》2020,13(6):1933-1947
Microorganisms strongly influence and are required to generate the selective substrate that provides nutrients and support for fungal growth, and ultimately to induce mushroom fructification under controlled environmental conditions. In this work, the fungal and bacterial microbiota living in the different substrates employed in a commercial crop (compost phase I, II and III, flush 1 and 2, and casing material on day 1, 6 and 8 after compost casing and during flush 1 and 2) have been characterized along the different stages of cultivation by metataxonomic analysis (16S rRNA and ITS2), analysis of phospholipid fatty acid content (PLFAs) and RT-qPCR. Additionally, laccase activity and the content of lignin and complex carbohydrates in compost and casing have been quantified. The bacterial diversity in compost and casing increased throughout the crop cycle boosted by the connection of both substrates. As reflected by the PLFAs, the total living bacterial biomass appears to be negatively correlated with the mycelium of the crop. Agaricus bisporus was the dominant fungal species in colonized substrates, displacing the pre-eminent Ascomycota, accompanied by a sustained increase in laccase activity, which is considered to be a major product of protein synthesis during the mycelial growth of champignon. From phase II onwards, the metabolic machinery of the fungal crop degrades lignin and carbohydrates in compost, while these components are hardly degraded in casing, which reflects the minor role of the casing for nourishing the crop. The techniques employed in this study provide a holistic and detailed characterization of the changing microbial composition in commercial champignon substrates. The knowledge generated will contribute to improve compost formulations (selection of base materials) and accelerate compost production, for instance, through biotechnological interventions in the form of tailored biostimulants and to design environmentally sustainable bio-based casing materials. 相似文献
240.