7 research outputs found
Ultrafast photochemistry produces superbright short-wave infrared dots for low-dose in vivo imaging
12 p.-5 fig.Optical probes operating in the second near-infrared window (NIR-II, 1,000-1,700 nm), where tissues are highly transparent, have expanded the applicability of fluorescence in the biomedical field. NIR-II fluorescence enables deep-tissue imaging with micrometric resolution in animal models, but is limited by the low brightness of NIR-II probes, which prevents imaging at low excitation intensities and fluorophore concentrations. Here, we present a new generation of probes (Ag2S superdots) derived from chemically synthesized Ag2S dots, on which a protective shell is grown by femtosecond laser irradiation. This shell reduces the structural defects, causing an 80-fold enhancement of the quantum yield. PEGylated Ag2S superdots enable deep-tissue in vivo imaging at low excitation intensities (<10 mW cm-2) and doses (<0.5 mg kg-1), emerging as unrivaled contrast agents for NIR-II preclinical bioimaging. These results establish an approach for developing superbright NIR-II contrast agents based on the synergy between chemical synthesis and ultrafast laser processing.Authors thank Dr A. Benayas (CICECO, U. Aveiro, Portugal), Prof G. Lifante and Prof J. García Sole (UAM) for helpful discussions. This work has been founded by Ministerio de Economı́a y Competitividad-MINECO (MAT2017-83111R and MAT2016-75362-C3-1-R) and the Comunidad de Madrid (B2017/BMD-3867 RENIM-CM) co-financed by European Structural and Investment Fund. D.M.-G. thanks UCM-Santander for a predoctoral contract (CT17/17-CT18/17). We thank the staff at the ICTS-National Centre for Electron Microscopy at the UCM for the help in the electron microscopy studies and C.M. at the beamline BL22-CLAESS of the Spanish synchrotron ALBA for his help in the XANES experiments. We also thank J.G.I at the Ultrafast Laser Laboratory at UCM for his help and fruitful discussion. Y.S. acknowledges the support from the China Scholarship Council (CSC File No. 201806870023). Additional funding was provided by the European Commission Horizon 2020 project NanoTBTech, the Fundación para la Investigación Biomédica del Hospital Universitario Ramón y Cajal project IMP18_38 (2018/0265). Ajoy K. Kar and Mark D. Mackenzie acknowledge support from the UK Engineering and Physical Sciences Research Council (Project CHAMP, EP/M015130/1). C. Jacinto thanks the financial support of the Brazilian agencies: CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) through the grants: Projeto Universal Nr. 431736/2018-9 and Scholarship in Research Productivity 1C under the Nr. 304967/20181; FINEP (Financiadora de Estudos e Projetos) through the grants INFRAPESQ-11 and INFRAPESQ-12; FAPEAL (Fundação de Amparo à Pesquisa do Estado de Alagoas) grant Nr. 1209/2016. H. D. A. Santos was supported by a graduate studentship from CNPq and by a sandwich doctoral program (PDSE-CAPES) developed at Universidad Autonoma de Madrid, Spain, Project Nr. 88881/2016-01.Peer reviewe
Tm<sup>3+</sup>-sensitized up- and down-conversions in nano-structured oxyfluoride glass ceramics
Spatial variability of the relationships of runoff and sediment yield with weather types throughout the Mediterranean basin
Este artículo contiene 16 páginas, 6 figuras, 2 tablas.Soil degradation by water is a serious environmental problem worldwide, with specific climatic factors being the
major causes. We investigated the relationships between synoptic atmospheric patterns (i.e. weather types, WTs)
and runoff, erosion and sediment yield throughout the Mediterranean basin by analyzing a large database of
natural rainfall events at 68 research sites in 9 countries. Principal Component Analysis (PCA) was used to
identify spatial relationships of the different WTs including three hydro-sedimentary variables: rainfall, runoff,
and sediment yield (SY, used to refer to both soil erosion measured at plot scale and sediment yield registered at
catchment scale). The results indicated 4 spatial classes of rainfall and runoff: (a) northern sites dependent on
North (N) and North West (NW) flows; (b) eastern sites dependent on E and NE flows; (c) southern sites dependent
on S and SE flows; and, finally, (d) western sites dependent on W and SW flows. Conversely, three
spatial classes are identified for SY characterized by: (a) N and NE flows in northern sites (b) E flows in eastern
sites, and (c) Wand SW flows in western sites. Most of the rainfall, runoff and SY occurred during a small number
of daily events, and just a few WTs accounted for large percentages of the total. Our results confirm that
characterization by WT improves understanding of the general conditions under which runoff and SY occur, and
provides useful information for understanding the spatial variability of runoff, and SY throughout the
Mediterranean basin. The approach used here could be useful to aid of the design of regional water management
and soil conservation measures.This research was supported by projects funded by the MINECOFEDER:
CGL2014-52135-C3-3-R, CGL2014-59946-R, CGL2015-65569-
R, CGL2015-64284-C2-2-R, and PCIN-2017-061/AEI. When this
manuscript was first submitted Estela Nadal-Romero and Damià Vericat
received a “Ramón y Cajal” postdoctoral contract (RYC-2013-14371
and RYC‐2010‐06264, Spanish Ministry of Economy and
Competitiveness, MEC). Damià Vericat is now a Serra Húnter Fellow at
the University of Lleida. María Fernández-Raga received a “José
Castillejo” postdoctoral grant (Spanish Ministry of Education, Culture
and Sports). Carla Ferreira was supported by a post-doctoral research
grant from the Portuguese Science and Technology Foundation (SFRH/
BPD/120093/2016). Mariano Moreno-de las Heras received a Juan de
la Cierva postdoctoral contract (IJCI-2015-26463) from the MEC. José
Andrés López-Tarazón received a Vicenç Mut postdoctoral fellowship
from the Autonomous Balearic Government (CAIB PD/038/2016). José
Andrés López-Tarazón and Ramon Batalla also acknowledge the
Secretariat for Universities and Research of the Department of the
Economy and Knowledge of the Autonomous Government of Catalonia
for supporting the Consolidated Research Group 2014 SGR 645 (RIUSFluvial
Dynamics Research Group), and the CERCA Programme. This
paper has benefited from the Lab and Field Data Pool created within the
framework of the COST action CONNECTEUR (ES1306).Peer reviewe
Analysis of the spatial variability of the relationships between rainfall, runoff, erosion and sediment yield and synoptic atmospheric patterns around the Mediterranean basin
Trabajo presentado en TERRAenVISION Environmental Issues Today: Scientific Solutions for Societal Issues, celebrado en Barcelona (España) del 27 de enero al 2 de febrero de 2018This contribution results from international collaborative efforts of different research groups
around the Mediterranean basin focusing on soil conservation and water management. We will
present the most complete database of runoff and soil erosion information and analyze the
records from 68 locations, including more than 22458 detail events between 1985-2015. Soil
conservation and water planning are two of the most challenging problems around the
Mediterranean basin due to climate conditions and human activity. We believe that future
advances on understanding soil degradation by water should be developed under global
approaches. In this contribution, we will present an analysis of atmospheric conditions, expressed
by weather types and the resulted rainfall, runoff, and erosion and sediment yield around the
Mediterranean basin. The weather types compile daily information about the different air masses
responsible for rainfall, runoff and eventually erosion and sediment yield, and their analyses let us
know the synchrony of the response at different sites around the Mediterranean basin. The
analyses of the global dataset display different spatial patterns for rainfall, runoff, and sediment
yield, related to different atmospheric patterns. This research will be a valuable tool for
understanding the evolution of these environmental variables, and therefore it will allow future
planning to design regional water management and soil conservation measuresPeer reviewe
Spatial variability of the relationships of runoff and sediment yield with weather types throughout the Mediterranean basin
Spatial variability of the relationships of runoff and sediment yield with weather types throughout the Mediterranean basin
Summarization: Soil degradation by water is a serious environmental problem worldwide, with specific climatic factors being the major causes. We investigated the relationships between synoptic atmospheric patterns (i.e. weather types, WTs) and runoff, erosion and sediment yield throughout the Mediterranean basin by analyzing a large database of natural rainfall events at 68 research sites in 9 countries. Principal Component Analysis (PCA) was used to identify spatial relationships of the different WTs including three hydro-sedimentary variables: rainfall, runoff, and sediment yield (SY, used to refer to both soil erosion measured at plot scale and sediment yield registered at catchment scale). The results indicated 4 spatial classes of rainfall and runoff: (a) northern sites dependent on North (N) and North West (NW) flows; (b) eastern sites dependent on E and NE flows; (c) southern sites dependent on S and SE flows; and, finally, (d) western sites dependent on W and SW flows. Conversely, three spatial classes are identified for SY characterized by: (a) N and NE flows in northern sites (b) E flows in eastern sites, and (c) W and SW flows in western sites. Most of the rainfall, runoff and SY occurred during a small number of daily events, and just a few WTs accounted for large percentages of the total. Our results confirm that characterization by WT improves understanding of the general conditions under which runoff and SY occur, and provides useful information for understanding the spatial variability of runoff, and SY throughout the Mediterranean basin. The approach used here could be useful to aid of the design of regional water management and soil conservation measures.Παρουσιάστηκε στο: Journal of Hydrolog