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Amine-rich carbon nitride nanoparticles:Synthesis,covalent functionalization with proteins and application in a fluorescence quenching assay

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Nano Research 2019年第8期12卷 1862-1870页

作者： Gabriele capilli Simone cavalera laura Anfossi cristina Giovannoli Marco Minella claudio Baggiani claudio Minero Department of chemistry and NIS center of Excellence University of Torino10125 TorinoItaly

carbon nitride nanoparticles (cNNPs) have been employed as fluorescent sensing tools owing to their unique features, e.g. low cost production, high stability in water and high photoluminescence quantum yield. Here, an easy and versatile synthetic approach was exploited to design fluorescent nanoparticles with surface functionalities suitable for covalent binding to bioligands. High hydrophilic, brightly fluorescent cNNPs, rich of superficial amines, were obtained from the thermal condensation of urea and lysine (cNNP^Lys) and by tuning the precursor ratio and the heating time. Structure and size of the functionalized nanoparticles were characterized through infrared (IR) spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS). Their optical properties were studied by ultraviolet-visible (UV-Vis) and fluorescence spectroscopy. The superficial primary amino groups, furnished by the lysine co-precursor, enabled for covalently linking cNNP^Lys to model proteins. The cNNP^Lys-protein conjugates excited under UV irradiation emit in the 400-450 nm visible range (quantum yield 24%). The applicability of cNNP^Lys as novel fluorescent probes was demonstrated by a fluorescence quenching assay, in which gold nanoparticles (GNPs) were attached to Staphylococcal protein A and employed to quench the cNNP^Lys fluorescence by Forster resonant energy transfer (FRET). The quenching occurred upon formation of the specific binding between the GNP-linked protein A and cNNP^Lys-tagged immunoglobulins, while the inhibition of the binding resulted in the recovery of cNNP^Lys luminescence. The synthetic strategy, based on combining a "conjugated polymer"-forming unit (urea) and a co-precursor able to provide the desired functional group (lysine), allows designing innovative materials for the development of new generation fluorescence biosensors in which easily functionalized fluorophores are needed.

关键词： fluorescent probe carbon nitride nanoparticles quenching assay fluorescent materials g-c3N4 Forster resonant energy transfer (FRET)

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MicroRNA-135a Modulates Hepatitis c Virus Genome Replication through Downregulation of Host Antiviral Factors

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Virologica Sinica 2019年第2期34卷 197-210页

作者： catherine Sodroski Brianna Lowey laura Hertz T.Jake Liang Qisheng Li Liver Diseases Branch National Institute of Diabetes and Digestive and Kidney Diseases National Institutes of Health

cellular microRNAs(miRNAs) have been shown to modulate HcV infection via directly acting on the viral genome or indirectly through targeting the virus-associated host factors. Recently we generated a comprehensive map of HcV–miRNA interactions through genome-wide miRNA functional screens and transcriptomics analyses. Many previously unappreciated cellular miRNAs were identified to be involved in HcV infection, including miR-135a, a human cancerrelated miRNA. In the present study, we investigated the role of miR-135a in regulating HcV life cycle and showed that it preferentially enhances viral genome replication. Bioinformatics-based integrative analyses and subsequent functional assays revealed three antiviral host factors, including receptor interacting serine/threonine kinase 2(RIPK2), myeloid differentiation primary response 88(MYD88), and c-X-c motif chemokine ligand 12(cXcL12), as bona fide targets of miR-135a. These genes have been shown to inhibit HcV infection at the RNA replication stage. Our data demonstrated that repression of key host restriction factors mediated the proviral effect of miR-135a on HcV propagation. In addition,miR-135a hepatic abundance is upregulated by HcV infection in both cultured hepatocytes and human liver, likely mediating a more favorable environment for viral replication and possibly contributing to HcV-induced liver *** results provide novel insights into HcV–host interactions and unveil molecular pathways linking miRNA biology to HcV pathogenesis.

关键词： Hepatitis c virus (HcV) Genome replication Virus-host interactions miR-135a Antiviral factors

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Asiatic callosciurus squirrels as seed dispersers of exotic plants in the Pampas

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current Zoology 2016年第3期62卷 215-219页

作者： S. Yasmin BOBADILLA Veronica V, BENITEZ M. laura GUIcHON Ecologia de Mamiferos Introducidos Departamento de Ciencias Basicas Instituto de Ecologia y Desarrollo Sustentable (INEDES) Universidad Nacional de Lujan Ruta 5 y 7 Lujan (6700) Buenos Aires Argentina

Seed dispersal by exotic mammals exemplifies mutualistic interactions that can modify the habitat by facilitating the establishment of certain species. We examined the potential for endozoochoric dispersal of exotic plants by callosciurus erythraeus introduced in the Pampas Region of Argentina. We identified and characterized entire and damaged seeds found in squirrel faeces and evaluated the germination capacity and viability of entire seeds in laboratory assays. We collected 120 samples of squirrel faeces that contained 883 pellets in seasonal surveys conducted between July 2011 and June 2012 at 3 study sites within the main invasion focus of c. erythraeus in Argentina. We found 226 entire seeds in 21% of the samples belonging to 4 species of exotic trees and shrubs. Germination in laboratory assays was recorded for Morus alba and casuarina sp.; however, germination percentage and rate was higher for seeds obtained from the fruits than for seeds obtained from the faeces. The largest size of entire seeds found in the faeces was 4.2 ~ 4.0 ram, whereas the damaged seeds had at least 1 dimension ≥ 4.7 ram. Our results indi- cated that c. erythraeus can disperse viable seeds of at least 2 species of exotic trees. c. erythraeus predated seeds of other naturalized species in the region. The morphometric description suggested a restriction on the maximum size for the passage of entire seeds through the digestive tract of squirrels, which provides useful information to predict its role as a potential disperser or predator of other species in other invaded communities.

关键词： Argentina callosciurus erythraeus endozoochory invasive species mutualism.

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Soil organic carbon stocks in native forest of Argentina:a useful surrogate for mitigation and conservation planning under climate variability

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Ecological Processes 2024年第1期13卷 3-24页

作者： Pablo L.Peri Juan Gaitán Matías Mastrangelo Marcelo Nosetto Pablo E.Villagra Ezequiel Balducci Martín Pinazo Roxana P.Eclesia Alejandra Von Wallis Sebastián Villarino Francisco Alaggia Marina González Polo Silvina Manrique Pablo A.Meglioli Julián Rodríguez-Souilla Martín Mónaco Jimena E.chaves Ariel Medina Ignacio Gasparri Eugenio Alvarez Arnesi María Paula Barral Axel von Müller Norberto M.Pahr Josefina Uribe Echevarria Pedro Fernández Marina Morsucci Dardo López Juan Manuel cellini Leandro Alvarez Ignacio Barberis Hernán colomb Ludmila La Manna Sebastián Barbaro cecilia Blundo Ximena Sirimarco laura cavallero Gualberto Zalazar Guillermo Martínez Pastur Instituto Nacional de Tecnología Agropecuaria (INTA) Universidad Nacional de la Patagonia Austral (UNPA) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Universidad Nacional de Luján Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Grupo de Estudio de Agroecosistemas y Paisajes Rurales (GEAP) Universidad Nacional de Mar del Plata Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET ) ccT San Luis Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Instituto Argentino de Nivología Glaciología y Ciencias Ambientales (IANIGLA) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Universidad Nacional de Cuyo Instituto de Investigaciones en Biodiversidad y Medioambiente (INIBIOMA) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Instituto de Investigaciones en Energía No convencional CCT Salta-JujuyConsejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Laboratorio de Recursos Agroforestales Centro Austral de Investigaciones Científicas (CADIC) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Dirección Nacional de Bosques Ministerio de Ambiente y Desarrollo Sostenible de la Nación Instituto de Ecología Regional Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET )Universidad Nacional de Tucumán Universidad Nacional de Rosario Instituto de Investigaciones en Ciencias Agrarias de Rosario Centro Científico Tecnológico CONICET Grupo de Estudio de Agroecosistemas y Paisajes Rurales (GEAP) Universidad Nacional de Mar del Plata Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) Laboratorio de Investigaciones en Maderas (LIMAD) Universidad Nacional de La Plata (UNLP) Administración de Parques Nacionales (APN) Parque Nacional Los Alerces centro de Estudios Ambientales Integrados (cEAI) Universidad Nacional de la Patagonia San Juan Bosco (UNPASJB) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET )

Background The nationally determined contribution（NDc） presented by Argentina within the framework of the Paris Agreement is aligned with the decisions made in the context of the United Nations Framework conven-tion on climate change（UNFccc） on the reduction of emissions derived from deforestation and forest degradation, as well as forest carbon conservation（REDD+）. In addition, climate change constitutes one of the greatest threats to forest biodiversity and ecosystem services. However, the soil organic carbon（SOc） stocks of native forests have not been incorporated into the Forest Reference Emission Levels calculations and for conservation planning under cli-mate variability due to a lack of information. The objectives of this study were:（i） to model SOc stocks to 30 cm of native forests at a national scale using climatic, topographic and vegetation as predictor variables, and（ii） to relate SOc stocks with spatial–temporal remotely sensed indices to determine biodiversity conservation concerns due to threats from high inter-annual climate *** We used 1040 forest soil samples（0–30 cm） to generate spatially explicit estimates of SOc native forests in Argentina at a spatial resolution of approximately 200 m. We selected 52 potential predictive environmental covari-ates, which represent key factors for the spatial distribution of SOc. All covariate maps were uploaded to the Google Earth Engine cloud-based computing platform for subsequent modelling. To determine the biodiversity threats from high inter-annual climate variability, we employed the spatial–temporal satellite-derived indices based on Enhanced Vegetation Index（EVI） and land surface temperature（LST） images from Landsat *** SOc model（0–30 cm depth） prediction accounted for 69% of the variation of this soil property across the whole native forest coverage in Argentina. Total mean SOc stock reached 2.81 Pg c（2.71–2.84 Pg c with a probability of 90%） for a total area of 460,790 km2,

关键词： Soil organic carbon Biodiversity Native forest climate change mitigation Modelling Resilience

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carpobrotus edulis(L.) ***. extract as a skin preserving agent: From traditional medicine to scientific validation

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Journal of Integrative Medicine 2021年第6期19卷 526-536页

作者： Miriam Bazzicalupo laura cornara Bruno Burlando Alberta cascini Marcella Denaro Antonella Smeriglio Domenico Trombetta3 Department for the Earth Environment and Life Sciences(DiSTAV)University of GenovaGenova 16132Italy Department of Pharmacy University of GenovaGenova 16132Italy Department of chemical BiologicalPharmaceutical and Environmental SciencesUniversity of MessinaMessina 98166Italy

Objective:carpobrotus edulis(L.)*** a succulent perennial plant native to South Africa and grows invasively in the Mediterranean *** is commonly used for the treatment of various diseases,including skin wound healing and regeneration,for which experimental validation is *** therefore evaluated the skin healing properties by testing a *** aqueous leaf extract(cAE)on cell cultures and in enzymatic ***:Micro-morphological analysis of leaves was carried out using scanning electron microscopy and light *** features and antioxidant activity of cAE were evaluated by reversed-phase liquid chromatography coupled with diode array detection and electrospray ion trap mass spectrometry(RP-Lc-DAD-ESI-MS),and in vitro cell-free *** activities were evaluated using keratinocytes and fibroblasts,as well as elastase,collagenase,and ***:cAE showed high carbohydrates(28.59%±0.68%),total phenols([101.9±6.0]g gallic acid equivalents/kg dry extract[DE]),and flavonoids([545.9±26.0]g rutin equivalents/kg DE).RP-Lc-DAD-ESI-MS revealed the predominant presence of hydroxycinnamic acids(51.96%),followed by tannins(14.82%)and flavonols(11.32%).The extract was not cytotoxic,had a strong and dose-dependent antioxidant activity,and inhibited collagenase(>90%at 500 mg/m L)and hyaluronidase(100%at 1000 mg/m L).In cell culture experiments,cAE increased wound closure and collagen production,which was consistent with its high polyphenol ***:Our data support the use of the *** for skin care and the treatment of skin ***,use of *** for skin care purposes could be an eco-friendly solution to reduce its invasiveness in the environment.

关键词： Traditional medicine carbohydrates Polyphenols Antioxidant Wound healing

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Retention and redistribution of biological legacies generate resource sinks in silvopastoral systems of Arid chaco forests

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Ecological Processes 2019年第1期8卷 344-359页

作者： laura cavallero Marcela Ledesma Dardo R.López carlos A.carranza centro científico Tecnológico(ccT)cONIcET córdoba CórdobaArgentina Estación Forestal INTA-Villa Dolores(EEA Manfredi) CórdobaArgentina

Background:Forests are used for multiple purposes worldwide,which often include timber harvest,firewood extraction and livestock *** excessive pressure on multipurpose systems may decrease soil cover,promoting soil erosion and causing the loss of other resources,as litter and *** forestry practices can help to decrease or mitigate resource loss in the managed ***,retaining and redistributing biological legacies(***,branches,woody debris)at strategic locations can create sediment,litter,and seed-sinks in the silvopastoral *** addition,grazing management could increase or,even,decrease the success of this *** this study,we assessed the effect of branch barriers and grazing management on resource run-off/runon processes in silvopastoral systems of Arid chaco(córdoba,Argentina).To do this,a 2-ha area was divided in two paddocks that were randomly assigned to different grazing managements:winter *** *** randomly selected 22 water run-off paths in each paddock,and in the half of them,we build elongated branch *** each run-off path(with and without branch barriers),we recorded the amount of accumulated and lost sediment(during the rainy season),litter biomass,germinable seed bank,richness and cover of plant species,and richness and density of seedlings and saplings of woody ***:Branch barriers promoted sediment accumulation during the first and the second year of the study,depending on grazing *** temporal and spatial scale of the effect of the branch barriers also depended on grazing *** barriers also trapped litter and seeds,which may have increased the richness and density of seedlings and saplings of woody ***:By intercepting the dominant flow of erosive agents,branch barriers trapped sediment,litter,and propagules of different species.A greater amount of sediment and litter would have improved microsite quality,favouring seed germination an

关键词： Branch barriers Ecosystem degradation Multipurpose forests Soil erosion Winter grazing

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A novel semantic segmentation approach based on U-Net,WU-Net,and U-Net++deep learning for predicting areas sensitive to pluvial flood at tropical area

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International Journal of Digital Earth 2023年第1期16卷 3661-3679页

作者： laura Melgar-García Francisco Martínez-álvarez Dieu Tien Bui Alicia Troncoso Data Science&Big Data Lab Pablo de Olavide UniversitySevilleSpain GIS Group Department of Business and ITUniversity of South-Eastern NorwayGullbringvegen 36B?i Telemark3800Norway

Floods remain one of the most devastating weather-induced disastersworldwide, resulting in numerous fatalities each year and severelyimpacting socio-economic development and the ***, the ability to predict flood-prone areas in advance is crucialfor effective risk management. The objective of this research is to assessand compare three convolutional neural networks, U-Net, WU-Net, andU-Net++, for spatial prediction of pluvial flood with a case study at atropical area in the north of Vietnam. They are relative new convolutionalgorithms developed based on U-shaped architectures. For this task, ageospatial database with 796 historical flood locations and 12 floodindicators was prepared. For training the models, the binary crossentropywas employed as the loss function, while the Adaptive momentestimation (ADAM) algorithm was used for the optimization of themodel parameters, whereas, F1-score and classification accuracy (Acc)were used to assess the performance of the models. The results unequivocally highlight the high performance of the three models,achieving an impressive accuracy rate of 96.01%. The flood susceptibility maps derived from this research possess considerable utility for local authorities, providing valuable insights and informationto enhance decision-making processes and facilitate the implementation of effective risk management strategies.

关键词： Flash-flood assessment convolutional networks climate change GIS

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Hepatitis c virus in the new era:Perspectives in epidemiology,prevention,diagnostics and predictors of response to therapy

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World Journal of Gastroenterology 2014年第29期20卷 9633-9652页

作者： Filippo Ansaldi Andrea Orsi laura Sticchi Bianca Bruzzone Giancarlo Icardi Department of Health Sciences University of Genoa Hygiene Unit I.R.C.C.S."A.O.U.San Martino-IST"16132 GenoaItaly

Despite the great successes achieved in the fields of virology and diagnostics,several difficulties affect improvements in hepatitis c virus(HcV)infection control and eradication in the new *** HcV infections still occur,especially in some of the poorest regions of the world,where HcV is endemic and long-term sequelae have a growing economic and health *** HcV vaccine is still no available,despite years of researches and discoveries about the natural history of infection and host-virus interactions:several HcV vaccine candidates have been developed in the last years,targeting different HcV antigens or using alternative delivery systems,but viral variability and adaption ability constitute major challenges for vaccine *** new antiviral drugs for HcV therapy are in preclinical or early clinical development,but different limitations affect treatment *** predictors are important tools,as they provide some guidance for the management of therapy in patients with chronic HcV infection:in particular,the role of host genomics in HcV infection outcomes in the new era of direct-acting antivirals may evolve for new therapeutic targets,representing a chance for modulated and personalized treatment management,when also very potent therapies will be *** the present review we discuss the most recent data about HcV epidemiology,the new perspectives for the prevention of HcV infection and the most recent evidence regarding HcV diagnosis,therapy and predictors of response to it.

关键词： Hepatitis c virus epidemiology Hepatitis c virus diagnosis Hepatitis c virus vaccine Direct-acting antivirals Predictors of response to hepatitis c virus therapy

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Effect of dephytinization on bioavailability of iron,calcium and zinc from infant cereals assessed in the caco-2 cell model

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World Journal of Gastroenterology 2009年第16期15卷 1977-1984页

作者： carmen Frontela Maria laura Scarino Simonetta Ferruzza Gaspar Ros carmen Martínez Department of Food Science and Nutrition Faculty of Veterinary Science and Food Science and TechnologyMurcia University INRAN National Research Institute for Food and Nutrition

AIM： To test the effect of the dephytinization of three different commercial infant cereals on iron, calcium, and zinc bioavailability by estimating the uptake, retention, and transport by caco-2 cells. METHODS： Both dephytinized （by adding an exogenous phytase） and non-dephytinized infant cereals were digested using an in vitro digestion protocol adapted to the gastrointestinal conditions of infants younger than 6 too. Mineral cell retention, transport, and uptake from infant cereals were measured using the soluble fraction of the simulated digestion and the caco-2 cells. RESULTS： Dephytinization of infant cereals significantly increased （P 〈 0.05） the cell uptake efficiency （from 0.66%-6.05% to 3.93%-13%）, retention （from 6.04%-16.68% to 14.75%-20.14%） and transport efficiency （from 0.14%-2.21% to 1.47%-6.02%）, of iron, and the uptake efficiency （from 5.0%-35.4% to 7.3%-41.6%） and retention （from 4.05%-20.53% to 14.45%-61.3%） of zinc, whereas calcium only cell uptake showed a significant increase （P 〈 0.05） after removing phytate from most of the samples analyzed. A positive relationship （P 〈 0.05） between mineral solubility and the cell uptake and transport efficiencies was observed. cONcLUSION： Removing phytate from infant cereals had a beneficial effect on iron and zinc bioavailability when infant cereals were reconstituted with water. Since in developing countries cereal-based complementary foods for infants are usually consumed mixed with water, exogenous phytase additions could improve the nutritional value of this weaning food.

关键词： Infant cereals Phytate Iron calcium Zinc caco-2 cells BioavaUability

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Munc18/SNARE proteins’ regulation of exocytosis in guinea pig duodenal Brunner’s gland acini

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World Journal of Gastroenterology 2008年第15期14卷 2314-2322页

作者： laura I cosen-Binker Gerry P Morris Stephen Vanner Herbert Y Gaisano Department of Medicine University of Toronto Toronto Ontario M5S 1A8 Canada Gastrointestinal Diseases Research Unit Queen's University Kingston Ontario KL7 5G2 Canada

AIM: To examine the molecular mechanism of exocytosis in the Brunner’s gland acinar cell. METHODS: We used a submucosal preparation of guinea pig duodenal Brunner’s gland acini to visualize the dilation of the ductal lumen in response to cholinergic stimulus. We correlated this to electron microscopy to determine the extent of exocytosis of the mucin-filled vesicles. We then examined the behavior of SNARE and interacting Munc18 proteins by confocal microscopy. RESULTS: One and 6 μmol/L carbachol evoked a dose- dependent dilation of Brunner’s gland acini lumen, which correlated to the massive exocytosis of mucin. Munc18c and its cognate SNARE proteins Syntaxin-4 and SNAP-23 were localized to the apical plasma membrane, and upon cholinergic stimulation, Munc18c was displaced into the cytosol leaving Syntaxin-4 and SNAP-23 intact. cONcLUSION: Physiologic cholinergic stimulation induces Munc18c displacement from the Brunner’s gland acinar apical plasma membrane, which enables apical membrane Syntaxin-4 and SNAP-23 to form a SNARE complex with mucin-filled vesicle SNARE proteins to affect exocytosis.

关键词： Apical exocytosis Brunner's gland acini Munc18c Syntaxin-4 carbachol

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