105 research outputs found
Cluster splitting in granular segregation driven by horizontal shaking
In a recent work [C. Lozano et al. Phys. Rev. Lett 114, 178002 (2015)] segregation in an horizontally shaken granular layer was studied by analysing the particle-particle interactions in the simplest case possible of a two particles cluster. There, it was found that all clusters are transient (they eventually split if one waits long enough) and the probability distribution function of the separation times displays a power law tail, indicating that the splitting probability is not constant over time. Here, we extend this study to clusters of 3, 5, 10 and 20 particles where we also observe the power law decay of the distribution of cluster splitting time. In addition, we observe a weak increase of the average cluster splitting time with the cluster size, suggesting that interaction forces are non-additive. Finally, we show interesting statistics on the way in which clusters break suggesting that escaping of individual particles in the cluster borders is more likely than cluster breakage in subclusters of similar size
La cova dels Galls Carboners (Mont-ral, Alt Camp), una cavitat d'inhumació col·lectiva durant l'edat del Bronze
Electrochemical oxidation of meglumine in a pharmaceutical formulation using a nanocomposite anode
The electrocatalytic oxidation of meglumine and gadoterate meglumine (Gd-DOTA) on a TiO2-Ni(SO4)0.3(OH)1.4 composite anode was investigated in alkaline medium (5 M KOH) using cyclic voltammetry and chronoamperometry. The composite was prepared by hydrothermal method and the morphology and structure of the produced nanoparticles were studied by scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray diffraction, atomic force microscopy, BET surface area analysis and Fourier transform infrared spectroscopy. The characterization revealed the formation of Ni(SO4)0.3(OH)1.4 nanobelts dispersed on TiO2 nanoaggregates. The composite was coated onto a porous graphite rod, showing good adherence without requiring any binder (according to their anodic and cathodic charges). The supported composite was electrocatalytic, allowing the oxidation of meglumine, either as pure reagent or contained in gadoterate meglumine solutions. Electrochemical methods allowed determining the kinetic parameters, such as the electron transfer coefficient α, the total number of electrons n and the standard heterogeneous rate constant k0 for the reaction of meglumine. The chronoamperometric tests informed about the good stability of the composite anode upon meglumine oxidation at +0.6 V for 10 h. The electrochemical oxidation of meglumine in a commercial pharmaceutical formulation (Dotarem®) was corroborated via ultra-high performance liquid chromatography coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry
Land-use change and windstorms legacies drove the recolonization dynamics of laurel forests in Tenerife, Canary islands
Laurel forests are quite relevant for biodiversity conservation and are among the island ecosystems most severely damaged by human activities. In the past, Canary laurel forests have been greatly altered by logging, livestock and agriculture. The remains of laurel forests are currently protected in the Canary Islands (Spain). However, we miss basic information needed for their restoration and adaptive management, such as tree longevity, growth potential and responsiveness to natural and anthropogenic disturbances. Using dendrochronological methods, we studied how forest dynamic is related to land-use change and windstorms in two well-preserved laurel forests on Tenerife Island. Wood cores were collected from over 80 trees per stand at three stands per forest. We used ring-width series to estimate tree ages and calculate annual basal area increments (BAI), cumulative diameter increases, and changes indicative of released and suppressed growth. Twelve tree species were found in all stands, with Laurus novocanariensis, Ilex canariensis and Morella faya being the most common species. Although some individuals were over 100 years old, 61.8%–88.9% of the trees per stand established between 1940 and 1970, coinciding with a post-war period of land abandonment, rural exodus and the onset of a tourism economy. Some trees have shown growth rates larger than 1 cm diameter per year and most species have had increasing BAI trends over the past decades. Strong growth releases occurred after windstorms at both sites, but the effects of windstorms were site-dependent, with the 1958 storm affecting mainly the eastern tip of the island (Anaga massif) and the 1991 storm the western tip (Teno massif). Given the great ability of laurel forest trees to establish after land use cessation and to increase growth after local disturbances such as windstorms, passive restoration may be sufficient to regenerate this habitat in currently degraded areas.12 página
Los Poyos del Molinillo (Frigiliana): new site of the Bronze Age in the East Axarquía (Málaga, Andalucía)
En este trabajo damos a conocer un nuevo yacimiento descubierto recientemente en el municipio de Frigiliana. La delimitación del área denominada Los Poyos del Molinillo permitió definir la existencia de un poblado y una covacha con restos de una inhumación. El estudio de los materiales arqueológicos, que incluye cerámica, piezas metálicas o elementos de molturación, o la datación AMS obtenida, permiten adscribir el yacimiento a la Edad del Bronce y ampliar el conocimiento de esta etapa en la Axarquía oriental (Málaga, Andalucía).In this work we present a new site recently discovered in the Frigiliana municipality (Málaga). The spatial delimitation of the so called Los Poyos del Molinillo area let us define a Bronze age settlement and an inhumation burial cave. The archaeological record includes ceramic, metallic items or grinding elements, all of them belonging to the Bronze Age, as well as an AMS Radiocarbon data. This site extends the knowledge about this period in the Eastern Axarquía (Málaga, Andalucía)
Desarrollo de la técnica de FICTION como nueva herramienta para el diagnóstico precoz de cáncer de pulmón
El cáncer de pulmón es una de las causas de muerte más frecuentes en el mundo occidental. La supervivencia global de los pacientes no supera el 15% a los 5 años, debido principalmente a que la mayor parte de los casos se diagnostican en estadios avanzados. Además de la prevención primaria, mediante la reducción del consumo de tabaco, son necesarias nuevas tecnologías para el diagnóstico precoz de la enfermedad.
Estudios recientes han demostrado que el TAC helicoidal del tórax es efectivo en la detección de nódulos pulmonares malignos en estadios precoces. En la actualidad se está valorando su eficacia en series amplias de pacientes de alto riesgo.
Recientemente se ha desarrollado una nueva técnica de citogenética molecular, el FICTION (Fluorescence Immunophenotyping and Interphase Cytogenetics as a Tool for the Investigation of Neoplasms). Esta técnica permite el análisis simultáneo de marcadores inmunofenotípicos y alteraciones genéticas presentes en las células tumorales. El objetivo de nuestro proyecto es su puesta a punto para el estudio de muestras de esputo y lavado broncoalveolar de pacientes con cáncer de pulmón. El fin último es estudiar la posibilidad de que esta técnica pueda ser utilizada, junto con el TAC helicoidal, en programas de detección precoz de cáncer de pulmón, para pacientes de alto riesgo.
En este trabajo presentamos una revisión de la contribución de las distintas técnicas de citogenética al estudio del cáncer de pulmón y la metodología de trabajo que vamos a llevar a cabo en nuestro proyecto
Biomarkers of tumor-reactive CD4+ and CD8+ TILs associate with improved prognosis in endometrial cancer
Background: Despite the growing interest in immunotherapeutic interventions for endometrial cancer (EC), the prevalence, phenotype, specificity and prognostic value of tumor infiltrating lymphocytes (TILs) in this tumor type remains unclear. Methods: To better understand the role of TILs in EC, we analyzed the phenotypic traits of CD8+ and CD4+ EC-resident T cells from 47 primary tumors by high-dimensional flow cytometry. In addition, CD8+ and CD4+ TIL subpopulations were isolated based on the differential expression of programmed cell death protein-1 (PD-1) (negative, dim and high) and CD39 (positive or negative) by fluorescence activated cell sorting (FACS), expanded in vitro, and screened for autologous tumor recognition. We further investigated whether phenotypic markers preferentially expressed on CD8+ and CD4+ tumor-reactive TIL subsets were associated with the four distinct molecular subtypes of EC, tumor mutational burden and patient survival. Results: We found that CD8+TILs expressing high levels of PD-1 (PD-1hi) co-expressed CD39, TIM-3, HLA-DR and CXCL13, as compared with TILs lacking or displaying intermediate levels of PD-1 expression (PD-1- and PD-1dim, respectively). Autologous tumor reactivity of sorted and in vitro expanded CD8+ TILs demonstrated that the CD8+PD-1dimCD39+ and PD-1hiCD39+ T cell subsets both contained tumor-reactive TILs and that a higher level of PD-1 expression was associated with increased CD39 and a superior frequency of tumor reactivity. With respect to CD4+ T conventional (Tconv) TILs, co-expression of inhibitory and activation markers was more apparent on PD-1hi compared with PD-1- or PD-1dim T cells, and in fact, it was the CD4+PD-1hi subpopulation that accumulated the antitumor T cells irrespective of CD39 expression. Most importantly, detection of CD8+PD-1hiCD39+ and CD4+PD-1hi tumor-reactive T-cell subsets, but also markers specifically expressed by these subpopulations of TILs, that is, PD-1hi, CD39, CXCL13 and CD103 by CD8+ TILs and PD-1hi and CXCL13 by CD4+ Tconv TILs, correlated with prolonged survival of patients with EC. Conclusions: Our results demonstrate that EC are frequently infiltrated by tumor-reactive TILs, and that expression of PD-1hi and CD39 or PD-1hi can be used to select and expand CD8+ and CD4+ tumor-reactive TILs, respectively. In addition, biomarkers preferentially expressed on tumor-reactive TILs, rather than the frequency of CD3+, CD8+ and CD4+ lymphocytes, hold prognostic value suggesting their protective role in antitumor immunity
Heterogenous presence of neutrophil extracellular traps in human solid tumours is partially dependent on IL-8
Neutrophil extracellular traps (NETs) are webs of extracellular nuclear DNA extruded by dying neutrophils infiltrating
tissue. NETs constitute a defence mechanism to entrap and kill fungi and bacteria. Tumours induce the formation of
NETs to the advantage of the malignancy via a variety of mechanisms shown in mouse models. Here, we investigated
the presence of NETs in a variety of human solid tumours and their association with IL-8 (CXCL8) protein expression
and CD8+ T-cell density in the tumour microenvironment. Multiplex immunofluorescence panels were developed to
identify NETs in human cancer tissues by co-staining with the granulocyte marker CD15, the neutrophil marker myeloperoxidase
and citrullinated histone H3 (H3Cit), as well as IL-8 protein and CD8+ T cells. Three ELISA methods to
detect and quantify circulating NETs in serum were optimised and utilised. Whole tumour sections and tissue microarrays
from patients with non-small cell lung cancer (NSCLC; n = 14), bladder cancer (n = 14), melanoma (n = 11),
breast cancer (n = 31), colorectal cancer (n = 20) and mesothelioma (n = 61) were studied. Also, serum samples
collected retrospectively from patients with metastatic melanoma (n = 12) and NSCLC (n = 34) were ELISA assayed
to quantify circulating NETs and IL-8. NETs were detected in six different human cancer types with wide individual
variation in terms of tissue density and distribution. At least in NSCLC, bladder cancer and metastatic melanoma, NET
density positively correlated with IL-8 protein expression and inversely correlated with CD8+ T-cell densities. In a
series of serum samples from melanoma and NSCLC patients, a positive correlation between circulating NETs and
IL-8 was found. In conclusion, NETs are detectable in formalin-fixed human biopsy samples from solid tumours
and in the circulation of cancer patients with a considerable degree of individual variation. NETs show a positive
association with IL-8 and a trend towards a negative association with CD8+ tumour-infiltrating lymphocytes
Quantitative and qualitative impairments in dendritic cell subsets of patients with ovarian or prostate cancer
Background
Dendritic cells (DCs) are the most efficient antigen-presenting cells, hence initiating a potent and cancer-specific immune response. This ability (mainly using monocyte-derived DCs) has been exploited in vaccination strategies for decades with limited clinical efficacy. Another alternative would be the use of conventional DCs (cDCs) of which at least three subsets circulate in human blood: cDC1s (CD141bright), cDC2s (CD1c+) and plasmacytoid DCs. Despite their paucity, technical advances may allow for their selection and clinical use. However, many assumptions concerning the DC subset biology depend on observations from mouse models, hindering their translational potential. In this study, we characterise human DCs in patients with ovarian cancer (OvC) or prostate cancer (PrC).
Patients and methods
Whole blood samples from patients with OvC or PrC and healthy donors (HDs) were evaluated by flow cytometry for the phenotypic and functional characterisation of DC subsets.
Results
In both patient groups, the frequency of total CD141+ DCs was lower than that in HDs, but the cDC1 subset was only reduced in patients with OvC. CD141+ DCs showed a reduced response to the TLR3 agonist poly (I:C) in both groups of patients. An inverse correlation between the frequency of cDC1s and CA125, the OvC tumour burden marker, was observed. Consistently, high expression of CLEC9A in OvC tissue (The Cancer Genome Atlas data set) indicated a better overall survival.
Conclusions
cDC1s are reduced in patients with OvC, and CD141+ DCs are quantitatively and qualitatively impaired in patients with OvC or PrC. CD141+ DC activation may predict functional impairment. The loss of cDC1s may be a bad prognostic factor for patients with OvC
Genomic characterization of individuals presenting extreme phenotypes of high and low risk to develop tobacco-induced lung cancer
Single nucleotide polymorphisms (SNPs) may modulate individual susceptibility to carcinogens. We designed a genome-wide association study to characterize individuals presenting extreme phenotypes of high and low risk to develop tobacco-induced non-small cell lung cancer (NSCLC), and we validated our results. We hypothesized that this strategy would enrich the frequencies of the alleles that contribute to the observed traits. We genotyped 2.37 million SNPs in 95 extreme phenotype individuals, that is: heavy smokers that either developed NSCLC at an early age (extreme cases); or did not present NSCLC at an advanced age (extreme controls), selected from a discovery set (n=3631). We validated significant SNPs in 133 additional subjects with extreme phenotypes selected from databases including >39,000 individuals. Two SNPs were validated: rs12660420 (p(combined)=5.66x10(-5); ORcombined=2.80), mapping to a noncoding transcript exon of PDE10A; and rs6835978 (p(combined)=1.02x10(-4); ORcombined=2.57), an intronic variant in ATP10D. We assessed the relevance of both proteins in early-stage NSCLC. PDE10A and ATP10D mRNA expressions correlated with survival in 821 stage I-II NSCLC patients (p=0.01 and p<0.0001). PDE10A protein expression correlated with survival in 149 patients with stage I-II NSCLC (p=0.002). In conclusion, we validated two variants associated with extreme phenotypes of high and low risk of developing tobacco-induced NSCLC. Our findings may allow to identify individuals presenting high and low risk to develop tobacco-induced NSCLC and to characterize molecular mechanisms of carcinogenesis and resistance to develop NSCLC
- …