80 research outputs found

    Alpinismo

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    Mountain-climbing

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    Alpinisme

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    Structural Characterisation of Printable Noble Metal/Poly(Vinyl-­Alcohol) Nanocomposites for Optical Applications

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    This work was conducted under the aegis of the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom (EP/I004173/1). Amin Abdolvand is an EPSRC Career Acceleration Fellow at the University of Dundee.In order to enable exploitation of noble metal/poly(vinyl-alcohol) nanocomposites for device fabrication, solutions of poly(vinyl-alcohol) suitable for piezo-driven inkjet printing techniques are identified and discussed in terms of their material properties. The printable poly(vinyl-alcohol) medium is then exploited as a host material through the formation of silver or gold nanoparticles in order to create nanocomposites that exhibit a surface plasmon resonance behaviour associated with the small metallic inclusions. To mitigate some of the material redistribution effects associated with the drying of printed droplets containing finely divided materials, the metallic nanoparticles are formed after the printing and drying process is completed, by way of an in-situ reduction of an appropriate metal salt by the poly(vinyl-alcohol)-host matrix itself, which takes place at modest temperatures compatible with most substrate materials. An obvious application for such nanocomposites is in optical elements whereby the surface plasmon resonance associated with the metal is the functional aspect of devices such as sensors or active optical elements. High Resolution Transmission Electron Microscopy was used to examine the dimensions, distribution, morphology and crystal structure of the silver and gold nanoparticles in detail allowing discussion of their suitability for these applications and what further optimisation may be necessary to adequately control their formation.Publisher PDFPeer reviewe

    Chemotactic Cues for NOTCH1-Dependent Leukemia

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    The NOTCH signaling pathway is a conserved signaling cascade that regulates many aspects of development and homeostasis in multiple organ systems. Aberrant activity of this signaling pathway is linked to the initiation and progression of several hematological malignancies, exemplified by T-cell acute lymphoblastic leukemia (T-ALL). Interestingly, frequent non-mutational activation of NOTCH1 signaling has recently been demonstrated in B-cell chronic lymphocytic leukemia (B-CLL), significantly extending the pathogenic significance of this pathway in B-CLL. Leukemia patients often present with high-blood cell counts, diffuse disease with infiltration of the bone marrow, secondary lymphoid organs, and diffusion to the central nervous system (CNS). Chemokines are chemotactic cytokines that regulate migration of cells between tissues and the positioning and interactions of cells within tissue. Homeostatic chemokines and their receptors have been implicated in regulating organ-specific infiltration, but may also directly and indirectly modulate tumor growth. Recently, oncogenic NOTCH1 has been shown to regulate infiltration of leukemic cells into the CNS hijacking the CC-chemokine ligand 19/CC-chemokine receptor 7 chemokine axis. In addition, a crucial role for the homing receptor axis CXC-chemokine ligand 12/CXC-chemokine receptor 4 has been demonstrated in leukemia maintenance and progression. Moreover, the CCL25/CCR9 axis has been implicated in the homing of leukemic cells into the gut, particularly in the presence of phosphatase and tensin homolog tumor suppressor loss. In this review, we summarize the latest developments regarding the role of NOTCH signaling in regulating the chemotactic microenvironmental cues involved in the generation and progression of T-ALL and compare these findings to B-CLL

    Clinical outcome of pediatric collagenous gastritis : case series and review of literature

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    Collagenous gastritis (CG) is characterized by patchy subepithelial collagen bands. Effective treatment and the clinical and histological outcome of CG in children are poorly defined. The aim of this study is to summarize the published literature on the clinical outcome and response to therapy of pediatric CG including two new cases. We performed a search in Pubmed, OVID for related terms; articles including management and clinical and/or endo-histologic follow up information were included and abstracted. Reported findings were pooled in a dedicated database including the corresponding data extracted from chart review in our patients with CG. Twenty-four patients were included (17 females) with a mean age of 11.7 years. The clinical presentation included iron deficiency anemia and dyspepsia. The reported duration of follow up (in 18 patients) ranged between 0.2-14 years. Despite most subjects presenting with anemia including one requiring blood transfusion, oral iron therapy was only documented in 12 patients. Other treatment modalities were antisecretory measures in 13 patients; proton pump inhibitors (12), or histamine-2 blockers (3), sucralfate (5), prednisolone (6), oral budesonide in 3 patients where one received it in fish oil and triple therapy (3). Three (13%) patients showed no clinical improvement despite therapy; conversely 19 out of 22 were reported with improved symptoms including 8 with complete symptom resolution. Spontaneous clinical resolution without antisecretory, anti-inflammatory or gastroprotective agents was noted in 5 patients (4 received only supplemental iron). Follow up endo-histopathologic data (17 patients) included persistent collagen band and stable Mononuclear cell infiltrate in 12 patients with histopathologic improvement in 5 patients. Neither collagen band thickness nor mono-nuclear cell infiltrate correlated with clinical course. Intestinal metaplasia and endocrine cell hyperplasia were reported (1) raising the concern of long term malignant transformation. In summary, CG in children is a chronic disease, typically with a variable clinical response and an indolent course that is distinct from the adult phenotype. Long term therapy usually inclused iron supplementation but cannot be standardized, given the chronicity of the disease, variability of response and potential for adverse events.peer-reviewe

    Biomarcatori di risposta in pazienti affetti da neoplasia del polmone metastatico in trattamento con immunoterapia

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    RAZIONALE Nonostante gli entusiasmanti risultati dell’impiego dell’immunoterapia nel trattamento delle neoplasie solide, solo il 30-40% dei pazienti presentato un beneficio a lungo termine mentre il restante 60-70% presenta progressione dopo i primi mesi di trattamento. La ricerca di biomarcatori in grado di selezionare i pazienti responsivi dai pazienti non responsivi rappresenta oggi la vera sfida dell’immuno-oncologia. In questo scenario si inserisce questo lavoro che ha l’obiettivo di investigare il ruolo prognostico/predittivo di alcuni biomarcatori. In particolare valuteremo il ruolo del pathway di IDO, il possibile ruolo del microbioma e il ruolo del fattore reumatoide. MATERIALI E METODI Sono stati arruolati pazienti affetti NSCLC in stadio IV seguiti presso Azienda Ospedaliera Sant’Andrea di Roma, Facoltà di Medicina e Psicologia Sapienza Università di Roma, da giugno 2016 a luglio 2017 Il trattamento con Nivolumab è stato somministrato a una dose standard di 3 mg / kg ogni 2 settimane fino a progressione di malattia o sviluppo di tossicità inaccettabile ANALISI CHINURENINE Abbiamo valutato i livelli sierici di trp, kyn e acido chinolinico con una cromatografia liquida modificata-metodo spettrometria di massa tandem (LC-MS / MS), ANALISI MICROBIOMA : Ogni campione di feci è stato raccolto e processato. Il DNA genomico è stato isolato dall'intero set di campioni, utilizzando il kit QIAamp DNA Stool Mini (Qiagen, Germania). La regione V1-V3 del locus RNA ribosomiale 16S (rRNA) è stata amplificata per la successiva fase di pirosequenziamento su un sequenziatore genoma 454-Junior (Roche 454 Life Sciences, Branford, USA). ANALISI DEL FATTORE REUMATOIDE In una coorte di pazienti, abbiamo determinato i livelli sierici di pre-trattamento di FR (kit ELISA in fase solida, valori superiori a 16 U / ml sono stati considerati positivi). RISULTATI ANALISI DELLE CHIMURENINE : La PFS era significativamente più lunga nei pazienti che presentavano valori inferiori di kyn / trp rispetto a pazienti con valori più elevati di kyn / trp (PFS mediana non raggiunta a 3 mesi; HR: 0,2; IC 95%: 0,06-0,62; p = 0,001). ANALISI MICROBIOMA : La meta-tassonomia del microbiota è stata descritta per i pazienti con NSCLC rispetto ai CTRL e ad ogni periodo di trattamento con Nivolumab. Nei pazienti affetti da NSCLC Rikenellaceae, Prevotella, Streptococco, Lactobacillus (p <0,05), Bacteroides plebeius, Oscillospira, Enterobacteriaceae (p <0,05) sono risultati aumentati rispetto ai CTRL. I non responder avevano Ruminococcus bromii, Dialister, Sutterella più abbondante dei pazienti responder alla terapia (p <0,05). Un po 'aumentato nei responder è apparso Akkermansia muciniphila, Bifidobacterium longum e Faecalibacterium prausnitzii (p <0,05). Propionibacterium acnes, Veillonella, Staphylococcus aureus, Peptostreptococcus apparivano significativamente sovraespressi, mentre il Clostridium perfringens era significativamente ridotto al C1 rispetto al punto temporale C3 del trattamento ANALISI DEL FATTORE REUMATOIDE : La progressione precoce della malattia è risultata significativamente più frequente nei pazienti con RF positiva (5/7, 71,4%) rispetto a quelli negativi (8/28, 28,6%, p <0,0001) CONCLUSIONE Il nostro studio suggerisce che i pazienti con elevato rapporto kyn/trp , un elevato livello plasmatico di FR sono caratterizzati da una prognosi estremamente infausta e da una resistenza primaria agli anti PD-1. Il nostro studio suggerisce inoltre che diversi profili di microbioma siano associati a rischio diverso di sviluppare cancro del polmone, ma anche come siano associati a differente risposta all’immunoterapia. I nostri dati si inseriscono nello scenario della medicina di precisione ed in particolare della immuno-oncologia di precisione in cui la ricerca del biomarcatore di risposta o resistenza è cruciale nel selezionare il paziente e ottimizzare le risorse ed i trattamenti disponibili

    Highly Permeable Fluorinated Polymer Nanocomposites for Plasmonic Hydrogen Sensing

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    Hydrogen (H2) sensors that can be produced en masse with cost-effective manufacturing tools are critical for enabling safety in the emerging hydrogen economy. The use of melt-processed nanocomposites in this context would allow the combination of the advantages of plasmonic hydrogen detection with polymer technology; an approach which is held back by the slow diffusion of H2 through the polymer matrix. Here, we show that the use of an amorphous fluorinated polymer, compounded with colloidal Pd nanoparticles prepared by highly scalable continuous flow synthesis, results in nanocomposites that display a high H2 diffusion coefficient in the order of 10-5 cm2 s-1. As a result, plasmonic optical hydrogen detection with melt-pressed fluorinated polymer nanocomposites is no longer limited by the diffusion of the H2 analyte to the Pd nanoparticle transducer elements, despite a thickness of up to 100 ÎĽm, thereby enabling response times as short as 2.5 s at 100 mbar (10 vol. %) H2. Evidently, plasmonic sensors with a fast response time can be fabricated with thick, melt-processed nanocomposites, which paves the way for a new generation of robust H2 sensors

    Identification of differentiating metabolic pathways between infant gut microbiome populations reveals depletion of function-level adaptation to human milk in the finnish population

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    ABSTRACT A variety of autoimmune and allergy events are becoming increasingly common, especially in Western countries. Some pieces of research link such conditions with the composition of microbiota during infancy. In this period, the predominant form of nutrition for gut microbiota is oligosaccharides from human milk (HMO). A number of gut-colonizing strains, such as Bifidobacterium and Bacteroides, are able to utilize HMO, but only some Bifidobacterium strains have evolved to digest the specific composition of human oligosaccharides. Differences in the proportions of the two genera that are able to utilize HMO have already been associated with the frequency of allergies and autoimmune diseases in the Finnish and the Russian populations. Our results show that differences in terms of the taxonomic annotation do not explain the reason for the differences in the Bifidobacterium/Bacteroides ratio between the Finnish and the Russian populations. In this paper, we present the results of function-level analysis. Unlike the typical workflow for gene abundance analysis, BiomeScout technology explains the differences in the Bifidobacterium/Bacteroides ratio. Our research shows the differences in the abundances of the two enzymes that are crucial for the utilization of short type 1 oligosaccharides. IMPORTANCE Knowing the limitations of taxonomy-based research, there is an emerging need for the development of higher-resolution techniques. The significance of this research is demonstrated by the novel method used for the analysis of function-level metagenomes. BiomeScout—the presented technology—utilizes proprietary algorithms for the detection of differences between functionalities present in metagenomic samples
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