340 research outputs found
Proteomic insights on the metabolism in inflammatory bowel disease
Inflammatory bowel diseases (IBD) are chronic and relapsing inflammatory conditions of the gut that include Crohn's disease and ulcerative colitis. The pathogenesis of IBD is not completely unraveled, IBD are multi-factorial diseases with reported alterations in the gut microbiota, activation of different immune cell types, changes in the vascular endothelium, and alterations in the tight junctions\u2019 structure of the colonic epithelial cells. Proteomics represents a useful tool to enhance our biological understanding and to discover biomarkers in blood and intestinal specimens. It is expected to provide reproducible and quantitative data that can support clinical assessments and help clinicians in the diagnosis and treatment of IBD. Sometimes a differential diagnosis of Crohn's disease and ulcerative colitis and the prediction of treatment response can be deducted by finding meaningful biomarkers. Although some non-invasive biomarkers have been described, none can be considered as the \u201cgold standard\u201d for IBD diagnosis, disease activity and therapy outcome. For these reason new studies have proposed an \u201cIBD signature\u201d, which consists in a panel of biomarkers used to assess IBD. The above described approach characterizes \u201comics\u201d and in this review we will focus on proteomics
Silicon Tetrachloride as innovative working fluid for high temperature Rankine cycles: Thermal Stability, material compatibility, and energy analysis
Silicon Tetrachloride (SiCl4) is proposed as a new potential working fluid for high-temperature Rankine Cycles. The capability to overcome the actual thermal stability limit of fluids commercially employed in the state-of-theart Organic Rankine Cycles (ORC) is demonstrated by static thermal stability and material compatibility tests. Experimental static test proves its thermo-chemical stability with a conventional stainless-steel alloy (AISI 316L) up to 650 degrees C. A preliminary material compatibility analysis performed with optical microscope on the AISI 316L cylinder, after exposure of 300 h to SiCl4 at temperature higher than 550 degrees C, confirms the potentiality of this fluid when coupled with high-grade heat sources. A thermodynamic analysis has been carried out accounting for the effect of operating conditions on the axial turbine efficiency. A comparison with fluids adopted in medium-high temperature ORCs is performed, evidencing that the proposed fluid could achieve more than + 10 % points as thermal efficiency gain compared to any commercial solutions when coupled with high-temperature sources such as solar, biomass, waste heat from industrial processes and prime movers. A 2 MW SiCl4 cycle operating fullelectric at 550 degrees C reaches a thermal efficiency of 38 %, exceeding values attainable by any other working fluid under similar conditions and power size
Diversity of human skeletal muscle in health and disease: contribution of proteomics
Muscle represents a large fraction of the human body mass. It is an extremely heterogeneous tissue featuring in its contractile structure various proportions of heavy- and light-chain slow type 1 and fast types 2A and 2X myosins, actins, tropomyosins, and troponin complexes as well as metabolic proteins (enzymes and most of the players of the so-called excitation-transcription coupling). Muscle is characterized by wide plasticity, i.e. capacity to adjust size and functional properties in response to endogenous and exogenous influences. Over the last decade, proteomics has become a crucial technique for the assessment of muscle at the molecular level and the investigation of its functional changes. Advantages and shortcomings of recent techniques for muscle proteome analysis are discussed. Data from differential proteomics applied to healthy individuals in normal and unusual environments (hypoxia and cold), in exercise, immobilization, aging and to patients with neuromuscular hereditary disorders (NMDs), inclusion body myositis and insulin resistance are summarized, critically discussed and, when required, compared with homologous data from pertinent animal models. The advantages as well as the limits of proteomics in view of the identification of new biomarkers are evaluate
Le segregazioni nei forgiati: esempi di rotture e possibili interventi per limitarne la presenza
I forgiati prodotti in acciaio al manganese presentano un numero di scarti per formazione di microcriccherilevabili con i controlli ad ultrasuoni nella fase finale del ciclo produttivo sopra alla media degli scarti tipicidelle famiglie di acciai da bonifica destinati alla realizzazione di pezzi forgiati. Tale anomalia è stataanalizzata nel presente lavoro, innanzitutto dal punto di vista microstrutturale, evidenziando come la causa ditali difetti sia riconducibile alla localizzazione di carbonio e manganese nelle zone che andranno incontro arottura in corrispondenza delle quali vi è una spiccata tendenza alla formazione di strutture fragili di tipobainitico o martensitico. Si è proceduto quindi alla verifica della possibilità di eliminare lo stato segregativocon trattamenti di omogeneizzazione effettuati alle massime temperature compatibili con i forni industriali(1320°C) senza però ottenere la totale eliminazione delle differenze locali di composizione chimica, condizionequesta che non elimina il rischio di ulteriore formazione di zone segregate durante i trattamenti dinormalizzazione o di tempra che vengono richiesti nelle specifiche tecniche per i forgiati in acciaio almanganese. Le prove effettuate, confermate anche da cicli termici appositamente realizzati in forni dilaboratorio, sottolineano l’importanza di produrre lingotti in acciaio al manganese con segregazioni più checontrollate per limitare i casi di non conformità dei pezzi forgiati prodotti in acciaio al manganese
On the aging of a hyper-eutectic Zn-Al alloy
Zinc alloys are widely used in different fields, like handles and locking, fashion and design as well as automotiveor electronics, thanks to their good mechanical and technological properties combined with low cost and easyformability. A limit to a wider use of these alloys is the aging phenomenon that causes a drop in their mechanicalproperties in time. In order to improve their use in competition with more expensive copper and aluminum alloys,in the last years the research has been addressed to develop new Zn-alloys compositions. One of these newalloys, containing 15 wt% of Al and 1 wt% of Cu, appears to be suitable for both foundry and plastic deformationforming processes, as resulted from preliminary laboratory and industrial trials. Being a newly developed alloy,many properties have still to be investigated, to better understand the effective potentiality for proper industrialapplications. In this paper the ageing behavior of die-cast Zn-15Al-1Cu hyper-eutectic alloy was studied by meansof tensile tests and microstructural analyses. It was demonstrated that the alloy suffers from a drop in mechanicalproperties, in particular at the very beginning of soaking at high temperature. A first analysis of the microstructureby optical and scanning electron microscope was not able to fully point out the causes of the aging phenomenon
Optimization of heat treatment parameters for additive manufacturing and gravity casting AlSi10Mg alloy
Additive manufacturing of metals is a production process developed in the last few years to realize net shape components with complex geometry and high performance. AlSi10Mg is one of the most widely used aluminium alloys, both in this field and in conventional foundry processes, for its significant mechanical properties combined with good corrosion resistance. In this paper the effect of heat treatment on AlSi10Mg alloy was investigated. Solution and ageing treatments were carried out with different temperatures and times on samples obtained by direct metal laser sintering and gravity casting in order to compare their performance. Microstructural analyses and hardness tests were performed to investigate the effectiveness of the heat treatment. The results were correlated to the sample microstructure and porosity, analysed by means of optical microscopy and density measurements. It was found that, in the additive manufactured samples, the heat treatment can reduce significantly the performance of the alloy also because of the increase of porosity due to entrapped gas during the deposition technique and that the higher the solution temperature the higher the increase of such defects. A so remarkable effect was not found in the conventional cast alloy
Effect of ultrasound treatment on Cu-Zn alloys
The application of power ultrasound to liquid and solidifying alloys is known to allow the formation of a nondendriticand fine microstructure suitable for semi-solid feedstock production. In literature several papersreport results about low melting point alloys but very limited data are available on Cu-base alloys.The aim of this paper is, therefore, to evaluate the effect of ultrasonic waves applied to Cu alloys duringsolidification in order to obtain a globular microstructure.Metallographic analyses showed the effectiveness of this technique in breaking the forming dendrites, givingrise to an almost globular structure, suitable for being used in semi-solid processing.The differences in microstructure morphology and phases composition resulted to affect the corrosionresistance of the analysed samples, in particular the semi-solid ones showed improved performance as aconsequence of the homogenizing effect induced by the ultrasound treatment
Endoplasmic Reticulum Associated Aminopeptidase 2 (ERAP2) is released in the secretome of activated MDMs and reduces in vitro HIV-1 infection
Background: Haplotype-specific alternative splicing of the endoplasmic reticulum (ER) aminopeptidase type 2 (ERAP2) gene results in either full-length (FL, haplotype A) or alternatively spliced (AS, haplotype B) mRNA. HapA/HapA homozygous (HomoA) subjects show a reduced susceptibility to HIV-1 infection, probably secondary to the modulation of the antigen processing/presenting machinery. ERAP1 was recently shown to be secreted from the plasma membrane in response to activation; we investigated whether ERAP2 can be released as well and if the secreted form of this enzyme retains its antiviral function. Methods: Human monocyte derived macrophages (MDMs) were differentiated from peripheral blood mononuclear cells (PBMCs) isolated from 6 HomoA healthy controls and stimulated with IFN\u3b3 and LPS. ERAP2-FL secretion was evaluated by mass spectrometry. PBMCs (14 HomoA and 16 HomoB) and CD8-depleted PBMCs (CD8-PBMCs) (4 HomoA and 4 HomoB) were in vitro HIV-infected in the absence/presence of recombinant human ERAP2-FL (rhERAP2) protein; p24 viral antigen quantification was used to assess viral replication. IFN\u3b3 and CD69 mRNA expression, as well as the percentage of perforin-producing CD8+ T Lymphocytes, were analyzed 3 and 7-days post in vitro HIV-1-infection, respectively. The effect of rhERAP2 addition in cell cultures on T cell apoptosis, proliferation, activation, and maturation was evaluated as well on 24 h-stimulated PBMCs. Results: ERAP2 can be secreted from human MDMs in response to IFN\u3b3/LPS stimulation. Notably, the addition of rhERAP2 to PBMC and CD8-PBMC cultures resulted in the reduction of viral replication, though these differences were statistically significant only in PBMCs (p < 0.05 in both HomoA and HomoB). This protective effect was associated with an increase in IFN\u3b3 and CD69 mRNA expression and in the percentage of perforin-expressing CD107+CD8+ cells. RhERAP2 addition also resulted in an increase in CD8+ activated lymphocyte (CD25+HLA-DRII+) and Effector Memory/Terminally differentiated CD8+ T cells ratio. Conclusions: This is the first report providing evidence for the release of ERAP2 in the secretome of immunocompetent cells. Data herein also indicate that exogenous ERAP2-FL exerts its protective function against HIV-1 infection, even in HomoB subjects who do not genetically produce it. Presumably, this defensive extracellular feature is only partially dependent on immune system modulation
Performance of a series of novel N-substituted acrylamides in capillary electrophoresis of DNA fragments
DNA separations by capillaryelectrophoresis in viscous solutions of novel polymers, made with \u3a9-hydroxyl, N-substitutedacrylamides (notably N-acryloyl amino propanol, AAP and N-acryloyl amino butanol, AAB) are evaluated. Whereas in standard poly(acrylamide), at 6% concentration, the theoretical plate number (N) does not exceed 500 000, in 6% poly(AAP) N reaches 922 000 and in 6% poly(AAB) N values as high as 1 200 000 are obtained. Also, copolymers of AAP and AAB give N values in excess of 1 million plates. The two novel monomers (AAP and AAB) remain extremely stable during alkaline hydrolysis and display very good hydrophilicity, while being devoid of the noxious habit of auto-polymerization and auto-reticulation exhibited by the previous monomer of this series (N-acryloyl amino ethoxy ethanol). The reasons for such a good performance of the \u3a9-substituted acrylamide derivatives could be that their polymers may form hydrogen bonds via their distal -OH group during DNA separation
Sphingolipid serum profiling in vitamin D deficient and dyslipidemic obese dimorphic adults
Recent studies on Saudi Arabians indicate a prevalence of dyslipidemia and vitamin D deficiency (25(OH)D) in both normal weight and obese subjects. In the present study the sphingolipid pattern was investigated in 23 normolipidemic normal weight (NW), 46 vitamin D deficient dyslipidemic normal weight (-vitDNW) and 60 vitamin D deficient dyslipidemic obese (-vitDO) men and women by HPTLC-primuline profiling and LC-MS analyses. Results indicate higher levels of total ceramide (Cer) and dihydroceramide (dhCers C18\u201322) and lower levels of total sphingomyelins (SMs) and dihydrosphingomyelin (dhSM) not only in -vitDO subjects compared to NW, but also in \u2013vitDNW individuals. A dependency on body mass index (BMI) was observed analyzing specific Cer acyl chains levels. Lower levels of C20 and 24 were observed in men and C24.2 in women, respectively. Furthermore, LC-MS analyses display dimorphic changes in NW, -vitDNW and \u2013vitDO subjects. In conclusion, LC-MS data identify the independency of the axis high Cers, dhCers and SMs from obesity per se. Furthermore, it indicates that long chains Cers levels are specific target of weight gain and that circulating Cer and SM levels are linked to sexual dimorphism status and can contribute to predict obese related co-morbidities in men and women
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