194 research outputs found

    Modelling sorption thermodynamics and mass transport of n-hexane in a propylene-ethylene elastomer

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    Optimization of post polymerization processes of polyolefin elastomers (POE) involving solvents is of considerable industrial interest. To this aim, experimental determination and theoretical interpretation of the thermodynamics and mass transport properties of POE-solvent mixtures is relevant. Sorption behavior of n-hexane vapor in a commercial propylene-ethylene elastomer (V8880 Vistamaxx™ from ExxonMobil, Machelen, Belgium) is addressed here, determining experimentally the sorption isotherms at temperatures ranging from 115 to 140 °C and pressure values of n-hexane vapor up to 1 atm. Sorption isotherms have been interpreted using a Non Random Lattice Fluid (NRLF) Equation of State model retrieving, from data fitting, the value of the binary interaction parameter for the n-hexane/V8880 system. Both the cases of temperature-independent and of temperature-dependent binary interaction parameter have been considered. Sorption kinetics was also investigated at different pressures and has been interpreted using a Fick’s model determining values of the mutual diffusivity as a function of temperature and of n-hexane/V8880 mixture composition. From these values, n-hexane intra-diffusion coefficient has been calculated interpreting its dependence on mixture concentration and temperature by a semi-empiric model based on free volume arguments

    Relation Between Wound Complication and Lymphocele After Kidney Transplantation: A Monocentric Study

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    Introduction: Wound complication frequently arises after kidney transplantation and its risk factors are well known. In a previous paper we analyzed these factors, and in this new retrospective study we evaluate the influence of lymphocele in the development of wound complications. Patients and methods: From January 2000 to December 2018, 731 consecutive kidney transplants have been performed in our center. We have analyzed the incidence of wound complication and lymphocele and their risk factors. Results: Out of 731 kidney transplants, we have observed wound complications in 115 patients (15.7%) and lymphocele in 158 patients (21.7%). Of these, 70 patients developed both complications (9.5%), but 6 patients have been excluded because they were in therapy with mammalian target of rapamycin inhibitors. Twenty-nine patients (45.3%) presented a first level and 35 patients (54.7%) showed second level wound complications. Lymphocele was the only present factor in just 3 cases (4.6%). The other patients showed diabetes in 28 cases (43.7%), overweight/obesity in 38 (59.3%), delayed graft function in 17 (26.5%), and 60 years or more in 38 (57.8%). The association has been found in 30 out 64 patients treated with tacrolimus (46.8%) and in 34 with cyclosporine (53.1%); 40 patients did not receive muscular layer's reconstruction (62.5%). Conclusion: Our experience shows that lymphocele alone is not a predisposing factor for wound dehiscence after kidney transplantation, and they often coexist because they share the same risk factors, the most important being obesity, diabetes and delayed graft function, older age, and surgical techniques. No relation has been observed with calcineurin inhibitor therapy

    Marked pseudoepitheliomatous hyperplasia secondary to a red-pigmented tattoo. a case report

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    Tattooing is gaining increasing popularity in developed countries in recent years. Adverse cutaneous reactions of many different types against coumponds in tattoo inks are being reported more and more often in medical literature,especially against red-pigmented tattoo. Delayed immune-mediated reactions can manifest in several ways and different histological patterns have been described This article is protected by copyright. All rights reserved

    Reverse Micelle Strategy for the Synthesis of MnOx-TiO2Active Catalysts for NH3-Selective Catalytic Reduction of NOxat Both Low Temperature and Low Mn Content

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    MnOx-TiO2catalysts (0, 1, 5, and 10 wt % Mn nominal content) for NH3-SCR (selective catalytic reduction) of NOxhave been synthesized by the reverse micelle-assisted sol-gel procedure, with the aim of improving the dispersion of the active phase, usually poor when obtained by other synthesis methods (e.g., impregnation) and thereby lowering its amount. For comparison, a sample at nominal 10 wt % Mn was obtained by impregnation of the (undoped) TiO2sample. The catalysts were characterized by using an integrated multitechnique approach, encompassing X-ray diffraction followed by Rietveld refinement, micro-Raman spectroscopy, N2isotherm measurement at −196 °C, energy-dispersive X-ray analysis, diffuse reflectance UV-vis spectroscopy, temperature-programmed reduction technique, and X-ray photoelectron spectroscopy. The obtained results prove that the reverse micelle sol-gel approach allowed for enhancing the catalytic activity, in that the catalysts were active in a broad temperature range at a substantially low Mn loading, as compared to the impregnated catalyst. Particularly, the 5 wt % Mn catalyst showed the best NH3-SCR activity in terms of both NOxconversion (ca. 90%) and the amount of produced N2O (ca. 50 ppm) in the 200-250 °C temperature range

    Fatal interstitial lung disease associated with oral erlotinib therapy for lung cancer

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    <p>Abstract</p> <p>Background</p> <p>Erlotinib is a Human Epidermal Growth Factor Receptor Type 1/tyrosine kinase (EGFR) inhibitor which is used for non-small-cell lung cancer treatment. Despite that erlotinib is considered to have a favorable safety profile, adverse events such as interstitial lung disease (ILD) were reported in pivotal studies. The authors report the first histologically confirmed case of fatal ILD associated with erlotinib therapy.</p> <p>Case Presentation</p> <p>The medical record of a patient who developed fatal ILD after receiving erlotinib treatment was reviewed to identify the cause of death and other factors potentially contributive to this adverse outcome. A 55-year-old smoker with no evidence of pre-existing interstitial disease developed bilateral ILD and respiratory failure which could be explained only as a toxicity of erlotinib. He had a history of stage IV left upper lobe squamous-cell carcinoma for which he had received three successive regimens of chemotherapy (ifosfamide plus gemcitabine, docetaxel, mitomycin plus navelbine), followed five months later by erlotinib. At initiation of erlotinib treatment there were no radiological signs suggestive of ILD disease or apparent clinical signs of respiratory distress. While the patient completed two months with erlotinib therapy he developed bilateral interstitial infiltrates; despite discontinuation of erlotinib he was admitted with respiratory failure two weeks later. Diagnostic work up for other causes of pneumonitis including infectious diseases, congestive cardiac failure and pulmonary infraction was negative. Empiric treatment with oxygene, corticosteroids and later with cyclophosphamide was ineffective and the patient progressively deteriorated and died. The clinical and post-mortem examination findings are presented and the possible association relationship between erlotinib induced ILD and previous chemotherapy is discussed.</p> <p>Conclusion</p> <p>Physicians should be alert to the fact that erlotinib related ILD, although infrequent, is potential fatal. The association between selective EGFR-inhibitors and ILD should be further investigated.</p

    The RING network: improvements to a GPS velocity field in the central Mediterranean

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    Since 2004, a continuous Global Positioning System (GPS) network has been operated by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) to investigate active tectonic processes in Italy and the surrounding regions, which are still largely debated. This important infrastructure is known as Rete Integrata Nazionale GPS (RING) network, and it consists of about 130 stations that are deployed all over Italy. The development and realization of a stable GPS monumentation, its integration with seismological instruments, and the choice of both satellite and internet data transmission, make this network one of the most innovative and reliable CGPS networks in the world. The technologically advanced development of the RING network has been accompanied by the development of different data processing strategies, which are mainly dependent on the use of different GPS analysis software. The different software-related solutions are here compared at different scales for this large network, and the consistency is evaluated and quantified within an RMS value of 0.3 mm/yr

    A Kir6.2 mutation causing severe functional effects in vitro produces neonatal diabetes without the expected neurological complications

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    AIMS/HYPOTHESIS: Heterozygous activating mutations in the pancreatic ATP-sensitive K+ channel cause permanent neonatal diabetes mellitus (PNDM). This results from a decrease in the ability of ATP to close the channel, which thereby suppresses insulin secretion. PNDM mutations that cause a severe reduction in ATP inhibition may produce additional symptoms such as developmental delay and epilepsy. We identified a heterozygous mutation (L164P) in the pore-forming (Kir6.2) subunit of the channel in three unrelated patients and examined its functional effects. METHODS: The patients (currently aged 2, 8 and 20 years) developed diabetes shortly after birth. The two younger patients attempted transfer to sulfonylurea therapy but were unsuccessful (up to 1.1 mg kg(-1) day(-1)). They remain insulin dependent. None of the patients displayed neurological symptoms. Functional properties of wild-type and mutant channels were examined by electrophysiology in Xenopus oocytes. RESULTS: Heterozygous (het) and homozygous L164P K(ATP) channels showed a marked reduction in channel inhibition by ATP. Consistent with its predicted location within the pore, L164P enhanced the channel open state, which explains the reduction in ATP sensitivity. HetL164P currents exhibited greatly increased whole-cell currents that were unaffected by sulfonylureas. This explains the inability of sulfonylureas to ameliorate the diabetes of affected patients. CONCLUSIONS/INTERPRETATION: Our results provide the first demonstration that mutations such as L164P, which produce a severe reduction in ATP sensitivity, do not inevitably cause developmental delay or neurological problems. However, the neonatal diabetes of these patients is unresponsive to sulfonylurea therapy. Functional analysis of PNDM mutations can predict the sulfonylurea response

    Effect of TREM-1 blockade and single nucleotide variants in experimental renal injury and kidney transplantation

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    Renal ischemia reperfusion (IR)-injury induces activation of innate immune response which sustains renal injury and contributes to the development of delayed graft function (DGF). Triggering receptor expressed on myeloid cells-1 (TREM-1) is a pro-inflammatory evolutionary conserved pattern recognition receptor expressed on a variety of innate immune cells. TREM-1 expression increases following acute and chronic renal injury. However, the function of TREM-1 in renal IR is still unclear. Here, we investigated expression and function of TREM-1 in a murine model of renal IR using different TREM-1 inhibitors: LP17, LR12 and TREM-1 fusion protein. In a human study, we analyzed the association of non-synonymous single nucleotide variants in the TREM1 gene in a cohort comprising 1263 matching donors and recipients with post-transplant outcomes, including DGF. Our findings demonstrated that, following murine IR, renal TREM-1 expression increased due to the influx of Trem1 mRNA expressing cells detected by in situ hybridization. However, TREM-1 interventions by means of LP17, LR12 and TREM-1 fusion protein did not ameliorate IR-induced injury. In the human renal transplant cohort, donor and recipient TREM1 gene variant p. Thr25Ser was not associated with DGF, nor with biopsy-proven rejection or death-censored graft failure. We conclude that TREM-1 does not play a major role during experimental renal IR and after kidney transplantation
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