190 research outputs found

    Light scattering as an easy tool to measure vesicles weight concentration

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    Over the last few decades, liposomes have emerged as promising drug delivery systems and effective membrane models for studying biophysical and biological processes. For all applications, knowing their concentration after preparation is crucial. Thus, the development of methods for easily controlling vesicles concentration would be of great utility. A new assay is presented here, based on a suitable analysis of light scattering intensity from liposome dispersions. The method, tested for extrusion preparations, is precise, easy, fast, non-destructive and uses a tiny amount of sample. Furthermore, the scattering intensity can be measured indifferently at different angles, or even by using the elastic band obtained from a standard spectrofluorimeter. To validate the method, the measured concentrations of vesicles of different matrix compositions and sizes, measured by light scattering with different angles and instruments, were compared to the data obtained by the standard Stewart assay. Consistent results were obtained. The light scattering assay is based on the assessment of the mass fraction lost in the preparation, and can be applied for methods such as extrusion, homogenization, French press and other microfluidic procedures

    Il volontariato religioso nell'ordinamento giuridico italiano (l'incompiuta integrazione tra societ\ue0 civile e societ\ue0 religiosa)

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    SOMMARIO: 1. Identikit d’una fattispecie “ibrida” sconosciuta al diritto positivo italiano - 2. L’assenza di una normativa ad hoc pattizia: alcune ragioni ipotizzabili – 3. Le fonti unilaterali: dall’indifferenza per il fenomeno della Legge-quadro del ’91 all’indirizzo restrittivo delle Linee-guida del 2010 - 4. Il problema a monte - 5. Conclusioni

    Duodenal Leiomyosarcoma Mimicking a Pancreatic Pseudocyst

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    A case of duodenal leiomyosarcoma presenting as a cystic mass is reported. Amylase, tumour markers levels in the cyst fluid and radiological findings suggested an inflammatory pancreatic pseudocyst. Exploratory laparotomy and frozen section examination showed a smooth muscle tumour of the duodenum. Pancreatoduodenectomy with pylorus-preser vation was performed and the patient remained symptom-free at 8 months follow-up

    Large-scale lateral saturated soil hydraulic conductivity as a metric for the connectivity of subsurface flow paths at hillslope scale

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    Lateral saturated soil hydraulic conductivity, Ks,l, is the soil property governing subsurface water transfer in hillslopes, and the key parameter in many numerical models simulating hydrological processes at the hillslope and catchment scales. Likewise, the hydrological connectivity of the lateral flow paths plays a significant role in determining the rate of the subsurface flow at various spatial scales. This study investigates the relationship between Ks,l and hydrological connectivity at the hillslope spatial scale. Ks,l was determined by the subsurface flow rates intercepted by drains and water table depths observed in a well network. The hydrological connectivity was evaluated by the synchronicity among water table peaks, and between these and the peaks of the drained flow. Rainfall and soil moisture were used to investigate the influence of the transient hydrological soil condition on connectivity and Ks,l. As the synchronicity of the water table response between wells increased, the lag times between the peaks of water levels and those of the drained subsurface flow decreased. Moreover, the most synchronic water table rises determined the highest drainage rates. The relationships between Ks,l and water table depths were highly non-linear, with a sharp increase in the values for water table levels close to the soil surface. Estimated Ks,l values for the full saturated soil were in the order of thousands of mm h−1, suggesting the activation of macropores in the root zone. The Ks,l values determined at the peak of the drainage events were correlated with the indicators of synchronicity. The sum of cumulative rainfall and antecedent soil moisture was correlated with the connectivity indicators and Ks,l. We suggest that, for simulating realistic processes at the hillslope scale, the hydrological connectivity could be implicitly considered in hydrological modelling through an evaluation of Ks,l at the same spatial scale

    A remote sensing and modeling integrated approach for constructing continuous time series of daily actual evapotranspiration

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    Satellite remote sensing-based surface energy balance (SEB) techniques have emerged as useful tools for quantifying spatialized actual evapotranspiration at various temporal and spatial scales. However, discontinuous data acquisitions and/or gaps in image acquisition due to cloud cover can limit the applicability of satellite remote sensing (RS) in agriculture water management where continuous time series of daily crop actual evapotranspiration (ETc act) are more valued. The aim of the research is to construct continuous time series of daily ETc act starting from temporal estimates of actual evapotranspiration obtained by SEB modelling (ETa eb) on Landsat-TM images. SEBAL model was integrated with the FAO 56 evaporation model, RS-retrieved vegetative biomass dynamics (by NDVI) and on-field measurements of soil moisture and potential evapotranspiration. The procedure was validated by an eddy covariance tower on a vineyard with partial soil coverage in the south of Sardinia Island, Italy. The integrated modeling approach showed a good reproduction of the time series dynamics of observed ETc act (R2 =0.71, MAE=0.54 mm d-1, RMSE=0.73 mm d-1). A daily and a cumulative monthly temporal analysis showed the importance of integrating parameters that capture changes in the soil-plant-atmosphere (SPA) continuum between Landsat acquisitions. The comparison with daily ETc act obtained by the referenced ET fraction (ETrF) method that considers only weather variability (by ETo) confirmed the lead of the proposed procedure in the spring/early summer periods when vegetation biomass changes and soil water evaporation have a significant weight in the ET process. The applied modelling approach was also robust in constructing the missing ETc act data under scenarios of limited cloud-free Landsat acquisitions. The presented integrated approach has a great potential for the near real time monitoring and scheduling of irrigation practices. Further testing of this approach with diverse dataset and the integration with the soil water modeling is to be analyzed in future work

    Improvement of resveratrol permeation through sublingual mucosa: Chemical permeation enhancers versus spray drying technique to obtain fast-disintegrating sublingual mini-tablets

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    Resveratrol (RSV) is a natural polyphenol with several interesting broad-spectrum pharmacological properties. However, it is characterized by poor oral bioavailability, extensive first-pass effect metabolism and low stability. Indeed, RSV could benefit from the advantage of the sublingual route of administration. In this view, RSV attitudes to crossing the porcine sublingual mucosa were evaluated and promoted both by six different chemical permeation enhancers (CPEs) as well as by preparing four innovative fast-disintegrating sublingual mini-tablets by spray drying followed by direct compression. Since RSV by itself exhibits a low permeation aptitude, this could be significantly enhanced by the use of CPEs as well as by embedding RSV in a spray-dried powder to be compressed in order to prepare fast-disintegrating mini-tablets. The most promising observed CPEs (menthol, lysine and urea) were then inserted into the most promising spray-dried excipients’ compositions (RSV-B and RSV-C), thus preparing CPE-loaded mini-tablets. However, this procedure leads to unsatisfactory results which preclude the possibility of merging the two proposed approaches. Finally, the best spray-dried composition (RSV-B) was further evaluated by SEM, FTIR, XRD and disintegration as well as dissolution behavior to prove its effectiveness as a sublingual fast-disintegrating formulation

    Diagnostic accuracy of fecal calprotectin assay in distinguishing organic causes of chronic diarrhea from irritable bowel syndrome: a prospective study in adults and children

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    Fecal calprotectin (FC) has been proposed as a marker of inflammatory bowel disease (IBD), but few studies have evaluated its usefulness in patients with chronic diarrhea of various causes. We evaluated the diagnostic accuracy of a FC assay in identifying "organic" causes of chronic diarrhea in consecutive adults and children

    Antiendomysium antibodies assay in the culture medium of intestinal mucosa: an accurate method for celiac disease diagnosis

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    Background Celiac disease (CD) diagnosis is becoming more difficult as patients with no intestinal histology lesions may also be suffering from CD. Aim To evaluate the diagnostic accuracy of antiendomysium (EmA) assay in the culture medium of intestinal biopsies for CD diagnosis. Patients and methods The clinical charts of 418 patients with CD and 705 non-CD controls who had all undergone EmA assay in the culture medium were reviewed. Results EmA assay in the culture medium had a higher sensitivity (98 vs. 80%) and specificity (99 vs. 95%) than serum EmA/antibodies to tissue transglutaminase (anti-tTG) assay. All patients with CD who were tested as false-negatives for serum EmA and/or anti-tTG (32 adults and 39 children) carried the human leukocyte antigen alleles associated to CD. Furthermore, during the follow-up, four patients with negative-serum EmA/anti-tTG, normal villi architecture, and positive-EmAs in the culture medium, developed villous atrophy and underwent gluten-free diet with consequent resolution of the symptoms and complete intestinal histology recovery. Conclusion EmA assay in the culture medium should be included in the diagnostic criteria for CD diagnosis in 'seronegative' patients. Eur J Gastroenterol Hepatol 23:1018-1023 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins
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