Emulsion stability during gastrointestinal conditions effects lipid digestion kinetics.

Oil-in-water emulsions were prepared with carrot- or tomato-enriched olive oil (5%w/v) and stabilized with Tween80 or sucrose esters (0.5%w/v) with different hydrophilic-lipophilic balance (8; 11 or 16). All emulsions had similar initial oil droplet sizes and were submitted to simulated gastrointestinal conditions using a kinetic digestion procedure. Sucrose esters induced an unstable system after gastric conditions leading to coalesced oil droplets, while Tween80 emulsions remained stable. Emulsion particle sizes at the end of the gastric phase were directly associated with the lipolysis kinetics during the intestinal phase. Moreover, a direct relationship was observed between lipolysis and carotenoid micellarisation for all emulsions, and depended mainly on the surfactant structure used. Tween80 emulsions led to a higher lipolysis extent (53-57%) and carotenoid bioaccessibility (17-42%) compared to sucrose ester emulsions (33-52% and 9-27%, respectively). These findings show the importance of the emulsifier structure and emulsion stability during gastrointestinal conditions in modulating lipolysis kinetics.

In situ Raman mapping of art objects.

Raman spectroscopy has grown to be one of the techniques of interest for the investigation of art objects. The approach has several advantageous properties, and the non-destructive character of the technique allowed it to be used for in situ investigations. However, compared with laboratory approaches, it would be useful to take advantage of the small spectral footprint of the technique, and use Raman spectroscopy to study the spatial distribution of different compounds. In this work, an in situ Raman mapping system is developed to be able to relate chemical information with its spatial distribution. Challenges for the development are discussed, including the need for stable positioning and proper data treatment. To avoid focusing problems, nineteenth century porcelain cards are used to test the system. This work focuses mainly on the post-processing of the large dataset which consists of four steps: (i) importing the data into the software; (ii) visualization of the dataset; (iii) extraction of the variables; and (iv) creation of a Raman image. It is shown that despite the challenging task of the development of the full in situ Raman mapping system, the first steps are very promising.This article is part of the themed issue 'Raman spectroscopy in art and archaeology'.

Intrascrotal Collection in an Acute Pancreatitis: A Case Report and Review of the Literature.

Context. An inguinoscrotal swelling occurring during an acute pancreatitis is very rare. Case Report. We report a case of right inguinoscrotal swelling appearing in connection with an interstitial edematous acute pancreatitis. We have noticed a spontaneous complete reduction of the right inguinoscrotal swelling after 10 days. Conclusion. The management of a scrotal swelling should be the least invasive possible method but also the most complete possible method to avoid unnecessary interventions. The exclusion of a pathology that could affect the vital prognosis of the testis remains the absolute priority. An acute scrotum swelling must be carried out by the clinical management by a professional and must be completed with an ultrasonography of the scrotum. Despite all that, if the original etiology of the acute scrotum remains unknown, an abdominopelvic CT scan could provide more details and so could offer a different diagnosis of exclusion, different from the diagnosis of acute idiopathic scrotal edema (AISE). This rare complication of acute pancreatitis reported could be mistaken for a more common pathology. If that complication is identified, it will not require a surgical intervention if there is a correct management of the acute pancreatitis which could justify a broader CT scan.

Effect of previous vaccination with pneumococcal conjugate vaccine on pneumococcal polysaccharide vaccine antibody responses.

During the past 10 years, pneumococcal conjugate vaccine (PCV) has become part of the standard childhood vaccination programme. This may impact upon the diagnosis of polysaccharide antibody deficiency by measurement of anti-polysaccharide immunoglobulin (Ig)G after immunization with unconjugated pneumococcal polysaccharide vaccine (PPV). Indeed, contrary to PPV, PCV induces a T-dependent, more pronounced memory response. The antibody response to PPV was studied retrospectively in patients referred for suspected humoral immunodeficiency. The study population was divided into four subgroups based on age (2-5 years versus ≥ 10 years) and time tested (1998-2005 versus 2010-12). Only 2-5-year-old children tested in 2010-12 had been vaccinated with PCV prior to PPV. The PCV primed group showed higher antibody responses for PCV-PPV shared serotypes 4 and 18C than the unprimed groups. To a lesser extent, this was also found for non-PCV serotype 9N, but not for non-PCV serotypes 19A and 8. Furthermore, PCV-priming elicited a higher IgG2 response. In conclusion, previous PCV vaccination affects antibody response to PPV for shared serotypes, but can also influence antibody response to some non-PCV serotypes (9N). With increasing number of serotypes included in PCV, the diagnostic assessment for polysaccharide antibody deficiency requires careful selection of serotypes that are not influenced by prior PCV (e.g. serotype 8). Further research is needed to identify more serotypes that are not influenced.

Evaluation of portable Raman spectroscopy and handheld X-ray fluorescence analysis (hXRF) for the direct analysis of glyptics.

In archaeometry, the advantages of a combined use of Raman spectroscopy and X-ray fluorescence spectroscopy are extensively discussed for applications such as the analysis of paintings, manuscripts, pottery, etc. Here, we demonstrate for the first time the advantage of using both techniques for analysing glyptics. These engraved gemstones or glass materials were originally used as stamps, to identify the owner, for instance on letters, but also on wine vessels. For this research, a set of 64 glyptics (42 Roman glass specimens and 22 modern ones), belonging to the collection of the museum 'Quinta das Cruzes' in Funchal (Madeira, Portugal), was analysed with portable Raman spectroscopy and handheld X-ray fluorescence (hXRF). These techniques were also used to confirm the gemological identification of these precious objects and can give extra information about the glass composition. Raman spectroscopy identifies the molecular composition as well as on the crystalline phases present. On the other hand, hXRF results show that the antique Roman glass samples are characterised with low Pb and Sn levels and that the modern specimens can be discriminated in two groups: lead-based and non-lead-based ones.

Value of allohaemagglutinins in the diagnosis of a polysaccharide antibody deficiency.

Polysaccharide antibody deficiency is characterized by a poor or absent antibody response after vaccination with an unconjugated pneumococcal polysaccharide vaccine. Allohaemagglutinins (AHA) are antibodies to A or B polysaccharide antigens on the red blood cells, and are often used as an additional or alternative measure to assess the polysaccharide antibody response. However, few studies have been conducted to establish the clinical significance of AHA. To investigate the value of AHA to diagnose a polysaccharide antibody deficiency, pneumococcal polysaccharide antibody titres and AHA were studied retrospectively in 180 subjects in whom both tests had been performed. Receiver operating characteristic curves for AHA versus the pneumococcal vaccine response as a marker for the anti-polysaccharide immune response revealed an area under the curve between 0·5 and 0·573. Sensitivity and specificity of AHA to detect a polysaccharide antibody deficiency, as diagnosed by vaccination response, were low (calculated for cut-off 1/4-1/32). In subjects with only low pneumococcal antibody response, the prevalence of bronchiectasis was significantly higher than in subjects with only low AHA (45·5 and 1·3%, respectively) or normal pneumococcal antibody response and AHA (2·4%). A logistic regression model showed that low pneumococcal antibody response but not AHA was associated with bronchiectasis (odds ratio 46·2). The results of this study do not support the routine use of AHA to assess the polysaccharide antibody response in patients with suspected immunodeficiency, but more studies are warranted to clarify the subject further.

Micro-Raman spectroscopy and chemometrical analysis for the distinction of copper phthalocyanine polymorphs in paint layers.

In art analysis, copper phthalocyanine (CuPc) is often identified as an important pigment (PB15) in 20th century artworks. Raman spectroscopy is a very valuable technique for the detection of this pigment in paint systems. However, PB15 is used in different polymorphic forms and identification of the polymorph could retrieve information on the production process of the pigment at the moment. Raman spectroscopy, being a molecular spectroscopic method of analysis, is able to discriminate between polymorphs of crystals. However, in the case of PB15, spectral interpretation is not straightforward, and Raman data treatment requires some improvements concerning the PB15 polymorphic discrimination in paints. Here, Raman spectroscopy is combined with chemometrical analysis in order to develop a procedure allowing us to identify the PB15 crystalline structure in painted layers and in artworks. The results obtained by Linear Discriminant Analysis (LDA), using intensity ratios as variables, demonstrate the ability of this procedure to predict the crystalline structure of a PB15 pigment in unknown paint samples.

The use of mobile Raman spectroscopy to compare three full-page miniatures from the Breviary of Arnold of Egmond.

The Breviary of Arnold of Egmond is one of the most wealthily illuminated fifteenth century manuscripts in the Northern Netherlands. The manuscript originally contained a number of full-page miniatures, which were all removed at an unknown date before 1902. The three remaining miniatures studied here, are today part of different collections, but they were brought together for an exhibition. Although several historical and art historical details of this breviary have extensively been studied, no examination of the materials used was undertaken before. Analytical techniques, such as mobile Raman spectroscopy, can be used to characterise and identify these materials in a non-invasive way. This paper presents the results of the in situ Raman analysis of three full-page miniatures of the Breviary of Arnold of Egmond. During this study, different pigments could be identified, such as lead white (2PbCO(3)·Pb(OH)(2)), lead-tin yellow type I (Pb(2)SnO(4)), ultramarine (Na(8-10)Al(6)Si(6)O(24)S(2-4)), massicot (PbO), vermilion (HgS) and red lead (Pb(3)O(4)). Next to identification of the pigments, visual analysis was used to detect differences and similarities between the stylistic elements of the three analysed folios.

The use of a multi-method approach to identify the pigments in the 12th century manuscript Liber Floridus.

A selection of illuminations of the 12th century manuscript Liber Floridus was analysed with Raman spectroscopy (in situ and laboratory measurements), X-ray fluorescence spectroscopy, UV-fluorescence photography and infrared reflectography (IRR). The aim of this study is to determine the pigments used, in order to search for anachronisms. Using a combination of Raman spectroscopy (molecular information) and X-ray fluorescence spectroscopy (elemental information) following pigments could be identified: ultramarine (Na(8-10)Al(6)Si(6)O(24)S(2-4)), azurite (2CuCO(3)·Cu(OH)(2)), caput mortuum (Fe(2)O(3)), vermilion (HgS), orpiment (As(2)S(3)) and lead white (2PbCO(3)·Pb(OH)(2)). Moreover, two synthetic red pigments, PR4 and PR176, and a degradation product, gypsum (CaSO(4)·2H(2)O), were present in the manuscript. To establish the origin of the modern materials UV-fluorescence photography was used. Infrared reflectography (IRR) was applied to visualise the underdrawing of the investigated folios.

Immunizing pigs with Ascaris suum haemoglobin increases the inflammatory response in the liver but fails to induce a protective immunity.

To determine whether purified Ascaris suum haemoglobin (AsHb) is a suitable vaccine candidate for the control of Ascaris infections, pigs were vaccinated with AsHb in combination with QuilA adjuvant and challenged with A. suum eggs. The number of liver lesions and worms in the intestine was assessed on day 14, 28 and 56 post-infection (p.i.). No significant differences were found in the number of worms recovered between vaccinated and control pigs on any of these days. However, significantly more white spots were counted on the livers of vaccinated pigs on day 14 (+86%) and day 28 (+118%) p.i. compared with nonvaccinated controls. To investigate whether the increased immunoreactivity against the liver stage L3s in vaccinated pigs was triggered by and directed against AsHb, the transcription and expression of AsHb in this larval life stage was analysed by RT-PCR and immunoblotting. The results showed that neither the AsHb transcript nor protein was detectable in freshly hatched L3. However, the immunoblot analysis showed that vaccination with AsHb resulted in the production of antibodies binding to several other antigens of the L3, suggesting that these might be involved in the increased white spot development.

University strategy for doctoral training: the Ghent University Doctoral Schools.

The Doctoral Schools at Ghent University have a three-fold mission: (1) to provide support to doctoral students during their doctoral research, (2) to foster a quality culture in (doctoral) research, (3) to promote the international and social stature and prestige of the doctorate vis-a-vis potential researchers and the potential labour market. The Doctoral Schools offer top-level specialized courses and transferable skills training to doctoral students as part of their doctoral training programme. They establish mechanisms of quality assurance in doctoral research. The Doctoral Schools initialize and support initiatives of internationalization. They also organize information sessions, promotional events and interaction with the labour market, and as such keep a finger on the pulse of external stakeholders.

Isotopic fractionation of Sn during methylation and demethylation reactions in aqueous solution.

Laboratory experiments, modeling the methylation of inorganic Sn(II) by methylcobalamin and the decomposition of methyltin under irradiation with UV light in aqueous solution, have been performed. Methyltin has been separated from inorganic Sn using anion-exchange chromatography and subjected to Sn isotope ratio measurements via solution nebulization multicollector inductively coupled plasma mass spectrometry (MC-ICPMS). The methylation of Sn(II) in the dark was accompanied by mass-dependent Sn isotopic fractionation, which resulted in preferential partitioning of the lighter Sn isotopes into the organic phase, with a shift of approximately 0.57 +/- 0.12 per thousand in terms of delta124/ 116Sn between methylated and inorganic Sn. The methylation of Sn(II) by methylcobalamin under UV irradiation resulted in the accelerated formation of methyltin in the beginning of the process, but was followed by the photolytic degradation of methyltin until its complete mineralization. The photolytic degradation of methyltin in the presence of methylcobalamin and inorganic Sn(II) was slower than that of pure solutions of commercially obtained monomethyltin. This is attributed to the methylating action of methyl radicals produced from photolytically decomposing methylcobalamin. Both synthesis and decomposition of methyltin under UV irradiation were accompanied by both mass-dependent and mass-independent Sn isotopic fractionation, with the latter due to the magnetic isotope effect. As a result of this, the lighter Sn isotopes preferentially partition into reaction products, while the odd isotopes, 117Sn and 119Sn, are selectively enriched relative to the other isotopes in the starting molecules. The extent of the observed variations in the isotopic composition of Sn is larger than that documented previouslyfor geological and archeological samples. These results indicate that Sn isotopic fractionation between various chemical forms of Sn in the natural aquatic systems may be significant and can provide new insights into the biogeochemical cycling of the element.

The Glossina morsitans tsetse fly saliva: general characteristics and identification of novel salivary proteins.

The tsetse fly (Glossina spp.) is an obligate blood-sucking insect that transmits different human-pathogenic and livestock threatening trypanosome species in Africa. To obtain more insight in the tsetse salivary function, some general aspects of the tsetse fly saliva and its composition were studied. Direct pH and protein content measurements revealed a moderately alkaline (pH approximately 8.0) salivary environment with approximately 4.3 microg soluble proteins per gland and a constant representation of the major saliva proteins throughout the blood-feeding cycle. Although major salivary genes are constitutively expressed, upregulation of salivary protein synthesis within 48 h after the blood meal ensures complete protein replenishment from day 3 onwards. Screening of a non-normalised Glossina morsitans morsitans lambdagt11 salivary gland expression library with serum from a saliva-immunized rabbit identified three full-length cDNAs encoding for novel salivary proteins with yet unknown functions: a 8.3 kDa glycine/glutamate-rich protein (G. morsitans morsitans salivary gland protein Gmmsgp1), a 12.0 kDa proline-rich protein (Gmmsgp2), and a 97.4 kDa protein composed of a metallophosphoesterase/5'nucleotidase region with a glutamate/aspartate/asparagines-rich region (Gmmsgp3).

Neuroglobin and cytoglobin as potential enzyme or substrate.

The possible enzymatic activities of neuro- and cytoglobin as well as their potential function as substrates in enzymatic reactions were studied. Neuro- and cytoglobin are found to show no appreciable superoxide dismutase, catalase, and peroxidase activities. However, the internal disulfide bond (CD7-D5) of human neuroglobin can be reduced by thioredoxin reductase. Furthermore, our in vivo and in vitro studies show that Escherichia coli cells contain an enzymatic reducing system that keeps the heme iron atom of neuroglobin in the Fe(2+) form in the presence of dioxygen despite the high autoxidation rate of the molecule. This reducing system needs a low-molecular-weight compound as co-factor. In vitro tests show that both NADH and NADPH can play this role. Furthermore, the reducing system is not specific for neuroglobin but allows the reduction of the ferric forms of other globins such as cytoglobin and myoglobin. A similar reducing system is present in eukaryotic tissue protein extracts.

A combined micro-resonance Raman and absorption set-up enabling in vivo studies under varying physiological conditions: The nerve globin in the nerve cord of Aphrodite aculeata.

We hereby report on the design of a set-up combining micro-resonance Raman and absorption spectroscopy with a microfluidic system. The set-up enabled us to study the nerve globin of Aphrodite aculeata in the functional isolated nerve cord under varying physiological conditions for extended periods of time. The oxygenation cycle of the organism was triggered by utilizing the microfluidic system that allowed for a fast switch between aerobic and anaerobic conditions. The nerve globin was found to very easily shift from a penta-coordinated high spin ferrous form to the oxy state upon a change from anaerobic to aerobic conditions. The observed fast reaction to varying O(2) concentrations supports an oxygen-carrying and/or -storing function of the nerve globin. In addition, by combining resonance Raman and absorption spectroscopy, the physiological response could be distinguished from light-induced effects.

Comparative study of mobile Raman instrumentation for art analysis.

In archaeometry, one of the main concerns is to extract information from an art object, without damaging it. Raman spectroscopy is being applied in this research field with recent developments in mobile instrumentation facilitating more routine analysis. This research paper evaluates the performances of five mobile Raman instruments (Renishaw RA100, Renishaw Portable Raman Analyser RX210, Ocean Optics RSL-1, Delta Nu Inspector Raman, Mobile Art Analyser--MArtA) in three different laboratories. A set of samples were collected, in order to obtain information on the spectral performances of the instruments including: spectral resolution, calibration, laser cut-off, the ability to record spectra of organic and inorganic pigments through varnish layers and on the possibilities to identify biomaterials. Spectra were recorded from predefined regions on a canvas painting to simulate the investigation of artworks and the capabilities to record spectra from hardly accessible areas was evaluated.

Analyzing heme proteins using EPR techniques: the heme-pocket structure of ferric mouse neuroglobin.

In this work, an electron paramagnetic resonance (EPR) strategy to study the heme-pocket structure of low-spin ferric heme proteins is optimized. Frozen solutions of ferric mouse neuroglobin (mNgb) are analyzed by means of electron spin echo envelope modulation and pulsed electron-nuclear double resonance techniques. The hyperfine and nuclear quadrupole couplings of the directly coordinating heme and histidine nitrogens are derived and are discussed in comparison with known data of other ferric porphyrin compounds. In combination with the hyperfine matrices of the imidazole protons, the 14N EPR parameters reveal structural information on the heme pocket of mNgb that is in agreement with previous X-ray diffraction data on neuroglobins.