In this study, we characterized and modeled the rheology of TEMPO-oxidized cellulose nanofibril (NFC) aqueous suspensions with electrostatically stabilized and unflocculated nanofibrous structures. ...These colloidal suspensions of slender and wavy nanofibers exhibited a yield stress and a shear thinning behavior at low and high shear rates, respectively. Both the shear yield stress and the consistency of these suspensions were power-law functions of the NFC volume fraction. We developed an original multiscale model for the prediction of the rheology of these suspensions. At the nanoscale, the suspensions were described as concentrated systems where NFCs interacted with the Newtonian suspending fluid through Brownian motion and long range fluid-NFC hydrodynamic interactions, as well as with each other through short range hydrodynamic and repulsive colloidal interaction forces. These forces were estimated using both the experimental results and 3D networks of NFCs that were numerically generated to mimic the nanostructures of NFC suspensions under shear flow. They were in good agreement with theoretical and measured forces for model colloidal systems. The model showed the primary role played by short range hydrodynamic and colloidal interactions on the rheology of NFC suspensions. At low shear rates, the origin of the yield stress of NFC suspensions was attributed to the combined contribution of repulsive colloidal interactions and the topology of the entangled NFC networks in the suspensions. At high shear rates, both concurrent colloidal and short (in some cases long) range hydrodynamic interactions could be at the origin of the shear thinning behavior of NFC suspensions.
Background
Leaks are considered one of the major complications of laparoscopic sleeve gastrectomy (LSG) with a reported rate up to 7 %. Drainage of the collection coupled with SEMS deployment is the ...most frequent treatment. Its success is variable and burdened by high morbidity and not irrelevant mortality. The aim of this paper is to suggest and establish a new approach by endoscopic internal drainage (EID) for the management of leaks.
Methods
Since March 2013, 67 patients presenting leak following LSG were treated with deployment of double pigtail plastic stents across orifice leak, positioning one end inside the collection and the other end in remnant stomach. The aim of EID is to internally drain the collection and at the same time promote leak healing.
Results
Double pigtails stent were successfully delivered in 66 out of 67 patients (98.5 %). Fifty patients were cured by EID after a mean time of 57.5 days and an average of 3.14 endoscopic sessions. Two died for event not related to EID. Nine are still under treatment; five failure had been registered. Six patients developed late stenosis treated endoscopically.
Conclusions
EID proved to be a valid, curative, and safe mini-invasive approach for treatment of leaks following SG. EID achieves complete drainage of perigastric collections and stimulates mucosal growth over the stent. EID is well tolerated, allows early re-alimentation, and it is burdened by fewer complications than others technique. Long-term follow-up confirms good outcomes with no motility or feeding alterations.
The energy budget and the photochemistry of a snowpack depend greatly on the penetration of solar radiation in snow. Below the snow surface, spectral irradiance decreases exponentially with depth ...with a decay constant called the asymptotic flux extinction coefficient. As with the albedo of the snowpack, the asymptotic flux extinction coefficient depends on snow grain shape. While representing snow by a collection of spherical particles has been successful in the numerical computation of albedo, such a description poorly explains the decrease of irradiance in snow with depth. Here we explore the limits of the spherical representation. Under the assumption of geometric optics and weak absorption by snow, the grain shape can be simply described by two parameters: the absorption enhancement parameter B and the geometric asymmetry factor gG. Theoretical calculations show that the albedo depends on the ratio B/(1-gG) and the asymptotic flux extinction coefficient depends on the product B(1-gG). To understand the influence of grain shape, the values of B and gG are calculated for a variety of simple geometric shapes using ray tracing simulations. The results show that B and (1-gG) generally covary so that the asymptotic flux extinction coefficient exhibits larger sensitivity to the grain shape than albedo. In particular it is found that spherical grains propagate light deeper than any other investigated shape. In a second step, we developed a method to estimate B from optical measurements in snow. A multi-layer, two-stream, radiative transfer model, with explicit grain shape dependence, is used to retrieve values of the B parameter of snow by comparing the model to joint measurements of reflectance and irradiance profiles. Such measurements were performed in Antarctica and in the Alps yielding estimates of B between 0.8 and 2.0. In addition, values of B were estimated from various measurements found in the literature, leading to a wider range of values (1.0–9.9) which may be partially explained by the limited accuracy of the data. This work highlights the large variety of snow microstructure and experimentally demonstrates that spherical grains, with B = 1.25, are inappropriate to model irradiance profiles in snow, an important result that should be considered in further studies dedicated to subsurface absorption of short-wave radiation and snow photochemistry.
High‐resolution profiles of ice dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP) concentrations were measured together with a suite of ancillary physical and biological properties during ...a time series of decaying summer‐level first‐year sea ice throughout December 2004 during the Ice Station Polarstern drift experiment (western Weddell Sea, Antarctica). Ice DMSP and DMS concentrations were always maximum at the bottom of the ice sheet (636–2627 and 292–1430 nM, respectively) where the highest chlorophyll a levels were also found (15–30 μg L−1). Throughout the observation period, the autotrophic surface community (32–205 μg C L−1) was dominated by Phaeocystis sp. while the bottom community (1622–3830 μg C L−1) mainly consisted of pennate diatoms. This illustrates that, although being known for lower DMSP‐to‐chlorophyll a ratios than Phaeocystis sp., diatoms dominated the overall DMSP production because of their much larger biomass. Decreasing DMSP concentrations and increasing DMS‐to‐DMSP ratios in the bottom layers with time suggested active DMSP‐to‐DMS conversion in a slowly degrading environment. Drastic temporal brine volume and brine salinity changes associated with the decaying sea ice cover are shown to directly impact (1) the migration of DMSP and DMS through the brine network, (2) the DMSP‐to‐DMS conversion processes within the ice interior, and (3) the physiological response of the ice algae. First‐order flux estimates show that decaying summer‐level first‐year sea ice alone can significantly contribute to the regional sulfur budget of the Weddell Sea with an estimated average loss rate of 5.7 μmol DMS(P) m−2 d−1) toward the atmosphere and the ocean.
Background The Behavior Problems Inventory‐01 (BPI‐01) is an informant‐based behaviour rating instrument that was designed to assess maladaptive behaviours in individuals with intellectual ...disabilities (ID). Its items fall into one of three sub‐scales: Self‐injurious Behavior (14 items), Stereotyped Behavior (24 items), and Aggressive/Destructive Behavior (11 items). Each item is rated on a frequency scale (0 = never to 4 = hourly), and a severity scale (0 = no problem to 3 = severe problem). The BPI‐01 has been successfully used in several studies and has shown acceptable to very good psychometric properties. One concern raised by some investigators was the large number of items on the BPI‐01, whichhas reduced its user friendliness for certain applications. Furthermore, researchers and clinicians were often uncertain how to interpret their BPI‐01 data without norms or a frame of reference.
Methods The Behavior Problems Inventory‐Short Form (BPI‐S) was empirically developed, based on an aggregated archival data set of BPI‐01 data from individuals with ID from nine locations in the USA, Wales, England, the Netherlands, and Romania (n = 1122). The BPI‐S uses the same rating system and the same three sub‐scales as the BPI‐01, but has fewer items: Self‐injurious Behavior (8 items), Stereotyped Behavior (12 items), and Aggressive/Destructive Behavior (10 items). Rating anchors for the severity scales of the Self‐injurious Behavior and the Aggressive/Destructive Behavior sub‐scales were added in an effort to enhance the objectivity of the ratings.
Results The sensitivity of the BPI‐S compared with the BPI‐01 was high (0.92 to 0.99), and so were the correlations between the analogous BPI‐01 and the BPI‐S sub‐scales (0.96 to 0.99). Means and standard deviations were generated for both BPI versions in a Sex‐by‐age matrix, and in a Sex‐by‐ID Level matrix. Combined sex ranges are also provided by age and level of ID.
Conclusion In summary, the BPI‐S is a very useful alternative to the BPI‐01, especially for research and evaluation purposes involving groups of individuals.
Background The Behavior Problems Inventory‐01 (BPI‐01) is an informant‐based behaviour rating instrument for intellectual disabilities (ID) with 49 items and three sub‐scales: Self‐injurious ...Behavior, Stereotyped Behavior and Aggressive/Destructive Behavior. The Behavior Problems Inventory‐Short Form (BPI‐S) is a BPI‐01 spin‐off with 30 items.
Methods The psychometric properties of these two versions of the scale were computed using aggregated archival data from nine different sites in the USA, Wales, England, the Netherlands and Romania with a total of 1122 cases with a BPI‐01 total score >0.
Results The internal consistency of the BPI‐01 and the BPI‐S ranged from fair to excellent with the BPI‐01 showing slightly stronger reliability. Construct validity (confirmatory and discriminant) was computed by comparing BPI sub‐scale scores with the scores of four other behaviour rating scales (the Aberrant Behavior Checklist, the Diagnostic Assessment for the Severely Handicapped‐II, the Nisonger Child Behavior Rating Form and the Inventory for Client and Agency Planning). Strong evidence for confirmatory and discriminant validity was found for both the BPI‐01 and the BPI‐S. Confirmatory fit indices for the BPI and the BPI‐S were comparable and suggesting that the factor structures fit the data well.
Conclusion In summary, both BPI versions were found to be equally sound psychometrically and can be endorsed for future use. However, independent future studies are needed to replicate the psychometrics of the BPI‐S with new data.
Iodide is captured by thyrocytes through the Na(+)/I(-) symporter (NIS) before being released into the follicular lumen, where it is oxidized and incorporated into thyroglobulin for the production of ...thyroid hormones. Several reports point to pendrin as a candidate protein for iodide export from thyroid cells into the follicular lumen. Here, we show that a recently discovered Ca(2+)-activated anion channel, TMEM16A or anoctamin-1 (ANO1), also exports iodide from rat thyroid cell lines and from HEK 293T cells expressing human NIS and ANO1. The Ano1 mRNA is expressed in PCCl3 and FRTL-5 rat thyroid cell lines, and this expression is stimulated by thyrotropin (TSH) in rat in vivo, leading to the accumulation of the ANO1 protein at the apical membrane of thyroid follicles. Moreover, ANO1 properties, i.e., activation by intracellular calcium (i.e., by ionomycin or by ATP), low but positive affinity for pertechnetate, and nonrequirement for chloride, better fit with the iodide release characteristics of PCCl3 and FRTL-5 rat thyroid cell lines than the dissimilar properties of pendrin. Most importantly, iodide release by PCCl3 and FRTL-5 cells is efficiently blocked by T16Ainh-A01, an ANO1-specific inhibitor, and upon ANO1 knockdown by RNA interference. Finally, we show that the T16Ainh-A01 inhibitor efficiently blocks ATP-induced iodide efflux from in vitro-cultured human thyrocytes. In conclusion, our data strongly suggest that ANO1 is responsible for most of the iodide efflux across the apical membrane of thyroid cells.
An experimental study of the ultrasonic compression moulding (UCM) to manufacture biobased composites made of semicrystalline starch powders and softwood fibres is described. The main objective was ...to assess the potential of using this fast and economical processing technique to elaborate a 100% biobased composite which might substitute more usual polymer materials for structural applications. The starch powder was chosen as raw material for the matrix while the reinforcement was made of softwood fibres. Tablets made of starch only and composite beams were processed under different conditions and characterised by several techniques. Three types of starch powders and two types of fibres were used as raw materials. A morphological and crystalline analysis was carried out by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The native semicrystalline structure of starch granules was not totally preserved so as to obtain a homogeneous material. Diametral compression tests on tablets were performed to improve the processing route and obtain the materials with the best properties. Bending tests were used on composite beams to quantify the mechanical properties and study the effects of the processing parameters. The optimum processing parameters were defined and allowed obtaining a matrix for which the flexural strength reached 21 MPa. Mechanical properties were improved when fibres were added into the matrix: three-points bending tests showed a Young's modulus of 6 GPa, a flexural strength of 75 MPa and a flexural strain at break of 6% for a bulk density of 1.25. Considering these results, UCM appears to be a promising process to design a 100% biobased composite with mechanical properties comparable to those of classical discontinuous fibre composites.
Ultrasonic moulding; Biobased composites; Starch granules; Wood fibres
An exome-sequencing study of families with multiple breast-cancer-affected individuals identified two families with XRCC2 mutations, one with a protein-truncating mutation and one with a probably ...deleterious missense mutation. We performed a population-based case-control mutation-screening study that identified six probably pathogenic coding variants in 1,308 cases with early-onset breast cancer and no variants in 1,120 controls (the severity grading was p < 0.02). We also performed additional mutation screening in 689 multiple-case families. We identified ten breast-cancer-affected families with protein-truncating or probably deleterious rare missense variants in XRCC2. Our identification of XRCC2 as a breast cancer susceptibility gene thus increases the proportion of breast cancers that are associated with homologous recombination-DNA-repair dysfunction and Fanconi anemia and could therefore benefit from specific targeted treatments such as PARP (poly ADP ribose polymerase) inhibitors. This study demonstrates the power of massively parallel sequencing for discovering susceptibility genes for common, complex diseases.
Lycopene (LYC) bioavailability is relatively low and highly variable, because of the influence of several factors. Recent in vitro data have suggested that dietary Ca can impair LYC micellarisation, ...but there is no evidence whether this can lead to decreased LYC absorption efficiency in humans. Our objective was to assess whether a nutritional dose of Ca impairs dietary LYC bioavailability and to study the mechanism(s) involved. First, in a randomised, two-way cross-over study, ten healthy adults consumed either a test meal that provided 19-mg (all-E)-LYC from tomato paste or the same meal plus 500-mg calcium carbonate as a supplement. Plasma LYC concentration was measured at regular time intervals over 7 h postprandially. In a second approach, an in vitro digestion model was used to assess the effect of increasing Ca doses on LYC micellarisation and on the size and zeta potential of the mixed micelles produced during digestion of a complex food matrix. LYC bioavailability was diminished by 83 % following the addition of Ca in the test meal. In vitro, Ca affected neither LYC micellarisation nor mixed micelle size but it decreased the absolute value of their charge by 39 %. In conclusion, a nutritional dose of Ca can impair dietary LYC bioavailability in healthy humans. This inhibition could be due to the fact that Ca diminishes the electrical charge of micelles. These results call for a thorough assessment of the effects of Ca, or other divalent minerals, on the bioavailability of other carotenoids and lipophilic micronutrients.
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