New Thiophilic Adsorbent for the Purification of Insulin and Immunoglobulins G

We have synthesized new supports for the purification of insulin and IgG by affinity chromatography. These supports combine the advantages of biospecific ligands with the excellent separation properties of thiophilic sorbents. The existence of N-acetyl-neuraminic acid in insulin receptor and in the antigenic determinant of IgG suggests that such an acid may develop specific interactions usable in affinity chromatography. Therefore, N-acetylneuraminic acid was used as an active ligand in comparison with the β-mercaptoethanol. The performances of these supports were tested under static and dynamic (LC) conditions. The support functionalized by sialic acid appears significantly more selective than the support grafted by β-mercaptoethanol; and its purification yield is better. This new support showed similar adsorption characteristics with thiophilic adsorbent. These affinity supports allowed a one-step separation of the insulin and IgG subclasses from a pancreatic extract and mouse ascitic fluids, respectively, by LC.     

Identification of physical parameters in pressing of rapeseeds from the oil flux measurements

In this paper, we are interested in the study of an inverse problem that occurs during the pressing of rapeseeds, where some physical parameters influence on rapeseed oil extraction yield. Our objective is to identify the consolidation coefficient of the press cake, the inverse characteristic time of consolidation in press cake, and inside the rapeseed in order to increase the rapeseed oil extraction yield. Three questions will be addressed: the identifiability, the identification, and the stability of the inverse problem. Finally, we provide numerical results to confirm the theoretical results.     

<Emphasis Type="Italic">l</Emphasis><Subscript>1</Subscript>-<Emphasis Type="Italic">l</Emphasis><Subscript>2</Subscript> regularization of split feasibility problems

Numerous problems in signal processing and imaging, statistical learning and data mining, or computer vision can be formulated as optimization problems which consist in minimizing a sum of convex functions, not necessarily differentiable, possibly composed with linear operators and that in turn can be transformed to split feasibility problems (SFP); see for example Censor and Elfving (Numer. Algorithms 8, 221–239 1994). Each function is typically either a data fidelity term or a regularization term enforcing some properties on the solution; see for example Chaux et al. (SIAM J. Imag. Sci. 2, 730–762 2009) and references therein. In this paper, we are interested in split feasibility problems which can be seen as a general form of Q-Lasso introduced in Alghamdi et al. (2013) that extended the well-known Lasso of Tibshirani (J. R. Stat. Soc. Ser. B 58, 267–288 1996). Q is a closed convex subset of a Euclidean m-space, for some integer m ≥ 1, that can be interpreted as the set of errors within given tolerance level when linear measurements are taken to recover a signal/image via the Lasso. Inspired by recent works by Lou and Yan (2016), Xu (IEEE Trans. Neural Netw. Learn. Syst. 23, 1013–1027 2012), we are interested in a nonconvex regularization of SFP and propose three split algorithms for solving this general case. The first one is based on the DC (difference of convex) algorithm (DCA) introduced by Pham Dinh Tao, the second one is nothing else than the celebrate forward-backward algorithm, and the third one uses a method introduced by Mine and Fukushima. It is worth mentioning that the SFP model a number of applied problems arising from signal/image processing and specially optimization problems for intensity-modulated radiation therapy (IMRT) treatment planning; see for example Censor et al. (Phys. Med. Biol. 51, 2353–2365, 2006).     

Dominant ferromagnetic coupling over antiferromagnetic in Ni doped ZnO: First-principles calculations

Frontiers of Physics - This article presents a review of our present understanding of the spin structure of the unpolarized hadron. Particular attention is paid to the quark sector at leading...     

Robust sensor fault estimation for fractional-order systems with monotone nonlinearities

Nonlinear Dynamics - This paper investigates the problem of sensor fault estimation for systems with monotone nonlinearities and unknown inputs. To the best of our knowledge, such a particular...     

Mechanistic Insight into Heptosyltransferase Inhibition by using Kdo Multivalent Glycoclusters

The synthesis of unprecedented multimeric Kdo glycoclusters based on fullerene and calix[4]arene central scaffolds is reported. The compounds were used to study the mechanism and scope of multivalent glycosyltransferase inhibition. Multimeric mannosides based on porphyrin and pillar[5]arenes were also generated in a controlled manner. Twelve glycoclusters and their monomeric ligands were thus assayed against heptosyltransferase WaaC, which is an important bacterial glycosyltransferase that is involved in lipopolysaccharide biosynthesis. It was first found that all the multimers interact solely with the acceptor binding site of the enzyme even when the multimeric ligands mimic the heptose donor. Second, the novel Kdo glycofullerenes displayed very potent inhibition (K_i=0.14 μm for the best inhibitor); an inhibition level rarely observed with glycosyltransferases. Although the observed “multivalent effects” (i.e., the enhancement of affinity of a ligand when presented in a multimeric fashion) were in general modest, a dramatic effect of the central scaffold on the inhibition level was evidenced: the fullerene and the porphyrin scaffolds being by far superior to the calix‐ and pillar‐arenes. We could also show, by dynamic light scattering analysis, that the best inhibitor had the propensity to form aggregates with the heptosyltransferase. This aggregative property may contribute to the global multivalent enzyme inhibition, but probably do not constitute the main origin of inhibition.     

Impact of Nonthermal Atmospheric Plasma on the Structure of Cellulose: Access to Soluble Branched Glucans

We have investigated the effect of non‐thermal atmospheric plasma (NTAP) on the structure of microcrystalline cellulose. In particular, by means of different characterization methods, we demonstrate that NTAP promotes the partial cleavage of the β‐1,4 glycosidic bond of cellulose leading to the release of short‐chain cellodextrins that are reassembled in situ, preferentially at the C6 position, to form branched glucans with either a glucosyl or anhydroglucosyl terminal residue. The ramification of cellulosic chain induced by NTAP yields branched glucans that are soluble in DMSO or in water, thus opening a straightforward access to processable glucans from cellulose. Importantly, the absence of solvent and catalyst considerably facilitates downstream processing as compared to (bio)catalytic processes which typically occur in diluted conditions.