Structure and functional complementation of engineered fragments from yeast phosphoglycerate kinase

Previous studies have shown that, although the isolated structuraldomains of yeast phosphoglycerate kinase recover a quasi-nativestructure in vitro as well as in vivo, they do not reassociatenor generate a functional enzyme. The aim of this work was firstto study the folding of complementary fragments different fromstructural domains and second to determine the requirementsfor their reassociation and functional complementation. Themethod used for producing rigorously defined fragments consistsof the introduction of a unique cysteinyl residue in the proteinfollowed by a specific cleavage by 5'5'-dithiobis(2-nitrobenzoate)/potassiumcyanide at this residue. Two pairs of complementary fragmentswere thus obtained, 1–96/97–415 and 1–248/249–415.The structure and stabilities of the different fragments werestudied. The short fragments, i.e. 1–96 and 249–415were found to contain some secondary structure, but to havea low stability. Each large fragment has a high structural contentand a stability close to that of the corresponding domain. Incontrast to that observed with the isolated domains, a weakbut significant complementation was observed for the two pairsof fragments; the pair of fragments 1–248/249–415recovered 8% of the activity of the native enzyme upon complementation.An independent refolding of the complementary fragments beforereassociation decreased the yield of complementation for thepair of fragments 1–96/97–415, but did not affectthe complementation for the other pair (1–248/249–415).From the present data and previous work on the isolated domains,it appears that the correct folding of the isolated fragmentsis not a prerequisite for their complementation.     

High performance liquid chromatographic separation of stereoisomeric bile acids as their UV-sensitive esters

High performance liquid chromatographic separation of a series of mono-, di- and trihydroxylated 5β-cholanic acids which differ only in position and configuration of hydroxyl groups at positions C-3, C-7 and/or C-12, is reported. The C-24 free acids were derivatized to four different classes of UV-sensitive esters, i.e.,p-bromophenacyl (BP),m-methoxyphenacyl (MP), 4-nitrophthalimidemethyl (NPM) and 9-anthrylmethyl (AM) esters, and chromatographed on two, variants of C₁₈ reversed-phase columns (Nova-Pak C₁₈ and Zorbax ODS) with methanol-water systems as mobile phase. Separation efficiency and elution order of some isomeric pairs were influenced by both the structure of the C-24 ester groups and the nature of the columns used. Excellent chromatographic properties were found for those derivatives, particularly for the NPM esters.     

Measuring three-dimensional surfaces with a two-dimensional data tablet

This paper describes a method for measuring the three-dimensional position of points on a surface using only a two-dimensional tablet or digitizer, standard photographic techniques and some computing power. The tablet is used to extract two-dimensional information from photographs of the surface. Data from multiple views of the surface is processed to give the three-dimensional position of points on the surface. This method has been successfully used to obtain point position data for the polygonal representation of several human faces and a human body.     

Einsatz von perowskitischen Hohlfasermembranen in einem Mikrowellenplasma

For the first time the combination of a separation process with a plasma process was successfully tested. In this case, a mixed‐conducting perovskite membrane separates the oxygen. At 1 kW a permeation of 2.24 mL min^?1cm^?2 could be achieved. Corresponding perovskite membranes have been manufactured as hollow fibers with a very good CO₂ stability. The hollow fibers showed a constant permeation over more than 200 h. Furthermore, a spinning process with a sulphur‐free polymer binder has been established.     

High‐Pressure High‐Temperature Transparent Fixed‐Bed Reactor for Operando Gas‐Liquid Reaction Follow‐up

A 3‐MPa, 350 °C fixed‐bed reactor was designed to follow‐up gas‐liquid‐solid reactions on a millimetric size heterogeneous catalyst with Raman spectroscopy. The transparent reactor is a quartz cylinder enclosed in a Joule effect heated stainless‐steel tube. A methodology to determine how to focus the microscope for liquid and solid phase characterization is presented. The setup was validated by performing diesel hydrodesulfurization on a CoMo/alumina extrudate catalyst with a conversion very close to expected values along with the acquisition of Raman spectra of the solid catalyst showing an evolution of the catalyst phase during sulfidation.     

Complement-Opsonized Nano-Carriers Are Bound by Dendritic Cells (DC) via Complement Receptor (CR)3, and by B Cell Subpopulations via CR-1/2, and Affect the Activation of DC and B-1 Cells

The development of nanocarriers (NC) for biomedical applications has gained large interest due to their potential to co-deliver drugs in a cell-type-targeting manner. However, depending on their surface characteristics, NC accumulate serum factors, termed protein corona, which may affect their cellular binding. We have previously shown that NC coated with carbohydrates to enable biocompatibility triggered the lectin-dependent complement pathway, resulting in enhanced binding to B cells via complement receptor (CR)1/2. Here we show that such NC also engaged all types of splenic leukocytes known to express CR3 at a high rate when NC were pre-incubated with native mouse serum resulting in complement opsonization. By focusing on dendritic cells (DC) as an important antigen-presenting cell type, we show that CR3 was essential for binding/uptake of complement-opsonized NC, whereas CR4, which in mouse is specifically expressed by DC, played no role. Further, a minor B cell subpopulation (B-1), which is important for first-line pathogen responses, and co-expressed CR1/2 and CR3, in general, engaged NC to a much higher extent than normal B cells. Here, we identified CR-1/2 as necessary for binding of complement-opsonized NC, whereas CR3 was dispensable. Interestingly, the binding of complement-opsonized NC to both DC and B-1 cells affected the expression of activation markers. Our findings may have important implications for the design of nano-vaccines against infectious diseases, which codeliver pathogen-specific protein antigen and adjuvant, aimed to induce a broad adaptive cellular and humoral immune response by inducing cytotoxic T lymphocytes that kill infected cells and pathogen-neutralizing antibodies, respectively. Decoration of nano-vaccines either with carbohydrates to trigger complement activation in vivo or with active complement may result in concomitant targeting of DC and B cells and thereby may strongly enhance the extent of dual cellular/humoral immune responses.     

New wireless connection between user and VE using speech processing

This paper presents a novel speak-to-VR virtual-reality peripheral network (VRPN) server based on speech processing. The server uses a microphone array as a speech source and streams the results of the process through a Wi-Fi network. The proposed VRPN server provides a handy, portable and wireless human machine interface that can facilitate interaction in a variety interfaces and application domains including HMD- and CAVE-based virtual reality systems, flight and driving simulators and many others. The VRPN server is based on a speech processing software development kits and VRPN library in C++. Speak-to-VR VRPN works well even in the presence of background noise or the voices of other users in the vicinity. The speech processing algorithm is not sensitive to the user’s accent because it is trained while it is operating. Speech recognition parameters are trained by hidden Markov model in real time. The advantages and disadvantages of the speak-to-VR server are studied under different configurations. Then, the efficiency and the precision of the speak-to-VR server for a real application are validated via a formal user study with ten participants. Two experimental test setups are implemented on a CAVE system by using either Kinect Xbox or array microphone as input device. Each participant is asked to navigate in a virtual environment and manipulate an object. The experimental data analysis shows promising results and motivates additional research opportunities.     

Applying a hybrid job shop procedure to a Belgian manufacturing company producing industrial wheels and castors in rubber

In this paper, several methods for job shop scheduling are combined, adjusted and successfully applied to a real-world scheduling problem at a Belgian manufacturer producing industrial wheels and castors in rubber. The procedure is an extension of a hybrid shifting bottleneck procedure with a tabu search algorithm while incorporating various company specific constraints. The various extensions to cope with the company specific constraints have a strong similarity with the complex job shop problem formulation of Mason, Fowler, and Carlyle (2002). The new procedure is used as a simulation engine to test the relevance of various scenarios in order to improve the current planning approach of the company. A detailed computational experiment highlights the main contribution of the novel procedure for the company.