International comparison CCQM-K111.1-propane in nitrogen

van der Veen, Adriaan M H,van der Hout, J Wouter,Ziel, Paul R,Jozela, Mudalo,Tshilongo, James,Ntsasa, Napo G,Botha, Angelique IOP Publishing 2017 METROLOGIA -BERLIN- Vol.54 No.1

A high-throughput microfluidic assay to study neurite response to growth factor gradients

Kothapalli, Chandrasekhar R.,van Veen, Ed,de Valence, Sarra,Chung, Seok,Zervantonakis, Ioannis K.,Gertler, Frank B.,Kamm, Roger D. Royal Society of Chemistry 2011 Lab on a chip Vol.11 No.3

<P>Studying neurite guidance by diffusible or substrate bound gradients is challenging with current techniques. In this study, we present the design, fabrication and utility of a microfluidic device to study neurite guidance under chemogradients. Experimental and computational studies demonstrated the establishment of a steep gradient of guidance cue within 30 min and stable for up to 48 h. The gradient was found to be insensitive to external perturbations such as media change and movement of device. The effects of netrin-1 (0.1–10 µg mL<SUP>−1</SUP>) and brain pulp (0.1 µL mL<SUP>−1</SUP>) were evaluated for their chemoattractive potential on neurite turning, while slit-2 (62.5 or 250 ng mL<SUP>−1</SUP>) was studied for its chemorepellant properties. Hippocampal or dorsal root ganglion (DRG) neurons were seeded into a micro-channel and packed onto the surface of a 3D collagen gel. Neurites grew into the matrix in three dimensions, and a gradient of guidance cue was created orthogonal to the direction of neurite growth to impact guidance. The average turning angle of each neurite was measured and averaged across multiple devices cultured under similar conditions to quantify the effect of guidance cue gradient. Significant positive turning towards gradient was measured in the presence of brain pulp and netrin-1 (1 µg mL<SUP>−1</SUP>), relative to control cultures which received no external guidance cue (<I>p</I> < 0.001). Netrin-1 released from transfected fibroblasts had the most positive turning effect of all the chemoattractive cues tested (<I>p</I> < 0.001). Slit-2 exhibited strong chemorepellant characteristics on both hippocampal and DRG neurite guidance at 250 ng mL<SUP>−1</SUP> concentration. Slit-2 also showed similar behavior on DRG neuron invasion into 3D collagen gel (<I>p</I> < 0.01 relative to control cultures). Taken together, the results suggest the utility of this microfluidic device to generate stable chemogradients for studying neurobiology, cell migration and proliferation, matrix remodeling and co-cultures with other cell lines, with potential applications in cancer biology, tissue engineering and regenerative medicine.</P> <P>Graphic Abstract</P><P>We describe a three-channel microfluidic device to study the role of chemogradients on neurite outgrowth and guidance in 3D scaffolds, using experimental and computational studies. The stable chemogradients in these devices could also be used to screen potential drugs for neuron pathway regeneration under disease/ injury conditions, cell migration and cell–cell interactions. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0lc00240b'> </P>

Nuclear Data Uncertainty Propagation: Total Monte Carlo vs. Covariances

D. Rochman,A. J. Koning,S. C. van der Marck,A. Hogenbirk,D. van Veen 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23

Two distinct methods of propagation for basic nuclear data uncertainties to large scale systems will be presented and compared. The "Total Monte Carlo" method is using a statistical ensemble of nuclear data libraries randomly generated by means of a Monte Carlo approach with the TALYS system. These libraries are then directly used in a large number of reactor calculations (for instance with MCNP) after which the exact probability distribution for the reactor parameter is obtained. The second method makes use of available covariance files and can be done in a single reactor calculation (by using the perturbation method). In this exercise, both methods are using consistent sets of data files, which implies that covariance files used in the second method are directly obtained from the randomly generated nuclear data libraries from the first method. This is a unique and straightforward comparison allowing to directly apprehend advantages and drawbacks of each method. Comparisons for different reactions and criticality-safety benchmarks from ^(19)F to actinides will be presented. We can thus conclude whether current methods for using covariance data are good enough or not.

HOMOCLINIC ORBITS IN TRANSITIONAL PLANE COUETTE FLOW

Julius Rhoan T. Lustro,Genta Kawahara,Lennaert van Veen,Masaki Shimizu 한국전산유체공학회 2015 한국전산유체공학회지 Vol.20 No.4

Recent studies on wall-bounded shear flow have emphasized the significance of the stable manifold of simple nonlinear invariant solutions to the Navier-Stokes equation in the formation of the boundary between the laminar and turbulent regions in state space. In this paper we present newly discovered homoclinic orbits of the Kawahara and Kida(2001) periodic solution in plane Couette flow. We show that as the Reynolds number decreases a pair of homoclinic orbits move closer to each other until they disappear to exhibit homoclinic tangency.

HOMOCLINIC ORBITS IN TRANSITIONAL PLANE COUETTE FLOW

Lustro, Julius Rhoan T.,Kawahara, Genta,van Veen, Lennaert,Shimizu, Masaki Korea Society of Computational Fluids Engineering 2015 한국전산유체공학회지 Vol.20 No.4

Recent studies on wall-bounded shear flow have emphasized the significance of the stable manifold of simple nonlinear invariant solutions to the Navier-Stokes equation in the formation of the boundary between the laminar and turbulent regions in state space. In this paper we present newly discovered homoclinic orbits of the Kawahara and Kida(2001) periodic solution in plane Couette flow. We show that as the Reynolds number decreases a pair of homoclinic orbits move closer to each other until they disappear to exhibit homoclinic tangency.

A Review of the Role of Bioreactors for iPSCs-Based Tissue-Engineered Articular Cartilage

Reina-Mahecha Alejandro,Beers Martine J.,van der Veen Hugo C.,Zuhorn Inge S.,van Kooten Theo G.,Sharma Prashant K. 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.7

BACKGROUND: Osteoarthritis (OA) is the most common degenerative joint disease without an ultimate treatment. In a search for novel approaches, tissue engineering (TE) has shown great potential to be an effective way for hyaline cartilage regeneration and repair in advanced stages of OA. Recently, induced pluripotent stem cells (iPSCs) have been appointed to be essential stem cells for degenerative disease treatment because they allow a personalized medicine approach. For clinical translation, bioreactors in combination with iPSCs-engineerd cartilage could match patients needs, serve as platform for large-scale patient specific cartilage production, and be a tool for patient OA modelling and drug screening. Furthermore, to minimize in vivo experiments and improve cell differentiation and cartilage extracellular matrix (ECM) deposition, TE combines existing approaches with bioreactors. METHODS: This review summarizes the current understanding of bioreactors and the necessary parameters when they are intended for cartilage TE, focusing on the potential use of iPSCs. RESULTS: Bioreactors intended for cartilage TE must resemble the joint cavity niche. However, recreating human synovial joints is not trivial because the interactions between various stimuli are not entirely understood. CONCLUSION: The use of mechanical and electrical stimulation to differentiate iPSCs, and maintain and test chondrocytes are key stimuli influencing hyaline cartilage homeostasis. Incorporating these stimuli to bioreactors can positively impact cartilage TE approaches and their possibility for posterior translation into the clinics.

Homoclinic Orbits in Minimal Plane Couette Flow

Julius Rhoan T. Lustro,Genta Kawahara,Lennaert van Veen,Masaki Shimizu 한국전산유체공학회 2014 한국전산유체공학회 학술대회논문집 Vol.2014 No.10

In wall-bounded shear flow recent studies have pointed the significance of the stable manifold of nonlinear simple invariant solutions, referred to as edge states, to the Navier-Stokes equation in the formation of the laminar-turbulent boundary. Here we present homoclinic orbits of the periodic edge state found by Kawahara and Kida[1] in plane Couette flow. It is observed that these homoclinic orbits collide and disappear to exhibit homoclinic tangency as the Reynolds number decreases.

International comparison CCQM-K116: 10 μmol mol^-1 water vapour in nitrogen

Brewer, P J,Gieseking, B,Feracci, V F,Ward, M,Wijk, J van,Veen, A M H van der,Lima, A A,Augusto, C R,Oh, S H,Kim, B M,Lee, S,Konopelko, L A,Kustikov, Y,Shimosaka, T,Niederhauser, B,Guillevic, M,Pascal BUREAU INTERNATIONAL DES POIDS ET MESURES 2018 METROLOGIA -BERLIN- Vol.55 No.1

Marine derived Ca-Mg complex supplementation basal diet during four subsequent parities improved longevity and performance of sows and their litters

Santi Devi Upadhaya,Woo Jeong Seok,Shanmugam Suresh kumar,Rudolf H. van der Veen,In Ho Kim 한국축산학회 2023 한국축산학회지 Vol.65 No.3

The aim of the present study was to evaluate the effects of dietary supplementation of Ca-Mg complex on the longevity and reproductive performance of sows. In total, seventy-two gilts ([Yorkshire × Landrace] × Duroc, average body weight 181 kg) were randomly allocated to 1 of 3 treatments during 4 successive parity in a 4 × 3 factorial arrangement. Treatments consisted of CON (basal diet), CM1 (basal diet -MgO - 0.3% limestone + 0.4% Ca-Mg complex), and CM2 (basal diet - MgO - 0.7% limestone + 0.4% Ca-Mg complex). A higher (p < 0.05) number of totals born and live piglets, and sows increased feed intake during gestation and lactation, increased backfat thickness, and increased estrus interval were observed (p < 0.05) during their third and fourth parity than during their first and second parity. Ca-Mg complex supplementation improved (p < 0.05) the number of total piglets during the first and second parity as well as live-born piglets during the first to third parity, reduction (p < 0.05) in backfat thickness during the third and fourth parity, a higher (p < 0.05) initial and final number of suckling piglets as well as higher weaning weight compared with sows fed CON diet during the first, second, and third parity. The average daily gain (ADG) was higher (p < 0.05) in piglets born to CM1 and CM2 sows regardless of parity. The treatment diets fed to sows lowered (p < 0.05) the duration of first to last piglet birth and placenta expulsion time compared with CON sows. A significant interactive effect (p = 0.042) between parities and treatment diets was observed for the first to last piglet birth. Thus, Ca-Mg complex supplementation by partially replacing limestone in the basal diet enhanced sow performance, specifically during their third and fourth parity, thereby improving sow longevity.

Marine-derived Ca-Mg complex influences lipid and glucose metabolism, serum metabolites, colostrum profile, and stress hormone in sows over four-parity periods

조성보,Santi Devi Upadhaya,Woo Jeong Seok,Seyoung Mun,Haeun Lee,Rudolf H. van der Veen,Kyudong Han,In Ho Kim 한국축산학회 2023 한국축산학회지 Vol.65 No.6

Minerals is required small amounts among various nutrients, but it has a significant impact on sow longevity and reproduction performance. This study was carried out to see the beneficial effects of marine-derived Ca-Mg complex on the reproductive performance of sows during four-parity periods. Seventy-two gilts ([Yorkshire × Landrace] × Duroc), with an average body weight of 181 kg, were randomly allocated to three groups; CON (basal diet), 0.3LC (CON - MgO - 0.3% limestone + 0.4% Ca-Mg complex), and 0.7LC (CON - MgO - 0.7% limestone + 0.4% Ca-Mg complex). During parity 3 and 4, the expression level of SCD gene was lower in the umbilical cord of piglets born to 0.3LC and 0.7LC sows compared with the CON sows. During parity 2, 3 and 4, SLC2A2 and FABP4 gene expressions were higher in the umbilical cord of piglets born to 0.7LC sows and the placenta of sows from 0.3LC groups, respectively. Ca-Mg complex increased (p < 0.05) Ca and Mg concentrations in sows and their piglets’ serum as well as in colostrum regardless of parities. The serum vitamin D concentration was higher (p < 0.05) in their first parity, whereas serum prolactin and estrogen concentrations were higher (p < 0.05) during the fourth and third parity, respectively. The growth hormone concentrations were higher (p < 0.05) in the piglets born to sows during the first and second parity. The fat and immunoglobulin A (IgA) concentrations in colostrum were higher (p < 0.05) during the third and fourth parity, respectively. A reduction (p < 0.05) in salivary cortisol, epinephrine, and norepinephrine concentrations was observed in 0.3LC and 0.7LC sow groups compared with CON after farrowing regardless of parity, however before farrowing, a reduction in norepinephrine was observed. Before farrowing, the epinephrine and norepinephrine concentrations were higher (p < 0.05) during the first and second parity. After farrowing, the concentration of these hormones was higher during the second parity. Taken together, sows’ parity and dietary Ca-Mg complex supplementation influenced serum metabolites, colostrum nutrients, stress hormones as well as the gene expressions related to lipid and glucose metabolism.