LES of the flow around two cylinders in tandem

The flow around an arrangement of two-in-tandem cylinders exhibits a remarkably complex behaviour that is of interest for many engineering problems, such as environmental flows or structural design. In the present paper, a Large Eddy Simulation using a staggered Cartesian grid has been performed for the flow around two-in-tandem cylinders of diameter D=20mm and height H=50mm submerged in an open channel with height h=60 mm. The two axes have a streamwise spacing of 2D. The Reynolds number is 1500, based on the cylinder diameter and the free-stream velocity u�. The results obtained show that no vortex shedding occurs in the gap between the two cylinders where the separated shear layers produced by the upstream cylinder reattach on the surface of the downstream one. The flow separates on the top of the first cylinder with the presence of two spiral nodes known as owl-face configuration. On top of the downstream cylinder, the flow is attached. A complex mean flow develops in the gap and also behind the second cylinder. Comparisons with PIV measurements reveal good general agreement, but there are differences concerning some details of the flow in the gap between the cylinders

A Triple Newman-Kwart Rearrangement at a Fully Substituted Benzene Ring

Theil H, Froehlich R, Glaser T. A Triple Newman-Kwart Rearrangement at a Fully Substituted Benzene Ring. ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES. 2009;64(11-12):1633-1638.The Newman-Kwart rearrangement of O-thiocarbamates to S-thiocarbamates is a versatile method for the conversion of phenols into thiophenols. The triple rearrangement of the O-trithiocarbamate 2,4,6-triacetyl-1,3,5-tri-(dimethylthiocarbamoyloxy)benzene (2) to the S-trithiocarbamate 2,4,6-triacetyl-1,3,5-tri-(dimethylthiocarbamoylthio)benzene (3) is performed, which is unprecendented for fully substituted benzene rings. The synthesis and characterization of the O-trithiocarbamate 2 and the S-trithiocarbamate 3 including the single-crystal X-ray structure analysis of compound 3 are presented

The first trinuclear manganese triplesalen complex: Synthesis, structural, and magnetic characterization of [(talen(NO2)){Mn-III(DMSO)(2)}(3)](ClO4)(3)

Glaser T, Heidemeier M, Froehlich R. The first trinuclear manganese triplesalen complex: Synthesis, structural, and magnetic characterization of [(talen(NO2)){Mn-III(DMSO)(2)}(3)](ClO4)(3). COMPTES RENDUS CHIMIE. 2007;10(1-2):71-78.The reaction of the nitro-substituted triplesalen ligand H(6)talen(NO2) with Mn(ClO4)(2)center dot 6H(2)O in CH3CN in the presence of Et3N and DMSO results in the formation of [(talen(NO2)){Mn-III(DMSO)(2)}(3)](ClO4)(3) (1) which has been characterized by elemental analysis, FTIR, UV-vis-NIR, ESI-MS, single-crystal X-ray diffraction, and magnetic measurements. The triplesalen ligand (talen(NO2))(6-) provides three salen-like coordination environments bridged in a meta-phenylene arrangement by a phloroglucinol backbone. The coordination environment of each Mn-III ion is completed by two O-bonded DMSO molecules. The folding of the triplesaten ligand results in an overall dish-like geometry for the trication in 1. The magnetic characterization has been performed by temperature dependent magnetic susceptibility measurements and variable temperature-variable field (VTVH) magnetization data in order to determine both the exchange couplings J between the S-i = 2 ion and the local zero-field splittings D-i. Simulations to the appropriate spin-Hamiltonian using a full-matrix diagonalization approach provided a weak antiferromagnetic interaction J = -0.30 +/- 0.05 cm(-1) but a strong magnetic anisotropy expressed by D = -4.0 +/- 0.4 cm(-1). The potential applications of 1 and forthcoming members of this new family of trinuclear manganese triplesalen complexes in molecule-based magnetism and homogenous catalysis are discussed

Exchange Interactions and Zero-Field Splittings in C-3-Symmetric (Mn6FeIII)-Fe-III: Using Molecular Recognition for the Construction of a Series of High Spin Complexes Based on the Triplesalen Ligand

Glaser T, Heidemeier M, Krickemeyer E, et al. Exchange Interactions and Zero-Field Splittings in C-3-Symmetric (Mn6FeIII)-Fe-III: Using Molecular Recognition for the Construction of a Series of High Spin Complexes Based on the Triplesalen Ligand. Inorganic Chemistry. 2009;48(2):607-620.The reaction of the tris(tetradentate) triplesalen ligand H(6)talen(t-Bu2), which provides three salen-like coordination environments bridged in a meta-phenylene arrangement by a phloroglucinol backbone, with Mn-II salts under aerobic conditions affords, in situ, the trinuclear Mn-III triplesalen complexes [(talen(2)(t-Bu)){Mn-III(solv)(n)}(3)](3+). These can be used as molecular building blocks in the reaction with [Fe(CN)(6)](3-) as a hexaconnector to form the heptanuclear complex [{(talen(2)(t-Bu)){Mn-III(solv)(n)}(3)}(2){Fe-III(CN)(6)}](3+) ([(Mn6FeIII)-Fe-III](3+)). The regular ligand folding observed in the trinuclear triplesalen complexes preorganizes the three metal ions for the reaction of three facially coordinated nitrogen atoms of a hexacyanometallate and provides a driving force for the formation of the heptanuclear complexes [(M6Mc)-M-t](n+) (M-t, terminal metal ion of the triplesalen building block; Me, central metal ion of the hexacyanometallate) by molecular recognition, as has already been demonstrated for the single-molecule magnet [(Mn6CrIII)-Cr-III](3+)center dot [{(talen(2)(t-Bu))(Mn-III(MeOH))(3)}(2){Fe-III(CN)(6)}][Fe-III(CN)(6)] (1) was characterized by single-crystal X-ray diffraction, FTIR, ESI- and MALDI-TOF-MS, Mossbauer spectroscopy, and magnetic measurements. The molecular structure of [(Mn6FeIII)-Fe-III](3+) is overall identical to that of [(Mn6CrIII)-Cr-III](3+) but exhibits a different ligand folding of the Mn-III salen subunits with a helical distortion. The Mossbauer spectra demonstrate a stronger distortion from octahedral symmetry for the central [Fe(CN)(6)](3-) in comparison to the ionic [Fe(CN)(6)](3-). At low temperatures in zero magnetic fields, the Mossbauer spectra show magnetic splittings indicative of slow relaxation of the magnetization on the Mossbauer time scale. Variable-temperature-variable-field and yen versus T magnetic data have been analyzed in detail by full-matrix diagonalization of the appropriate spin-Hamiltonian, consisting of isotropic exchange, zero-field splitting, and Zeeman interaction taking into account the relative orientation of the D tensors. Satisfactory reproduction of the experimental data has been obtained for parameters sets J(Mn-Mn) = -(0.85 +/- 0.15) cm(-1), J(Fe-Mn) = +(0.70 +/- 0.30) cm(-1), and D-Mn = -(3.0 +/- 0.7) cm(-1). Comparing these values to those of [Mn Cr-III(6)III](3+) provides insight into why [(Mn6FeIII)-Fe-III](3+) is not a single-molecule magnet

Improved cryotolerance and developmental potential of in vitro and in vivo matured mouse oocytes by supplementing with a glutathione donor prior to vitrification

Trapphoff T, Heiligentag M, Simon J, et al. Improved cryotolerance and developmental potential of in vitro and in vivo matured mouse oocytes by supplementing with a glutathione donor prior to vitrification. MOLECULAR HUMAN REPRODUCTION. 2016;22(12):867-881.STUDY QUESTION: Can supplementation of media with a glutathione (GSH) donor, glutathione ethyl ester (GEE), prior to vitrification protect the mouse oocyte from oxidative damage and critical changes in redox homeostasis, and thereby improve cryotolerance? SUMMARY ANSWER: GEE supplementation supported redox regulation, rapid recovery of spindle and chromosome alignment after vitrification/warming and improved preimplantation development of mouse metaphase II (MII) oocytes. WHAT IS KNOWN ALREADY: Cryopreservation may affect mitochondrial functionality, induce oxidative stress, and thereby affect spindle integrity, chromosome segregation and the quality of mammalian oocytes. GEE is a membrane permeable GSH donor that promoted fertilization and early embryonic development of macaque and bovine oocytes after IVM. STUDY DESIGN, SIZE, DURATION: Two experimental groups consisted of (i) denuded mouse germinal vesicle (GV) oocytes that were matured in vitro in the presence or absence of 1 mM GEE (IVM group 1) and (ii) in vivo ovulated (IVO) MII oocytes that were isolated from the ampullae and exposed to 1 mM GEE for 1 h prior to vitrification (IVO group 2). Recovery of oocytes from both groups was followed after CryoTop vitrification/warming for up to 2 h and parthenogenetic activation. PARTICIPANTS/MATERIALS, SETTING, METHODS: Reactive oxygen species (ROS), spindle morphology and chromosome alignment were analyzed by confocal laser scanning microscopy (CLSM) and polarization microscopy in control and GEE-supplemented MII oocytes. The relative overall intra-oocyte GSH content was assessed by analysis of monochlorobimane (MBC)-GSH adduct fluorescence in IVM MII oocytes. The GSH-dependent intra-mitochondrial redox potential (Em GSH) of IVM MII oocytes was determined after microinjection with specific mRNA at the GV stage to express a redox-sensitive probe within mitochondria (mito-Grx1-roGFP2). The absolute negative redox capacity (in millivolts) was determined by analysis of fluorescence of the oxidized versus the reduced form of sensor by CLSM and quantification according to Nernst equation. Proteome analysis was performed by quantitative 2D saturation gel electrophoresis (2D DIGE). Since microinjection and expression of redox sensor mRNA required removal of cumulus cells, and IVM of denuded mouse oocytes in group 1 induces zona hardening, the development to blastocysts was not assessed after IVF but instead after parthenogenetic activation of vitrified/warmed MII oocytes from both experimental groups. MAIN RESULTS AND ROLE OF CHANCE: IVM of denuded mouse oocytes in the presence of 1 mM GEE significantly increased intraoocyte GSH content. ROS was not increased by CryoTop vitrification but was significantly lower in the IVM GEE group compared to IVM without GEE before vitrification and after recovery from vitrification/warming (P < 0.001). Vitrification alone significantly increased the GSH-dependent intra-mitochondrial redox capacity after warming (E-GSH(m), P < 0.001) in IVM oocytes, presumably by diffusion/uptake of cytoplasmic GSH into mitochondria. The presence of 1 mM GEE during IVM increased the redox capacity before vitrification and there was no further increase after vitrification/warming. None of the reproducibly detected 1492 spots of 2D DIGE separated proteins were significantly altered by vitrification or GEE supplementation. However, IVM of denuded oocytes significantly affected spindle integrity and chromosome alignment right after warming from vitrification (0 h) in group 1 and spindle integrity in group 2 (P < 0.05). GEE improved recovery in IVM group as numbers of oocytes with unaligned chromosomes and aberrant spindles was not significantly increased compared to unvitrified controls. The supplementation with GEE for 1 h before vitrification also supported more rapid recovery of spindle birefringence. GEE improved significantly development to the 2-cell stage for MII oocytes that were activated directly after vitrification/warming in both experimental groups, and also the blastocyst rate in the IVO GEE-supplemented group compared to the controls (P < 0.05). LARGE SCALE DATA: None LIMITATIONS, REASONS FOR CAUTION: The studies were carried out in a mouse model, in IVM denuded rather than cumulus-enclosed oocytes, and in activated rather than IVF MII oocytes. Whether the increased GSH-dependent intra-mitochondrial redox capacity also improves male pronuclear formation needs to be studied further experimentally. The influence of GEE supplementation requires also further examination and optimization in human oocytes before it can be considered for clinical ART. WIDER IMPLICATIONS OF THE FINDINGS: Although GEE supplementation did not alter the proteome at MII, the GSH donor may support cellular homeostasis and redox regulation and, thus, increase developmental competence. While human MII oocyte vitrification is an established procedure, GEE might be particularly beneficial for oocytes that suffer from oxidative stress and reduced redox capacity (e.g. aged oocytes) or possess low GSH due to a reduced supply of GSH from cumulus. It might also be of relevance for immature human oocytes that develop without cumulus to MII in vitro (e.g. in ICSI cycles) for ART. STUDY FUNDING AND COMPETING INTERESTS: The study has been supported by the German Research Foundation (DFG FOR 1041; EI 199/3-2). There are no conflict of interests

Edutainment (semester?), IPRO 329: Edutainment IPRO 329 Project Plan Sp05

This semester IPRO 329, Edutainment, turns its complete efforts toward an educational computer gaming suite targeted at fourth-grade students and the subjects these students struggle with most in school. It is tentatively entitled Scholars of the Lost Exhibit. Work on this project began last semester as the team completed their award-winning game College Pursuit. During this semester, we will focus on the design, development, testing, and marketing of Scholars of the Lost Exhibit.Deliverables for IPRO 329: Edutainment for the Spring 2005 semeste

Edutainment (semester?), IPRO 329: Edutainment IPRO 329 Poster 2 Sp05

This semester IPRO 329, Edutainment, turns its complete efforts toward an educational computer gaming suite targeted at fourth-grade students and the subjects these students struggle with most in school. It is tentatively entitled Scholars of the Lost Exhibit. Work on this project began last semester as the team completed their award-winning game College Pursuit. During this semester, we will focus on the design, development, testing, and marketing of Scholars of the Lost Exhibit.Deliverables for IPRO 329: Edutainment for the Spring 2005 semeste

Edutainment (semester?), IPRO 329: Edutainment IPRO 329 Midterm Report Sp05

This semester IPRO 329, Edutainment, turns its complete efforts toward an educational computer gaming suite targeted at fourth-grade students and the subjects these students struggle with most in school. It is tentatively entitled Scholars of the Lost Exhibit. Work on this project began last semester as the team completed their award-winning game College Pursuit. During this semester, we will focus on the design, development, testing, and marketing of Scholars of the Lost Exhibit.Deliverables for IPRO 329: Edutainment for the Spring 2005 semeste

Edutainment (semester?), IPRO 329: Edutainment IPRO 329 Poster 1 Sp05

This semester IPRO 329, Edutainment, turns its complete efforts toward an educational computer gaming suite targeted at fourth-grade students and the subjects these students struggle with most in school. It is tentatively entitled Scholars of the Lost Exhibit. Work on this project began last semester as the team completed their award-winning game College Pursuit. During this semester, we will focus on the design, development, testing, and marketing of Scholars of the Lost Exhibit.Deliverables for IPRO 329: Edutainment for the Spring 2005 semeste

Edutainment (semester?), IPRO 329: Edutainment IPRO 329 Abstract Sp05

This semester IPRO 329, Edutainment, turns its complete efforts toward an educational computer gaming suite targeted at fourth-grade students and the subjects these students struggle with most in school. It is tentatively entitled Scholars of the Lost Exhibit. Work on this project began last semester as the team completed their award-winning game College Pursuit. During this semester, we will focus on the design, development, testing, and marketing of Scholars of the Lost Exhibit.Deliverables for IPRO 329: Edutainment for the Spring 2005 semeste