Wafer level reliability testing: An idea whose time has come

Wafer level reliability testing has been nurtured in the DARPA supported workshops, held each autumn since 1982. The seeds planted in 1982 have produced an active crop of very large scale integration manufacturers applying wafer level reliability test methods. Computer Aided Reliability (CAR) is a new seed being nurtured. Users are now being awakened by the huge economic value of the wafer reliability testing technology

Modular Palladium Bipyrazoles for the Isomerization of Allylbenzenes - Mechanistic Considerations and Insights into Catalyst Design and Activity, Role of Solvent, and Additive Effects

The catalytic activity of novel bidentate N,N-chelated palladium complexes derived from electron excessive, backbone fused 3,3′-bipyrazoles in the selective isomerization of terminal arylpropenoids and 1-alkenes is described. The catalysts are easily modified by appropriate wing tip substitution, while maintaining the same bulky, rigid unreactive aliphatic backbone. Eleven novel palladium complexes with different electronic and steric properties were investigated. Their performance in the palladium(II)-catalyzed isomerization of a series of substituted allylbenzenes was evaluated in terms of electronic as well as steric effects. Besides the clear finding of a general trend towards higher catalyst activity with more electron-donating properties of the coordinated N,N-bidentate ligands, we found that the catalytic process strongly depends on the choice of solvents and additives. Extensive solvent screening revealed that reactions run best in a 2:1 toluene-methanol mixture, with the alcohol employed being a crucial factor in terms of electronic and steric factors. A reaction mechanism involving a hydride addition–elimination mechanism starting with a palladium hydride species generated in situ in alcoholic solutions, as corroborated by experiments using deuterium labeled allylbenzene, seems to be most likely. The proposed mechanism is also supported by the observed reaction rate orders of κobs[cat.]≈1 (0.94), κobs [substrate]=0.20→1.0 (t→∞) and κobs [methanol]=−0.51 for the isomerization of allylbenzene. Furthermore, the influence of acid and base, as well as the role of the halide coordinated to the catalyst, are discussed. The system catalyzes the isomerization of allylbenzenes very efficiently yielding high E:Z selectivities under very mild conditions (room temperature) and at low catalyst loadings of 1 mol% palladium even in unpurified solvents. The integrity and stability of the catalyst system were confirmed by multiple addition reaction cycles, successive filtration and isolation experiments, and the lack of palladium black formation

Grapevine breeding under climate change: Applicability of a molecular marker linked to véraison

Viticulture is of high economic value. Traditional grapevine cultivars (Vitis vinifera L.) are used in adaptation to the climatic conditions from Northern to Southern European growing areas. However, the recent trend of global warming causes quality deficits due to a shift of the plant's development to earlier times in the year. As a consequence, premature ripening happens under warm temperatures and interferes with the balanced accumulation of sugars, acids, aroma profiles and berry coloration. Modern grapevine breeding is challenged to include the ripening behavior as an important trait (besides pathogen resistance and other characteristics) into the development of novel cultivars well suited for sustainable viticulture. Breeders nowadays apply molecular markers to follow the introgression of desired traits on the genetic level. Previous work has identified a molecular tag on grapevine chromosome 16 strongly linked to the time of véraison, the start of the second phase of berry ripening, in a segregating cross population. In this study we analyzed the transferability of this marker to a set of 36 grapevine cultivars commonly used in German viticulture. Association analysis verified the predictive character of the time point of véraison for maturation time and confirmed the diagnostic potential of the véraison-linked marker in this extended set of cultivars

Molecular interconversion behaviour in comprehensive two-dimensional gas chromatography

Comprehensive two-dimensional gas chromatography (GC x GC) is shown to provide information on dynamic molecular behaviour (interconversion), with the interconversion process occurring on both columns in the coupled-column experiment. The experiment requires suitable adjustment of both experimental conditions and relative dimensions of each of the columns. In this case, a longer column than normally employed in GC x GC allows sufficient retention duration on the second column, which permits the typical plateau-shape recognised for the interconversion process to be observed. The extent of interconversion depends on prevailing temperature, retention time, and the phase type. Polyethylene glycol-based phases were found to result in high interconversion kinetics, although terephthalic acid-terminated polyethylene glycol had a lesser extent of interconversion. Much less interconversion was seen for phenyl-methylpolysiloxane and cyclodextrin phases. This suggests that for the oximes, interconversion largely occurs in the stationary phase. Examples of different extents of interconversion in both dimensions are shown, including peak coalescence on the first column with little interconversion on the second column

A 'Regent' pedigree update: ancestors, offspring and their confirmed resistance loci

'Regent' is the fungal resistant grapevine cultivar with the highest acreage in Germany and an important resistance donor in international breeding programs. It carries the resistance loci Rpv3.1 as well as Ren3 and Ren9 against downy and powdery mildew, respectively. As the parents of 'Chambourcin', the resistant paternal ancestor of 'Regent', did not coincide with the breeder's information, the germplasm repository of JKI Geilweilerhof was screened to find the missing ancestors. SSR marker analysis revealed that 'Joannes Seyve 11369' and 'Plantet' are the true parents of 'Chambourcin' and not 'Seyve Villard 12-417' and 'Chancellor'. Furthermore, the origin of the resistance loci Ren3 and Ren9 could be traced back to the genotypes 'Seibel 4614' and 'Munson'. Since the breeder Hermann Jaeger mentioned 'Munson' as a direct descendant of Vitis aestivalis Michx. var. linsecomii (Buckley) L. H. Bailey and Vitis rupestris Scheele, one of these wild species might have been the donor of the loci

Domain wall pinning in a circular cross-section wire with modulated diameter

Domain wall propagation in cylindrical nanowires with modulations of diameter is a key phenomenon to design physics-oriented devices, or a disruptive three-dimensional magnetic memory. This chapter presents a combination of analytical modelling and micromagnetic simulations, with the aim to present a comprehensive panorama of the physics of pinning of domain walls at modulations, when moved under the stimulus of a magnetic field or a spin-polarized current. For the sake of considering simple physics, we consider diameters of a few tens of nanometers at most, and accordingly domain walls of transverse type. Modeling with suitable approximations provides simple scaling laws, while simulations are more accurate, refining the results and defining the range of validity of the models. While pinning increases with the relative change of diameter, a key feature is the much larger efficiency of pinning at an increase of diameter upon considering current rather than field, due to the drastic decrease of current density related to the increase of diameter.Comment: 37 pages, 14 figures, overview chapte

Preproglucagon neurons in the hindbrain have IL-6 Receptor α (IL-6Rα) and show Ca 2+ influx in response to IL-6

Neuronal circuits in the hypothalamus and hindbrain are of importance for control of food intake, energy expenditure, and fat mass. We have recently shown that treatment with exendin-4 (Ex-4), an analog of the proglucagon-derived molecule glucagon-like peptide 1 (GLP-1), markedly increases mRNA expression of the cytokine interleukin-6 (IL-6) in the hypothalamus and hindbrain and that this increase partly mediates the suppression of food intake and body weight by Ex-4. Endogenous GLP-1 in the central nervous system (CNS) is produced by preproglucagon (PPG) neurons of the nucleus of the solitary tract (NTS) in the hindbrain. These neurons project to various parts of the brain, including the hypothalamus. Outside the brain, IL-6 stimulates GLP-1 secretion from the gut and pancreas. In this study, we aim to investigate whether IL-6 can affect GLP-1-producing PPG neurons in the nucleus of the solitary tract (NTS) in mouse hindbrain via the ligand binding part of the IL-6 receptor, IL-6 receptor-α (IL-6Rα). Using immunohistochemistry, we found that IL-6Rα was localized on PPG neurons of the NTS. Recordings of these neurons in GCaMP3/GLP-1 reporter mice showed that IL-6 enhances cytosolic Ca2+ concentration in neurons capable of expressing PPG. We also show that the Ca2+ increase originates from the extracellular space. Furthermore, we found that IL-6Rα was localized on cells in the caudal hindbrain expressing immunoreactive NeuN (a neuronal marker) or CNP:ase (an oligodendrocyte marker). In summary, IL-6Rα is present on PPG neurons in the NTS, and IL-6 can stimulate these cells by increasing influx of Ca2+ to the cytosol from the extracellular space

Bulky and Modular 3,3′-Bipyrazoles as Ligands: Synthesis, Characterization, and Catalytic Activity of Pd Complexes

In the present study, the properties of a new bidentate N,N′-chelating ligand class that bears an electron-excessive 3,3′-bipyrazole core have been investigated. The ligands are easily accessible in a three-step procedure by condensation with diethyl oxalate followed by tandem condensation with hydrazine hydrate and finally by aryl- or alkylation exclusively at the N-1,1′-pyrazole positions to furnish overall eleven new ligands with different electronic properties. After structural analysis of the ligands, their coordination to palladium, copper, and cobalt has been studied. These ligands coordinate the 2,2′-pyrazolyl nitrogen atoms in a bidentate fashion to the metals to realize complexes with an (L)MX2 motif. We present two crystal structures of Pd and Cu complexes, which to the best of our knowledge represent the first d8 and d9 2,2′-bipyrazole compounds coordinated through bidentate complexation. Initial catalytic experiments have been performed with palladium complexes with three bipyrazole ligands of this new class; the palladium-catalyzed copper-free Wacker oxidation of different alkenes showed superior activity compared to 2,2′-bipyridines. We attribute this to a higher redox potential of the 3,3′-bipyrazoles, which are ― besides electronic effects ― also strongly influenced by steric effects. These might be enforced by the extended ligand backbone, the choice of the wingtip substitution, and the smaller coordination cavity within the N2,N2′ atoms compared to 2,2′-bipyridine ligands