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Bei Patienten mit Diabetes mellitus Typ 2 muss im Falle einer unklaren Bewusstseinsstorung und/oder Bauchschmerzen eine Natrium/Glukose-Kotransporter-2(SGLT-2)-Inhibitor-induzierte diabetische Ketoazidose in die Differenzialdiagnose einbezogen werden. Dabei konnen die Blutzuckerspiegel trotz ausgepragter Azidose nur moderat erhoht sein. Bei Nachweis ist eine umgehende intensivmedizinische Therapie unerlasslich.

Prokalzitonin (PCT) wird bei systemischen Inflammationszustanden IL6-, IL8- und TNF-α-vermittelt in multiplen Organen und Strukturen des Korpers gebildet. Dabei werden insbesondere bei der Sepsis deutlich erhohte Werte gemessen. Die Hohe des PCT korreliert dabei gut mit der Krankheitsschwere, ein signifikanter Abfall unter Therapie mit der Prognose. In der differenzialdiagnostischen Abklarung kann die PCT-Bestimmung zwischen bakteriellen und viralen Infektionen unterscheiden. Nichtinfektiosbedingte inflammatorische Reaktionen konnen jedoch moderat erhohte PCT-Werte zeigen. Cut-off-Werte sind abhangig von der renalen und hepatischen Funktion. Ein Therapiealgorithmus zur Antibiotikadauer mit PCT-Verlaufsbestimmungen kann den Antibiotikagebrauch reduzieren. In dieser Arbeit sollen die differenzialdiagnostischen und differenzialtherapeutischen Moglichkeiten einer Prokalzitoninbestimmung bei kritisch kranken Patienten erortert werden.

Patients with type 2 diabetes who present with confusion and/or abdominal pains should be screened for sodium-glucose cotransporter 2 (SGLT-2)-induced diabetic ketoacidosis. Severe acidosis was diagnosed despite only moderately increased blood sugar levels. If so, immediate ICU treatment is essential.Bei Patienten mit Diabetes mellitus Typ 2 muss im Falle einer unklaren Bewusstseinsstörung und/oder Bauchschmerzen eine Natrium/Glukose-Kotransporter-2(SGLT-2)-Inhibitor-induzierte diabetische Ketoazidose in die Differenzialdiagnose einbezogen werden. Dabei können die Blutzuckerspiegel trotz ausgeprägter Azidose nur moderat erhöht sein. Bei Nachweis ist eine umgehende intensivmedizinische Therapie unerlässlich.

En 2014, l'INRS s'est doté d'un système de génération de nanoaérosols adapté aux études de toxicologie par inhalation. Baptisé NanoTIREx pour « Nanomaterial Toxicology Inhalation system for Rodent Exposure », ce dispositif a depuis été mis en ?uvre au cours d'une quinzaine de campagnes d'exposition subaiguë (1 mois) avec différents types d'aérosols (issus de différentes natures de poudre et avec des granulométries et des niveaux de concentrations variés). Nous proposonsde faire un retour d'expérience et d'évoquer quels ont été les challenges à relever pour mener à bien ce type d'expérimentation et en quoi la mise en place d'une stratégie de métrologie des aérosols adaptée a permis de surmonter certains obstacles et de répondre aux besoins de la toxicologie., INRS has developped a nanoaerosol generation system adapted to inhalation toxicology studies called NanoTIREx for "Nanomaterial Toxicology Inhalation System for Rodent Exposure". Since 2014, this inhalation facility has been implemented during fifteen subacute exposure campaigns (1 month) with different types of aerosols (from different powder and with varying sizes distributions and concentrations). We proposeto make a 5-year feedback and to discuss what were the challenges to be faced with this type of experimentation and how a well-designed aerosol metrology strategy allowed to overcome certain obstacles and meet the needs of toxicology.

Salimabromide is an antibiotic polyketide that was previously isolated from the obligate marine myxobacterium Enhygromyxa salina, and its densely functionalized and conformationally rigid tetracyclic framework is unprecedented in nature. Herein we report the first chemical synthesis of the target structure by employing a series of well-orchestrated, robust transformations, highlighted by an acid-promoted, powerful Wagner-Meerwein rearrangement/Friedel-Crafts cyclization sequence to forge the two adjacent quaternary carbon centers embedded in the tetrahydronaphthalene. A high-yielding ketiminium mediated [2+2]-cycloaddition was also utilized for the simultaneous construction of the remaining three stereocenters.

Lagrangian floats and current meter measurements from two moored arrays are analyzed, in combination with altimetry data, in order to investigate the recirculation of Antarctic Intermediate Waters (AAIW), and of the Intermediate Western Boundary Current (IWBC) at the Tubarao Bight, in the vicinity of the Vitoria-Trindade Ridge (VTR), Brazil. Results from a high-resolution numerical simulation provide a complementary view of the flow at intermediate and surface levels. The data depict a topographically-induced cyclonic recirculation at intermediate levels, and five Argo floats are successively trapped inside the bight for two-and-a-half years, performing a total of 10 closed clockwise gyres during this period of time. In situ measurements at the western side of the bight show an intense alongshore flow at intermediate levels, with averaged velocities at 800 m of ~30 cm/s, and peak velocities exceeding 50 cm/s, magnitudes comparable to the Brazil Current (BC) flow at surface levels. The recirculation extends from at least 1000 m deep up to 370 m, reaching sometimes depths as shallow as 150 m, but is mostly uncoupled from the surface flow during the one-and-a-half year long current meter record. Three different flow patterns are observed, and simulated, at surface levels inside the bight during the time the recirculation is well established at intermediate levels: a shallow cyclonic circulation, somewhat akin to the Vitoria Eddy; a recurrent anticyclonic flow that encompasses the entire bight; and a southwestward-oriented circulation, associated with the BC being reorganized in a coherent flow after negotiating its way through the VTR channels. A significant portion (about 50% according to the model) of the inflow of intermediate waters recirculates, enhancing the flow of the IWBC within the bight, and increasing the age of AAIW that will eventually cross the VTR on its way to lower latitudes. Although the data are not conclusive about a preferential pathway of the intermediate flow across the VTR, the simulation indicates that up to 70% will exit through the main channel located between the Besnard Bank and the Vitoria Seamount, while 30% will follow eastward to the south of the VTR, in a region of intense mesoscale activity, and then cross the ridge farther east.

Due to the limited transportable length of power cables, especially with large conductor cross-sections, it is necessary to connect several cable sections to cover long distances. Today, mostly screw connectors are used for such connections. It is not sufficiently known how to connect optimally the conductor ends in order to achieve a long lasting reliability of the connection system and thus the availability of the entire cable route. For this reason, it makes sense to optimize the cable connectors in such a way that transmission reliability is guaranteed. In order to achieve this, it is necessary to simulate the contact behaviour of different conductor constructions in a screw connector with regard to its transmission resistance, the current densities occurring, and the resulting power dissipation. Preliminary investigations have been carried out with the objective to understand the behaviour of an existing screw connector for MV (Medium Voltage) cables based on FEM (Finite Element Method) simulations. Main questions have been how the current density behaves in a standard connector and how the current density distribution can be optimized by changing the screw position, number, size and torque. The second step has been to investigate the transmission behaviour of connector for Single-Core (SC) conductor in detail. For this purpose, FEM simulations and practical measurements, based on e.g. the VDE (German: Verband der Elektrotechnik, Elektronik und Informationstechnik) standard are used to determine and compare the transmission resistance of a conductor connection with a standard connector. Based on these investigations, it shall be determined which factors are decisive for the optimization of such a connection.

We describe the evolution of a synthetic strategy for the construction of the marine polyketide salimabromide. Combining a bicyclo[3.1.0]hexan-2-one ring-expansion to build up a functionalized naphthalene and an unprecedented rearrangement/cyclization cascade, enabled synthesis of a dearomatized tricyclic subunit of the target compound. Alternatively, an intramolecular ketiminium [2+2]-cycloaddition and subsequent Baeyer-Villiger ring-expansion gave access to the sterically encumbered architecture of salimabromide. Sequential oxidation of the carbon framework finally enabled the total synthesis of this unusual natural product.

Fusarium head blight (FHB) in triticale (× Triticosecale Wittmack) results in yield losses and mycotoxin contamination, for example, by deoxynivalenol (DON). This study aimed to analyse the correlation between FHB severity and DON content in a DH population of 146 entries across environments. Additionally, Fusarium damaged kernel (FDK) rating, heading stage and plant height were recorded. Highly significant (P

Described is the development of a highly efficient 2π disrotatory ring-opening aromatization sequence using bicyclo[3.1.0]hexan-2-ones. This unprecedented transformation efficiently proceeds under thermal conditions and allows facile construction of uniquely substituted and polyfunctionalized benzoates. In the presence of either amines or alcohols formation of substituted anilines or ethers, respectively, is achieved. Additionally, the utility of this method was demonstrated in a short synthesis of sekikaic acid methyl ester.

A MEMS scanner with a high level of motion freedom has been developed. It includes a 2D mechanical tilting capability of +/- 15°, a piston motion of 50μm and a focus/defocus control system of a 2mm diameter mirror. The tilt and piston motion is achieved with an electromagnetic actuation (moving magnet) and the focus control with a deformation of the reflective surface with pneumatic actuation. This required the fabrication of at least one channel on the compliant membrane and a closed cavity below the mirror surface and connected to an external pressure regulator (vacuum to several bars). The fabrication relies on 3 SOI wafers, 2 for forming the compliant membranes and the integrated channel, and 1 to form the cavity mirror. All wafers were then assembled by fusion bonding. Pneumatic actuation for focus control can be achieved from front or back side; function of packaging concept. A reflective coating can be added at the mirror surface depending of the application. The tilt and piston actuation is achieved by electromagnetic actuation for which a magnet is fixed on the moving part of the MEMS device. Finally the MEMS device is mounted on a ceramic PCB, containing the actuation micro-coils. Concept, fabrication, and testing of the devices will be presented. A case study for application in an endoscope with an integrated high power laser and a MEMS steering mechanism will be presented.

This review highlights the chemistry of trihaloethene building blocks with a special focus on commercially available 1,1,2-trichloroethene. The topics surveyed herein include the use of trihaloethenes as C2-building blocks for transition metal-catalyzed coupling reactions, addition, elimination and cycloaddition reactions as well as natural product syntheses.

We report the synthesis of orthogonally functionalized naphthalenes from simple, commercially available indanones in four steps. The developed method proceeds through a two-step process that features a thermally induced fragmentation of a cyclopropane indanone with simultaneous 1,2-chloride shift. Migration of the chloride substituent occurs in a regioselective manner to preferentially afford the para-chloronaphthol substitution pattern. The obtained naphthols are versatile building blocks that can be selectively modified and used for the efficient construction of biologically active molecules. This has enabled the total synthesis of the potent anticancer natural product chartarin through a highly convergent retrosynthetic bond disconnection.

This review highlights the chemistry of trihaloethene building blocks with a special focus on commercially available 1,1,2-trichloroethene. The topics surveyed herein include the use of trihaloethenes as C2-building blocks for transition metal-catalyzed coupling reactions, addition, elimination and cycloaddition reactions as well as natural product syntheses.

Described is the development of a highly efficient 2π disrotatory ring-opening aromatization sequence using bicyclo[3.1.0]hexan-2-ones. This unprecedented transformation efficiently proceeds under thermal conditions and allows facile construction of uniquely substituted and polyfunctionalized benzoates. In the presence of either amines or alcohols formation of substituted anilines or ethers, respectively, is achieved. Additionally, the utility of this method was demonstrated in a short synthesis of sekikaic acid methyl ester.

This paper summarizes the experimental investigations on joint resistance and current distribution of connections with straight connectors. Different sizes (2–4 covers) and types of contact surface (as cast, riffled) are reviewed. Connectors with 2 covers have the lowest joint resistance whereas connectors with 4 covers do have the best performance factor. The kind of contact surface does not affect the initial joint resistance. To compare these two conductor groove shapes long term tests are necessary. Calculations using a resistance network prove the measured initial joint resistances. The current distribution in the connector body is influenced insignificantly by the joint resistance. The more covers a connector possesses the longer is the estimated lifetime.

Case series. To evaluate the risk of pump- and catheter-related complications of intrathecal drug delivery systems. Tertiary care center in Switzerland. The medical records of all in- and out-patient adults treated at our institution during a 12-year period were reviewed. All patients that had received intrathecal drug therapy via an implanted pump were invited to a structured interview. One hundred patients, representing therapy with 175 implanted pumps and 132 intrathecal catheters over 552 years, participated in the study. During the observation period, 217 surgical procedures (including 100 primary pump implants) and 5863 pump refills were performed. The annual rate for complications requiring surgical measures was 10.5%, with 35% being pump related and 65% being catheter related. The incidence of infections in our patients was 0.7% per year; all infections appeared during the first 3 months after implantation of the first pump. Complication rates of the patients treated in our center, where we have long-term experience with the indication, implantation and continuous care of patients with intrathecal infusion systems, are in the lowest ranges when compared with other published studies. We consider intrathecal testing before implantation, standardized perioperative procedures and consequent long-term care of the patients in a specialized outpatient clinic to be essential factors for the avoidance of complications.

Electrical joints can be a weak points and with it endanger the reliability of electrical power-transmission systems. On the example of Aluminium-to-Aluminium and Aluminium-to-Copper busbar joints is shown how one can get information about the principle ageing behaviour from long-term test. Furthermore a possibility is presented to determine limiting values for the joint resistance and to calculate the lifetime of a joint depending on the construction, conductor material and loading.

Electrical joints are subjected to an ageing process which can endanger the reliability of electrical power transmission systems. A mathematical model is presented with the help of which the ageing behaviour of electrical joints can be estimated depending on the conductor material, the construction of the joint, the assembly technology and the loading construction. The model is based on theoretical reflections as well as practical investigations on busbar joints for more than 16 years.

V1 and V2b interneurons (INs) are essential for the production of an alternating flexor–extensor motor output. Using a tripartite genetic system to selectively ablate either V1 or V2b INs in the caudal spinal cord and assess their specific functions in awake behaving animals, we find that V1 and V2b INs function in an opposing manner to control flexor–extensor-driven movements. Ablation of V1 INs results in limb hyperflexion, suggesting that V1 IN-derived inhibition is needed for proper extension movements of the limb. The loss of V2b INs results in hindlimb hyperextension and a delay in the transition from stance phase to swing phase, demonstrating V2b INs are required for the timely initiation and execution of limb flexion movements. Our findings also reveal a bias in the innervation of flexor- and extensor-related motor neurons by V1 and V2b INs that likely contributes to their differential actions on flexion–extension movements. DOI: http://dx.doi.org/10.7554/eLife.04718.001, eLife digest Although there are many different movements an animal can make with its limbs—from reaching to walking—they all basically involve two sets of muscles that act as opposing levers around each joint. ‘Flexor’ muscles contract to bend the limb, and ‘extensor’ muscles contract to extend the limb. When an animal is walking these two sets of muscles contract repeatedly, one after the other. Inhibitory neurons in the spinal cord coordinate these walking movements by preventing the flexor or extensor muscles from contracting at the same time. In 2014, researchers discovered that two groups of inhibitory neurons, known as the V1 and V2b interneurons, are essential for this alternating pattern of flexing and extending of the limbs of newborn mice. However, these experiments were not able to assess the particular contribution that the V1 and V2b neurons each make to limb movements. Now, Britz et al.—including several of the researchers involved in the 2014 study—have used a sophisticated genetic technique in mice to investigate the role that each group of neurons plays separately. This involved introducing a gene into either the V1 or V2b neurons that makes them susceptible to being killed with the diphtheria toxin. Injecting the mice with diphtheria toxin selectively removed these cells from the regions of the spinal cord that controls hindlimb movements. Britz et al. found that removing either group of neurons prevented the mice from walking normally. Eliminating the V1 neurons caused extreme flexing of the hindlimbs, revealing that the V1 neurons are needed to extend the limb by inhibiting the motor neurons that contract the flexor muscles. In contrast, the loss of V2b neurons caused exaggerated hindlimb extension, indicating that the V2b neurons inhibit the motor neurons that innervate extensor muscles. Both the V1 and V2b groups of neurons contain a wide range of different cell types. Future studies will therefore need to explore how these different cells are involved in coordinating the motions involved in walking. DOI: http://dx.doi.org/10.7554/eLife.04718.002

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetically heterogeneous heart-muscle disorder characterized by progressive fibrofatty replacement of right ventricular myocardium and an increased risk of sudden cardiac death. Mutations in desmosomal proteins that cause ARVC have been previously described; therefore, we investigated 88 unrelated patients with the disorder for mutations in human desmosomal cadherin desmocollin-2 (DSC2). We identified a heterozygous splice-acceptor-site mutation in intron 5 (c.631-2A--G) of the DSC2 gene, which led to the use of a cryptic splice-acceptor site and the creation of a downstream premature termination codon. Quantitative analysis of cardiac DSC2 expression in patient specimens revealed a marked reduction in the abundance of the mutant transcript. Morpholino knockdown in zebrafish embryos revealed a requirement for dsc2 in the establishment of the normal myocardial structure and function, with reduced desmosomal plaque area, loss of the desmosome extracellular electron-dense midlines, and associated myocardial contractility defects. These data identify DSC2 mutations as a cause of ARVC in humans and demonstrate that physiologic levels of DSC2 are crucial for normal cardiac desmosome formation, early cardiac morphogenesis, and cardiac function.

Erythropoietin (EPO) is required for cell survival during differentiation and for progenitor expansion during stress erythropoiesis. Although signaling pathways may couple directly to docking sites on the EPO receptor (EpoR), additional docking molecules expand the signaling platform of the receptor. We studied the roles of the docking molecules Grb2-associated binder-1 (Gab1) and Gab2 in EPO-induced signal transduction and erythropoiesis. Inhibitors of phosphatidylinositide 3-kinase and Src kinases suppressed EPO-dependent phosphorylation of Gab2. In contrast, Gab1 activation depends on recruitment and phosphorylation by the tyrosine kinase receptor RON, with which it is constitutively associated. RON activation induces the phosphorylation of Gab1, mitogen-activated protein kinase (MAPK), and protein kinase B (PKB) but not of signal transducer and activator of transcription 5 (Stat5). RON activation was sufficient to replace EPO in progenitor expansion but not in differentiation. In conclusion, we elucidated a novel mechanism specifically involved in the expansion of erythroblasts involving RON as a downstream target of the EpoR. (Blood. 2004;103:4457-4465)

We analyze transition from amplified spontaneous emission to Q-switched lasing in InGaN laser with absorber. We find narrow region that requires us to evoke cooperative recombination of two electron-hole pairs in X or ? configuration.

SummarySensory circuits in the dorsal spinal cord integrate and transmit multiple cutaneous sensory modalities including the sense of light touch. Here, we identify a population of excitatory interneurons (INs) in the dorsal horn that are important for transmitting innocuous light touch sensation. These neurons express the ROR alpha (RORα) nuclear orphan receptor and are selectively innervated by cutaneous low threshold mechanoreceptors (LTMs). Targeted removal of RORα INs in the dorsal spinal cord leads to a marked reduction in behavioral responsiveness to light touch without affecting responses to noxious and itch stimuli. RORα IN-deficient mice also display a selective deficit in corrective foot movements. This phenotype, together with our demonstration that the RORα INs are innervated by corticospinal and vestibulospinal projection neurons, argues that the RORα INs direct corrective reflex movements by integrating touch information with descending motor commands from the cortex and cerebellum.

In the development of the mammalian intestine, Notch and Wnt/{beta}-catenin signals control stem cell maintenance and their differentiation into absorptive and secretory cells. Mechanisms that regulate differentiation of progenitors into the three secretory lineages, goblet, paneth, or enteroendocrine cells, are not fully understood. Using conditional mutagenesis in mice, we observed that Shp2-mediated MAPK signaling determines the choice between paneth and goblet cell fates and also affects stem cells, which express the leucine-rich repeat-containing receptor 5 (Lgr5). Ablation of the tyrosine phosphatase Shp2 in the intestinal epithelium reduced MAPK signaling and led to a reduction of goblet cells while promoting paneth cell development. Conversely, conditional mitogen-activated protein kinase kinase 1 (Mek1) activation rescued the Shp2 phenotype, promoted goblet cell and inhibited paneth cell generation. The Shp2 mutation also expanded Lgr5+ stem cell niches, which could be restricted by activated Mek1 signaling. Changes of Lgr5+ stem cell quantities were accompanied by alterations of paneth cells, indicating that Shp2/MAPK signaling might affect stem cell niches directly or via paneth cells. Remarkably, inhibition of MAPK signaling in intestinal organoids and cultured cells changed the relative abundance of Tcf4 isoforms and by this, promoted Wnt/{beta}-catenin activity. The data thus show that Shp2-mediated MAPK signaling controls the choice between goblet and paneth cell fates by regulating Wnt/{beta}-catenin activity.

We report on optical injection locking of Q-switched InGaN multi-section diode laser from CW tunable laser to produce solitary pulses at precise wavelength. To the best of our knowledge, this has never been done before.

The results of investigations on corona charged thin mesogenic films consisting of solid mixtures of achiral liquid crystalline side-chain polymers and their monomers are presented. A pyroelectric modulation and a low frequency piezoelectric technique were used to confirm the polar properties of these compounds. The pyroelectric coefficient γ and the apparent longitudinal piezoelectric coefficient d33 were measured in the glassy state to be 3.2 nC/cm2K and 9 pC/N. The pyroelectric currents versus modulation frequency for various polar materials were studied for comparison.

We report on the application of in situ electroabsorption measurements for the evaluation of local electric field distributions in double layer polymer films. The temporal dependence of the measured signal indicates that besides the relation of ohmic resistivities of the different polymer layers, the influence of the electric properties of polymer/electrode and polymer/polymer interfaces must also be considered for the DC field, which is present in the electrooptic active layer.

Interneurons in the dorsal spinal cord process and relay innocuous and nociceptive somatosensory information from cutaneous receptors that sense touch, temperature and pain. These neurons display a well-defined organization with respect to their afferent innervation. Nociceptive afferents innervate lamina I and II, while cutaneous mechanosensory afferents primarily innervate sensory interneurons that are located in lamina III–IV. In this study, we outline a combinatorial transcription factor code that defines nine different inhibitory and excitatory interneuron populations in laminae III–IV of the postnatal cord. This transcription factor code reveals a high degree of molecular diversity in the neurons that make up laminae III–IV, and it lays the foundation for systematically analyzing and manipulating these different neuronal populations to assess their function. In addition, we find that many of the transcription factors that are expressed in the dorsal spinal cord at early postnatal times continue to be expressed in the adult, raising questions about their function in mature neurons and opening the door to their genetic manipulation in adult animals.

Seit den sechziger Jahren wird weltweit fieberhaft nach einem Emitter fur blaues Licht gesucht, dem enorme praktische Bedeutung zukommt, sofern er die strengen Anforderungen industrieller Anwendbarkeit erfullt. Dieses Rennen hat vor kurzem Nichia Chemical Industries gewonnen, eine relativ kleine Firma auf Japans Shikoku-Insel. Der folgende Beitrag beschreibt die wesentlichen Schritte auf dem Weg zur blauen LED auf der Basis von Indium-Gallium-Nitrid/Aluminium-Gallium-Nitrid-Heterostrukturen. Er basiert auf einem Besuch bei Nichia und Gesprachen mit dem verantwortlichen Wissenschaftler Nakamura und dem zustandigen Business-Manager und zeigt, das dieser Erfolg bemerkenswert, aber sicher kein Zufall ist. Feldionenmikroskopie, kombiniert mit Flugzeit-Massenspektrometrie und einem neuentwickelten ortsauflosenden Detektor, erlaubt es jetzt erstmals, Bilder von der chemischen Struktur einer Volumenprobe mit atomarer Auflosung zu gewinnen. Die Methode — Tomographische Atomsonde, kurz: TAP genannt — eroffnet einen neuen und vielversprechenden Weg zur ortsauflosenden Grenzflachenanalyse.

Bei dieser Frage denkt man an die Experimente zur Rohrstromung von O. Reynolds (1883), bei denen durch Injektion von Farbstoff die glatten Linien laminarer Stromung und die wild verschlungenen, verwirbelten und sich verteilenden Linien turbulenter Stromung eindrucksvoll vor Augen gefuhrt werden. Man denkt an die Reynoldszahl Re = Ul/v und an das Reynoldssche Gesetz der Ahnlichkeit von Stromungen in gegebener Geometrie bei unterschiedlichen Geschwindigkeiten U, Langenskalen l und kinematischer Viskositat v, wenn nur die Reynoldszahl dieselbe ist. Und man weis, das Turbulenz erst bei groseren Reynoldszahlen auftritt. Wie aber kommt es uberhaupt dazu? Erst jetzt, mehr als 150 Jahre nach dem Hagen-Poiseuilleschen Gesetz, scheinen wir dem Mechanismus der Turbulenzentstehung auf der Spur zu sein. Er hat wohl wenig mit den so intensiv studierten Instabilitaten und Musterbildungsprozessen zu tun. Es ist die trickreiche Kunst der hydrodynamischen Nichtlinearitat, die durch nicht-normale Ankopplung an die laminare Grundstromung kleine Storungen trotz globaler Stabilitat vorubergehend verstarken kann, sie dann im erstarkten Zustand, bevor sie weggedampft werden, Wechsel wirken last, so das wieder neue verstarkbare Stromungsstorungen erzeugt werden, usw. Weil nicht-linearitatsbedingt, folgen Wachstum-Verstarkung-Umverteilung/Dampfung und wieder Wachstum usw. einander unregelmasig, nichtperiodisch, chaotisch und zudem konvektiv, kurz: turbulent. Es liegt an der Nicht-Normalitat der um die laminare Stromung linearisierten Bewegungsgleichungen, weshalb es nicht allein auf die Eigenwerte ankommt, die uberraschenderweise durchaus alle dampfend bleiben konnen, sondern auch auf die Eigenvektoren. Diese sind nicht mehr orthogonal, sondern als Folge der Nicht-Normalitat richtungsgebundelt an die laminare Stromung angepast. Um nicht angepaste Storungen ebenfalls in Stromungsrichtung zu drehen, kommt es zur Energieentnahme aus der Grundstromung und dadurch zur vorubergehenden Verstarkung. Dann kann die Nichtlinearitat eingreifen und neu mischen. Nicht-normale Eigenwertprobleme fristeten bisher in der Physik ein Mauerblumchendasein — zu unrecht, wie sich jetzt zeigt.

Intermetallic compounds (IMC) resulting from interdiffusion processes at bimetal joints or coated metals usually have worse electrical and mechanical properties compared to the pure metals (e.g. higher specific electric resistance, high brittleness). For a better understanding of the aging of Al-Cu bimetallic joints by interdiffusion, an extensive characterization of the IMC's physical properties is necessary. For that purpose, phase-pure samples of three phases (AlCu, Al2Cu and Al4Cu9) have been prepared by different processes such as physical vapor deposition or electrochemical deposition. The transition from ductile to brittle behavior complicates the mechanical handling of the samples and some phases could not be prepared in pure form, yet. By adjusting and optimizing the manufacturing processes and the development of a suitable experimental setup, first results for the characterization of IMC's electrical properties were obtained. Established values for the specific electric resistance of the phase AlCu could not be confirmed. In a further step, the so far poorly studied temperature coefficient of resistivity of each IMP will be determined.

The expanding generation and transmission of renewable energies causes an enhanced deployment of power connections under severe operating conditions. These technical and climate based operating conditions are classified as extreme conditions. Over the lifetime of electrical joints, ageing processes take place after a certain time which is often beyond a time period not indicated by short term investigations (t

The tyrosine phosphatase Shp2 acts downstream of various growth factors, hormones or cytokine receptors. Mutations of the Shp2 gene are associated with several human diseases. Here we have ablated Shp2 in the developing kidneys of mice, using the ureteric bud epithelium-specific Hoxb7/Cre. Mutant mice produced a phenotype that is similar to mutations of the genes of the GDNF/Ret receptor system, that is: strongly reduced ureteric bud branching and downregulation of the Ret target genes Etv4 and Etv5. Shp2 mutant embryonic kidneys also displayed reduced cell proliferation at the branch tips and branching defects, which could not be overcome by GDNF in organ culture. We also examined compound mutants of Shp2 and Sprouty1, which is an inhibitor of receptor tyrosine kinase signaling in the kidney. Sprouty1 single mutants produce supernumerary ureteric buds, which branch excessively. Sprouty1 mutants rescued branching deficits in Ret−/− and GDNF−/− kidneys. Sprouty1; Shp2 double mutants showed no rescue of kidney branching. Our data thus indicate an intricate interplay of Shp2 and Sprouty1 in signaling downstream of receptor tyrosine kinases during kidney development. Apparently, Shp2 mediates not only GDNF/Ret but also signaling by other receptor tyrosine kinases in branching morphogenesis of the embryonic kidney.

Modules consisting of multiple single emitters pose demanding challenges on assembly, production capabilities and cost. A fiber coupled module has been produced delivering 100 W optical power from a 105 μm, NA 0.15 fiber. The module consists of two times six vertically stacked single emitters combined by polarization multiplexing. Special attention was paid to the development of a very robust low cost pigtail. The developed semiautomatic highly accurate process enables assembly times way faster than possible in a purely manual procedure. The achievable yield in combination with low material costs proofs the excellent potential for the manufacturing of cost efficient laser modules.