Total Synthesis of the Biphenyl Alkaloid (−)-Lythranidine

A sequence comprising a ring-closing alkyne metathesis of a propargyl alcohol derivative, followed by a ruthenium-catalyzed redox isomerization of the derived cycloalkyne and a transannular aza-Michael addition allowed the formation of the distinguishing piperidine-metacyclophane framework of the Lythraceum alkaloid lythanidine in a few high-yielding steps. This application attests to the excellent functional-group tolerance of a molybdenum alkylidyne complex endowed with triphenylsilanolate ligands, which enabled the macrocyclization even in the presence of protic functionalities, and thus illustrates the power of contemporary catalytic acetylene chemistry for target-oriented synthesis

The use of plasma ashers and Monte Carlo modeling for the projection of atomic oxygen durability of protected polymers in low Earth orbit

The results of ground laboratory and in-space exposure of polymeric materials to atomic oxygen has enabled the development of a Monte Carlo computational model which simulates the oxidation processes of both environments. The cost effective projection of long-term low-Earth-orbital durability of protected polymeric materials such as SiO(x)-coated polyimide Kapton photovoltaic array blankets will require ground-based testing to assure power system reliability. Although silicon dioxide thin film protective coatings can greatly extend the useful life of polymeric materials in ground-based testing, the projection of in-space durability based on these results can be made more reliable through the use of modeling which simulates the mechanistic properties of atomic oxygen interaction, and replicates test results in both environments. Techniques to project long-term performance of protected materials, such as the Space Station Freedom solar array blankets, are developed based on ground laboratory experiments, in-space experiments, and computational modeling

Embolization of uterine artery pseudoaneurysm during pregnancy: case report and review of the literature

Objectives: Uterine artery pseudoaneurysm (UAP) is a rare but sinister complication during pregnancy. Diagnosis can be made by color Doppler ultrasound. Previous abdominal- and obstetric surgery increase the risk for UAP formation. Case presentation: We present a case of a 36 year young healthy women, presenting at 27 weeks of gestation with acute lower abdominal pain. UAP was detected by color Doppler ultrasound. An endovascular coil embolization was performed, with good maternal and fetal outcome. Furthermore, a review of the literature looking at UAP embolization in pregnancy was performed. Conclusions: UAP is reported to appear as a complication of endometriosis. UAP should be treated by endovascular coil embolization, which is a safe and with almost 100% success rate an effective treatment during pregnancy

Sicherheit und Wirksamkeit von subkutan angewendetem GA-EPO zur Behandlung der Anämie bei Patienten mit chronischer Niereninsuffizienz

Bei 16 niereninsuffizienten Patienten wurden Hämoglobin, Hämatokrit, hypochrome Erythrozyten, Serumferritin sowie Transferrinsättigung als Wirksamkeitsparameter bestimmt. Als Sicherheitsparameter dienten Thrombozyten- und Leukozytenzahl, Aluminiumspiegel, Parathormon sowie Blutdruck, Sollgewicht und unerwünschte Ereignisse. Zum Vergleich mit rHuEPO wurden Daten von 6 Monaten vor Studienbeginn herangezogen. Ziel war ein Hämoglobinwert zwischen 10-12 g/dl. Der Hämoglobinspiegel stieg unter GA-EPO-Therapie und Eisensubstitution initial auf 12,5 g/dl an und lag bei Studienende bei 11,2 g/dl. Serumferritin und Transferrinsättigung verzeichneten einen adäquaten Anstieg, die hypochromen Erythrozyten fielen im Sinne einer eisensuffizienten Erythropoese ab. Insgesamt konnte eine Reduktion der EPO-Dosis um 31% verzeichnet werden. Vom Sicherheitsprofil unterschied sich GA-EPO nicht von rHuEPO. GA-EPO ist ein dem rHuEPO vergleichbares Medikament zur Anämiekorrektur bei chronischer Niereninsuffizienz. Der deutliche Hämoglobinanstieg kann jedoch sowohl der GA-EPO-Therapie als auch der Eisensubstitution zu Grunde liegen

A configurational approach to servitization: Review and research directions

In this article, the authors extend the current literature on servitization by taking a configurational perspective, aiming to understand the interplay between the drivers (conditions) that lead to certain equifinal outcomes of servitization. By taking stock of the servitization literature using the contingency theory of strategy as a foundational theory and the strategy–structure–environment approach as a primary framework to systematically review and analyze the identified configurational servitization studies, the authors identify commonalities and gaps in the literature and set directions for future research. EPSRC New Industrial Systems: OMMS - Optimising Me Manufacturing System [EP/R022534/1

ESTIMATING THE SUBJECT BY TREATMENT INTERACTION IN NON-REPLICATED CROSSOVER DIET STUDIES

Researchers in human nutrition commonly refer to the ‘consistent’ diet effect (i.e. the main effect of diet) and an ‘inconsistent’ diet effect (i.e. a subject by diet interaction). However, due to the non-replicated designs of most studies, one can only estimate the first part using ANOVA; the latter (interaction) is confounded with the residual noise. In many diet studies, it appears that subjects do respond differently to the same diet, so the subject by diet interaction may be large. In a search of over 40,000 published human nutrition studies, most using a crossover design, we found that in none was a subject by diet interaction effect estimated. For this paper, we examined LDL-cholesterol data from a non-replicated crossover study with four diets, the typical American diet, with and without added plant sterols, and a cholesterol-lowering Step-1 diet, with and without sterols. We also examined LDL-cholesterol data from a second crossover study with some replications with three diets, representing the daily supplement of 0, 1 or 2 servings of pistachio nuts. These two data sets were chosen because experience suggested that LDLcholesterol responses to diet tend to be subject-specific. The second data set, with some replication, allowed us to estimate the subject by diet interaction term in a traditional ANOVA framework. One approach to estimating an interaction effect in non-replicated studies is through the use of a multiplicative decomposition of the interaction (sometimes called AMMI―additive main effects, multiplicative interaction). In this type of analysis, residuals, formed after estimated main effects are subtracted from the data, are arrayed in a matrix with diets as columns and subjects as rows. A singular value decomposition of the matrix is performed and the first, or first and second, principal component(s) are used as estimates of the interaction, and can be tested for significance using approximate F-tests. Using the R gnm package, we found large and significant subject by diet interaction effects in both data sets; estimates of the interaction in the second data set were similar to interaction estimates from traditional ANOVA. Of an additional 26 dependent variables from the first and a third data set (the latter investigating the effect of mild alcohol consumption on blood variables), 19 had significant subject by diet interactions, based on the AMMI methodology. These results suggest that the subject by diet interaction is often important and should not be ignored when analyzing data obtained from non-replicated crossover designs―the AMMI methodology works well and is readily available in statistical software packages

Determination of the charge carrier compensation mechanism in Te-doped GaAs by scanning tunneling microscopy.

We identified the charge carrier compensation mechanism in Te-doped GaAs with atomically resolved scanning tunneling microscopy. Three types of defects were found: tellurium donors (Te-As), Ga vacancies (V-Ga), and Ga vacancy-donor complexes (V-Ga-Te-As). We show quantitatively that the compensation in Te-doped bulk GaAs is exclusively caused by vacancy-donor complexes in contrast to Si-doped GaAs. This is explained with the Fermi-level effect as the universal mechanism leading to Ga vacancy formation in n-doped GaAs, and a Coulomb interaction leading to the formation of the complexes. The quantification of the carrier compensation yields a -3e charge state of V-Ga in bulk GaAs. (C) 2003 American Institute of Physics