Direct determination of the band offset in atomic layer deposited ZnO hydrogenated amorphous silicon heterojunctions from X ray photoelectroscopy valence band spectra

The chemical composition and band alignment at the heterointerface between ALD grown zinc oxide ZnO and hydrogenated amorphous silicon a Si H is investigated using monochromatized X ray photoelectron spectroscopy. A new approach for obtaining the valence band offset DeltaEV is developed, which consists in fitting the valence band VB spectrum obtained for a Si H with a thin ZnO overlayer as the sum of experimentally obtained VB spectra of a bulk a Si H film and a thick ZnO film. This approach allows obtaining DeltaEV 2.71 0.15 eV with a minimum of assumptions, and also yields information on the change in band bending of both substrate and ZnO film. The band offset results are compared to values obtained using the usual approach of comparing valence band edge to core level energy differences, DeltaEB,CL DeltaEB,VB. Furthermore, a theoretical value for the VB offset is calculated from the concept of charge neutrality level line up, using literature data for the CNLs and the experimentally determined ZnO a Si H interface dipole. The thus obtained value of DeltaEVCNL 2.65 0.3 eV agrees well with the experimental DeltaE

Controlled airway pressure therapy, nitric oxide inhalation, prone position, and extracorporeal membrane oxygenation (ECMO) as components of an integrated approach to ARDS. Anesthesiology

Background: Recent years have seen the introduction of innovative additive therapies for acute respiratory distress syndrome. However, because there are no reliable predictors of response to a particular therapy, potential responders to a specific therapeutic intervention may be lost. Therefore, the authors evaluated the effect of a combined therapeutic approach on the survival of patients with acute respiratory distress syndrome, when treated according to a strict algorithm. Methods: During a 2.5-yr period, 84 patients with acute respiratory distress syndrome were assigned to a standardized treatment protocol. Data analysis was performed by retrospective review of patient charts. Patients were treated using a stepwise treatment algorithm of pressure-controlled ventilation (peak airway pressure < 35 cm H 2 O), positive end-expiratory pres

Evidence of the Anomalous Fluctuating Magnetic State by Pressure Driven 4f Valence Change in EuNiGe3

In rare earth compounds with valence fluctuation, the proximity of the 4f level to the Fermi energy leads to instabilities of the charge configuration and the magnetic moment. Here, we provide direct experimental evidence for an induced magnetic polarization of the Eu3 atomic shell with J 0, due to intra atomic exchange and spin orbital coupling interactions with the Eu2 atomic shell. By applying external pressure, a transition from antiferromagnetic to a fluctuating behavior in EuNiGe3 single crystals is probed. Magnetic polarization is observed for both valence states of Eu2 and Eu3 across the entire pressure range. The anomalous magnetism is discussed in terms of a homogeneous intermediate valence state where frustrated Dzyaloshinskii Moriya couplings are enhanced by the onset of spin orbital interaction and engender a chiral spin liquid like precurso

Evolution of Vitamin B 2 Biosynthesis. A Novel Class of Riboflavin Synthase in Archaea †

The open reading frame MJ1184 of Methanococcus jannaschii with similarity to riboflavin synthase of Methanothermobacter thermoautotrophicus was cloned into an expression vector but was poorly expressed in an Escherichia coli host strain. However, a synthetic open reading frame that was optimized for expression in E. coli directed the synthesis of abundant amounts of a protein with an apparent subunit mass of 17.5 kDa. The protein was purified to apparent homogeneity. Hydrodynamic studies indicated a relative mass of 88 kDa suggesting a homopentamer structure. The enzyme was shown to catalyze the formation of riboflavin from 6,7-dimethyl-8-ribityllumazine at a rate of 24 nmol mg K1 min K1 at 40 8C. Divalent metal ions, preferably manganese or magnesium, are required for maximum activity. In contrast to pentameric archaeal type riboflavin synthases, orthologs from plants, fungi and eubacteria are trimeric proteins characterized by an internal sequence repeat with similar folding patterns. In these organisms the reaction is achieved by binding the two substrate molecules in an antiparallel orientation. With the enzyme of M. jannaschii, 13 C NMR spectroscopy with 13 C-labeled 6,7-dimethyl-8-ribityllumazine samples as substrates showed that the regiochemistry of the dismutation reaction is the same as observed in eubacteria and eukaryotes, however, in a non-pseudo-c 2 symmetric environment. Whereas the riboflavin synthases of M. jannaschii and M. thermoautotrophicus are devoid of similarity with those of eubacteria and eukaryotes, they have significant sequence similarity with 6,7-dimethyl-8-ribityllumazine synthases catalyzing the penultimate step of riboflavin biosynthesis. 6,7-Dimethyl-8-ribityllumazine synthase and the archaeal riboflavin synthase appear to have diverged early in the evolution of Archaea from a common ancestor. Some Archaea have eubacterial type riboflavin synthases which may have been acquired by lateral gene transfer

Knowledge levels of medical faculty students and residents about ionizing radiation

This study aimed to evaluate the knowledge levels of medical school students and residents about ionising radiation. The study is designed as descriptive research, and it was conducted with 369 medical school students and residents. A survey form was used in the research. A Chi-square test was used to compare categorical variables. In the study, 369 people were reached within the scope of the research. A total of 60.7% of the research participants were clinical medicine students (4th, 5th, 6th grade) and 39.3% were residents. A total of 42.0% of the participants of the study were male, 58.0% were women. It was found that 17.9% of the clinical medical students and 18.6% of the residents had sufficient knowledge of ionising radiation (p=0.002). A total of 87.0% of the participants in the study answered correctly that magnetic resonance imaging (MRI) does not contain radiation and 93.5% answered correctly that ultrasonography (USG) does not contain radiation. 74.8% of the participants stated that having knowledge about ionising radiation would contribute to “protecting sensitive groups from ionising radiation” in medical practice. This ratio is 77.2% in clinical medicine students and 71.0% in residents. The study found that knowledge levels of medical faculty students and residents about ionising radiation were insufficient. Medical students and residents are recommended to be trained on radiation and the radiological requests of residents to be evaluated

Transparente leitfähige Oxide TCO in Silizium Heterostruktursolarzellen Elektronische Eigenschaften des TCO a Si H Kontakts

In dieser Arbeit wurden transparente leitfähige Oxide transparent conductive oxide, TCO , wie sie als Vorderseitenkontakt in a Si H c Si Solarzellen zum Einsatz kommen, hinsichtlich ihres Einflusses auf die Funktion der Solarzellen untersucht. Der Schwerpunkt liegt hierbei in der Untersuchung des Kontakts zwischen dem transparenten leitfähigen Oxid und der als Emitterschicht eingesetzten p dotierten amorphen Siliziumschicht p a Si H sowie des Einflusses auf den angrenzenden amorph kristallinen Silizium a Si H c Si Heterokontakt. Hierfür wurden aluminiumdotierte Zinkoxidschichten ZnO Al , zinndotierte Indiumoxidschichten ITO und mittels Atomlagenabscheidung hergestellte undotierte Zinkoxidschichten auf a Si H analysier