Self-assembly of melem on Ag(111)—emergence of porous structures based on amino-heptazine hydrogen bonds

Self-assembly of melem on Ag(111) as studied by Scanning-Tunneling-Microscopy (STM) in ultra-high vacuum revealed a great structural variety. In total, five porous and two densely packed monolayer polymorphs were observed. All structures are stabilized by intermolecular hydrogen bonds, where melem–melem arrangements are based on very few basic motifs. Six out of seven polymorphs can be described by a unified concept

Blood–brain barrier dysfunction and folate and vitamin B12 levels in first-episode schizophrenia-spectrum psychosis: a retrospective chart review

Vitamin deficiency syndromes and blood–brain barrier (BBB) dysfunction are frequent phenomena in psychiatric conditions. We analysed the largest available first-episode schizophrenia-spectrum psychosis (FEP) cohort to date regarding routine cerebrospinal fluid (CSF) and blood parameters to investigate the association between vitamin deficiencies (vitamin B12 and folate) and BBB impairments in FEP. We report a retrospective analysis of clinical data from all inpatients that were admitted to our tertiary care hospital with an ICD-10 diagnosis of a first-episode F2x (schizophrenia-spectrum) between January 1, 2008 and August 1, 2018 and underwent a lumbar puncture, blood-based vitamin status diagnostics and neuroimaging within the clinical routine. 222 FEP patients were included in our analyses. We report an increased CSF/serum albumin quotient (Qalb) as a sign of BBB dysfunction in 17.1% (38/222) of patients. White matter lesions (WML) were present in 29.3% of patients (62/212). 17.6% of patients (39/222) showed either decreased vitamin B12 levels or decreased folate levels. No statistically significant association was found between vitamin deficiencies and altered Qalb. This retrospective analysis contributes to the discussion on the impact of vitamin deficiency syndromes in FEP. Although decreased vitamin B12 or folate levels were found in approximately 17% of our cohort, we found no evidence for significant associations between BBB dysfunction and vitamin deficiencies. To strengthen the evidence regarding the clinical implications of vitamin deficiencies in FEP, prospective studies with standardized measurements of vitamin levels together with follow-up measurements and assessment of symptom severity in addition to CSF diagnostics are needed

The relationship between blood–brain barrier dysfunction and neurocognitive impairments in first-episode psychosis: findings from a retrospective chart analysis

Background Even before the onset of psychotic symptoms, individuals with schizophrenia display cognitive impairments. Simultaneously, increasing amounts of individuals exhibit dysfunction of the blood–brain barrier (BBB). However, the impact of BBB dysfunction on neurocognitive impairment in people with first-episode psychosis has not yet been investigated. Aims To advance understanding of said relationship, we considered one of the largest first-episode psychosis cohorts with cerebrospinal fluid parameters available, and investigated whether BBB dysfunction is related to working memory, working speed and attention. Method We conducted a retrospective chart review of 121 in-patients diagnosed with a first episode of a schizophrenia spectrum disorder. Patients underwent neurocognitive testing and a lumbar puncture within routine clinical care. To define BBB dysfunction, albumin cerebrospinal fluid/serum quotients, immunoglobulin G ratios and oligoclonal band types were evaluated, and gender-specific differences investigated. Neurocognitive functioning was assessed by the Wechsler Adult Intelligence Scale, Test of Attentional Performance and Repeatable Battery for the Assessment of Neuropsychological Status. We performed simple and multiple linear regression analyses to interpret associations of interest. Results Of those tested, 16% showed an alteration in albumin quotients and 12% had an oligoclonal band type indicating BBB dysfunction. Notably, male patients were more likely to have an increased albumin quotient and a higher immunoglobulin G ratio than female patients. We found no significant association between BBB dysfunction and neurocognitive assessments. Conclusions The hypothesised relationship between BBB and neurocognitive impairments was not detectable in our retrospective cohort. Further cerebrospinal fluid-based studies with a longitudinal assessment of cognitive functioning and disease trajectory are urgently needed

Interface engineering for light-driven water oxidation: unravelling the passivating and catalytic mechanism in BiVO_4 overlayers

Artificial photosynthetic approaches require the combination of light absorbers interfaced with overlayers that enhance charge transport and collection to perform catalytic reactions. Despite numerous efforts that have coupled various catalysts to light absorbing semiconductors, the optimization of semiconductor/catalyst as well as catalyst/electrolyte interfaces and the identification of the role of the catalyst still remain a key challenge. Herein, we assemble (NiFeCoCe)O_x multi-component overlayers, interfaced with bismuth vanadate photoanodes, and determine the roles of different elements on promoting interfacial charge transfer and catalytic reaction over competitive photocarrier recombination loss processes. Through this understanding, and aided by complementary macroscopic photoelectrochemical measurements and nanoscale atomic force microscopy techniques, a bifunctional (CoFeCe/NiFe)O_x overlayer was rationally engineered. The resulting multi-functional coating yields BiVO_4 photoanodes with almost 100% efficient surface collection of holes under oxygen evolving reaction conditions. The (CoFeCe)O_x component excels at efficient capture and transport of photogenerated holes in BiVO_4 through the availability of redox active states, whereas (NiFe)O_x plays a vital role in reducing charge recombination at the BiVO_4/electrolyte interface. In addition, this study supports the hypothesis that catalytic sites act as electronically active trap states on uncoated BiVO_4 photoanodes

Interface engineering for light-driven water oxidation: unravelling the passivating and catalytic mechanism in BiVO_4 overlayers

Artificial photosynthetic approaches require the combination of light absorbers interfaced with overlayers that enhance charge transport and collection to perform catalytic reactions. Despite numerous efforts that have coupled various catalysts to light absorbing semiconductors, the optimization of semiconductor/catalyst as well as catalyst/electrolyte interfaces and the identification of the role of the catalyst still remain a key challenge. Herein, we assemble (NiFeCoCe)O_x multi-component overlayers, interfaced with bismuth vanadate photoanodes, and determine the roles of different elements on promoting interfacial charge transfer and catalytic reaction over competitive photocarrier recombination loss processes. Through this understanding, and aided by complementary macroscopic photoelectrochemical measurements and nanoscale atomic force microscopy techniques, a bifunctional (CoFeCe/NiFe)O_x overlayer was rationally engineered. The resulting multi-functional coating yields BiVO_4 photoanodes with almost 100% efficient surface collection of holes under oxygen evolving reaction conditions. The (CoFeCe)O_x component excels at efficient capture and transport of photogenerated holes in BiVO_4 through the availability of redox active states, whereas (NiFe)O_x plays a vital role in reducing charge recombination at the BiVO_4/electrolyte interface. In addition, this study supports the hypothesis that catalytic sites act as electronically active trap states on uncoated BiVO_4 photoanodes

Zur Zukunft der Bereichsethiken – Herausforderungen durch die Ökonomisierung der Welt

Der vorliegende achte Band der Schriftenreihe des Zentrums für Technik- und Wirtschaftsethik am Karlsruher Institut für Technologie soll - wie die Schriftenreihe insgesamt - den überfachlichen Dialog fördern. Zu einem solchen Dialog gehört auch der Themenkomplex „Zur Zukunft der Bereichsethiken - Herausforderungen durch die Ökonomisierung der Welt“. Die vielfältigen, multidimensionalen Ökonomisierungsprozesse prägen und verändern zusammen mit Technik und Wissenschaft auf mannigfache Weise und in einem nie gekanntem Ausmaß unsere Welt. Gesellschaften, das Zusammenleben der Menschen und das Arbeitsleben in der Gegenwart und noch stärker in der Zukunft erfahren ständig sich beschleunigende Veränderungen. Die im Band versammelten Beiträge stellen Ansätze und Beispiele dar, die Herausforderungen der Ökonomisierung der Welt mithilfe ethischer Überlegungen anzugehen und damit auch einen Beitrag zur Zukunft(sfähigkeit) der Ethik bzw. der Bereichsethiken zu leisten. Der Band enthält hierzu sowohl stärker grundsätzlich orientierte als auch eher bereichsbezogene Aufsätze. Zu den behandelten Themen gehören u.a.: die Renaissance der Geisteswissenschaften im Anthropozän-Diskurs, die Ethik der Veränderung, die Ökonomisierung als Triebkraft zur Anwendung der Ethik, zur Zukunft der Technik-, Wirtschafts- und Wissenschaftsethik, die Ökonomisierung der gesellschaftlichen Arbeit, der Sozialen Arbeit, der Medien, der persönlichen Beziehungen, der Wasserversorgung, des Gesundheitswesens sowie des Sports

An estimate of the number of tropical tree species

The high species richness of tropical forests has long been recognized, yet there remains substantial uncertainty regarding the actual number of tropical tree species. Using a pantropical tree inventory database from closed canopy forests, consisting of 657,630 trees belonging to 11,371 species, we use a fitted value of Fisher’s alpha and an approximate pantropical stem total to estimate the minimum number of tropical forest tree species to fall between ∼40,000 and ∼53,000, i.e. at the high end of previous estimates. Contrary to common assumption, the Indo-Pacific region was found to be as species-rich as the Neotropics, with both regions having a minimum of ∼19,000–25,000 tree species. Continental Africa is relatively depauperate with a minimum of ∼4,500–6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological framework for estimating species richness in trees that may help refine species richness estimates of tree-dependent taxa