Institution
Free University of Berlin
Education•Berlin, Germany•
About: Free University of Berlin is a education organization based out in Berlin, Germany. It is known for research contribution in the topics: Population & Context (language use). The organization has 35195 authors who have published 66525 publications receiving 2094403 citations. The organization is also known as: FU Berlin.
Topics: Population, Context (language use), Excited state, Receptor, Politics
Papers published on a yearly basis
Papers
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TL;DR: In this paper, an electrodeposited Mn oxide (MnCat) was reported to catalyzes electrochemical water oxidation at neutral pH at rates that approach the level needed for direct coupling to photoactive materials.
Abstract: In the sustainable production of non-fossil fuels, water oxidation is pivotal. Development of efficient catalysts based on manganese is desirable because this element is earth-abundant, inexpensive, and largely non-toxic. We report an electrodeposited Mn oxide (MnCat) that catalyzes electrochemical water oxidation at neutral pH at rates that approach the level needed for direct coupling to photoactive materials. By choice of the voltage protocol we could switch between electrodeposition of inactive Mn oxides (deposition at constant anodic potentials) and synthesis of the active MnCat (deposition by voltage-cycling protocols). Electron microscopy reveals that the MnCat consists of nanoparticles (100 nm) with complex fine-structure. X-ray spectroscopy reveals that the amorphous MnCat resembles the biological paragon, the water-splitting Mn4Ca complex of photosynthesis, with respect to mean Mn oxidation state (ca. +3.8 in the MnCat) and central structural motifs. Yet the MnCat functions without calcium or other bivalent ions. Comparing the MnCat with electrodeposited Mn oxides inactive in water oxidation, we identify characteristics that likely are crucial for catalytic activity. In both inactive Mn oxides and active ones (MnCat), extensive di-μ-oxo bridging between Mn ions is observed. However in the MnCat, the voltage-cycling protocol resulted in formation of MnIII sites and prevented formation of well-ordered and unreactive MnIVO2. Structure–function relations in Mn-based water-oxidation catalysts and strategies to design catalytically active Mn-based materials are discussed. Knowledge-guided performance optimization of the MnCat could pave the road for its technological use.
406 citations
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University of Ulm1, University of Erlangen-Nuremberg2, University of Münster3, University of Düsseldorf4, University of Göttingen5, University of Greifswald6, University of Hamburg7, University of Marburg8, Augsburg College9, University of Mannheim10, Free University of Berlin11, University of Innsbruck12, University of Tübingen13
TL;DR: The perioperative application of octreotide reduces the occurrence of typical postoperative complications after pancreatic resection, particularly in patients with tumors.
Abstract: Though morbidity and mortality rates following pancreatic resection have improved in recent years, they are still around 35% and 5%, respectively. Typical complications, such as pancreatic fistula, abscess, and subsequent sepsis, are chiefly associated with exocrine pancreatic secretion. In order to clarify whether the perioperative inhibition of exocrine pancreatic secretion prevents complications, we assessed the efficacy of octreotide, a long-acting somatostatin analogue. We conducted a randomized, double-blind, placebo-controlled, multicenter trial in 246 patients undergoing major elective pancreatic surgery. Patients were stratified into a high-risk stratum (limited to patients with pancreatic and periampullary tumors) or low-risk stratum (patients with chronic pancreatitis). Patients received octreotide (3 x 100 micrograms) or placebo subcutaneously for 7 days perioperatively. Eleven complications were defined: death, leakage of anastomosis, pancreatic fistula, abscess, fluid collection, shock, sepsis, bleeding, pulmonary insufficiency, renal insufficiency, and postoperative pancreatitis. Two hundred patients underwent pancreatic head resection, 31 patients underwent left resection, and 15 patients had other procedures. The overall mortality rate within 90 days was 4.5%, with 3.2% in the octreotide group and 5.8% in the placebo group. The complication rate was 32% in the patients receiving octreotide (40 of 125 patients) and 55% in patients receiving placebo (67 of 121 patients) (p less than 0.005). In the patients in the high-risk stratum, complications were observed in 26 of the 68 (38%) patients treated with octreotide and in 46 of 71 (65%) patients given placebo (p less than 0.01). Whereas in patients in the low-risk stratum, the complication rate was 25% (14 of 57 patients) in those treated with octreotide and 42% (21 of 50 patients) in patients given placebo (p = NS). The perioperative application of octreotide reduces the occurrence of typical postoperative complications after pancreatic resection, particularly in patients with tumors.
406 citations
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TL;DR: Immediate implementation of mcr-screening including this novel gene variant is required for Salmonella and E. coli from humans and food-producing animals in Europe.
Abstract: A novel mcr colistin resistance gene was identified in a strain of Salmonella enterica, monophasic variant of serovar Typhimurium (4,5,12:i:- ), isolated from a pig at slaughter in Italy in 2013, and in Escherichia coli strains collected during routine diagnostic of post-weaning diarrhoea in pigs from Spain and Belgium in 2015 and 2016. Immediate implementation of mcr-screening including this novel gene variant is required for Salmonella and E. coli from humans and food-producing animals in Europe.
405 citations
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Spanish National Research Council1, University of Alicante2, Pablo de Olavide University3, Swansea University4, Henan University of Technology5, Chinese Academy of Sciences6, International Trademark Association7, National University of Luján8, National Scientific and Technical Research Council9, University of Bern10, Université du Québec à Trois-Rivières11, Free University of Berlin12, Santa Fe Institute13
TL;DR: Investigation of how 20 structural and functional ecosystem attributes respond to aridity in global drylands found evidence for a series of abrupt ecological events occurring sequentially in three phases, culminating with a shift to low-cover ecosystems that are nutrient- and species-poor at high aridity values.
Abstract: Aridity, which is increasing worldwide because of climate change, affects the structure and functioning of dryland ecosystems. Whether aridification leads to gradual (versus abrupt) and systemic (versus specific) ecosystem changes is largely unknown. We investigated how 20 structural and functional ecosystem attributes respond to aridity in global drylands. Aridification led to systemic and abrupt changes in multiple ecosystem attributes. These changes occurred sequentially in three phases characterized by abrupt decays in plant productivity, soil fertility, and plant cover and richness at aridity values of 0.54, 0.7, and 0.8, respectively. More than 20% of the terrestrial surface will cross one or several of these thresholds by 2100, which calls for immediate actions to minimize the negative impacts of aridification on essential ecosystem services for the more than 2 billion people living in drylands.
405 citations
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TL;DR: This review elucidate FGNs-bioorganism interactions and summarize recent advancements on designing FGN-based two-dimensional and three-dimensional architectures as multifunctional biological platforms.
Abstract: Functional graphene nanomaterials (FGNs) are fast emerging materials with extremely unique physical and chemical properties and physiological ability to interfere and/or interact with bioorganisms; as a result, FGNs present manifold possibilities for diverse biological applications. Beyond their use in drug/gene delivery, phototherapy, and bioimaging, recent studies have revealed that FGNs can significantly promote interfacial biointeractions, in particular, with proteins, mammalian cells/stem cells, and microbials. FGNs can adsorb and concentrate nutrition factors including proteins from physiological media. This accelerates the formation of extracellular matrix, which eventually promotes cell colonization by providing a more beneficial microenvironment for cell adhesion and growth. Furthermore, FGNs can also interact with cocultured cells by physical or chemical stimulation, which significantly mediate their cellular signaling and biological performance. In this review, we elucidate FGNs–bioorganism int...
405 citations
Authors
Showing all 35717 results
Name | H-index | Papers | Citations |
---|---|---|---|
Andreas Pfeiffer | 149 | 1756 | 131080 |
Nicholas A. Peppas | 141 | 825 | 90533 |
Robert H. Purcell | 139 | 666 | 70366 |
Andrea Castro | 132 | 1500 | 90019 |
Klaus Ley | 129 | 495 | 57964 |
Klaus-Robert Müller | 129 | 764 | 79391 |
Britton Chance | 128 | 1112 | 76591 |
Stefan H. E. Kaufmann | 126 | 925 | 58891 |
Thomas F. Tedder | 123 | 426 | 48374 |
Aravinda Chakravarti | 120 | 451 | 99632 |
Jerome Ritz | 120 | 644 | 47987 |
Thomas C. Quinn | 120 | 827 | 65881 |
Angela D. Friederici | 120 | 701 | 50191 |
E. K. U. Gross | 119 | 1154 | 75970 |
Alexander Rich | 115 | 539 | 50171 |