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Institution

Martin Luther University of Halle-Wittenberg

EducationHalle, Germany
About: Martin Luther University of Halle-Wittenberg is a education organization based out in Halle, Germany. It is known for research contribution in the topics: Population & Liquid crystal. The organization has 20232 authors who have published 38773 publications receiving 965004 citations. The organization is also known as: MLU & University of Wittenberg.


Papers
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Journal ArticleDOI
TL;DR: In this article, the authors analyzed pool size and isotopic composition (14C, 13C) of mineral-protected and recalcitrant organic carbon (OC) in 12 subsurface horizons from 10 acidic forest soils, showing that stabilization of OM by interaction with poorly crystalline minerals and polymeric metal species is the most important mechanism for preservation of OM in these acid subsoil horizons.
Abstract: Soil organic matter (OM) can be stabilized against decomposition by association with minerals, by its inherent recalcitrance and by occlusion in aggregates. However, the relative contribution of these factors to OM stabilization is yet unknown. We analyzed pool size and isotopic composition (14C, 13C) of mineral-protected and recalcitrant OM in 12 subsurface horizons from 10 acidic forest soils. The results were related to properties of the mineral phase and to OM composition as revealed by CPMAS 13C-NMR and CuO oxidation. Stable OM was defined as that material which survived treatment of soils with 6 wt% sodium hypochlorite (NaOCl). Mineral-protected OM was extracted by subsequent dissolution of minerals by 10% hydrofluoric acid (HF). Organic matter resistant against NaOCl and insoluble in HF was considered as recalcitrant OM. Hypochlorite removed primarily 14C-modern OM. Of the stable organic carbon (OC), amounting to 2.4–20.6 g kg−1 soil, mineral dissolution released on average 73%. Poorly crystalline Fe and Al phases (Feo, Alo) and crystalline Fe oxides (Fed−o) explained 86% of the variability of mineral-protected OC. Atomic Cp/(Fe+Al)p ratios of 1.3–6.5 suggest that a portion of stable OM was associated with polymeric Fe and Al species. Recalcitrant OC (0.4–6.5 g kg−1 soil) contributed on average 27% to stable OC and the amount was not correlated with any mineralogical property. Recalcitrant OC had lower Δ14C and δ13C values than mineral-protected OC and was mainly composed of aliphatic (56%) and O-alkyl (13%) C moieties. Lignin phenols were only present in small amounts in either mineral-protected or recalcitrant OM (mean 4.3 and 0.2 g kg−1 OC). The results confirm that stabilization of OM by interaction with poorly crystalline minerals and polymeric metal species is the most important mechanism for preservation of OM in these acid subsoil horizons.

703 citations

Journal ArticleDOI
01 Aug 1985-Nature
TL;DR: A novel type of cardiac Ca channel with several properties that distinguish it from the hitherto-identified Ca channel in heart cells is described, which activates and inactivates at relatively negative potentials and remains functional long after patch excision.
Abstract: Calcium influx is vital for several aspects of cardiac activity, so it is important to ask if heart cells possess a single or multiple types of Ca channel. Only one Ca channel type has been identified in patch-clamp studies of unitary current, despite suggestions to the contrary from whole-cell recordings in heart cells and unitary recordings from other cells. Here we describe a novel type of cardiac Ca channel with several properties that distinguish it from the hitherto-identified Ca channel in heart cells. Its conductance in isotonic Ba is small (8 pS), and is no larger in Ba than in Ca. It activates and inactivates at relatively negative potentials and remains functional long after patch excision. It is insensitive to dihydropyridines such as nimodipine and the Ca agonist Bay K 8644, and is more resistant to block by external Cd than the previously described type of cardiac Ca channel.

699 citations

Journal ArticleDOI
TL;DR: This article is the first of a series providing guidance for the use of the GRADE system of rating quality of evidence and grading strength of recommendations in systematic reviews, health technology assessments, and clinical practice guidelines addressing alternative management options.

695 citations

Journal ArticleDOI
TL;DR: This work considers the nature of drug targets, and by classifying known drug substances on the basis of the discussed principles it provides an estimation of the total number of current drug targets.
Abstract: What is a drug target? And how many such targets are there? Here, we consider the nature of drug targets, and by classifying known drug substances on the basis of the discussed principles we provide an estimation of the total number of current drug targets.

693 citations

Journal ArticleDOI
TL;DR: CAC scoring results in a high reclassification rate in the intermediate-risk cohort, demonstrating the benefit of imaging of subclinical coronary atherosclerosis and supporting its application, especially in carefully selected individuals with intermediate risk.

690 citations


Authors

Showing all 20466 results

NameH-indexPapersCitations
Niels Birbaumer14283577853
Michael Schmitt1342007114667
Niels E. Skakkebæk12759659925
Stefan D. Anker117415104945
Pedro W. Crous11580951925
Eric Verdin11537047971
Bernd Nilius11249644812
Josep Tabernero11180368982
Hans-Dieter Volk10778446622
Dan Rujescu10655260406
John I. Nurnberger10552251402
Ulrich Gösele10260346223
Wolfgang J. Parak10246943307
Martin F. Bachmann10041534124
Munir Pirmohamed9767539822
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202397
2022331
20212,038
20202,007
20191,617
20181,604