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排序方式: 共有744条查询结果,搜索用时 15 毫秒
101.
Mette Schmedes Asker Daniel Brejnrod Eli Kristin Aadland Pia Kiilerich Karsten Kristiansen Hlne Jacques Charles Lavigne Ingvild Eide Graff
yvin Eng Asle Holthe Gunnar Mellgren Jette Feveile Young Ulrik Krmer Sundekilde Bjrn Liaset Hanne Christine Bertram 《Molecular nutrition & food research》2019,63(1)
102.
103.
104.
Jasmina Ga
anin Jana Hedrich Stefanie Sieste Gunnar Glaßer Ingo Lieberwirth Corinna Schilling Stephan Fischer Holger Barth Bernd Knll Christopher V. Synatschke Tanja Weil 《Advanced materials (Deerfield Beach, Fla.)》2019,31(2)
The synthesis of hybrid hydrogels by pH‐controlled structural transition with exceptional rheological properties as cellular matrix is reported. “Depsi” peptide sequences are grafted onto a polypeptide backbone that undergo a pH‐induced intramolecular O–N–acyl migration at physiological conditions affording peptide nanofibers (PNFs) as supramolecular gelators. The polypeptide–PNF hydrogels are mechanically remarkably robust. They reveal exciting thixotropic behavior with immediate in situ recovery after exposure to various high strains over long periods and self‐repair of defects by instantaneous reassembly. High cytocompatibility, convenient functionalization by coassembly, and controlled enzymatic degradation but stability in 2D and 3D cell culture as demonstrated by the encapsulation of primary human umbilical vein endothelial cells and neuronal cells open many attractive opportunities for 3D tissue engineering and other biomedical applications. 相似文献
105.
Mass Spectrometric Analysis of Cerebrospinal Fluid Ubiquitin in Alzheimer's Disease and Parkinsonian Disorders
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Simon Sjödin Oskar Hansson Annika Öhrfelt Gunnar Brinkmalm Henrik Zetterberg Ann Brinkmalm Kaj Blennow 《Proteomics. Clinical applications》2017,11(11-12)
1 Purpose
Dysfunctional proteostasis, with decreased protein degradation and an accumulation of ubiquitin into aggregated protein inclusions, is a feature of neurodegenerative diseases. Identifying new potential biomarkers in cerebrospinal fluid (CSF) reflecting this process could contribute important information on pathophysiology.2 Experimental design
A developed method combining SPE and PRM‐MS is employed to monitor the concentration of ubiquitin in CSF from subjects with Alzheimer's disease (AD), Parkinson's disease (PD), and progressive supranuclear palsy (PSP). Four independent cross‐sectional studies are conducted, studies 1–4, including controls (n = 86) and participants with AD (n = 60), PD (n = 15), and PSP (n = 11).3 Results
The method shows a repeatability and intermediate precision not exceeding 6.1 and 7.9%, respectively. The determined LOD is 0.1 nm and the LOQ range between 0.625 and 80 nm . The CSF ubiquitin concentration is 1.2–1.5‐fold higher in AD patients compared with controls in the three independent AD‐control studies (Study 1, p < 0.001; Study 2, p < 0.001; and Study 3, p = 0.003). In the fourth study, there is no difference in PD or PSP, compared to controls.4 Conclusion and clinical relevance
CSF ubiquitin may reflect dysfunctional proteostasis in AD. The described method can be used for further exploration of ubiquitin as a potential biomarker in neurodegenerative diseases. 相似文献106.
Metal contamination at a wood preservation site: characterisation and experimental studies on remediation 总被引:2,自引:0,他引:2
Bhattacharya P Mukherjee AB Jacks G Nordqvist S 《The Science of the total environment》2002,290(1-3):165-180
The aim of this investigation was to determine the occurrence of As, Cu, Cr and Zn in the soil at an abandoned wood preservation unit and to examine some possible extractants for the contaminants in the soil. The mean As content of the contaminated surface soils (0-10 cm) was 186 mg kg(-1), where as the mean concentrations of Cu, Cr and Zn in soils from the contaminated area were 26, 29 and 91 mg kg(-1), respectively. The elevated As content in the mineral soils is related to adsorption of inorganic As phases in the fine grained fractions, which are characterised by large surface area and high positive surface charge under the current acidic conditions. Cu and Cr were found to be rather mobile, which is reflected in their lower abundance in soils and significant accumulation in sediments in the drainage leaving the area. The fine fraction of the soil (<0.125 mm) has an average metal content increased by nearly 34% as compared to the <2-mm fraction conventionally used for the analysis and assessment of soil contamination. The <2-mm fraction constitutes approximately 65% of the total weight while the fine fraction (<0.125 mm) constitutes approximately 10%. These facts, taken together, are essential for the choice of remediation measures. Oxalate solutions have been tested as extractants for soil remediation. Dark acid oxalate extraction dissolves the amorphous Al- and Fe-oxides and hydroxides and mobilises the adsorbed inorganic As species. Oxalate also acts as a ligand for the cationic heavy metals, releasing them from exchangeable sites. With a three-step sequential leaching, up to 98-99% of the metals could be removed. At lower concentrations and higher pH, the leaching decreased to approximately 70%. 相似文献
107.
Kindlmann G Ennis DB Whitaker RT Westin CF 《IEEE transactions on medical imaging》2007,26(11):1483-1499
Guided by empirically established connections between clinically important tissue properties and diffusion tensor parameters, we introduce a framework for decomposing variations in diffusion tensors into changes in shape and orientation. Tensor shape and orientation both have three degrees-of-freedom, spanned by invariant gradients and rotation tangents, respectively. As an initial demonstration of the framework, we create a tunable measure of tensor difference that can selectively respond to shape and orientation. Second, to analyze the spatial gradient in a tensor volume (a third-order tensor), our framework generates edge strength measures that can discriminate between different neuroanatomical boundaries, as well as creating a novel detector of white matter tracts that are adjacent yet distinctly oriented. Finally, we apply the framework to decompose the fourth-order diffusion covariance tensor into individual and aggregate measures of shape and orientation covariance, including a direct approximation for the variance of tensor invariants such as fractional anisotropy. 相似文献
108.
Lundberg Ulf; Dohns Ingela Elfsberg; Melin Bo; Sandsj? Leif; Palmerud Gunnar; Kadefors Roland; Ekstr?m Maria; Parr Deirdre 《Canadian Metallurgical Quarterly》1999,4(3):245
This study examined psychological and physiological stress, as well as muscle tension and musculoskeletal symptoms, among 72 female supermarket cashiers. Stress levels were found to be significantly elevated at work, as reflected in the catecholamines, blood pressure, heart rate, electromyographic (EMG) activity, and self-reports. Fifty cashiers (70%) suffering from neck-shoulder pain (trapezius myalgia) were found to have higher EMG activity at work and reported more tension after work. Women who kept a diary for 1 week and reported more musculoskeletal pain (above the median) were older, had higher blood pressure, and reported more work stress and psychosomatic symptoms. The elevated stress levels at work are consistent with data from workers involved in other types of repetitive tasks and can be important for the high prevalence of neck and shoulder symptoms among the cashiers. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
109.
Gunnar Mller 《Bautechnik》2004,81(6):480-488
Calculation of lateral stability loads for timber constructions. Stability loads for lateral bracings are usually calculated by using a simplified method according to the standard for timber constructions. In this article two methods for an accurate calculation of stability loads for lateral bracings will be presented. The first possibility is based on the energy method and can be used for single‐span beams with continuous lateral support. Equations to determine the lateral loads for single‐span beams with constant normal forces or constant bending moments can be determined by using the energy method. Another possibility of verification is the computation of lateral stability loads using the 2nd order flexural torsion theory for a three‐dimensional loaded beam with discrete lateral supports with any support and load cases by employing the transfer matrix method. The results of both methods will be compared in several examples. 相似文献
110.
Arthur H. Schmidt Gunnar Kircher Mathias Spring Markus W. Hendriok Christian Künz 《Advanced Synthesis \u0026amp; Catalysis》1997,339(1):564-574
Oxocarbons and Related Compounds. 27. Synthesis of Dihydrocyclobuta[a]naphthalene-1,2-diones and Cyclobuta[a]naphthalene-1,2-diones via Annulation of Alkoxy-(1-alkenyl)benzenes with 3-Chloro-3-cyclobutene-1,2-dione. Scope and Limitations The reaction of alkoxy-(1-alkenyl)benzenes with semisquaric chloride ( 3 ) has been investigated systematically. 1,2-Dialkoxy- and 1-alkoxy'-2-alkoxy″-4-(1-alkenyl)benzenes ( 6a–j ) and ( 11a–i ) react with 3 to give the 3,4-dihydrocyclobuta[a]naphthalene-1,2-diones ( 8a–j ) and ( 12a–i ). Treatment of the dihydrocyclobuta[a]naphthalene-1,2-diones with 1.2 equiv. bromine effects dehydrogenation and affords cyclobuta[a]naphthalene-1,2-diones ( 9a–e ) and ( 13b–f ). Any efforts to extend this annulation reaction to dimethoxy-(1-alkenyl)benzenes with the methoxy groups in other than the 1,2-positions, e. g. 14a, b, 16a, b have been unsuccessful. The reaction of 1,2,3-trimethoxy-4-(1-propenyl) [and 4-(1-butenyl)]-benzenes ( 18a ) and ( 18b ) with semisquaric chloride ( 3 ) leads to the elimination of HCl and CH3OH and gives 5,6-dimethoxy-3-methyl [and 3-ethyl]-cyclobuta[a]naphthalene-1,2-diones ( 20a ) and ( 20b ). The reaction pathway of this novel annulation reaction is discussed. 相似文献