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1H NMR‐based metabolomics exploring urinary biomarkers correlated with proteinuria in focal segmental glomerulosclerosis: a pilot study 下载免费PDF全文
Shiva Kalantari Mohsen Nafar Shiva Samavat Mahmoud Parvin B. Fatemeh Nobakht M.GH. Farnaz Barzi 《Magnetic resonance in chemistry : MRC》2016,54(10):821-826
Focal segmental glomerulosclerosis (FSGS) is a common glomerulonephritis, and its rates of occurrence are increasing worldwide. Proteinuria is a clinical defining feature of FSGS which correlates with the severity of podocyte injury in patients with nephrotic‐range protein excretion. Metabolite biomarkers corresponding with the level of proteinuria could be considered as non‐invasive complementary prognostic factors to proteinuria. The urine samples of 15 patients (n = 6 women and n = 9 men) with biopsy‐proven FSGS were collected and subjected to nuclear magnetic resonance (NMR) analysis for metabolite profiling. Multivariate statistical analyses, including principal component analysis and orthogonal projection to latent structure discriminant analysis, were applied to construct a predictive model based on patients with proteinuria >3000 mg/day and <3000 mg/day. In addition, random forest was performed to predict differential metabolites, and pathway analysis was performed to find the defective pathways responsible for proteinuria. Ten metabolites, significant in both statistical methods (orthogonal projection to latent structure discriminant analysis and random forest), were considered as prognostic biomarkers for FSGS: citrulline, dimethylamine, proline, acetoacetate, alpha‐ketoisovaleric acid, valine, isobutyrate, D‐Palmitylcarnitine, histidine, and N‐methylnicotinamide. Pathway analysis revealed impairment of the branched‐chain amino acid degradation pathways in patients with massive proteinuria. This study shows that metabolomics can reveal the molecular changes corresponding with disease progression in patients with FSGS and provide a new insight for pathogenic pathways. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Palkovits R Nieddu I Kruithof CA Klein Gebbink RJ Weckhuysen BM 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(29):8995-9005
Glycerol is considered a potential renewable building block for the synthesis of existing as well as new chemicals. A promising route is the telomerization of 1,3-butadiene with glycerol leading to C8 chain ethers of glycerol with applications in, for example, surfactant chemistry. Recently, we reported a new set of palladium-based homogeneous catalytic systems for the telomerization of 1,3-butadiene with glycerol and found that palladium complexes bearing methoxy-functionalized triphenylphosphine ligands are highly active catalysts capable of converting crude glycerol without any significant loss of activity. Herein, we present a detailed account of these investigations by reporting on the influence of the butadiene/glycerol ratio, temperature, and reaction time on product selectivity and activity allowing further optimization of catalyst performance. Maximum activity and yield were reached for high 1,3-butadiene/glycerol ratios at a temperature of 90 degrees C, whereas the selectivity for mono- and diethers of glycerol could be optimized by combining high reaction temperatures and short reaction times with low butadiene/glycerol ratios. Variation of the PdII metal precursors and the metal/ligand ratio showed that palladium precursors with halogen ligands gave unsatisfying results, in contrast to precursors with weakly coordinated ligands such as [Pd(OAc)2] and [Pd(acac)2]. [Pd(dba)2], the only Pd0 precursor tested, gave the best results in terms of activity, which illustrates the importance of the ability to form a Pd0 species in the catalytic cycle. Finally, base addition resulted in a shortening of the reaction time and most likely facilitates the formation of a Pd0 species. Based on these results, we were able to realize the first attempts towards a rational ligand design aimed at a high selectivity for mono- and diether formation. 相似文献
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Roger T Büscher J Bastin B Kirsebom OS Raabe R Alcorta M Äystö J Borge MJ Carmona-Gallardo M Cocolios TE Cruz J Dendooven P Fraile LM Fynbo HO Galaviz D Gasques LR Giri GS Huyse M Hyldegaard S Jungmann K Kruithof WL Lantz M Perea A Riisager K Saastamoinen A Santra B Shidling PD Sohani M Sørensen AJ Tengblad O Traykov E van der Hoek DJ Van Duppen P Versolato OO Wilschut HW 《Physical review letters》2012,108(16):162502
A measurement of the final state distribution of the (8)B β decay, obtained by implanting a (8)B beam in a double-sided silicon strip detector, is reported here. The present spectrum is consistent with a recent independent precise measurement performed by our collaboration at the IGISOL facility, Jyv?skyl? [O. S. Kirsebom et al., Phys. Rev. C 83, 065802 (2011)]. It shows discrepancies with previously measured spectra, leading to differences in the derived neutrino spectrum. Thanks to a low detection threshold, the neutrino spectrum is for the first time directly extracted from the measured final state distribution, thus avoiding the uncertainties related to the extrapolation of R-matrix fits. Combined with the IGISOL data, this leads to an improvement of the overall errors and the extension of the neutrino spectrum at high energy. The new unperturbed neutrino spectrum represents a benchmark for future measurements of the solar neutrino flux as a function of energy. 相似文献
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Skin surfaces are used for the visualization of molecules. They form a class of tangent continuous surfaces defined in terms of a set of balls (the atoms of the molecule) and a shrink factor. More recently, skin surfaces have been used for approximation purposes.
We present an algorithm that approximates a skin surface with a topologically correct mesh. The complexity of the mesh is linear in the size of the Delaunay triangulation of the balls, which is worst case optimal.
We also adapt two existing refinement algorithms to improve the quality of the mesh and show that the same algorithm can be used for meshing a union of balls. 相似文献
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Lucy Rutten Dr. Birgit Wieczorek Jean‐Paul B. A. Mannie Cornelis A. Kruithof Dr. Harm P. Dijkstra Dr. Maarten R. Egmond Prof. Martin Lutz Dr. Robertus J. M. Klein Gebbink Prof. Piet Gros Prof. Gerard van Koten Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(17):4211-4211
The interfacial enzyme cutinase…? shown at the air–water interface on the cover, was site‐selectively modified with two different ECE‐pincer–metal complexes. The resulting cutinase–pincer–metal hybrids crystallized under halide‐rich conditions to give monomeric crystal structures, but also crystallized under halide‐poor conditions to form a metal‐induced dimer. See the Full Paper by R. J. M. Klein Gebbink, P. Gros, G. van Koten et al. on page 4270 ff. , for details of the chemistry and the crystal structures. Photograph: View from the island of Saba (Netherlands Antilles) taken by Birgit Wieczorek. Design: Birgit Wieczorek and Cornelis A. Kruithof.
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M H MOGHTADER DINDARLU M KAVOSH TEHRANI H SAGHAFIFAR A MALEKI GH SOLOOKINEJAD M JABBARI 《Pramana》2017,88(2):36
In this paper, an analytical model for temperature distribution of the side-pumped laser rod is extracted. This model can be used for side-pumped laser rods whose absorbed pump profile is a Gaussian profile. Then, it is validated by numerical results which exhibit a good agreement with the analytical results. Afterwards, by considering a general expression for super-Gaussian and top-hat profiles, and solving the heat equation, the influence of profile width and super-Gaussian exponent of the profile on temperature distribution are investigated. Consequently, the profile width turns out to have a greater influence on the temperature compared to the type of the profile. 相似文献
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Biofouling in spiral wound membrane systems: Three-dimensional CFD model based evaluation of experimental data 总被引:1,自引:0,他引:1
J.S. Vrouwenvelder C. Picioreanu J.C. Kruithof M.C.M. van Loosdrecht 《Journal of membrane science》2010,346(1):71-85
A three-dimensional (3D) computational model describing fluid dynamics and biofouling of feed channels of spiral wound reverse osmosis and nanofiltration membrane systems was developed based on results from practice and experimental studies. In the model simulations the same feed spacer geometry as applied in practice and the experimental studies was used. The 3D mathematical model showed the same trends for (i) feed channel pressure drop, (ii) biomass accumulation, (iii) velocity distribution profile, resulting in regions of low and high liquid flow velocity also named channeling. The numerical model predicted a dominant biomass growth on the feed spacer, consistent with direct in situ observations on biofouling of spiral wound membrane modules and monitors using Magnetic Resonance Imaging (MRI). The model confirms experimental results that feed spacer fouling is more important than membrane fouling. The paper shows that mathematical modeling techniques have evolved to a stage that they can be used hand-in-hand with experiments to understand the processes involved in membrane fouling. 相似文献
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Dijkstra HP Kruithof CA Ronde N Van De Coevering R Ramón DJ Vogt D Van Klink GP Van Koten G 《The Journal of organic chemistry》2003,68(3):675-685
Shape-persistent multi(NCN-palladium and/or -platinum) complexes having one- (5 and 6), two- (1 and 2), and three-dimensional (3 and 4) geometries were prepared in moderate to good yields. Two different approaches were used to construct the multimetallic materials: (i) the construction of the multisite ligands followed by the permetalation step and (ii) selective and mild one-pot coupling of monometallic buiding blocks to a multifunctional shape-persistent organic core molecule. The first approach was used to prepare the palladated and/or platinated tris- (2) and bis(NCN-pincer) (5) complexes, while the second approach afforded the palladated and platinated octakis- (3) and dodecakis(NCN-pincer) (4) complexes. Complexes 1-6 were subjected to nanofiltration (NF) experiments in order to investigate the influence of rigidity and geometry on the retention of these molecules by NF membranes. For this purpose, the corresponding (NCN-Pt-X)(n)() complexes (1c-4c, 5, and 6) were used since exposing these complexes to sulfur dioxide in solution resulted in the formation of bright orange complexes, allowing the use of UV/vis spectroscopy to accurately determine the concentrations of 1-6 in both retentate and permeate. Using the MPF-60 (MWCO = 400) NF-membrane, retention rates of 82.4 (6), 93.9 (1c), 98.7 (2c), 99.5 (3c), 99.6 (5), and >99.9% (4c) were found, while 2c and 4c in combination with the MPF-50 (MWCO = 700) NF-membrane were retained in 97.6 and 99.9%, respectively. A clear relationship is observed between the dimensions calculated by molecular modeling and the retention rates of 1-6. The one-dimensional bis(pincer-platinum) complex 5, however, shows an unexpectedly high retention rate (99.6%) that can be due to precipitation of the complex in the membrane (clogging of the membrane) and/or to the formation of larger aggregates near the membrane. In addition, comparison of 2 and 4 with flexible nickelated G0- and G1-dendrimers with similar dimensions proved that a high degree of rigidity in the backbone of macromolecular complexes indeed leads to more efficient retentions of these multimetallic materials by NF-membranes. 相似文献