Nankai University

About: Nankai University is a education organization based out in Tianjin, China. It is known for research contribution in the topics: Catalysis & Enantioselective synthesis. The organization has 42964 authors who have published 51866 publications receiving 1127896 citations. The organization is also known as: Nánkāi Dàxué.

Metal–Organic-Framework-Based Tandem Molecular Sieves as a Dual Platform for Selective Microextraction and High-Resolution Gas Chromatographic Separation of n-Alkanes in Complex Matrixes

Abstract: Metal–organic frameworks (MOFs) were employed to design tandem molecular sieves as a dual platform for selective solid-phase microextraction (SPME) and high-resolution gas chromatographic (GC) separation of target analytes in complex matrixes. An elegant combination of a ZIF-8-coated fiber for SPME with a ZIF-8-coated capillary for GC allows selective extraction and separation of n-alkanes from complex matrixes such as petroleum-based fuel and biological fluids. The proposed tandem ZIF-8 molecular sieves not only offered good enhancement factors from 235 (hexane) to 1212 (nonane), but also exhibited wide linearity with 3 orders of magnitude for the tested linear alkanes. The limits of detection for the linear alkanes ranged from 0.46 ng L–1 (nonane) to 1.06 ng L–1(hexane). The relative standard deviations of retention time, peak area, peak height, and half peak width for five replicate determinations of the tested n-alkanes at 30 ng L–1 were 0.02–0.26%, 1.9–8.6%, 1.4–6.0%, and 1.3–7.2%, respectively. The ...

Architecture of the mitochondrial calcium uniporter

Abstract: Mitochondria from many eukaryotic clades take up large amounts of calcium (Ca(2+)) via an inner membrane transporter called the uniporter. Transport by the uniporter is membrane potential dependent and sensitive to ruthenium red or its derivative Ru360 (ref. 1). Electrophysiological studies have shown that the uniporter is an ion channel with remarkably high conductance and selectivity. Ca(2+) entry into mitochondria is also known to activate the tricarboxylic acid cycle and seems to be crucial for matching the production of ATP in mitochondria with its cytosolic demand. Mitochondrial calcium uniporter (MCU) is the pore-forming and Ca(2+)-conducting subunit of the uniporter holocomplex, but its primary sequence does not resemble any calcium channel studied to date. Here we report the structure of the pore domain of MCU from Caenorhabditis elegans, determined using nuclear magnetic resonance (NMR) and electron microscopy (EM). MCU is a homo-oligomer in which the second transmembrane helix forms a hydrophilic pore across the membrane. The channel assembly represents a new solution of ion channel architecture, and is stabilized by a coiled-coil motif protruding into the mitochondrial matrix. The critical DXXE motif forms the pore entrance, which features two carboxylate rings; based on the ring dimensions and functional mutagenesis, these rings appear to form the selectivity filter. To our knowledge, this is one of the largest membrane protein structures characterized by NMR, and provides a structural blueprint for understanding the function of this channel.

Observation of a Charged (D(D)over-bar*)(+/-) Mass Peak in e(+)e(-) -> pi D(D)over-bar* at root s=4.26 GeV

Abstract: We report on a study of the process e(+)e(-) -> pi(+/-) (D (D) over bar*)(-/+) at root s = 4.26 GeV using a 525 pb(-1) data sample collected with the BESIII detector at the BEPCII storage ring. A distinct charged structure is observed in the (D (D) over bar*)(-/+) invariant mass distribution. When fitted to a mass- dependent- width Breit- Wigner line shape, the pole mass and width are determined to be M-pole (3883: 9 +/- 1.5 (stat) +/- 4.2 dsyst__ MeV= c(2) and Gamma(pole) = (24: 8 +/- 3.3 (stat) +/- 11: 0 (syst)) MeV. The mass and width of the structure, which we refer to as Z(c)(3885), are 2 sigma and 1 sigma, respectively, below those of the Z(c)(3900) -> pi(+/-) J/psi peak observed by BESIII and Belle in pi(+)pi(-) J/psi final states produced at the same center- of- mass energy. The angular distribution of the pi Z(c)(3885) system favors a J(P) = J(P) = 1(+) quantum number assignment for the structure and disfavors 1(-) or 0(-). The Born cross section times the (D (D) over bar*) branching fraction of the Z(c)(3885) is measured to be sigma(e(+)e(-) -> pi(+/-)Z(c)(3885)(-/+)) x B(Z(c)(3885)-/+ -> (D (D) over bar*)(-/+) = (83.5 +/- 6.6 (stat) +/- 22.0 (syst)) pb. Assuming the Z(c)(3885) -> (D (D) over bar*)(-/+) signal reported here and the Z(c)(3900) -> pi J/psi signal are from the same source, the partial width ratio (Gamma(Z(c)(3885) -> D (D) over bar*)/Gamma(Z(c)(3900) -> pi J/psi)) = 6.2 +/- 1.1 (stat) +/- 2.7 (syst) is determined.

Porous Multishelled Ni2P Hollow Microspheres as an Active Electrocatalyst for Hydrogen and Oxygen Evolution

Abstract: Tailoring the morphology and microstructure of electrocatalysts is important in improving catalytic performance. Herein, porous multishelled Ni2P hollow microspheres assembled by nanoparticles were prepared through a simple and economical self-templating approach followed by phosphorization. Compared with nanoparticles and hierarchical solid-interior microspheres, the synthesized multishelled, hollow microstructures of Ni2P exhibit significantly higher electrocatalytic activity for the hydrogen evolution reaction in a 1 M KOH electrolyte. Additionally, a NiOOH layer is formed on the surface of Ni2P during anodic polarization, as revealed by electron microscopy, X-ray photoelectron spectroscopy, and in situ Raman analysis. The Ni2P/NiOOH derivative outperforms the benchmark RuO2 in catalyzing the oxygen evolution reaction. Furthermore, pairing the carbon fiber paper-supported multishelled Ni2P as both the anode and cathode results in superior overall alkaline water splitting performance, generating 10 and ...