Endohedral Metallofullerene Derivatives

Trimetallic nitride endohedral metallofullerene derivatives and their preparation are described. The trimetallic nitride endohedral metallofullerene derivatives have the general formula A(sub 3-n)X(sub n)@C(sub m)(R) where n ranges from 0 to 3, A and X may be trivalent metals and may be either rare earth metal or group IIIB metals, m is between about 60 and about 200, and R is preferably an organic group. Derivatives where the R group forms cyclized derivatives with the fullerene cage are also described

High Blocking Temperature of Magnetization and Giant Coercivity in the Azafullerene Tb 2 @C 79 N with a Single-Electron Terbium–Terbium Bond

The azafullerene Tb 2 @C 79 N is found to be a single-molecule magnet with a high 100-s blocking temperature of magnetization of 24 K and large coercivity. Tb magnetic moments with an easy-axis single-ion magnetic anisotropy are strongly coupled by the unpaired spin of the single-electron Tb−Tb bond. Relaxation of magnetization in Tb 2 @C 79 N below 15 K proceeds via quantum tunneling of magnetization with the characteristic time τ QTM =16 462±1230 s. At higher temperature, relaxation follows the Orbach mechanism with a barrier of 757±4 K, corresponding to the excited states, in which one of the Tb spins is flipped. © 2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

I. The crystal structure of trimesic acid. II. Topics in crystallographic calculations

I. Trimesic acid (1, 3, 5-benzenetricarboxylic acid) crystallizes with a monoclinic unit cell of dimensions a = 26.52 A, b = 16.42 A, c = 26.55 A, and β = 91.53° with 48 molecules /unit cell. Extinctions indicated a space group of Cc or C2/c; a satisfactory structure was obtained in the latter with 6 molecules/asymmetric unit - C54O36H36 with a formula weight of 1261 g. Of approximately 12,000 independent reflections within the CuKα sphere, intensities of 11,563 were recorded visually from equi-inclination Weissenberg photographs. The structure was solved by packing considerations aided by molecular transforms and two- and three-dimensional Patterson functions. Hydrogen positions were found on difference maps. A total of 978 parameters were refined by least squares; these included hydrogen parameters and anisotropic temperature factors for the C and O atoms. The final R factor was 0.0675; the final "goodness of fit" was 1.49. All calculations were carried out on the Caltech IBM 7040-7094 computer using the CRYRM Crystallographic Computing System. The six independent molecules fall into two groups of three nearly parallel molecules. All molecules are connected by carboxylto- carboxyl hydrogen bond pairs to form a continuous array of sixmolecule rings with a chicken-wire appearance. These arrays bend to assume two orientations, forming pleated sheets. Arrays in different orientations interpenetrate - three molecules in one orientation passing through the holes of three parallel arrays in the alternate orientation - to produce a completely interlocking network. One third of the carboxyl hydrogen atoms were found to be disordered. II. Optical transforms as related to x-ray diffraction patterns are discussed with reference to the theory of Fraunhofer diffraction. The use of a systems approach in crystallographic computing is discussed with special emphasis on the way in which this has been done at the California Institute of Technology. An efficient manner of calculating Fourier and Patterson maps on a digital computer is presented. Expressions for the calculation of to-scale maps for standard sections and for general-plane sections are developed; space-group-specific expressions in a form suitable for computers are given for all space groups except the hexagonal ones. Expressions for the calculation of settings for an Eulerian-cradle diffractometer are developed for both the general triclinic case and the orthogonal case. Photographic materials on pp. 4, 6, 10, and 20 are essential and will not reproduce clearly on Xerox copies. Photographic copies should be ordered.</p

Toward Microfluidic Label-Free Isolation and Enumeration of Circulating Tumor Cells from Blood Samples

The isolation, analysis, and enumeration of circulating tumor cells (CTCs) from cancer patient blood samples are a paradigm shift for cancer patient diagnosis, prognosis, and treatment monitoring. Most methods used to isolate and enumerate these target cells rely on the expression of cell surface markers, which varies between patients, cancer types, tumors, and stages. Here, we propose a label-free high-throughput platform to isolate, enumerate, and size CTCs on two coupled microfluidic devices. Cancer cells were purified through a Vortex chip and subsequently flowed in-line to an impedance chip, where a pair of electrodes measured fluctuations of an applied electric field generated by cells passing through. A proof-of-concept of the coupling of those two devices was demonstrated with beads and cells. First, the impedance chip was tested as a stand-alone device: (1) with beads (mean counting error of 1.0%, sizing information clearly separated three clusters for 8, 15, and 20 um beads, respectively) as well as (2) with cancer cells (mean counting error of 3.5%). Second, the combined setup was tested with beads, then with cells in phosphate-buffered saline, and finally with cancer cells spiked in healthy blood. Experiments demonstrated that the Vortex HT chip enriched the cancer cells, which then could be counted and differentiated from smaller blood cells by the impedance chip based on size information. Further discrimination was shown with dual high-frequency measurements using electric opacity, highlighting the potential application of this combined setup for a fully integrated label-free isolation and enumeration of CTCs from cancer patient samples. (c) 2019 International Society for Advancement of Cytometr

Isolation and Crystallographic Characterization of ErSc2N@C80: an Endohedral Fullerene Which Crystallizes with Remarkable Internal Order

The ErnSc3-nN@C80 (n = 0-3) family of four endohedral fullerenes was prepd. by vaporization of graphite rods packed with 2% Sc2O3/3% Er2O3/95% graphite powder in a Kratschmer-Huffman fullerene generator under dynamic flow of helium and dinitrogen. ErSc2N@C80 was isolated in pure form via three stages of HPLC and characterized by mass spectrometry. The 1st structure of a mixed metal endohedral, ErSc2N@C80, was detd. by single-crystal x-ray diffraction at 90 K on [email protected](OEP).cntdot.1.5C6H6.cntdot.0.3CHCl3, which was obtained by diffusion of a soln. of ErSc2N@C80 in benzene into a soln. of CoII(OEP) (OEP is the dianion of octaethylporphyrin) in chloroform. The structure of ErSc2N@C80 consists of a planar ErSc2N unit surrounded by an icosahedral C80 cage. The nominal Er-N distance is 2.089(9) .ANG. and the Sc-N distance is, as expected, shorter, 1.968(6) .ANG.. Despite its location within the C80 cage, the ErSc2N unit displays a remarkable degree of order within the solid-state structure. The metal ions make close contact with individual carbon atoms of the cage with shortest Sc-C distances, at 2.03-2.12 .ANG., and shortest Er-C distances of 2.20 and 2.22 .ANG.. Two different, but equally populated, orientations of the Ih C80 cage were required to describe the fullerene portion of the structure. Although these C80 cages are located on a crystallog. mirror plane, that plane does not coincide with a mirror plane of the cages themselves. Consequently, the cage is disordered over four superimposed sites.The ErnSc3-nN@C80 (n = 0−3) family of four endohedral fullerenes has been prepared by vaporization of graphite rods packed with 2% Sc2O3/3% Er2O3/95% graphite powder in a Krätschmer−Huffman fullerene generator under dynamic flow of helium and dinitrogen. ErSc2N@C80 has been isolated in pure form via three stages of high-pressure liquid chromatography and characterized by mass spectrometry. The first structure of a mixed metal endohedral, ErSc2N@C80, has been determined by single-crystal X-ray diffraction at 90 K on ErSc2N@C80·CoII(OEP)·1.5C6H6·0.3CHCl3, which was obtained by diffusion of a solution of ErSc2N@C80 in benzene into a solution of CoII(OEP) (OEP is the dianion of octaethylporphyrin) in chloroform. The structure of ErSc2N@C80 consists of a planar ErSc2N unit surrounded by an icosahedral C80 cage. The nominal Er−N distance is 2.089(9) Å and the Sc−N distance is, as expected, shorter, 1.968(6) Å. Despite its location within the C80 cage, the ErSc2N unit displays a remarkable degree of order within the solid-state structure. The metal ions make close contact with individual carbon atoms of the cage with shortest Sc−C distances, in the range of 2.03−2.12 Å, and shortest Er−C distances of 2.20 and 2.22 Å. Two different, but equally populated, orientations of the Ih C80 cage were required to describe the fullerene portion of the structure. Although these C80 cages are located on a crystallographic mirror plane, that plane does not coincide with a mirror plane of the cages themselves. Consequently, the cage is disordered over four superimposed sites

Menenjit ve ansefalit:İnsidans,etyoloji,klinik,BOS,EEG, tedavi,prognoz

Surfactant molecules self-organize in water,[1] often producing nearly spherical aggregates called micelles in dilute solutions, and lyotropic mesophases at higher concentrations. The polar headgroups of these aggregates lie near the bulk aqueous phase, whereas the hydrocarbon chains extend inwardly to avoid unfavorable water contacts