scholarly journals Hydrothermal Synthesis and Structural Investigation of a Crystalline Uranyl Borosilicate

Inorganics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 25
Author(s):  
Kristen A. Pace ◽  
Vladislav V. Klepov ◽  
Mark D. Smith ◽  
Travis Williams ◽  
Gregory Morrison ◽  
...  
Keyword(s):  
Synthesis Method ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Exploratory Research ◽  
The Novel ◽  
Orthorhombic Space Group ◽  
Crystalline Materials ◽  
Waste Remediation ◽  
And Storage ◽  
X Ray Absorption

The relevance of multidimensional and porous crystalline materials to nuclear waste remediation and storage applications has motivated exploratory research focused on materials discovery of compounds, such as actinide mixed-oxoanion phases, which exhibit rich structural chemistry. The novel phase K1.8Na1.2[(UO2)BSi4O12] has been synthesized using hydrothermal methods, representing the first example of a uranyl borosilicate. The three-dimensional structure crystallizes in the orthorhombic space group Cmce with lattice parameters a = 15.5471(19) Å, b = 14.3403(17) Å, c = 11.7315(15) Å, and V = 2615.5(6) Å3, and is composed of UO6 octahedra linked by [BSi4O12]5− chains to form a [(UO2)BSi4O12]3− framework. The synthesis method, structure, results of Raman, IR, and X-ray absorption spectroscopy, and thermal stability are discussed.

scholarly journals Nanofiber-Mâché Hollow Ball Mimicking the Three-Dimensional Structure of a Cyst

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2273
Author(s):  
Wan-Ying Huang ◽  
Norichika Hashimoto ◽  
Ryuhei Kitai ◽  
Shin-ichiro Suye ◽  
Satoshi Fujita
Keyword(s):  
Three Dimensional ◽  
Hollow Structure ◽  
Dimensional Structure ◽  
The Novel ◽  
Fibrous Scaffold ◽  
Hydrogel Beads ◽  
Inner Surface ◽  
Intracranial Epidermoid ◽  
Hollow Ball

The occasional malignant transformation of intracranial epidermoid cysts into squamous cell carcinomas remains poorly understood; the development of an in vitro cyst model is urgently needed. For this purpose, we designed a hollow nanofiber sphere, the “nanofiber-mâché ball.” This hollow structure was fabricated by electrospinning nanofiber onto alginate hydrogel beads followed by dissolving the beads. A ball with approximately 230 mm3 inner volume provided a fibrous geometry mimicking the topography of the extracellular matrix. Two ducts located on opposite sides provided a route to exchange nutrients and waste. This resulted in a concentration gradient that induced oriented migration, in which seeded cells adhered randomly to the inner surface, formed a highly oriented structure, and then secreted a dense web of collagen fibrils. Circumferentially aligned fibers on the internal interface between the duct and hollow ball inhibited cells from migrating out of the interior, similar to a fish bottle trap. This structure helped to form an adepithelial layer on the inner surface. The novel nanofiber-mâché technique, using a millimeter-sized hollow fibrous scaffold, is excellently suited to investigating cyst physiology.

scholarly journals Identification, Characterization, and Three-Dimensional Structure of the Novel Circular Bacteriocin, Enterocin NKR-5-3B, fromEnterococcus faecium

Biochemistry ◽  
2015 ◽  
Vol 54 (31) ◽  
pp. 4863-4876 ◽  
Author(s):  
Kohei Himeno ◽  
K. Johan Rosengren ◽  
Tomoko Inoue ◽  
Rodney H. Perez ◽  
Michelle L. Colgrave ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
The Novel ◽  
Three Dimensional Structure ◽  
Circular Bacteriocin

scholarly journals Solving the Structure and Dynamics of Metal Nanoparticles by Combining X-Ray Absorption Fine Structure Spectroscopy and Atomistic Structure Simulations

2019 ◽  
Vol 12 (1) ◽  
pp. 501-522 ◽  
Author(s):  
J. Timoshenko ◽  
Z. Duan ◽  
G. Henkelman ◽  
R.M. Crooks ◽  
A.I. Frenkel
Keyword(s):  
Fine Structure ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Structural Refinement ◽  
Particle Structure ◽  
X Ray ◽  
Structure And Dynamics ◽  
Absorption Fine ◽  
Metal Metal ◽  
X Ray Absorption

Extended X-ray absorption fine structure (EXAFS) spectroscopy is a premiere method for analysis of the structure and structural transformation of nanoparticles. Extraction of analytical information about the three-dimensional structure and dynamics of metal–metal bonds from EXAFS spectra requires special care due to their markedly non-bulk-like character. In recent decades, significant progress has been made in the first-principles modeling of structure and properties of nanoparticles. In this review, we summarize new approaches for EXAFS data analysis that incorporate particle structure modeling into the process of structural refinement.

scholarly journals Acmonidesite, a new ammonium sulfate chloride from La Fossa crater, Vulcano, Aeolian Islands, Italy

2018 ◽  
Vol 83 (1) ◽  
pp. 137-142 ◽  
Author(s):  
Francesco Demartin ◽  
Carlo Castellano ◽  
Italo Campostrini
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Chlorine Atoms ◽  
Calculated Density ◽  
Sulfate Ions ◽  
Aeolian Islands ◽  
Fossa Crater

AbstractThe new mineral acmonidesite, (NH4,K,Pb2+,Na)9Fe42+(SO4)5Cl8, was found in an active fumarole (fumarole FA, temperature ~250°C) at La Fossa crater, Vulcano, Aeolian Islands, Sicily, Italy. It occurs on a pyroclastic breccia as brown prismatic crystals up to 0.10 mm long, in association with salammoniac, alunite and adranosite. The mineral is orthorhombic, space group C2221 (no. 20) with a = 9.841(1), b = 19.448(3) c = 17.847(3) Å, V = 3415.7(9) Å3 and Z = 4. The six strongest reflections in the powder X-ray diffraction pattern are: [dobs in Å(I)(hkl)] 8.766(100)(110), 1.805(88)(390), 5.178(45)(131), 4.250(42)(221), 2.926(42)(330) and 2.684(32)(261). The empirical formula (based on 28 anions per formula unit [pfu]) is (NH4)5.77K1.42Pb0.62Na1.24Fe3.96Mn0.08S5.04O20.16Cl7.97Br0.08. The idealised formula is (NH4,K,Pb2+,Na)9Fe42+(SO4)5Cl8. The calculated density is 2.551 g cm–3. Using single-crystal diffraction data, the structure was refined to a final R(F) = 0.0363 for 4614 independent observed reflections [I > 2σ(I)]. The structure contains two independent, distorted octahedral iron sites, Fe1 and Fe2, with the iron atoms in the 2+ oxidation state, as confirmed by the interatomic distances and bond-valence calculations (2.06 and 1.94 vu, respectively). Fe1 is surrounded by two chlorine atoms and four oxygens of the sulfate ions, with the following average distances (Å): Fe1–O 2.125 and Fe1–Cl 2.472; and Fe2 is surrounded by three chlorine atoms and three oxygens of the sulfate ions, with the following average distances (Å): Fe2–O 2.110 and Fe2–Cl 2.531. Three independent sulfate anions are also present and are connected with the iron polyhedra to form a three-dimensional structure containing voids occupied by four independent ammonium ions (two of them partially replaced by K+), one Na+/Pb2+ site and one Cl– ion.

scholarly journals Computing Novel Multiplicative Zagreb Connection Indices of Metal Organic Networks

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Usman Ali
Keyword(s):  
Three Dimensional ◽  
Structural Diversity ◽  
Recent Decade ◽  
Organic Ligands ◽  
Complex Structures ◽  
The Novel ◽  
Crystalline Materials ◽  
Nano Structures ◽  
Metal Organic ◽  
Organic Networks

Metal organic networks (MONs) are defined as one, two and three dimensional unique complex structures of porous material and subclass of polymer’s coordination. These networks also show extreme surface area, morphology, excellent chemical stability, large pore volume, highly crystalline materials. The major advantages of MONs are tailorability, structural diversity, versatile applications, highly controllable nano-structures and functionality. So, the multi-functional applications of these MONs are made them more helpful tools in many fields of science in recent decade. In this paper, we light on the two different MONs with respect to the number of increasing layers of metal and organic ligands together. We define the novel multiplicative Zagreb connection indices (ZCIs) such that multiplicative fourth ZCI and multiplicative fifth ZCI. We also compute the main results for multiplicative Zagreb connection indices of two different MONs (zinc oxide and zinc silicate).

Die Lanthanoid(III)-Chlorid-Oxoselenate(IV) MCl[SeO3] (M = Sm–Lu) imHoCl[TeO3]- oder B-Typ / The Lanthanoid(III) Chloride Oxoselenates(IV) MCl[SeO3] (M = Sm–Lu) with HoCl[TeO3]- or B-Type Structure

2008 ◽  
Vol 63 (3) ◽  
pp. 229-236 ◽  
Author(s):  
Christian Lipp ◽  
Thomas Schleid
Keyword(s):  
Three Dimensional ◽  
Eutectic Mixture ◽  
Structure Type ◽  
Selenium Dioxide ◽  
Type Structure ◽  
Dimensional Structure ◽  
Normal Range ◽  
Orthorhombic Space Group ◽  
Coordination Numbers ◽  
Lattice Constants

The B-type lanthanoid(III) chloride oxoselenates(IV) MCl[SeO3] (M = Sm- Lu) crystallize in the orthorhombic space group Pnma (no. 62) with Z = 4 in the structure type of HoCl[TeO3]. Their lattice constants are decreasing following the lanthanoid contraction from a = 730.01(7), b = 707.90(7), c = 895.64(9) pm for SmCl[SeO3] to a = 714.63(7), b = 681.76(7), c = 864.05(9) pm for LuCl[SeO3]. In contrast to NdCl[SeO3], the only representative of the A-type structure, where the coordination numbers of the Nd3+ cations are 7+2 and 8, the B-type structure is dominated by pentagonal bipyramids [MO5Cl2]9− (CN(M3+) = 7), which are connected via trans-oriented O・ ・ ・O edges to 1∞{[MOe4/2Ot1/1Clt2/1]5−} chains (e = edge-sharing, t = terminal) running parallel to the [010] direction. Their inclination relative to each other allows for an alternating interconnection of these chains via Cl− and ψ1-tetrahedral [SeO3]2− anions to form a three-dimensional structure. The distances within the [SeO3]2− groups are in the normal range (d(Se−O) = 165 - 172 pm), while those of the O2− and Cl− anions to the central M3+ cation diminish in dependence of the increasing atomic number (d(M−O) = 226 - 244 pm / 216 - 232 pm, d(M−Cl) = 277 - 278 pm / 266 - 270 pm, M = Sm/Lu). For the synthesis of the chloride oxoselenates(IV) MCl[SeO3] the respective lanthanoid sesquioxide (M2O3) and selenium dioxide (SeO2) were reacted with either an eutectic mixture of RbCl and LiCl or with the corresponding lanthanoid trichloride (MCl3) in evacuated silica ampoules for either five weeks at 500 °C or one week at 850 °C.

scholarly journals Efficacy of Novel Hemagglutinin-Neuraminidase Inhibitors BCX 2798 and BCX 2855 against Human Parainfluenza Viruses In Vitro and In Vivo

2004 ◽  
Vol 48 (5) ◽  
pp. 1495-1502 ◽  
Author(s):  
Irina V. Alymova ◽  
Garry Taylor ◽  
Toru Takimoto ◽  
Tsu-Hsing Lin ◽  
Pooran Chand ◽  
...  
Keyword(s):  
Sendai Virus ◽  
Three Dimensional ◽  
Parainfluenza Virus ◽  
Dimensional Structure ◽  
The Novel ◽  
Virus Infections ◽  
Parainfluenza Viruses ◽  
Human Parainfluenza Viruses

ABSTRACT Human parainfluenza viruses are important respiratory tract pathogens, especially of children. However, no vaccines or specific therapies for infections caused by these viruses are currently available. In the present study we characterized the efficacy of the novel parainfluenza virus inhibitors BCX 2798 and BCX 2855, which were designed based on the three-dimensional structure of the hemagglutinin-neuraminidase (HN) protein. The compounds were highly effective in inhibiting hemagglutinin (HA) and neuraminidase (NA) activities and the growth of hPIV-1, hPIV-2, and hPIV-3 in LLC-MK2 cells. The concentrations required to reduce the activity to 50% of that of a control ranged from 0.1 to 6.0 μM in HA inhibition assays and from 0.02 to 20 μM in NA inhibition assays. The concentrations required to inhibit virus replication to 50% of the level of the control ranged from 0.7 to 11.5 μM. BCX 2798 and BCX 2855 were inactive against influenza virus HA and NA and bacterial NA. In mice infected with a recombinant Sendai virus whose HN gene was replaced with that of hPIV-1 [rSV(hHN)], intranasal administration of BCX 2798 (10 mg/kg per day) and of BCX 2855 (50 mg/kg per day) 4 h before the start of infection resulted in a significant reduction in titers of virus in the lungs and protection from death. Treatment beginning 24 h after the start of infection did not prevent death. Together, our results indicate that BCX 2798 and BCX 2855 are effective inhibitors of parainfluenza virus HN and may limit parainfluenza virus infections in humans.

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