Poly[dipotassium [(µ6-2,2',2'',2'''-{[pyrazine-2,3,5,6-tetra-yltetra-kis-(methyl-ene)]tetra-kis-(sulfanedi-yl)}tetra-acetato)-disilver(I)] 5.2-hydrate].

The reaction of AgNO3 with the ligand 2,2',2'',2'''-{[pyrazine-2,3,5,6-tetra-yltetra-kis-(methyl-ene)]tetra-kis-(sulfanedi-yl)}tetra-acetic acid in the presence of a potassium acetate buffer lead to the formation of a silver(I)-potassium-organic framework, poly[dipotassium [(µ6-2,2',2'',2'''-{[pyrazine-2,3,5,6-tetra-yltetra-kis(methyl-ene)]tetra-kis-(sulfanedi-yl)}tetra-acetato)-disilver(I)] 5.2-hydrate], {K2[Ag2(C16H16N2O8S4)]·5.2H2O} n , (I). The asymmetric unit is composed of half a binuclear silver complex located about a center of symmetry, a potassium cation and 2.6 disordered water mol-ecules. The whole binuclear silver complex is generated by inversion symmetry with the pyrazine ring being located about an inversion centre. The ligand coordinates in a bis-tetra-dentate manner. The binuclear silver complex anions are linked via bridging Ag⋯S⋯Ag zigzag bonds, forming a network lying parallel to the bc plane. The networks are linked by Ocarboxyl-ate⋯K +⋯Ocarboxyl-ate bridging bonds to form a framework. The disordered water mol-ecules are present near to the K+ cations.

A new tetra-kis-substituted pyrazine carb-oxy-lic acid, 3,3',3'',3'''-{[pyrazine-2,3,5,6-tetra-yltetra-kis(methyl-ene)]tetra-kis-(sulfanedi-yl)}tetra-propionic acid: crystal structures of two triclinic polymorphs and of two potassium-organic frameworks.

Two polymorphs of the title tetra-kis-substituted pyrazine carb-oxy-lic acid, 3,3',3'',3'''-{[pyrazine-2,3,5,6-tetra-yltetra-kis-(methyl-ene))tetra-kis-(sulfanedi-yl]}tetra-propionic acid, C20H28N2O8S4, (H4L1), have been obtained, H4L1_A and H4L1_B. Each structure crystallized with half a mol-ecule in the asymmetric unit of a triclinic P unit cell. The whole mol-ecules are generated by inversion symmetry, with the pyrazine rings being located about inversion centers. The crystals of H4L1_B were of poor quality, but the X-ray diffraction analysis does show the change in conformation of the -CH2-S-CH2-CH2- side chains compared to those in polymorph H4L1_A. In the crystal of H4L1_A, mol-ecules are linked by two pairs of O-H⋯O hydrogen bonds, enclosing R 2 2(8) ring motifs forming layers parallel to plane (100), which are linked by C-H⋯O hydrogen bonds to form a supra-molecular framework. In the crystal of H4L1_B, mol-ecules are also linked by two pairs of O-H⋯O hydrogen bonds enclosing R 2 2(8) ring motifs, however here, chains are formed propagating in the [001] direction and stacking up the a-axis. Reaction of H4L1 with Hg(NO3)2 in the presence of a potassium acetate buffer did not produce the expected binuclear complex, instead crystals of a potassium-organic framework were obtained, poly[(µ-3-{[(3,5,6-tris-{[(2-carb-oxy-eth-yl)sulfan-yl]meth-yl}pyrazin-2-yl)meth-yl]sulfan-yl}propano-ato)potassium], [K(C20H27N2O8S4)] n (KH3L1). The organic mono-anion possesses inversion symmetry with the pyrazine ring being located about an inversion center. A carb-oxy H atom is disordered by symmetry and the charge is compensated for by a potassium ion. A similar reaction with Zn(NO3)2 resulted in the formation of crystals of a dipotassium-organic framework, poly[(µ-3,3'-{[(3,6-bis-{[(2-carb-oxy-eth-yl)sulfan-yl]meth-yl}pyrazine-2,5-di-yl)bis(methyl-ene)]bis-(sulfanedi-yl)}dipropionato)dipotassium], [K2(C20H26N2O8S4)] n (K2H2L1). Here, the organic di-anion possesses inversion symmetry with the pyrazine ring being located about an inversion center. Two symmetry-related acid groups are deprotonated and the charges are compensated for by two potassium ions.

Creation of a medical ward from non-clinical space amidst the Covid-19 pandemic.

INTRODUCTION: Hospitals were mandated to dramatically increase capacity during the Covid-19 crisis in New York City. Conversion of non-clinical space into medical units designated for Covid-19 patients became necessary to accommodate this mandate. METHODS: Non-clinical space was converted into medical units at multiple campuses of a large academic hospital system over 1 week. The conversion required construction to deliver basic care including oxygen supplementation. Creation of provider workspaces, handwashing areas, and colour-coded infection control zones was prioritized. Selection criteria were created with a workflow to determine appropriate patients for transfer into converted space. Staffing of converted space shifted as hospitalizations surged. RESULTS: The unit was open for 18 days and accommodated 170 unique patients. Five patients (2.9%) required transfer to a higher level of care. There were no respiratory arrests, cardiac arrests, or deaths in the new unit. CONCLUSION: Converting non-clinical space to a medical unit was accomplished quickly with staffing, workflow for appropriate patients, few patients who returned to a higher level of care, and no respiratory or cardiac arrests or deaths on the unit.

(µ-2,2',2'',2'''-{[Pyrazine-2,3,5,6-tetra-yltetra-kis(methyl-ene)]tetra-kis(sulfanedi-yl)}tetra-acetato)bis-[aqua-nickel(II)] hepta-hydrate.

Reaction of the ligand 2,2',2'',2'''-{[pyrazine-2,3,5,6-tetra-yltetra-kis-(methyl-ene)]tetra-kis-(sulfanedi-yl)}tetra-acetic acid (H4L1), with NiCl2 leads to the formation of a binuclear complex, (µ-2,2',2'',2'''-{[pyrazine-2,3,5,6-tetra-yltetra-kis-(methyl-ene)]tetra-kis-(sulfanedi-yl)}tetra-acetato-κ5 O,S,N 1,S',O':κ5 O'',S'',N 4,S''',O''')bis[aqua-nickel(II)] hepta-hydrate, {[Ni2(C16H16N2O8S4)(H2O)2]·7H2O} (I). It crystallizes with two half mol-ecules in the asymmetric unit. The complete mol-ecules are generated by inversion symmetry, with the center of the pyrazine rings being located at crystallographic centres of inversion. The ligand coordinates two NiII ions in a bis-penta-dentate manner and the sixfold coordination sphere of each nickel(II) atom (NiS2O3N) is completed by a water mol-ecule. The complex crystallized as a hepta-hydrate. The binuclear complexes are linked by Owater-H⋯Ocarbon-yl hydrogen bonds, forming layers parallel to the (101) plane. This layered structure is additionally stabilized by weak C-H⋯O hydrogen bonds. Further O-H⋯O hydrogen bonds involving binuclear complexes and solvent water mol-ecules, together with weak C-H⋯S hydrogen bonds, link the layers to form a supra-molecular framework.

Synthesis and optical characterization of submicrometer gold nanotubes grown on goethite rods.

Goethite (FeOOH) rods were used as templates for growing gold nanotubes with a length of a few hundred nanometers and an aspect ratio between 3 and 4. Successful uniform growth required surface modification, followed by the attachment of small Au seeds and one-step seeded growth using formaldehyde as a reducing agent, as previously reported for the growth of Au shells on silica spheres and hematite spindles. The thickness and surface roughness of the obtained shells could be adjusted by simply varying the concentration ratio between seeds (modified goethite rods) and growth reagents (HAuCl 4 and formaldehyde). The morphology of the synthesized gold nanotubes was thoroughly characterized by TEM, SEM, and AFM/MFM. The resulting gold nanotubes display well-defined plasmon resonances, with a strong longitudinal mode centered around ca. 1400 nm and a broad band in the visible resulting from the overlap of a transverse mode and a multipolar mode, as was found from theoretical modeling using the boundary element method, which provides reasonable agreement with the experimental results.

Dimeric structures of alpha-synuclein bind preferentially to lipid membranes.

There is substantial evidence which implicates alpha-synuclein and its ability to aggregate and bind vesicle membranes as critical factors in the development of Parkinson's disease. In order to investigate the interaction between alpha-synuclein wild type (Wt) and its familial mutants, A53T and A30P with lipid membranes, we developed a novel lipid binding assay using surface enhanced laser desorption/ionisation-time of flight-mass spectrometry (SELDI-TOF MS). Wt and A53T exhibited similar lipid binding profiles; monomeric species and dimers bound with high relative affinity to the lipid surface, the latter of which exhibited preferential binding. Wt and A53T trimers and tetramers were also detected on the lipid surface. A30P exhibited a unique lipid binding profile; monomeric A30P bound with a low relative affinity, however, the dimeric species of A30P exhibited a higher binding ability. Larger order A30P oligomers were not detected on the lipid surface. Tapping mode atomic force microscopy (AFM) imaging was conducted to further examine the alpha-synuclein-lipid interaction. AFM analysis revealed Wt and its familial mutants can penetrate lipid membranes or disrupt the lipid and bind the hydrophobic alkyl self-assembled monolayer (SAM) used to form the lipid layer. The profile of these studied proteins revealed the presence of 'small features' consistent with the presence of monomeric and dimeric forms of the protein. These data collectively indicate that the dimeric species of Wt and its mutants can bind and cause membrane perturbations.

Superhydrophobic effects of self-assembled monolayers on micropatterned surfaces: 3-D arrays mimicking the lotus leaf.

The contact angle of water has been measured on a series of self-assembled monolayers (SAM) on thermally evaporated and sputter coated silver surfaces. It is found that micropatterning the surface using nanosphere lithography leads to large increases in the contact angle and generates superhydrophobic surfaces with contact angles >150 degrees. The type of functional groups on the SAMs, the metal island size, and the metal island thickness all contribute to the measured contact angle. The maximum contact angle found was 161 degrees for a fluorinated alkanethiol on 80 nm thick silver islands.

Two triclinic polymorphs of 2,3,5,6-tetrakis(naphthalen-2-ylsulfanylmethyl)pyrazine.

The title compound, C(48)H(36)N(2)S(4), can be crystallized as two polymorphic structures, (I) and (II), both of which are in the triclinic space group P-1 and possess C(i) symmetry. In the crystal structure of polymorph (I), the adjacent naphthalene moieties are orientated towards one another and are inclined to one another by 78.7 (1) degrees, resulting in weak C-H.pi interactions. In polymorph (II), the adjacent substituents are orientated away from one another, enclosing the pyrazine N atoms. In this way, the S atom of one substituent sits below the plane of the naphthalene ring of the other substituent.

Framework fluxionality of organometallic oxides: synthesis, crystal structure, EXAFS, and DFT studies on [[Ru(eta6-arene)]4Mo4O16] complexes.

Reactions of the molybdates Na(2)MoO4.2 H2O and (nBu(4)N)2[Mo2O7] with [[Ru(arene)Cl(2)](2)] (arene=C(6)H5CH3, 1,3,5-C6H3(CH3)(3), 1,2,4,5-C6H2(CH3)4) in water or organic solvents led to formation of the triple-cubane organometallic oxides [[Ru(eta(6)-arene)](4)Mo4O16], whose crystal and molecular structures were determined. Refluxing triple cubane [[Ru(eta(6)-C6H5CH3)](4)Mo4O16] in methanol caused partial isomerization to the windmill form. The two isomers of [[Ru(eta(6)-C6H5CH3)](4)Mo4O16] were characterized by Raman and Mo K-edge X-ray absorption spectroscopy (XAS), both in the solid-state and in solution. This triple-cubane isomer was also used as a spectroscopic model to account for isomerization of the p-cymene windmill [[Ru(eta(6)-1,4-CH3C6H4CH(CH3)2)](4)Mo4O16] in solution. Using both Raman and XAS techniques, we were then able to determine the ratio between the windmill and triple-cubane isomers in dichloromethane and in chloroform. Density functional calculations on [[Ru(eta(6)-arene)](4)Mo4O16] (arene=C6H6, C6H5CH3, 1,3,5-C6H3(CH3)3, 1,4-CH3C6H4CH(CH3)2, C6(CH3)6) suggest that the windmill form is intrinsically more stable, provided the complexes are assumed to be isolated. Intramolecular electrostatic interactions and steric bulk induced by substituted arenes were found to modulate but not to reverse the energy difference between the isomers. The stability of the triple-cubane isomers should therefore be accounted for by effects of the surroundings that induce a shift in the energy balance between both forms.