3,600 research outputs found
catena-Poly[[dinitratocopper(II)]-μ-4,4′′-bis(1H-benzimidazol-1-yl)-1,1′:4′,1′′-terphenyl]
In the title one-dimensional coordination polymer, [Cu(NO3)2(C32H22N4)]n, the Cu2+ ion (site symmetry 2) is coordinated by two nitrate O atoms and two N atoms from two 4,4′-bis(benzoimidazol-1-yl)terphenyl (L) ligands in a distorted cis-CuN2O2 square-planar coordination geometry. An alternative description of the metal coordination geometry, if long Cu—O contacts to the bonded nitrate anions are considered, is an extremely distorted cis-CuN2O4 octahedron. The complete L ligand is generated by crystallographic twofold symmetry and connects the metal ions into infinite chains propagating in [10]. The dihedral angle between the benzimidazole ring system and the adjacent benzene (B) ring is 51.12 (11)° and the dihedral angle between the B ring and the central ring is 19.45 (13)°
Thermal stability and inactivation of hepatitis C virus grown in cell culture
<p>Abstract</p> <p>Background</p> <p>Hepatitis C virus (HCV) is a blood-borne flavivirus that infects many millions of people worldwide. Relatively little is known, however, concerning the stability of HCV and reliable procedures for inactivating this virus.</p> <p>Methods</p> <p>In the current study, the thermostability of cell culture-derived HCV (HCVcc, JFH-1 strain) under different environmental temperatures (37°C, room temperature, and 4°C) and the ability of heat, UVC light irradiation, and aldehyde and detergent treatments to inactivate HCVcc were evaluated. The infectious titers of treated viral samples were determined by focus-forming unit (FFU) assay using an indirect immunofluorescence assay for HCV NS3 in hepatoma Huh7-25-CD81 cells highly permissive for HCVcc infection. MTT cytotoxicity assay was performed to determine the concentrations of aldehydes or detergents at which they were no longer cytotoxic.</p> <p>Results</p> <p>HCVcc in culture medium was found to survive 37°C and room temperature (RT, 25 ± 2°C) for 2 and 16 days, respectively, while the virus was relatively stable at 4°C without drastic loss of infectivity for at least 6 weeks. HCVcc in culture medium was sensitive to heat and could be inactivated in 8 and 4 min when incubated at 60°C and 65°C, respectively. However, at 56°C, 40 min were required to eliminate HCVcc infectivity. Addition of normal human serum to HCVcc did not significantly alter viral stability at RT or its susceptibility to heat. UVC light irradiation (wavelength = 253.7 nm) with an intensity of 450 μW/cm<sup>2 </sup>efficiently inactivated HCVcc within 2 min. Exposures to formaldehyde, glutaraldehyde, ionic or nonionic detergents all destroyed HCVcc infectivity effectively, regardless of whether the treatments were conducted in the presence of cell culture medium or human serum.</p> <p>Conclusions</p> <p>The results provide quantitative evidence for the potential use of a variety of approaches for inactivating HCV. The ability of HCVcc to survive ambient temperatures warrants precautions in handling and disposing of objects and materials that may have been contaminated with HCV.</p
Study on the Application of Biological Tactile in Fast Meat Freshness Detection
The author aimed to explore the application of biological tactile in fast non-destructive meat freshness detection. Used WDW-20 electronic universal testing machine, surveyed chicken, pork and beef the pressure characteristic curves, analysed respectively the relationship between the pressure characteristic curve parameters and the meat freshness. The author also analysed the relationship between the shape of pressure characteristic curve and the meat freshness. The results indicated that in the meal pressure characteristic curve, the curve shape and a number of mechanical parameters could reflect its freshness. Also, different types meat had different structures led them to the different mechanical properties; different types meat characteristic curves, the meat pressure characteristic curve shape and parameters reflected their fresh meat differently. Biological tactile can evaluate meat freshness in a few seconds. This is a promising, economic, simple and practicable way of fast meat freshness detection. Key words: Biological tactile; TVBN; pressure Characteristic curv
Y Chromosomes of 40% Chinese Are Descendants of Three Neolithic Super-grandfathers
Demographic change of human populations is one of the central questions for
delving into the past of human beings. To identify major population expansions
related to male lineages, we sequenced 78 East Asian Y chromosomes at 3.9 Mbp
of the non-recombining region (NRY), discovered >4,000 new SNPs, and identified
many new clades. The relative divergence dates can be estimated much more
precisely using molecular clock. We found that all the Paleolithic divergences
were binary; however, three strong star-like Neolithic expansions at ~6 kya
(thousand years ago) (assuming a constant substitution rate of 1e-9/bp/year)
indicates that ~40% of modern Chinese are patrilineal descendants of only three
super-grandfathers at that time. This observation suggests that the main
patrilineal expansion in China occurred in the Neolithic Era and might be
related to the development of agriculture.Comment: 29 pages of article text including 1 article figure, 9 pages of SI
text, and 2 SI figures. 5 SI tables are in a separate ancillary fil
3,3′-(Butane-1,4-diyl)diimidazole-1,1′-diium bis(triiodide)
The cations and anions of the salt, C10H16N4
2+·2I3
−, are linked by N—H⋯I hydrogen bonds and π–π stacking interactions(with interplanar distances of 3.575 and 3.528 Å) into a three-dimensional supramolecular network. The asymmetric unit contains two anions and two half-cations; each cation is centrosymmetric
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