Notes

The analogy not only applies to the π-band, but also extends to the 50 valence σ-electrons
The occupied σ-orbitals are assigned on the basis of radial and angular nodes of the scalar disk waves. The magnetic response of the cluster was examined by Nucleus Independent Chemical Shift (NICS) values and current density calculations based on the ipsocentric model. B20(2-) is found to exhibit a remarkable inner paratropic current in the σ-channel and an outer diatropic current in the π-channel. The orbital excitations responsible for the antiaromaticity in σ and the disk-aromaticity in One-Pot Synthesis of Icosahedral Silver Nanoparticles by Using a Photoassisted Tartrate Reduction Method under UV Light with a Wavelength of 310 nm.A photoassisted citrate reduction reaction under blue LEDs is an easy and highly reproducible method to synthesize high-yield decahedral silver nanoparticles (AgNPs) in the absence of seeds in the initial photochemical reaction. In UV-Activated Acid Generator , icosahedral AgNPs with sizes of 80 to 150 nm could be synthesized by using the photoassisted tartrate reduction method under UV light with a wavelength of λ=(310±12) nm.

The product yield of icosahedral AgNPs is higher than 90 %. SAED (selected-area electron diffraction) patterns and XRD (X-ray diffraction) spectra show that these AgNPs have multiply twinned structures. High-resolution TEM and dark-field TEM show that the facet of the triangular planes of these icosahedral AgNPs is 111. This is the first report of icosahedral AgNPs synthesized by using a seed-free photochemical method. SERS (surface-enhanced Raman scattering) of Crystal Violet (CV) measurements show that the as-prepared icosahedral AgNP colloids have excellent SERS enhancement factors, which are approximately four and six times the enhancement factors of decahedral AgNP colloids and thermal-citrate-reduction AgNP colloids, © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Access to Functionalized Pyrenes, Peropyrenes, Terropyrenes, and Quarterropyrenes via Reductive Aromatization.

Marburg, Hans Meerwein Strasse 4, 35032, Marburg, Germany.Herein we report a versatile concept for the synthesis of fourfold functionalized, soluble pyrenes, peropyrenes, terropyrenes, and quarterropyrenes. They were obtained by a modular stepwise approach towards the rylene scaffold via Suzuki-Miyaura cross coupling, oxidative cyclodehydrogenation in the presence of caesium hydroxide under air, and finally zinc-mediated reductive silylation. The silylated reaction products were characterized by X-ray crystallography. The first example of a synthesized and crystallized quarterropyrene is presented and its oxidation reaction investigated. The functionalized ropyrenes were systematically characterized by means of UV/Vis-NIR and photoluminescence spectroscopy showing a bathochromic shift of 80 nm per naphthalene unit and a nearly linear increase of the extinction coefficients. Cyclic voltammograms and DFT calculations identify them as electron-rich dyes and show a narrowing of the electrochemically determined HOMO-LUMO gap and lower oxidation potentials for the higher homologues.

Full-color micro-LED displays with cadmium-free quantum dots patterned by photolithography technology: retraction.The referenced article [Appl. Opt9, 11112 Escherichia coli W as a new platform strain for the enhanced production of L-valine by systems metabolic engineering.Department of Chemical and Biomolecular Engineering (BK21 Program), KAIST, A less frequently employed Escherichia coli strain W, yet possessing useful metabolic characteristics such as less acetic acid production and high L-valine tolerance, was metabolically engineered for the production of L-valine. The ilvA gene was deleted to make more pyruvate, a key precursor for L-valine, available for enhanced L-valine biosynthesis. The lacI gene was deleted to allow constitutive expression of genes under the tac or trc promoter. The ilvBN(mut) genes encoding feedback-resistant acetohydroxy acid synthase (AHAS) I and the L-valine biosynthetic ilvCED genes encoding acetohydroxy acid isomeroreductase, dihydroxy acid dehydratase, and branched chain amino acid aminotransferase, respectively, were amplified by plasmid-based overexpression.

The global regulator Lrp and L-valine exporter YgaZH were also amplified by plasmid-based overexpression. The engineered E. coli W (ΔlacI ΔilvA) strain overexpressing the ilvBN(mut) , ilvCED, ygaZH, and lrp genes was able to produce an impressively high concentration of 60 g/L L-valine by fed-batch culture in 29 h, resulting in a high volumetric productivity of 26 g/L/h. The most notable finding is that there was no other byproduct produced during L-valine production. The results obtained in this study suggest that E. coli W can be a good alternative to Corynebacterium glutamicum and E. coli K-12, which have so far been the most efficient L-valine producer.

Furthermore, it is expected that various bioproducts including other amino acids might be more efficiently produced by this revisited platform strain of E. coli.CuBr/NHPI co-catalyzed aerobic oxidative [3 + 2] cycloaddition-aromatization to access 5,6-dihydro-pyrrolo[2,1-a]isoquinolines.An efficient and enviromentally friendly CuBr/NHPI co-catalyzed aerobic oxidative [3 + 2] cycloaddition-aromatization cascade was realized with N-substituted tetrahydroisoquinolines and electron-deficient olefins.
Here's my website: http://ezproxy.cityu.edu.hk/login?url=http://en.wikipedia.org/wiki/Photoacid