When treated with difluorocarbene, which was generated from FSO2CF2CO2SiMe3 a 1,8-bis(dimethylamino)naphthalene catalyst, N-(thioacyl)amidines underwent [4 + 1] cycloaddition to afford the corresponding amino-substituted 5,5-difluorothiazolines. Both dehydrofluorination and Hofmann elimination/SN2?-type reaction sequence enabled aromatization of obtained products, affording 5-fluorothiazoles. T...

We have developed a set of DNA circuits that execute during gel electrophoresis to yield immobile, fluorescent features in the gel. The parallel execution of orthogonal circuits led to the simultaneous production of different fluorescent lines at different positions in the gel. The positions of the lines could be rationally manipulated by changing the mobilities of the reactants. The ability to...

The success of oligonucleotide ligation assays in probing specific sequences of DNA arises in large part from high enzymatic selectivity against base mismatches at the ligation junction. We describe here a study of the effect of mismatches on a new non-enzymatic, reagent-free method for ligation of oligonucleotides. In this approach, two oligonucleotides bound at adjacent sites on a complementa...

The reaction mechanism and kinetics of the thermal decomposition of uranium dinitride/uranium sesquinitride to uranium mononitride under inert atmosphere at elevated temperature were studied. An increase in the lattice parameter of the UN(2)/alpha-U(2)N(3) phase was observed as the reaction temperature increased, corresponding to a continuous removal of nitrogen. Electron density calculations f...

The diversity of reaction mechanisms employed by Type II restriction enzymes was investigated by analysing the reactions of seven endonucleases at the same DNA sequence. NarI, KasI, Mly113I, SfoI, EgeI, EheI and BbeI cleave DNA at several different positions in the sequence 5'-GGCGCC-3'. Their reactions on plasmids with one or two copies of this sequence revealed five distinct mechanisms. These...

The polymerase chain reaction (PCR) is an in vitro methocl for selectively amplifying, or synthesizing millions of copies of, a short region of a DNA molecule. The reaction is carried out enzymatically in a test tube and has been successfully applied to regions as small as 100 base pairs and as large as 6000 base pairs. In contrast, DNA cloning is a nonselective in vivo method for replicating D...

Abstract. We report herein the synthesis of [7,5]-fused bicyclic acetals, also named furooxepines through a gold(I)-catalyzed domino reaction. During this transformation, two molecules homopropargyl alcohol react together, in sequence including an intramolecular hydroalkoxylation, condensation, 1,6-enyne cycloisomerization, acetalization and isomerization. This reaction allow formation three bo...

Let R be a commutative Noetherian ring and let M be a nitely generated R-module. If I is an ideal of R generated by M-regular sequence, then we study the vanishing of the rst Tor functors. Moreover, for Artinian modules and coregular sequences we examine the vanishing of the rst Ext functors.

Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is one of the most important pest of vegetable and fruit crops. This polyphagous pest has a range of natural enemies including the parasitoid Eretmocerus mundus (Merect) (Hymenoptera: Aphelinidae). To determine the molecular profile and taxonomic status of Iranian isolates of E. mundus, parasitized B. tabaci samples were collected from cotton...