A self-condensation cyclization reaction mediated by phosphorus pentoxide (P2O5) and catalyzed by zinc bromide (ZnBr2) is presented for the synthesis of polysubstituted 4-pyridones and 2-pyridones from β-keto amides. A variety of β-keto amides are used in this approach, and a wide range of functionalized 4-pyridones and 2-pyridones were obtained in good to excellent yields. When employing the N...

This review discusses about phosphorus and zinc fertilizer consumption led to increasing yield components of the crops. The objectives this were focuses on impact application fertilizers crop plants their importance performance enhancement. other important aspect nutrition is interaction effect between them, especially in soils marginally deficient zinc. When fertilized together, such soils, yi...

Most corn planted on tropical acidic soils suffers substantial yield loss caused by low crop phosphorus (P) uptake. Humic acid is recommended to increase P uptake since it capable of competing with be bound soil adsorption complexes. extracted from composted manure (MHA) a good alternative humic because more reactive and has higher complexation ability compared leonardite. Therefore, the effect...

In this study, the effects of high-LET radiation on DNA were investigated and compared with the effects of gamma radiation. Hydrated DNA samples at 77 K were irradiated with argon-ion beams ((36)Ar or (40)Ar beam at energies between 60 and 100 MeV/nucleon). The individual free radicals formed were identified and their yields were investigated by electron spin resonance spectroscopy. Argon-ion i...

Semi-intensive shrimp production in Honduras is based upon use of formulated diets to supply nutrients for shrimp growth. Unconsumed feed contributes nutrients to pond water, which when discharged may deteriorate water quality in receiving waters. This experiment focused on the development of nutrient budgets (nitrogen and phosphorus) in semi-intensively managed shrimp ponds receiving a low or ...

Phosphorus (P) in rivers in the Mississippi River basin (MRB) contributes to hypoxia in the Gulf of Mexico and impairs local water quality. We analyzed the spatial pattern of P in the MRB to determine the counties with the greatest January to June P riverine yields and the most critical factors related to this P loss. Using a database of P inputs and landscape characteristics from 1997 through ...

Sequential nucleophilic substitution of phosphorus trichloride with alcohols has been achieved. Over-reaction was suppressed by rapid mixing through micro-flow technology, and asymmetric phosphotriesters containing acid- and/or base-labile functional groups were synthesized in good to high yields. Moreover, a mechanistic study using DFT calculations suggested interesting reaction pathways. More...