Results 61 to 70 of about 108,024 (198)

Caracterização da dinâmica de nutrientes em solos sob floresta primária e em clareiras de diferentes idades de reflorestamento na província petrolífera de Urucu - Coari, AM. [PDF]

, 2014
A retirada da floresta e dos horizontes superficiais do solo provoca a diminuição da fertilidade do mesmo. Com o reflorestamento dessas áreas, ocorre uma recuperação lenta e contínua da qualidade e quantidade de matéria orgânica.
CRUZ, M. E. G. da, ENCINAS, O. C., MACEDO, R. S., MARTINS, G. C., NEVES JUNIOR, A. F., RODRIGUES, M. do R. L., TEIXEIRA, W. G.   +6 more
core  

Poly(Ionic) Liquid‐Enhanced Ion Dynamics in Cellulose‐Derived Gel Polymer Electrolytes

ChemSusChem, Volume 18, Issue 6, March 15, 2025.
Advancing Energy Storage: Gel Polymer Electrolytes with Promising Potential Gel polymer electrolytes (GPEs) incorporating methyl cellulose and a range of ionic/polymeric achieved Li+ transference numbers comparable to traditional liquid electrolytes.
Tiago G. Paiva, Maykel Klem, Sara L. Silvestre, João Coelho, Neri Alves, Elvira Fortunato, Eurico J. Cabrita, Marta C. Corvo   +7 more
wiley   +1 more source

Uso de modelado molecular como herramienta didáctica en el primer curso de grado de Química Orgánica

Educación Química, 2018
El primer curso de Química Orgánica (Química Orgánica 101) de la Facultad de Química, Universidad de la República (Montevideo, Uruguay) se dicta para las carreras de Química Farmacéutica, Ingeniería Química, Química, Bioquímica Clínica e Ingeniería en ...
Gustavo Seoane, Hugo Cerecetto, M. Boiani, M. González, Marina Miguez Palermo, P. Buccino, P. Saenz, Silvia Loureiro, V. López, Ximena Otegui   +9 more
doaj   +1 more source

Chiral Separations in Preparative Scale: A Medicinal Chemistry Point of View

Molecules, 2020
Enantiomeric separation is a key step in the development of a new chiral drug. Preparative liquid chromatography (LC) continues to be the technique of choice either during the drug discovery process, to achieve a few milligrams, or to a scale-up during ...
Madalena M.M. Pinto, Carla Fernandes, Maria E. Tiritan   +2 more
doaj   +1 more source

Mechanistic Paths for the Gold(I)‐Catalyzed Heteroannulation of Salicylic Amides With Apolar Alkynes Explored With Density Functional Theory Calculations

European Journal of Organic Chemistry, EarlyView.
A manifold of catalytic reaction paths can operate in the Au(I)‐catalyzed heteroannulation of salicylic amides and alkynes. However, a subtle initial nucleophilic advantage of N versus O and a kinetic bottleneck at an advanced stage of the mechanistic machinery seems to suffice for the reaction to run on a single path and with exquisite selectivity. We
Ioannis Stylianakis, Evaggelia Vlachou, Carlos Silva López, Antonios Kolocouris   +3 more
wiley   +1 more source

Elementos estruturadores da química orgânica implícitos na argumentação de professor e alunos de graduação [PDF]

, 2013
Mullins (2008) propõe que o bom desempenho em tópicos de Química Orgânica seria consequência do domínio adequado de elementos fundamentais quais sejam, eletronegatividade, ligação covalente polar, efeito estérico, efeito indutivo, ressonância e ...
Filho, M. A. Bueno, Nascimento, G. M.
core   +2 more sources

Pd‐Catalyzed Cyclotrimerization and Cycloaddition of 5,6‐Didehydrobenzo[8]annulenes (BenzoCOTynes): Formation of Nonplanar Tri[8]annulenes and Diels–Alder Cycloadducts

European Journal of Organic Chemistry, EarlyView.
A Pd(0)‐catalyzed cyclotrimerization of benzoCOTynes to form tri(benzo[8]annulenes) was developed. Three distinct isomers were isolated and structurally characterized by single‐crystal X‐ray diffraction. Ligand modulation proved crucial for enhancing regioselectivity: P(4‐OMePh), and (S)‐tBu‐Phox promoted the formation of the symmetric isomers.
Jesús Bello‐García, Jesús A. Varela, Carlos Saá   +2 more
wiley   +1 more source

Metal‐Free Electrophilic Borylative Cyclizations of Alkynes

The Chemical Record, EarlyView.
Metal‐free borylative cyclizations based on electrophilic alkyne activation by boron Lewis acids provide efficient access to borylated hetero‐ and carbocycles. Early studies using B(C6F5)3 displayed limited scope and application, whereas recent ClBcat‐ and BCl3‐based methods enable mild CB and CC/CX bond formation for the synthesis of cycles ...
Jaime Mateos‐Gil, Marcos Humanes, Manuel A. Fernández‐Rodríguez, Patricia García‐García   +3 more
wiley   +1 more source

Dendrimeric Antigens for Passive Mast Cell Activation in the Evaluation of Amoxicillin Allergy

Allergy, EarlyView.
DeAns with defined nanoscale structure reveal that conjugate size and determinant density govern IgE‐mediated effector‐cell activation in AX allergy. All DeAn generations bind to sIgE in inhibition immunoassay, but only larger DeAns trigger FcεRI‐dependent responses in mouse MC, huRBL‐2H3, and LUVA cells.
Amene Tesfaye Ayane, Maria Salas, Sara Benede, Maria J. Rodriguez‐Sanchez, Maria J. Rodriguez‐Sojo, Isabel M. Jiménez‐Sánchez, Gador Bogas, Ezequiel Perez‐Inestrosa, Cristobalina Mayorga, Juan L. Paris, Alba Rodríguez‐Nogales, María J. Torres, María I. Montañez   +12 more
wiley   +1 more source

POTENTIOMETRIC DETERMINATION OF CAPTOPRIL IN PHARMACEUTICAL FORMULATIONS

Eclética Química, 2018
A simple, precise, rapid and low-cost potentiometric method for captopril determination in pure form and in pharmaceutical preparations is proposed. Captopril present in tablets containing known quantity of drug was potentiometrically titrated in aqueous
P. R. da S. RIBEIRO, A. O. SANTINI, H. R. PEZZA, L. PEZZA   +3 more
doaj   +1 more source