Szegedski topološki indeksi in učinkovitost prerezne metode: primer melemskih struktur

The Szeged index is a bond-additive topological descriptor that quantifies each bond\u27s terminal atoms based on their closeness sets which is measured by multiplying the number of atoms in the closeness sets. Based on the high correlation between the Szeged index and the physico-chemical properties of chemical compounds, Szeged-like indices have been proposed by considering closeness sets with bond counts and other mathematical operations like addition and subtraction. As there are many ways to compute the Szeged-like indices, the cut method is predominantly used due to its complexity compared to other approaches based on algorithms and interpolations. Yet, we here analyze the usefulness of the cut method in the case of melem structures and find that it is less effective when the size and shape of the cavities change in the structures.Szegedski indeks je topološki deskriptor, ki kvantificira končne atome vsake vezi na podlagi njihovih množic bližine, ki se merijo s številom atomov v množicah bližine. Na podlagi visoke korelacije med szegedskim indeksom in fizikalno-kemijskimi lastnostmi kemičnih spojin so bili predlagani podobni indeksi in sicer z upoštevanjem množic bližine, štetjem vezi ter drugimi matematičnimi operacijami, kot sta seštevanje in odštevanje. Ker obstaja veliko načinov za izračun szegedskih indeksov, se prerezna metoda pretežno uporablja zaradi svoje kompleksnosti v primerjavi z drugimi pristopi, ki temeljijo na algoritmih in interpolacijah. Tukaj analiziramo uporabnost prerezne metode v primeru melemskih struktur in ugotavljamo, da je manj učinkovita, če se v strukturah spremenita velikost in oblika votlin

Bioherbicidal potential of some allelopathic agroforestry and fruit plant species against Lepidium sativum

Herbicide resistance and environmental pollution are the risks associated with chemical control of weeds. Allelopathic plant extracts may be exploited for weed management as an alternative to commercial herbicides. Before development of allelochemical-based eco-friendly herbicides, bioherbicidal potential of plants need to be evaluated. Present study was conducted to evaluate phytotoxic allelopathic impact of leaf extract from eight agroforestry and fruit plant species against Lepidium sativum. The results showed that all plant species delayed germination and inhibited root length, shoot length and seedling dry weight of Lepidium sativum. Four plant species such as Moringa oleifera, Mangifera indica, Albizia procera and Delonix regia were most phytotoxic with Lepidium sativum root growth inhibition of ≥85% as compared with control and seedling persistence index <30% of control. Phenolic contents were maximum in Mangifera indica (137 mg g-1 leaf dry weight) followed by Delonix regia (130 mg g-1 leaf dry weight). The results suggest that phytotoxic action of leaf extract of plant species may be due to presence of phenolic allelochemicals that may be exploited further either directly for weed management or development of bioherbicides