Phytosociology of weeds in coffee plants with different soil management techniques

The adoption of different soil management techniques in coffee plants can alter the phytosociology of the weed community and, therefore, identifying the technique that most contributes to an integrated weed management is fundamental. In this context, the objective of this study was to evaluate the phytosociology of weeds in coffee plants under different soil management techniques. The land was planted in January 2016 with coffee seedlings of the species Coffea arabica L., cultivar Mundo Novo IAC 379-19. The design used was in randomized blocks, arranged in a 2 x 6 factorial scheme, with 3 replications. Two evaluations were carried out: in the rainy season and in the dry season, in 2017. The management techniques applied inter-rows were: i) control (spontaneous vegetation in the area); ii) management with Urochloa decumbens. On the coffee in-rows, the treatments were: iii) coffee husk; iv) organic compound; v) plant residues of U. decumbens; vi) plant residues of U. decumbens with coffee husk; vii) plant residues of U. decumbens with organic compound; viii) control (without coverage). For the evaluations, a square (0.25 m²) was randomly launched and the phytosociological indices were subsequently calculated. The species of the families Poaceae and Asteraceae were the most frequent in the area. The management with U. decumbens inter-rows and the crop residues deposited in the row associated with the coffee husk, or organic compound, decreases the amount and the diversity of weed species.

Synthesis and Characterization of Some New 1,3,4-thiadiazole Compounds Derived from 3,4-(Methylenedioxy)cinnamic Acid and their Antimicrobial Activities

Some new 1,3,4-thiadiazole compounds derived from 3,4-(methylenedioxy)cinnamic acid were synthesized in this study. Their structures were determined using UV-Vis, IR, 1H-NMR, and 13C-NMR spectroscopy. Moreover, the antibacterial activities of the new 1,3,4-thiadiazole derivatives were tested against Gram positive (Enterococcus durans, Bacillus subtilis, and Staphylococcus aureus) and gram negative (Salmonella typhimurium, Escherichia coli, Salmonella enteritidis, Salmonella infantis, Salmonella kentucky, Enterobacter aerogenes) bacteria using the disk diffusion method. Furthermore, their antifungal activity was tested against Candida albicans using the disk diffusion method. Some of the synthesized compounds (V, VII, XIII, and XIV) showed antibacterial activity against S. aureus. Also, one synthesized compound (VIII) showed antibacterial activity against E. coli, exhibiting 8 and 9 mm inhibition zones using 50 and 80 µL. One compound (IX) showed antibacterial activity against E. aerogenes, exhibiting a 12 mm inhibition zone using 80 µL. One compound (XIII) showed antibacterial activity against S. kentucky, exhibiting an inhibition zone of about 9 mm using 80 µL. Also, one compound (VII) showed antibacterial activity against E. durans, exhibiting 7, 7, and 8 mm inhibition zones using 30, 50, and 80 µL. None of the compounds (I-XV) showed antifungal activity against C. albicans. These results showed that some of the synthesized compounds could be used as antibacterial agents.

Novel ammonium phosphinates containing peptide moiety: Synthesis, structure, and in vitro antimicrobial activity

Five new ammonium phosphinates with formula [XC6H4NHC(O)NHP(O)YO]−[H2Y]+ (Y = N(CH3)(CH2C6H5), X = H (IV), CH3 (V), NO2 (VI); Y = NH(CH2C6H5), X = H (VII), NO2 (VIII)) were synthesised by the reaction of N-arylureidophoshoryl dichlorides with N-methylbenzylamine or benzylamine in the presence of an excess amount of the corresponding amine. All new compounds were characterised by NMR and IR spectral data and elemental analysis. Their antimicrobial activity was tested against some Gram-positive and Gram-negative bacteria and fungi. Compounds IV and VIII exhibited moderate activity in vitro against Bacillus subtilis. In addition, compound VIII moderately inhibited Pseudomonas aeruginosa. The crystal structure of benzylmethylammonium(3-phenylureido)(benzylmethylamino)phosphinate (IV) was also determined. This compound crystallises in the orthorhombic system.

Nine N-aryl-2-chloronicotinamides: supramolecular structures in one, two and three dimensions

Structures are reported here for eight further substituted N-aryl-2-chloronicotinamides, 2-ClC5H3NCONHC6H4 X-4′. When X = H, compound (I) (C12H9ClN2O), the molecules are linked into sheets by N—H...N, C—H...π(pyridyl) and C—H...π(arene) hydrogen bonds. For X = CH3, compound (II) (C13H11ClN2O, triclinic P\bar 1 with Z′ = 2), the molecules are linked into sheets by N—H...O, C—H...O and C—H...π(arene) hydrogen bonds. Compound (III), where X = F, crystallizes as a monohydrate (C12H8ClFN2O·H2O) and sheets are formed by N—H...O, O—H...O and O—H...N hydrogen bonds and aromatic π...π stacking interactions. Crystals of compound (IV), where X = Cl (C12H8Cl2N2O, monoclinic P21 with Z′ = 4) exhibit inversion twinning: the molecules are linked by N—H...O hydrogen bonds into four independent chains, linked in pairs by C—H...π(arene) hydrogen bonds. When X = Br, compound (V) (C12H8BrClN2O), the molecules are linked into sheets by N—H...O and C—H...N hydrogen bonds, while in compound (VI), where X = I (C12H8ClIN2O), the molecules are linked into a three-dimensional framework by N—H...O and C—H...π(arene) hydrogen bonds and an iodo...N(pyridyl) interaction. For X = CH3O, compound (VII) (C13H11ClN2O2), the molecules are linked into chains by a single N—H...O hydrogen bond. Compound (VIII) (C13H8ClN3O, triclinic P\bar 1 with Z′ = 2), where X = CN, forms a complex three-dimensional framework by N—H...N, C—H...N and C—H...O hydrogen bonds and two independent aromatic π...π stacking interactions.

Hydrated metal(II) complexes of N-(6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl) derivatives of glycine, glycylglycine, threonine, serine, valine and methionine: a monomeric complex and coordination polymers in one, two and three dimensions linked by hydrogen bonding. Corrigendum

Some of the data collection details for compound (VIII) were incorrectly given in Table 1 of Godino Salido et al. (2004). The data for compound VIII in this paper were collected using synchrotron radiation at the Daresbury SRS station 9.8, λ = 0.6935 Å (Cernik et al., 1997; Clegg, 2000). The data were collected using a Bruker SMART 1K CCD diffractometer using ω rotation with narrow frames. The computer program used in the data collection was SMART (Bruker, 2001) and for cell refinement and data reduction SAINT (Bruker, 2001).

Immediate effects of intravenous tobramycin and gentamicin on human cochlear function

SummaryImmediate electrocochleographic changes have been studied in a series of patients following intravenous infusion of either tobramycin or gentamicin. In patients receiving tobramycin, as soon as peak serum levels of antibiotic were reached, a dramatic decrease occurred in the magnitude of the compound VIII nerve action potential (AP), and of the cochlear microphonic (CM). The shape of the AP also changed. The N1component of the waveform became very small, and N2increased in size; this is the dissociated pattern of basal coil cochlear damage. The speed of onset of these electrical changes and their apparent reversibility suggests a temporary metabolic block caused by tobramycin. No such changes were observed following infusion of gentamicin.