Glycosidases in pear pollen tube development

During the in vitro germination of pear pollen, several hydrolases were released into the medium. They were apparently eluted from the pollen grain, since the activity was the same when germination was inhibited. These enzymes, once released, had no role in tube growth, since resuspension of pollen in fresh medium after 1.5 hr of incubation did not result in a change of the subsequent tube growth. Homogenates of the pollen suspension at different stages of development showed no significant changes in phosphatase, β-glucosidase, or β-galactosidase activity. However, patent β-glucosidase activity measured directly in suspensions of intact pollen did increase after germination in proportion to tube wall development. Nojirimycin, a specific inhibitor of glucosidases, reduced this β-glucosidase activity by 75% at 10−5M and significantly reduced growth rate at 10−4

Non-proteinuric chronic kidney disease in diabetes patients: reality or effect of control

El declinar de la tasa de filtración glome-rular (eGFR4) es generalmente observado en pacientes con diabetes mellitus (DM) siguiendo a macroalbuminu-ria. Hay evidencia que puede presentarse durante micro (MA) y aun normo albuminuria (NA). En el estudio del riñón de la Clínica Joslin en pacientes con DM tipo1 en un seguimiento de 8 años el declinar de eGFR ocurrió en el 10% de los NA y el 35% de MA. En un estudio de DM tipo2 con enfermedad renal Crónica (ERC) el 30% no presentó retinopatía ni albuminuria patológica. Objetivo: conocer la frecuencia de enfermedad renal crónica (ERC) no proteinúrica y sus factores asociados en los diabéticos atendidos en el consultorio de diabeto-logía del Hospital L. Lagomaggiore

Zipper Assembly of Vectorial Rigid-Rod π-Stack Architectures with Red and Blue Naphthalenediimides: Toward Supramolecular Cascade n/p-Heterojunctions

Zipped up: Supramolecular 3D organization on gold with interdigitating intra- and interlayer recognition motifs (see picure, black p-oligophenyl rods; red, blue naphthalenediimide (NDI) stacks) is designed to access supramolecular cascade n/p-heterojunctions or the adaptable directionality needed to control fill factors in current–voltage curves

Rigid-rod push–pull naphthalenediimide photosystems

Design, synthesis and evaluation of advanced rigid-rod π-stack photosystems with asymmetric scaffolds are reported. The influence of push–pull rods on self-organization, photoinduced charge separation and photosynthetic activity is investigated and turns out to be surprisingly small overall

Ultrafast Photoinduced Charge Separation in Naphthalene Diimide Based Multichromophoric Systems in Liquid Solutions and in a Lipid Membrane

The photophysical properties of multichromophoric systems consisting of eight red or blue naphthalene diimides (NDIs) covalently attached to a p-octiphenyl scaffold, as well as a blue bichromophoric system with a biphenyl scaffold, have been investigated in detail using femtosecond time-resolved spectroscopy. The blue octachromophoric systems have been recently shown to self-assemble as supramolecular tetramers in lipid bilayer membranes and to enable generation of a transmembrane proton gradient upon photoexcitation (Bhosale, S.; Sisson, A. L.; Talukdar, P.; Fürstenberg, A.; Banerji, N.; Vauthey, E.; Bollot, G.; Mareda, J.; Röger, C.; Würthner, F.; Sakai, N.; Matile, S. Science2006, 313, 84). A strong reduction of the fluorescence quantum yield was observed when going from the single NDI units to the multichromophoric systems in methanol, the effect being even stronger in a vesicular lipid membrane. Fluorescence up-conversion measurements reveal ultrafast self-quenching in the multichromophoric systems, whereas the formation of the NDI radical anion, evidenced by transient absorption measurements, points to the occurrence of photoinduced charge separation. The location of the positive charge could not be established unambiguously from the transient absorption measurements, but energetic considerations indicate that charge separation should occur between two NDI units in the blue systems, whereas both an NDI unit and the p-octiphenyl scaffold could act as electron donor in the red system. The lifetime of the charge-separated state was found to increase from 22 to 45 ps by going from the bi- to the octachromophoric blue systems in methanol, while a 400 ps decay component was observed in the lipid membrane. This lifetime lengthening is explained in terms of charge migration that is most efficient when the octachromophoric systems are assembled as supramolecular tetramers in the lipid membrane. Furthermore, the average charge-separated state lifetime of the red system in methanol is even larger and amounts to 750 ps. This effect cannot be simply explained in terms of Marcus inverted regime as the driving force for charge recombination in the red system is only slightly larger than in the blue one. A better spatial separation of the charges in the red system stemming from the localization of the hole on the p-octiphenyl scaffold could additionally contribute to the slowing down of charge recombination

First records of two mealybug species in Brazil and new potential pests of papaya and coffee

Five mealybug (Hemiptera: Pseudococcidae) plant pest species: Dysmicoccus grassii (Leonardi), Ferrisia malvastra (McDaniel), Ferrisia virgata (Cockerell), Phenacoccus tucumanus Granara de Willink, and Pseudococcus elisae Borchsenius are recorded for the first time in the state of Espírito Santo, Brazil. These are the first records of D. grassii in Brazil, from papaya (Carica papaya, Caricaceae), and from coffee (Coffea canephora, Rubiaceae). Ferrisia malvastra is also newly recorded in Brazil, where it was found on Bidens pilosa (Asteraceae). Ferrisia virgata was collected from an unidentified weed and Phenacoccus tucumanus from Citrus sp. (Rutaceae). Plotococcus capixaba Kondo was found on pitanga (Eugenia cf. pitanga, Myrtaceae) and Pseudococcus elisae on Coffea canephora, which are new host records for these mealybugs