Ss

An important class of cytolytic antimicrobial peptides (AMPs) assumes an amphipathic, α-helical conformation that permits efficient interaction with biological membranes. Host defence peptides of this type are widespread in nature, and numerous synthetic model AMPs have been derived from these or designed de novo based on their characteristics. In this review we provide an overview of the ‘sequence template’ approach

ABSTRACT Silicon nanowire (SiNW) field effect transistors (FETs) have been widely investigated as biological sensors for their remarkable sensitivity due to their large surface to volume ratio (S/V) and high selectivity towards a myriad of analytes through functionalization. In this work, we propose a long channel (L > 500 nm) junctionless nanowire transistor (JNT) SiNW sensor based on a highly doped, ultrathin body field-effect transistor with an organic gate dielectric εr = 1.7. The operation regime (threshold voltage Vth) and electrical characteristics of JNTs can be directly tuned by the careful design of the NW/Fin FET. JNTs are investigated through 3D Technology Computer Aided Design (TCAD) simulations performed as a function of geometrical dimensions and channel doping concentration Nd for a p-type tri-gated structure. Two different materials, namely, an oxide and an organic monolayer, with varying dielectric constants εr provide surface passivation. Mildly doped Nd = 1 × 1019 cm−3, thin bodied structures (fin width Fw < 20 nm) with an organic dielectric (εr = 1.7) were found to have promising electrical characteristics for FET sensor structures such as Vth ~ 0 V, high relative sensitivities in the subthreshold regime S > 95%, high transconductance values at threshold gm,Vfg=0 V > 10 nS, low subthreshold slopes SS ~ 60 mV/dec, high saturation currents Id,max ~ 1–10 μA and high Ion/Ioff > 104–1010 ratios. Our results provide useful guidelines for the design of junctionless FET nanowire sensors that can be integrated into miniaturized, low power biosensing systems.

A great diversity of bean cultivars is developed each year, but, to our knowledge, there is a dearth of information regarding the physicochemical and technological properties of the grains, as well as its starch characteristics. Therefore, this study aims to evaluate the physicochemical and technological properties of five cultivars from the carioca bean group and five cultivars from the black bean group as freshly harvested grains. Moreover, the physicochemical, crystallinity and pasting properties of isolated starch were also determined. The results showed differences in all of the studied properties as a function of genotype. High grain thickness and low seed coat percentage were associated with the low cooking time. The highest protein and starch content were exhibited by grains from the “Pérola” and “Estilo” cultivars, respectively. Similar crystalline structure was observed in all starches, but the relative crystallinity and the physicochemical and pasting properties were depe...

Author(s): Cline, Shelly M | Abstract: Captured in a rare photograph, Commandant Richard Baer and former commandant Rudolf Hoss strode away from the dedication of an SS hospital in Auschwitz in late 1944. Following behind them, are officers of lesser note, and behind them- in the background- a few nurses. Mostly hidden behind these men, head down, glove in gloved hand is Maria Mandel, the chief overseer of the women’s camp. She is the most powerful, important woman in Auschwitz and yet she barely makes the shot. Mandel walks alone, not accompanied by her fellow Aufseherinnen subordinates. She is not in front with her colleagues of equal rank, nor is she at the back with the nurses who share her gender. Instead, Maria Mandel occupies a space of her own: an awkward, middle area that lacks a conceptual framework. Though her job was identical to that of a man’s, her gender kept her from being “one of the boys.” And though she was a woman, her job prohibited her from being “one of the gi...

Very little is known about growth and proliferation in relation to the cell cycle regulation of algae. The lack of knowledge is even greater when referring to the potential toxic effects of pollutants on microalgal cell division. To assess the effect of terbutryn, a triazine herbicide, on the proliferation of the freshwater microalga Chlorella vulgaris three flow cytometric approaches were used: (1) in vivo cell division using 5-,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) staining was measured, (2) the growth kinetics were determined by cytometric cell counting and (3) cell viability was evaluated with the membrane-impermeable double-stranded nucleic acid stain propidium iodide (PI).The results obtained in the growth kinetics study using CFSE to identify the microalgal cell progeny were consistent with those determined by cytometric cell counting. In all C. vulgaris cultures, each mother cell had undergone only one round of division through the 96 h of assay and the cell division occurred during the dark period. Cell division of the cultures exposed to the herbicide was asynchronous. Terbutryn altered the normal number of daughter cells (4 autospores) obtained from each mother cell. The number was only two in the cultures treated with 250 nM. The duration of the lag phase after the exposure to terbutryn could be dependent on the existence of a critical cell size to activate cytoplasmic division. Cell size, complexity and fluorescence of chlorophyll a of the microalgal cells presented a marked light/dark (day/night) cycle, except in the non-dividing 500 nM cultures, where terbutryn arrested cell division at the beginning of the cycle. Viability results showed that terbutryn has an algastatic effect in C. vulgaris cells at this concentration.The rapid and precise determination of cell proliferation by CFSE staining has allowed us to develop a model for assessing both the cell cycle of C. vulgaris and the in vivo effects of pollutants on growth and reproduction at microalgal cell level.

Lotus japonicus and Medicago truncatula model legumes, which form determined and indeterminate nodules, respectively, provide a convenient system to study plant–Rhizobium interaction and to establish differences between the two types of nodules under salt stress conditions. We examined the effects of 25 and 50 mM NaCl doses on growth and nitrogen fixation parameters, as well as carbohydrate content and carbon metabolism of M. truncatula and L. japonicus nodules. The leghemoglobin (Lb) content and nitrogen fixation rate (NFR) were approximately 10.0 and 2.0 times higher, respectively, in nodules of L. japonicus when compared with M. truncatula. Plant growth parameters and nitrogenase activity decreased with NaCl treatments in both legumes. Sucrose was the predominant sugar quantified in nodules of both legumes, showing a decrease in concentration in response to salt stress. The content of trehalose was low (less than 2.5% of total soluble sugars (TSS)) to act as an osmolyte in nodules, despite its concentration being increased under saline conditions. Nodule enzyme activities of trehalose-6-phosphate synthase (TPS) and trehalase (TRE) decreased with salinity. L. japonicus nodule carbon metabolism proved to be less sensitive to salinity than in M. truncatula, as enzymatic activities responsible for the carbon supply to the bacteroids to fuel nitrogen fixation, such as sucrose synthase (SS), alkaline invertase (AI), malate dehydrogenase (MDH) and phosphoenolpyruvate carboxylase (PEPC), were less affected by salt than the corresponding activities in barrel medics. However, nitrogenase activity was only inhibited by salinity in L. japonicus nodules.