Hemocytes ultrastructure of Aedes aegypti (Diptera: Culicidae)

Mosquitoes have an efficient defence system against infection. Insect blood cells (hemocytes) play an essential role in defense against parasites and other pathogenic organisms that infect insects. We have identified by light and transmission electron microscopy six hemocytes cell types from the hemolymph of Aedes aegypti. They were: prohemocytes (20%), adipohemocytes (29%), granulocytes (16%), plasmatocytes (27%), oenocytoids (7%) and thrombocytoids (0.9%). The prohemocytes were the smallest hemocytes found in the hemolymph. Its cytoplasm occupies only a narrow area around the nucleus. The adipohemocytes were the most abundant cell type presented. These hemocytes exhibited a large lipid like vesicle and mitochondria. In electron micrographs, the granulocytes showed cytoplasm containing dilated rough endoplasmic reticulum (RER) and a round or elongated mitochondria. Electron-dense granules with a proteinaceous material were also present. The plasmatocytes were polymorphic and exhibited plasma membrane with irregular processes, philopodia and pseudopodia. Ultrastructural investigation revealed that the reticular cytoplasm showed a well-developed RER, a Golgi and vacuoles. Oenocytoids showed homogeneous cytoplasm with many mitochondria and ribosomes are scattered throughout the cytoplasm, abundant RER and a small smooth endoplasmic reticulum (SER) present at the cell poles. Thrombocytoids were very fragile and few in number. Similar characteristics were found in oenocytoids, possessing a homogeneous cytoplasm with poorly developed organelles, few mitochondria and granules.     

New proton conducting hybrid membranes for HT-PEMFC systems based on polysiloxanes and SO3H-functionalized mesoporous Si-MCM-41 particles

For increased efficiency of high-temperature polymer electrolyte membrane fuel cells (HT-PEMFC), new types of membranes have to be developed. This approach has been realized by preparing hybrid membranes containing SO₃H-functionalized mesoporous Si-MCM-41 as hydrophilic inorganic modifier in a polysiloxane matrix exhibiting sulfonic acid groups and basic heterocyclic groups like benzimidazole. The proton conductivity of sulfonated particles was modelled on the atomic scale in order to understand the influence of the density of sulfonic acid groups and of the presence of water molecules. The different hybrid membranes are characterized concerning their thermal stability, water uptake, and proton conductivity. Whereas the proton conductivity of well-established, but expensive and at >120 °C not long-time stable Nafion membranes continuously decreases with increasing temperature, the polysiloxane membranes, which suffer from a low-proton conductivity at around 100 °C, recover at about 120 °C due to intrinsic proton transport. At 180 °C the pure polysiloxane shows a proton conductivity which is only one order of magnitude lower than that of Nafion. Moreover, if the polysiloxane membrane contains additionally 10 wt.% of an SO₃H-modified Si-MCM-41, the proton conductivity of such hybrid membrane at temperatures >180 °C and low relative humidity <10% is higher than that of Nafion membranes by a factor of 10.     

The action modes of Lippia sidoides (Cham) essential oil as penetration enhancers on snake skin

The aim of this work was to study the effect of Lippia sidoides essential oil (LSEO) on stratum corneum lipids and the permeation of salicylic acid. DSC and FTIR spectroscopy were applied. LSEO 1% (v/v) significantly enhanced salicylic acid flux through snake skin. According to the DSC curves changes in the transition temperature of the lipids were observed indicating that LSEO can interact with stratum corneum. The IR spectrum of skin treated with LSEO showed a decrease in the peak intensity for CH₂ stretchings (2920–2850 cm^–1) however the peak positions did not alter suggesting the extraction of the lipids.     

Purification and Characterization of a Mannose Recognition Lectin from <Emphasis Type="Italic">Oreochromis niloticus</Emphasis> (Tilapia Fish): Cytokine Production in Mice Splenocytes

The aim of this work was to purify and partially characterize a mannose recognition lectin from Nile tilapia (Oreochromis niloticus) serum, named OniL. OniL was isolated through precipitation with ammonium sulfate and affinity chromatography (Concanavalin A–Sepharose 4B). In addition, we evaluated carbohydrate specificity, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS–PAGE) profiles, and in vitro immunomodulatory activity on mice splenocyte experimental cultures through cytotoxic assays and cytokine production. The ammonium sulfate fraction F2 showed the highest specific hemagglutinating activity (331) and was applied to affinity matrix. Adsorbed proteins (OniL) were eluted with methyl-α-d-mannopyranoside. OniL, a 17-kDa protein by SDS–PAGE constituted by subunits of 11 and 6.6 kDa, showed highest affinity for methyl-α-d-mannopyranoside and d-mannose. Immunological assays, in vitro, showed that OniL did not show cytotoxicity against splenocytes, induced higher IFN-γ production and lower IL-10 as well as nitrite release. In conclusion, OniL lectin was successfully purified and showed a preferential Th1 response in mice splenocytes.     

Global well-posedness and exponential decay rates for a KdV–Burgers equation with indefinite damping

We consider the KdV–Burgers equation _ut+_uxxx−_uxx+λu+u_ux=0$u_t+u_{xxx}-u_{xx}+\lambda u+u{u}_x=0$ and its linearized version _ut+_uxxx−_uxx+λu=0$u_t+u_{xxx}-u_{xx}+\lambda u=0$ on the whole real line. We investigate their well-posedness their exponential stability when λ is an indefinite damping.     

The Lefschetz property, formality and blowing up in symplectic geometry

In this paper we study the behaviour of the Lefschetz property under the blow-up construction. We show that it is possible to reduce the dimension of the kernel of the Lefschetz map if we blow up along a suitable submanifold satisfying the Lefschetz property. We use this, together with results about Massey products, to construct compact nonformal symplectic manifolds satisfying the Lefschetz property.

     

Formality in generalized Kähler geometry

We prove that no nilpotent Lie algebra admits an invariant generalized Kähler structure. This is done by showing that a certain differential graded algebra associated to a generalized complex manifold is formal in the generalized Kähler case, while it is never formal for a generalized complex structure on a nilpotent Lie algebra.     

Erratum to “Master equation for structured reservoirs” [Photonics Nanostruct.: Fundam. Appl. 2/3 (2004) 167]

In this work we generalize the formalism developed in our previous work [D. Mogilevtsev, S. Kilin, S.B. Cavalcanti, PNFA (2–3) (2004) 161]. We derive a master equation suitable to describe atom-field interaction in structured reservoirs, particulary those that exhibit ‘freezing’ of spontaneous decay as well as atom-field bound states. For a wide range of reservoir densities-of-states, this equation can be reduced to the Markovian form. In this work we extend the range of applicability of the method to times comparable to those of the atom-field bound state formation. We discuss novel features that such an extension brings forth and confirm predictions made in our previous work, namely, the stationary positive atomic inversion, a possibility of in-reservoir coherent control of the atom-field bound state and bipartite character of such a state in the absence of external perturbations.