Ultrastructure and heteromorphism of spermatozoa in five species of bugs (Pentatomidae: Heteroptera)

Pentatomidae is one of the largest Heteroptera families, comprising about 10% of the species estimated for the suborder. In spite of existing studies, doubts remain regarding the systematics of Pentatomomorpha. In this study, five species of Pentatomidae spermatozoa were examined to achieve characteristics that enable inferences in the phylogeny of the group and in behavioral issues associated with the presence of polymorphisms. Spermatozoa polymorphisms, characterized by two classes of sizes, are found in Podisus nigrispinus, Podisus distinctus, and Brontocoris tabidus, whereas Thynacanta marginata (Dallas) and Supputius cincticeps have single-size spermatozoa. The head region consists of an acrosome, a nucleus, and part of the centriolar adjunct. In the more anterior region, the nucleus is parallel to the centriolar adjunct. In the nucleus-flagellum transition region, the nucleus overlaps the anterior region of the mitochondrial derivatives, just above the axoneme. The mitochondrial derivatives and the axoneme run the entire extent of the flagellum. In species in which the spermatozoa are polymorphic, the larger spermatozoa have derivatives mitochondrial approximately 3-fold larger than the smaller spermatozoa. Characteristics derived from the morphology of spermatozoa indicate synapomorphies and are promising for systematic studies.     

Interference of Different Types of Mastication on Static Balance in Individuals without Temporomandibular Disorder

Purpose: This study was to determine whether non-habitual (isotonic) bilateral and unilateral mastication with eyes open and eyes closed exerts an influence on static balance in individuals without temporomandibular disorder (TMD). Method: An observational, cross-sectional study was conducted involving 20 volunteers aged 20 to 40 years without temporomandibular disorder. Static balance was assessed with the individuals in a quiet standing position on a force plate performing different types of mastication under six separate conditions. Results: Significant differences (p < .05) were found in the area of oscillation during bilateral mastication (eyes open) and the right unilateral mastication, significant differences were only found for oscillation area with eyes open and mediolateral center of pressure with eyes closed (p < .05). Conclusions: The findings of the present study reveal that the stomatognathic system (bilateral and unilateral mastication) promote changes in some variables of static balance.     

Multiple Emulsion Templating of Hybrid Ag/SiO2 Capsules for Antibacterial Applications

Silver nanoparticles (NPs) encapsulated in amorphous silica shells are synthesized and evaluated for their antibacterial action using the Gram‐negative Escherichia coli bacterium. These inorganic capsules are synthesized using a new approach that comprises the use of oil‐in‐water‐in‐oil (O/W/O) multiple emulsions to fabricate SiO₂ capsules incorporating organically capped Ag NPs. This strategy is explored as a mean to promote the bioadhesion of the microorganisms to the silica rough surfaces while still keeping the system with a high surface area for the active metal. The results have shown that the hybrid capsules enable a slow release of cationic silver from the interior of the silica microsphere to the external medium probably through the pore channels in the shell. The antibacterial activity against E. coli is mainly determined by the Ag⁺ ion release rate, suggesting that these particulates can be employed as a robust system for prolonged used as an antimicrobial material.     

Single PON network design with unconstrained splitting stages

A Passive Optical Network (PON) is a network technology for deploying access networks based on passive optical components. In a single PON access network, the client terminals are connected to a Central Office through optical splitters and interconnecting fibers where each splitter splits in equal parts the input optical signal coming from the Central Office over its different output fibers. In this paper, we consider PON topology solutions where the splitting ratio and the number of splitting stages are not constrained to a given target design but, instead, are decided based on the cost of the solutions. We present different Integer Linear Programming formulations to model this problem and provide computational results showing that the optimal solutions can be computed for realistic problem instances. In addition, we describe how the formulations can be adapted for the traditional PON topology approaches and present computational results showing that significant cost gains are obtained with the unconstrained splitting stage approach.     

On the Ulam‐Hyers stabilities of the solutions of Ψ‐Hilfer fractional differential equation with abstract Volterra operator

In this paper, we consider the new class of the fractional differential equation involving the abstract Volterra operator in the Banach space and investigate existence, uniqueness and stabilities of Ulam‐Hyers on the compact interval Δ = [a,b] and on the infinite interval I = [a,∞). Our analysis is based on the application of the Banach fixed‐point theorem and the Gronwall inequality involving generalized Ψ‐fractional integral. At last, we performed out an application to elucidate the outcomes got.     

Glass/SU‐8 microchip for electrokinetic applications

In this communication, we describe the fabrication and electric characterization of a hybrid glass/SU‐8 microchannels for high‐performance electrokinetic applications. The bonding process employed SU‐8 film as intermediate layer with reduced baking times; all the procedure took less than 50 min (only about 10 min disregarding the cleaning and dehydration steps). Additionally, further steps to improve the adhesion of the substrate to the SU‐8 were not needed. The developed configuration aggregates the advantages of both substrates, including (i) simple fabrication techniques; (ii) high compatibility for integration of microelectromechanical, optical, and electrochemical components (SU‐8); (iii) high and stable electroosmotic mobility (μ_EO); and (iv) satisfactory heat dissipation capacity (glass). Electroosmotic mobilities were measured as a function of the pH using the current monitoring method, whereas the heat dissipation capacity was investigated through Ohm's law plots for both glass and glass/SU‐8 microchips. The measured μ_EO values were similar for both microdevices, with mobilities of the order of 4.0–4.5 × 10^?4 cm² V^?1 cm^?1 at 4–12 pH range using phosphate buffer (10 and 20 mmol/L). The heat dissipation assays were carried out in microchannels filled with 20 mmol/L phosphate buffer. A considerable Joule heating was observed only at electric field strengths greater than 580 V cm^?1 in hybrid glass/SU‐8 microdevices, representing a substantial increase of 48% when compared to all SU‐8 microdevices.     

Synthesis of an Alkylidene 2-Oxazolidinone via Gold-Catalyzed Cyclization of a N-Boc-Allenylaniline

N-Boc-allenylaniline undergoes cyclization in the presence of a catalytic amount of a cationic gold complex to exclusively form 2-oxazolidinones, whereas the N-Moc-allenylaniline affords dihydroquinolines.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Investigation of Chemoselective Reaction of 2-Amino-8-hydroxyquinoline with Arylsulfonylchloride Derivatives

The reactions of 2-amino-8-hydroxyquinoline and 2-amino-4(1H)quinolone with different sulfonyl chlorides have been investigated. The chemoselectivity was observed to afford exclusively the arylsulfonate ester derivatives. The mechanism of the reaction is also discussed.     

New approach in RNA quantification using arginine-affinity chromatography: potential application in eukaryotic and chemically synthesized RNA

The knowledge of RNA’s role in biological systems and the recent recognition of its potential use as a reliable biotherapeutic tool increase the demand for development and validation of analytical methods for accurate analysis of RNA. Affinity chromatography is a unique technique because of the versatility of applications reliant on the affinity ligand used. Recently, an arginine-based matrix has been effectively applied in the purification of RNA because of the specific recognition mechanism for RNA molecules. This interaction is suggested to be due to the length of arginine side chain and its ability to produce good hydrogen bonding geometries, which promote multi-contact with RNA backbone or RNA bases, based on RNA folding. Thus, this work presents the development and validation of an analytical method with ultraviolet detection for the quantification of RNA using affinity chromatography with arginine amino acid as immobilized ligand. The method was validated according to International and European legislation for bioanalytical methods. The results revealed that the proposed method is suitable for the reliable detection, separation, and quantification of RNA, showing that the method is precise and accurate for concentrations up to 200 ng/μL of RNA. Furthermore, the versatility of the methodology was demonstrated by its applicability in the quantification of RNA from different eukaryotic cells and in crude samples of chemically synthesized RNA. Therefore, the proposed method demonstrates a potential multipurpose applicability in molecular biology RNA-based analysis and RNA therapeutics.

The size of solid lipid nanoparticles: an interpretation from experimental design

This study aimed to investigate the role of different factors affecting the size of solid lipid nanoparticles (SLN), prepared by the emulsification-solvent evaporation method. A double factorial design was conducted so as to cover a wide range of sizes, highlighting zones with different behaviour with respect to changes in the controlled variables: lipid concentration, solvent:lipid ratio and emulsifier concentration. The solvent:lipid ratio constituted the main factor influencing particle size. Increasing the amount of solvent induced a decrease in the size. This was a general trend, essentially independent from solvent and lipid type. The amount of emulsifier had a non-trivial impact on size, depending on whether systems were located below, above or close to the optimal surface coverage. The amount of lipid had a limited influence upon particle size, being more relevant for lower lipid concentrations. An optimal formulation was selected for intermediate levels of the three variables. Sonication reduced both particle size and polydispersity. These particles were also tested as drug carriers using simvastatin as a model of lipophilic drug. SLN were able to entrap a high amount of simvastatin, with little effect upon size and zeta potential, constituting a promising carrier for lipophilic drugs.