Postnatal development of Mongolian gerbil female prostate: An immunohistochemical and 3D modeling study

The development of the prostate in male rodents, which involves complex epithelial–mesenchymal interactions between the urogenital sinus epithelium (UGE) and the urogenital sinus mesenchyme (UGM), has been deeply studied. In females, however, this process is not very clear. In this study, the postnatal development of the prostate in female Mongolian gerbils employing three‐dimensional (3D) reconstructions, histochemical, and immunohistochemical techniques was characterized. It was observed that prostatic branching and differentiation in females was induced by a single mesenchyme localized at a ventrolateral position, which was named as ventrolateral mesenchyme (VLM); furthermore, the canalization of solid buds began on the third postnatal day (P3) and the branching morphogenesis on P5. We observed secretions in the acini at the end of the first month, and, on P45, the acini were completely differentiated. The strong cell proliferation phase in the first week coincided with the mesenchymal expression of estrogen receptor 1 (ESR1). The expression of androgen receptor (AR) paralleled cell differentiation, and, on P30, immunolabelling with p63 was restricted to basal cells. This study serves as a baseline parameter for future research on disruptions that could affect the development of the female prostate. Microsc. Res. Tech. 79:438–446, 2016. © 2016 Wiley Periodicals, Inc.     

Output regulation for linear systems via adaptive internal model

Given a stabilizable and detectable linear system with additive disturbances and output references generated by a linear stable exosystem with unknown parameters and known order, the problem of designing a global output feedback regulator which asymptotically achieves output regulation and disturbance rejection is considered. The system is assumed to be known while the frequencies of the exosystem are unknown; all exosystem oscillatory modes are assumed to be excited by the initial condition. A global solution is proposed consisting of a dynamic output feedback controller which includes exponentially convergent estimates of the unknown frequencies.     

A Distribution Design Methodology for Object DBMS

The design of distributed databases involves making decisions on the fragmentation and placement of data and programs across the sites of a computer network. The first phase of the distribution design in a top-down approach is the fragmentation phase, which clusters in fragments the information accessed simultaneously by applications. Most distribution design algorithms propose a horizontal or vertical class fragmentation. However, the user has no assistance in the choice between these techniques. In this work we present a detailed methodology for the design of distributed object databases that includes: (i) an analysis phase, to indicate the most adequate fragmentation technique to be applied in each class of the database schema; (ii) a horizontal class fragmentation algorithm, and (iii) a vertical class fragmentation algorithm. Basically, the analysis phase is responsible for driving the choice between the horizontal and the vertical partitioning techniques, or even the combination of both, in order to assist distribution designers in the fragmentation phase of object databases. Experiments using our methodology have resulted in fragmentation schemas offering a high degree of parallelism together with an important reduction of irrelevant data.     

A global tracking control for speed-sensorless induction motors

The problem of controlling an induction motor without rotor speed measurements is addressed. Arbitrary smooth reference signals for rotor speed and rotor flux modulus are required to be tracked globally (i.e. from any initial condition). A global second-order tracking control is obtained, which is based on a novel rotor speed observer. Simulation results are provided which illustrate the controller performance.     

A class of globally output feedback stabilizable nonlinear nonminimum phase systems

It is shown that any observable nonlinear system in output feedback form can be globally exponentially stabilized by a dynamic output feedback controller, provided that it is minimum phase with respect to a linear combination of its state variables, even though it is nonminimum phase with respect to the measured output.     

Global compensation of unknown sinusoidal disturbances for a class of nonlinear nonminimum phase systems

A class of output feedback stabilizable nonlinear systems with known output dependent nonlinearities and affected by unknown sinusoidal disturbances is considered: Nonminimum phase systems are also allowed. The problem of designing a global output feedback compensator which drives the state of the system exponentially to zero is solved when the disturbance consists of a known number of biased sinusoids with any unknown bias, magnitudes, phases, and frequencies.     

Gellan gum microspheres crosslinked with trivalent ion: effect of polymer and crosslinker concentrations on drug release and mucoadhesive properties

Gellan gum microspheres were obtained by ionotropic gelation technique, using the trivalent ion Al³⁺. The percentage of entrapment efficiency ranged from 48.76 to 87.52% and 2² randomized full factorial design demonstrated that both the increase of polymer concentration and the decrease of crosslinker concentration presented a positive effect in the amount of encapsulated drug. Microspheres size and circularity ranged from 700.17 to 938.32?μm and from 0.641 to 0.796?μm, respectively. The increase of polymer concentration (1–2%) and crosslinker concentration (3–5%) led to the enlargement of particle size and circularity. However, the association of increased crosslinker concentration and reduced polymer content made the particles more irregular. In vitro and ex vivo tests evidenced the high mucoadhesiveness of microspheres. The high liquid uptake ability of the microspheres was demonstrated and the pH variation did not affect this parameter. Drug release was pH dependent, with low release rates in acid pH (42.40% and 44.93%) and a burst effect in phosphate buffer pH (7.4). The Weibull model had the best correlation with the drug release data, demonstrating that the release process was driven by a complex mechanism involving the erosion and swelling of the matrix or by non-Fickian diffusion.     

A 3D Real‐Scale,Biomimetic, and Biohybrid Model of the Blood‐Brain Barrier Fabricated through Two‐Photon Lithography

The investigation of the crossing of exogenous substances through the blood‐brain barrier (BBB) is object of intensive research in biomedicine, and one of the main obstacles for reliable in vitro evaluations is represented by the difficulties at the base of developing realistic models of the barrier, which could resemble as most accurately as possible the in vivo environment. Here, for the first time, a 1:1 scale, biomimetic, and biohybrid BBB model is proposed. Microtubes inspired to the brain capillaries were fabricated through two‐photon lithography and used as scaffolds for the co‐culturing of endothelial‐like bEnd.3 and U87 glioblastoma cells. The constructs show the maturation of tight junctions, good performances in terms of hindering dextran diffusion through the barrier, and a satisfactory trans‐endothelial electrical resistance. Moreover, a mathematical model is developed, which assists in both the design of the 3D microfluidic chip and its characterization. Overall, these results show the effective formation of a bioinspired cellular barrier based on microtubes reproducing brain microcapillaries to scale. This system will be exploited as a realistic in vitro model for the investigation of BBB crossing of nanomaterials and drugs, envisaging therapeutic and diagnostic applications for several brain pathologies, including brain cancer.     

Stenosis and thrombosis—unveiled complications of buttonhole cannulation

The vascular access is the mainstay of hemodialysis. Arteriovenous fistula has been prioritized as the first choice of long‐term vascular access for its inferior rate of complications and improved patient survival. Rope ladder and buttonhole venipuncture are the most common techniques for arteriovenous fistulae cannulation. Much of the concern regarding buttonhole cannulation is the increased risk for potentially severe systemic infections. Increased risk for stenosis and thrombosis has been addressed but not confirmed. We discuss two cases of stenosis and thrombosis related to buttonhole puncture which heralded angiography intervention, raising awareness for the demand of close surveillance of arteriovenous fistulae when using buttonhole cannulation.