The Role of NLRP3 Inflammasome Activation and Oxidative Stress in Varicocele-Mediated Male Hypofertility

Varicocele (VC) is the most common abnormality identified in men evaluated for hypofertility. Increased levels of reactive oxygen species (ROS) and reduced antioxidants concentrations are key contributors in varicocele-mediated hypofertility. Moreover, inflammation and alterations in testicular immunity negatively impact male fertility. In particular, NLRP3 inflammasome activation was hypothesized to lead to seminal inflammation, in which the levels of specific cytokines, such as IL-1β and IL-18, are overexpressed. In this review, we described the role played by oxidative stress (OS), inflammation, and NLRP3 inflammasome activation in VC disease. The consequences of ROS overproduction in testis, including inflammation, lipid peroxidation, mitochondrial dysfunction, chromatin damage, and sperm DNA fragmentation, leading to abnormal testicular function and failed spermatogenesis, were highlighted. Finally, we described some therapeutic antioxidant strategies, with recognized beneficial effects in counteracting OS and inflammation in testes, as possible therapeutic drugs against varicocele-mediated hypofertility.     

Post-cracking behaviour of steel and macro-synthetic fibre-reinforced concretes

The present paper describes the results of an experimental investigation on the performances of concrete specimens reinforced with either steel or macro-synthetic fibres under three-point bending. Steel fibres are often used to improve the flexural toughness of concrete and are used in various structural applications while synthetic fibres are more often used to reduce crack opening due to shrinkage. Macro-synthetic fibres have been proposed more recently with the aim of creating an alternative to steel fibres in structural applications but their use is still limited.In the tests performed, specimens cast with the same concrete mix, but containing different dosages of either steel or macro-synthetic fibres, were used and compared. In general steel fibres were more efficient in increasing the toughness of concrete than macro-synthetic fibres, even though their results were significantly more scattered.Test results were used to calculate the parameters of stress-crack opening relations via inverse analysis using a cracked hinge model. This numerical model provided results, in terms of force-Crack Mouth Opening Displacement (CMOD) curves, in very good agreement with the experimental data.     

Vicenza International Courses on hemodialysis: Educational events where science meets clinical practice

International Vicenza Courses represent important educational events held yearly in the city of Palladio. Claudio Ronco organizes since 1982 international courses on peritoneal dialysis, hemodialysis and critical care nephrology. The faculty is outstanding and the content very informative and useful for beginners and for experts in the various fields. Every year the entire course is recorded in a DVD and the proceedings are available at the beginning of the course. Information can be obtained at http://www.vicenzanephrocourses.com .     

Light and Strong SiC Networks

The directional freezing of microfiber suspensions is used to assemble highly porous (porosities ranging between 92% and 98%) SiC networks. These networks exhibit a unique hierarchical architecture in which thin layers with honeycomb‐like structure and internal strut length in the order of 1–10 μm in size are aligned with an interlayer spacing ranging between 15 and 50 μm. The resulting structures exhibit strengths (up to 3 MPa) and stiffness (up to 0.3 GPa) that are higher than aerogels of similar density and comparable to other ceramic microlattices fabricated by vapor deposition. Furthermore, this wet processing technique allows the fabrication of large‐size samples that are stable at high temperature, with acoustic impedance that can be manipulated over one order of magnitude (0.03–0.3 MRayl), electrically conductive and with very low thermal conductivity. The approach can be extended to other ceramic materials and opens new opportunities for the fabrication of ultralight structures with unique mechanical and functional properties in practical dimensions.     

Technological development of Brazilian telecommunications in past decades

Brazilian telecommunications sector has undergone important modifications in the last 40 years. From a badly structured system of municipal level operators in 1960, with barely one million fixed lines to a large, nation-wide system with about 50 million fixed plus another 75 million mobile lines in 2005. This work paper reviews the institutional framework of telecommunications industrial and technological policy in Brazil in the last four decades, its results and present situation. Infrastructure and services modernisation and expansion process that happened in early 1970s were carried out at the expense of massive import of products and technology. A government strategy was, then, devised to stimulate local industrial and technological development in telecommunications, under the general guidelines of import substitution policy. Essential to this strategy was the creation of an innovation system around TELEBRÁS Research and Development Centre. This technological development model was successful while a protectionist economic policy existed. When economic and political circumstances could not anymore sustain an import substitution approach, in the 1990-decade, the model fell apart and has not been replaced by any other sectorial policy. A critical assessment is carried out, analysing the adopted actions in face of the digital technology maturing process that occurred in meantime.     

The Effect of He Implantation on the Tensile Properties and Microstructure of Cu/Fe Nano‐Bicrystals

In situ uniaxial tensile experiments on as‐fabricated and helium‐implanted 100 nm‐diameter Cu/Fe bicrystals unearth the effect of individual face‐centred‐cubic/body‐centred‐cubic (fcc‐bcc) interfaces on improving radiation‐damage tolerance and helium absorption. Arrays of nanotensile specimens, each containing a single Cu grain in the bottom half and a single Fe grain on top, were fabricated by templated electron‐beam lithography and electrodeposition. Helium is implanted at 200 keV to a dose of 10¹⁴ ion/cm² nominally into the interface region. High‐resolution, site‐specific transmission electron microscopy (TEM) and through‐focus analysis reveal that the interfaces are nonplanar and contain ≈5 nm‐spaced He bubbles with diameters of 1–2 nm. Nanomechanical experimental results show that the irradiated samples exhibit yield and ultimate tensile strengths more than 60% higher than the as‐fabricated ones, while they retain comparable ductility. Tensile failure always occurs gradually, along the interfaces, with no noticeable shape localization. The absence of brittle failure in He‐irradiated metals might be explained, in part, by the inability of the small He bubbles to serve as sufficient stress concentrators for cracking. In addition, the non‐orthogonal orientation of the interfaces with respect to the loading axes results in the development of both normal‐ and shear‐stress components. Tensile loading along the pillar axes may cause those interfacial regions subjected to normal stresses to detach, while the inclined regions, subjected to shear, to carry plastic deformation until final fracture.     

Wavelength Conversion Technologies

This paper reports a review of the different technologies used for wavelength conversion in wavelength-division multiplexed networks. The strengths and the weaknesses of the competing technologies, including optoelectronic wavelength conversion, four-wave mixing, difference frequency generation, cross-gain and cross-phase modulation in semiconductor optical amplifiers, are stressed with regard to conversion speed, transparency and regeneration of the converted signal.     

State‐of‐the‐Art Neutral Tint Multichromophoric Polymers for High‐Contrast See‐Through Electrochromic Devices

Two new multichromophoric electrochromic polymers featuring a conjugated EDOT/ProDOT copolymer backbone (PXDOT) and a reversible Weitz‐type redox active small molecule electrochrome (WTE) tethered to the conjugated chain are reported here. The careful design of the WTEs provides a highly reversible redox behavior with a colorless red switching that complements the colorless blue switching of the conjugated backbone. Subtractive color mixing successfully provides high performing solution processable polymeric layers with colorless neutral tint switchable limiting states for application in see‐through electrochromic devices. Design, synthesis, comprehensive chemical and spectroelectrochemical characterization as well as the preparation of a proof‐of‐concept device are discussed.     

Adaptive nonuniform polar quantization application to high quality speech compression

The logarithmic companding technique has shown to be extremely useful in speech quantization with rate of 8 bits/sample. However, for lower bit rates it is not the ideal solution for high quality speech coding. Because of that, in this paper we establish source coding scheme which enables better spectrum efficiency for input that has a large dynamic range. Since our wish is also to improve signal quality in comparison with quality defined with standards G.711 and G.712, we opt for adaptive technique application to the speech coding. Our research shows that proper design of forward gain-adaptive polar quantization can enable compression of about 1 bit/sample as well as significantly better quality than in case of using coder designed according to standard G.711. Furthermore, performances can be sustained over the whole speech dynamic range. Also, if the requisite speech quality is not supposed to be lower than G.712 standard quality, the achieved compression can be almost 1.5 bits/sample. Besides, we propose knew simple encoding rule which can additionally reduce bit rate for 0.1 bit/sample.