Hall-Petch strengthening of the constrained metallic binder in WC-Co cemented carbides: Experimental assessment by means of massive nanoindentation and statistical analysis

WC–Co cemented carbides are geometrically complex composites constituted for two interpenetrating networks of the constitutive ceramic and metal phases. Accordingly, assessment of microstructural effects on the local mechanical properties of each phase is a challenging task, especially for the metallic binder. In this work, it is attempted by combining massive nanoindentation, statistical analysis, and implementation of a thin film model for deconvolution of the intrinsic hardness and flow stress of the metallic phase. Plotting of yield stress values as a function of the binder mean free path results in a Hall-Petch strengthening relationship with a slope (ky) of 0.98 MPa m1/2. This value points out the effectiveness of WC–Co phase boundaries as strong obstacles to slip propagation; and thus, for toughening of the brittle phase (WC) by means of crack-bridging ductile (Co) reinforcement.Peer ReviewedPostprint (author's final draft

Complexity and project management: a general overview

As projects have become more and more complex, there has been an increasing concern about the concept of project complexity. An understanding of project complexity and how it might be managed is of significant importance for project managers because of the differences associated with decision-making and goal attainment that are related to complexity. Complexity influences project planning and control; it can hinder the clear identification of goals and objectives, it can affect the selection of an appropriate project organization form, or it can even affect project outcomes. Identifying the different concepts associated to project complexity, its main factors and characteristics, the different types of project complexity, and the main project complexity models, can be of great support in assisting the global project management community. In this paper, we give a general overview of how complexity has been investigated by the project management community and propose several ideas to address this topic in the future

Los puertos y las exportaciones fluviales de Entre Ríos (1945-1983)

En el presente trabajo nos avocamos al análisis de la actividad exportadora de los puertos de Entre Ríos entre 1945 (sin conectividad material con el continente) y 1983 (con conectividad casi plena tanto con la Argentina como con la República Oriental del Uruguay). Comenzaremos con un análisis general de la participación de los puertos entrerrianos en los valores aduaneros exportados del período y los productos que fueron objeto de exportación para luego realizar un análisis más detallado de los procesos que fueron vividos en los dieciséis puertos (cinco sobre el Río Uruguay y once sobre el Río Paraná) con actividad portuaria durante el período. La principal fuente utilizada son los Anuarios Estadísticos o Anuarios de Comercio Exterior de la Argentina publicados entre esos años

Effects of Whole-Body Vibration Therapy in Patients with Fibromyalgia: A Systematic Literature Review

Objective. To review the literature on the effects of whole-body vibration therapy in patients with fibromyalgia. Design. Systematic literature review. Patients. Patients with fibromyalgia. Methods. An electronic search of the literature in four medical databases was performed to identify studies on whole-body vibration therapy that were published up to the 15th of January 2015. Results. Eight articles satisfied the inclusion and exclusion criteria and were analysed. According to the Dutch CBO guidelines, all selected trials had a B level of evidence. The main outcomes that were measured were balance, fatigue, disability index, health-related quality of life, and pain.Whole-body vibration appeared to improve the outcomes, especially balance and disability index. Conclusion.Wholebody vibration could be an adequate treatment for fibromyalgia as a main therapy or added to a physical exercise programme as it could improve balance, disability index, health-related quality of life, fatigue, and pain. However, this conclusion must be treated with caution because the paucity of trials and the marked differences between existing trials in terms of protocol, intervention, and measurement tools hampered the comparison of the trials

Keratitis after Implantation of Intrastromal Corneal Rings with Spontaneous Extrusion of the Segment

Purpose: To report a case of bacterial keratitis in a patient with a history of intrastromal corneal ring segments (INTACS®) implantation to correct keratoconus. Methods: The patient’s history, clinical presentation, pathological analysis and therapeutic management were reviewed. Results: A 36-year-old-man was referred to our department due to decreased vision and intense pain in his left eye, 40 days after INTACS® implantation for keratoconus. Slit-lamp examination revealed epithelial defects and stromal infiltrates in the lower channel without evidence of the inferior ring. The anterior chamber also showed a significant fibrin reaction to hypopyon. A low-tension suture was removed at the site of the incision. Microbiological study of the conjunctival swab was positive for Staphylococcus epidermidis, but the corneal culture was sterile. The patient was treated with topical fortified and systemic antibiotics. The infection slowly resolved, leaving opacity at the inferior segment site. Conclusions: Infectious keratitis following INTACS implantation is an infrequent complication that can have important consequences without suitable and early therapeutic management

Effect of Exposure to Seminal Plasma Through Natural Mating in Cattle on Conceptus Length and Gene Expression

peer-reviewedA growing body of evidence suggests that paternal factors have an impact on offspring development. These studies have been mainly carried out in mice, where seminal plasma (SP) has been shown to regulate endometrial gene expression and impact embryo development and subsequent offspring health. In cattle, infusion of SP into the uterus also induces changes in endometrial gene expression, however, evidence for an effect of SP on early embryo development is lacking. In addition, during natural mating, the bull ejaculates in the vagina; hence, it is not clear whether any SP reaches the uterus in this species. Thus, the aim of the present study was to determine whether SP exposure leads to improved early embryo survival and developmental rates in cattle. To this end, Day 7 in vitro produced blastocysts were transferred to heifers (12–15 per heifer) previously mated to vasectomized bulls (n = 13 heifers) or left unmated (n = 12 heifers; control). At Day 14, heifers were slaughtered, and conceptuses were recovered to assess size, morphology and expression of candidate genes involved in different developmental pathways. Additionally, CL volume at Day 7, and weight and volume of CL at Day 14 were recorded. No effect of SP on CL volume and weight not on conceptus recovery rate was observed. However, filamentous conceptuses recovered from SP-exposed heifers were longer in comparison to the control group and differed in expression of CALM1, CITED1, DLD, HNRNPDL, PTGS2, and TGFB3. In conclusion, data indicate that female exposure to SP during natural mating can affect conceptus development in cattle. This is probably achieved through modulation of the female reproductive environment at the time of mating. Keywords: seminal plasma, embryo development, corpus luteu