Past Achievements and Future Challenges in 3D Photonic Metamaterials

Photonic metamaterials are man-made structures composed of tailored micro- or nanostructured metallo-dielectric sub-wavelength building blocks that are densely packed into an effective material. This deceptively simple, yet powerful, truly revolutionary concept allows for achieving novel, unusual, and sometimes even unheard-of optical properties, such as magnetism at optical frequencies, negative refractive indices, large positive refractive indices, zero reflection via impedance matching, perfect absorption, giant circular dichroism, or enhanced nonlinear optical properties. Possible applications of metamaterials comprise ultrahigh-resolution imaging systems, compact polarization optics, and cloaking devices. This review describes the experimental progress recently made fabricating three-dimensional metamaterial structures and discusses some remaining future challenges

Histone deacetylase controls adult stem cell aging by balancing the expression of polycomb genes and jumonji domain containing 3

Aging is linked to loss of the self-renewal capacity of adult stem cells. Here, we observed that human multipotent stem cells (MSCs) underwent cellular senescence in vitro. Decreased expression of histone deacetylases (HDACs), followed by downregulation of polycomb group genes (PcGs), such as BMI1, EZH2 and SUZ12, and by upregulation of jumonji domain containing 3 (JMJD3), was observed in senescent MSCs. Similarly, HDAC inhibitors induced cellular senescence through downregulation of PcGs and upregulation of JMJD3. Regulation of PcGs was associated with HDAC inhibitor-induced hypophosphorylation of RB, which causes RB to bind to and decrease the transcriptional activity of E2F. JMJD3 expression regulation was dependant on histone acetylation status at its promoter regions. A histone acetyltransferase (HAT) inhibitor prevented replicative senescence of MSCs. These results suggest that HDAC activity might be important for MSC self-renewal by balancing PcGs and JMJD3 expression, which govern cellular senescence by p16INK4A regulation

Features of chronic hemodialysis practice after the Marmara earthquake

After disasters, treatment of chronic hemodialysis (HD) patients is problematic because of logistic and medical reasons. This study analyzes features of HD practice in the regions affected by the Marmara earthquake that struck northwestern Turkey in August 1999. Questionnaires asking about HD infrastructure, medical/social problems of chronic dialysis patients, and the fate of dialysis personnel after the disaster were sent to dialysis units located in the affected region. Data gathered from eight HD centers that responded to questionnaires were then analyzed. The number of HD centers and machines were 12 and 124, respectively, before the earthquake. The number of weekly HD sessions in the analyzed eight centers declined from 1093 before the disaster to 520, 616, and 729 1 wk, I mo, and 3 mo after the earthquake, respectively. In the effective seven centers, the number of HD personnel was 112 before the earthquake, which dropped to 86 and 94 1 and 3 mo after the disaster, respectively. Overall, there were 439 patients in the analyzed eight centers before the disaster, whereas data were provided on 356 (212 were male; mean age, 47.6 +/- 15.1 yr) dialysis patients. Six patients died, and seven were seriously and 28 mildly injured by the direct effects of trauma. The percentage of patients who received once-weekly dialysis increased from 2.3 to 7.2% within the first week, with a return to lower figures (4.1 and 2.8%) 1 and 3 mo afterward. Despite a decrease in the number of HD sessions, interdialytic weight gain decreased I wk after the disaster and BP measurements did not change significantly before and after the earthquake. A total of 301 and 3 1 patients left their dialysis centers, temporarily and permanently. After catastrophic earthquakes, despite a decrease in the number of HD sessions, patients comply with disaster conditions, likely by strictly following dietary and fluid restrictions

PRP therapy

Osteochondral lesions remain as a clinical challenge despite the advances in orthopedic regenerative strategies. Biologics, in particular, platelet-rich plasma, has been applied for the reparative and regenerative effect in many tissues, and osteochondral tissue is not an exception. Platelet-rich plasma is an autologous concentrate prepared from the collected blood; thus, this safe application is free of immune response or risk of transmission of disease. It has a high potential to promote regeneration, thanks to its content, and can be applied alone or can reinforce a tissue engineering strategy. The relevant works making use of platelet-rich plasma in osteochondral lesions are overviewed herein. The practical success of platelet-rich plasma is uncertain since there are many factors involved including but not limited to its preparation and administration method. Nevertheless, today, the issues and challenges of platelet-rich plasma have been well acknowledged by researchers and clinicians. Thus, it is believed that a consensus will be built it, and then with high-quality randomized controlled trials and standardized protocols, the efficacy of platelet-rich plasma therapy can be better evaluated.This work is a result of the project FROnTHERA (NORTE-01-0145-FEDER-000023), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). IFC thanks the Portuguese Foundation for Science and Technology (FCT) for the Ph.D. scholarship (SFRH/BD/99555/2014). JMO also thanks the FCT for the funds provided under the program Investigador FCT 2012 and 2015 (IF/00423/2012 and IF/01285/2015).info:eu-repo/semantics/publishedVersio

Technical challenges and enhancements in smart grid applications

This chapter deals with novel technologies in terms of power electronics, power converters, information and communication technologies (ICTs), energy storage systems (ESSs), electric vehicles (EVs), and microgeneration systems in the context of smart grid applications. Although the smart grid was a concept defining ICT-enabled conventional grid at the beginning, it has now improved its own infrastructure with particularly tailored applications and technologies. During this improvement stage; researchers, engineers, and technology improving alliances have overcome many technical challenges. This chapter presents a number of innovative solutions enhanced against challenges met during improvement era. They have been introduced in terms of power electronics and power converters, integration of communication systems to power devices; improved microgrid, generation and transmission systems, the demand side management (DSM) policies, smart home management systems, ESSs and EVs. The surveyed device topologies and technologies are particularly selected in order to present a set of recent application in smart grid infrastructure. Therefore, widely known devices, systems, and methods that can be found in any regular textbook are not considered in this section