Sistemi radiomobili di quinta generazione

La tesi tratta le tecnologie radiomobili di quinta generazione. Analizza i principali problemi, e le più importanti proposte risolutive. Elenca le più importanti idee per ottenere i requisiti richiesti nella quinta generazione di sistemi radiomobili, tra cui il x1000 nella capacità del canale, la latenza < 1ms ecc.. Affronta il dettaglio delle tecnologie proposte da HUAWEI, F-OFDM e SCMA, illustrandone i vantaggi. Si conclude con una parte di simulazioni numeriche Matlab a proposito dell'SCMA

Diagnostic Workup for Disorders of Bone and Mineral Metabolism in Patients with Chronic Kidney Disease in the Era of KDIGO Guidelines

KDIGO (Kidney Disease: Improving Global Outcomes) is an international nonprofit organization devoted to “improve the care and outcomes of kidney disease patients worldwide through promoting coordination, collaboration, and integration of initiatives to develop and implement clinical practice guidelines.” The mineral and bone disorder (MBD) in patients with chronic kidney disease (CKD) has been the first area of interest of KDIGO international initiative. KDIGO guidelines on CKD-MBD were published in 2009 with the intent to modify the previous KDOQI guidelines that had failed to consistently change the global outcome of CKD patients. After the publication of KDOQI guidelines for bone metabolism and disease in 2003, a large number of observational data emerged in literature linking disordered mineral metabolism with adverse clinical outcomes. Notwithstanding this large body of observational data, a paucity of evidence from high-quality clinical trials was available for the development of KDIGO guidelines. Herein, a summary will be provided of the most important findings of KDIGO guidelines regarding the diagnostic workup and clinical monitoring of CKD-MBD patients

Effectiveness of endoscopic trans-tendineous repair for partial-thickness tears of medius gluteus: A systematic review of literature

Tears of the gluteus medius can result in chronic hip pain over time. Pathological onsets involving the gluteus medius cause pain and weakness of abductor strength. Endoscopic repair is a suitable, effective and safe surgical alternative to traditional open techniques and give satisfactory results over time restoring the footprint of gluteus medius. The purpose of this systematic review is to analyse the effectiveness of endoscopic trans-tendinous technique for partial-thickness tears, analysing the subjective and functional outcome over the time. A search of literature (PubMed, Scopus, WebOfKnowledge) was performed. The PRISMA method was used to screen the articles. A total of 4 articles was screened and included for qualitative analysis. For data extraction patient characteristics, pre-clinical examination, imaging, timing from symptoms to surgery, technique performed, subjective scales, functional outcomes, post-operative clinical assessment were analysed. Subjective scores at mean follow-up of 18 months show a significative improvement in all the scales reported, in relief of pain (VAS score) and in terms of strength of abductor. Trans-tendinous technique represents the gold standard to treat endoscopically these injuries. Furthermore, other studies with larger number of patients and longer follow-up are required to validate the best surgical approach for these injuries

Predictive Value ofMeasures of Vascular Calcification Burden and Progression for Risk of Death in Incident to Dialysis Patients

Abstract: Background: Vascular calcification (VC) is a marker of cardiovascular (CV) disease and various methods allow for presence and extension assessment in different arterial districts. Nevertheless, it is currently unclear which one of these methods for VC evaluation best predict outcome and if this piece of information adds to the predictive value of traditional CV risk factors in patients receiving hemodialysis (HD). Methods: data of 184 of the 466 patients followed in the Independent study (NCT00710788) were post hoc examined to assess the association three concurrent measures of vascular calcification and all-cause survival. Specifically, coronary artery calcification (CAC) was determined by the Agatston and the volume score while abdominal aorta calcification was determined by plain X-ray of the lumbar spine (Kauppila score (KS)). Survival and regression models as well as metrics of risk recalculation were used to test the association of VC and outcome beyond the Framingham risk score. Results: Middle-age (62.6(15.8) years) men (51%) and women (49%) starting HD were analyzed. Over 36 (median 36; interquartile range: 8–36) months of follow-up 69 patients expired. Each measure of VC (CAC or KS) predicted all-cause mortality independently factors commonly associated with all-cause survival (p &lt; 0.001). Far more importantly, each measurement of VC significantly improved risk prediction and patient reclassification (p &lt; 0.001) beyond traditional cardiovascular risk factors. Conclusions: Overall, presence and extension of VC, irrespective of the arterial site, predict risk of all-cause of death in patients starting hemodialysis. Of note, both CAC and KS increase risk stratification beyond traditional CV risk factors. However, future efforts are needed to assess whether a risk-based approach encompassing VC screening to guide HD patient management improves survival

Chromosome instability in lymphocytes of Friesian cows naturally exposed to dioxins being raised close to a metallurgic factory area in southern Italy

Dioxins (PCDDs, PCDFs and DL-PCBs) are a large family of congeners that are considered highly toxic and are reported to be teratogenic, mutagenic, carcinogenic, immunotoxic and hepatotoxic, also affecting the nervous and reproductive systems. Farm animals are particularly exposed to these chemicals when they are fed with grass produced close to polluted areas such as those located in vicinity of metallurgic factories. Cytogenetic tests can be very useful to check genetic damage occurring to domestic animal cells exposed to these chemicals. Fifty-two randomly selected Italian Friesian cows (Bos taurus, 2n&nbsp;=&nbsp;60) from two farms located in the vicinity of and (as a control) far from the a metallurgic industrial area underwent cytogenetic investigations to ascertain possible differences in their chromosome fragility. One farm was under legal sequestration due to the presence in the milk mass of higher mean values of dioxins (24.78&nbsp;±&nbsp;3.19 pg&nbsp;g−1 of fat as sum of PCDD + PCDF + DL-PCBs as WHO-TEQ (World Health Organization-Toxic Equivalent Quantity), with DL-PCBs being the main chemical component) than those permitted (5.5 pg&nbsp;g−1 of fat as WHO-TEQ). Cytogenetic analyses, performed by using both the chromosome abnormality (CA) test (chromosome and chromatid breaks) and sister chromatid exchange (SCE) test, revealed a significantly (p&nbsp;&lt;&nbsp;0.01) higher chromosome fragility in cells of exposed cows (26 cows) compared to those of the control (23 cows)

Well Design Challenges in Geothermal Energy Applications

Geothermal resources represent precious energy sources to ensure sustainable power generation. As proposed in the majority of the future sustainable energy scenarios, geothermal energy exploitation is going to play a significant role in the energy mix to meet carbon neutrality target. Upon the different technologies involved, geothermal wells constitute the core and turning point for proper fluid/heat mining. Indeed, the number of suitable candidates for geothermal applications could be significantly enhanced by overcoming a series of wells related technological issues. Therefore, the object of this work is to provide a general overview of the principal challenges that characterized well design and construction in geothermal applications which are mainly related to the type of geological system and its relative temperature level. As a matter of fact, reservoir temperature guides most of the choices referring to geothermal systems not only in the selection of the final energy application purpose (direct use, power generation, combined heat and power) but also in well design definition. Based on temperature range, geothermal fields are usually grouped in enthalpy classes (low, medium and high) referring to fields characterized by similar energy potential. From a well design and construction perspective, the low and medium enthalpy classes, in the range of temperature lower than 150 °C, do not present specific criticalities. On the contrary, high enthalpy scenarios, for temperatures higher than 170 °C, present many challenges for most of the current drilling and completion technologies. Even though some field applications exist in high/ultra-high enthalpy scenarios, they still present an elevated risk of failure. Therefore, dedicated studies shall be conducted for all the elements involved in the well construction process such as: drilling fluids, cement slurry, metallurgy, drilling and completion equipment to properly account for their specific technical limitations. In this framework, a clear picture of the actual technical gaps constitutes the starting point for current and next research activities. In the close future, the growing interest in geothermal applications will surely boost the born and development of dedicated tools to unlock the enormous potential of geothermal energy