62 research outputs found
Non-Invasive Estimation of Plasma Sodium Concentration During Hemodialysis via Capacitively-Coupled Electrical Impedance Spectroscopy
This paper presents a compact, low-cost, and noninvasive system for real-time estimation of plasma sodium
concentration ([Na]Pl) during a hemodialysis (HD) session with
state-of-the-art accuracy. It is based on electrical impedance
spectroscopy (EIS) performed with a capacitively-coupled
impedance sensing cell and a high-frequency measurement
device, both custom-built. The EIS data are processed to infer the
resistance of the liquid inside the cell, which is used together with
an optical hemoglobin sensor to estimate the [Na]Pl. Validation of
the EIS was performed by estimating the conductivity of bloodmimicking fluid (BMF). The complete method was validated
using whole bovine blood, comparing the results to those
obtained with standard instruments. The system was able to
estimate the [Na]Pl with sufficient accuracy (RMS error of 3.0
mol/m3 with respect to reference data) to provide clinically useful
information. The proof-of-concept hardware can be converted to
a cheap and compact circuit board for integration into an HD
machine
Etica minima
L'etica minima \ue8 figlia del pensiero debole, ne mette in evidenza la vocazione pratica e l'esercizio critico. E' il terreno "minimo" da salvaguardare contro ogni slittamento autoritarstico e contro ogni violenza quotidiana, quella violenza che si annida nel castello di false verit\ue0 del nostro presente, nel qui e ora della cosiddetta "anomalia italiana"
Growth and nutrient uptake of microalgae (Nannochloropsis sp. ) in a tubular photobioreactor
Hyperdiluted Calcium Hydroxylapatite 1: 2 for Mid and Lower Facial Skin Rejuvenation: Efficacy and Safety
BACKGROUND: Diluted/hyperdiluted calcium hydroxylapatite (CaHA) represents an emerging biostimulatory treatment. However, limited data concerning the effects of this agent on the face have been provided so far. OBJECTIVE: To investigate the efficacy and safety of hyperdiluted CaHA 1:2 treatment for mid and lower face rejuvenation. PATIENTS AND METHODS: A retrospective study of 40 patients seeking skin rejuvenation for mid and lower face, treated with hyperdiluted CaHA 1:2 technique at baseline (T0), was performed. Patients were classified according to validated scales of aging in the mid to lower face at T0 and efficacy was established with scales calculated again at 4-month post-treatment (T1). In addition, efficacy was assessed by blinded evaluation of T0/T1 clinical pictures, non-invasive skin imaging and patient satisfaction. Safety was assessed through pain scale and minor/major adverse events. RESULTS: Hyperdiluted CaHA 1:2 successfully decreased aging severity scores of the mid and lower face. Variations of collagen morphology and increased vessel density at T1 were observed with noninvasive skin imaging. Most patients were very satisfied. Mean pain score was low and only minor adverse events were reported. CONCLUSION: Hyperdiluted CaHA 1:2 technique seems to be effective and safe for mid and lower face skin rejuvenation
Chaotic Electronics in Telecommunications
Over the past decade, there has been significant interest in exploiting chaotic dynamics in communications. Topics which have been explored include chaotic encryption for security, chaotic spreading codes for multi-user access in spread-spectrum systems, and chaotic modulation for the transmission
of analog and digital information.
In this book, we consider applications of chaotic electronics in telecommunications at three levels. At code level, discrete-time chaotic systems can be used to generate spreading codes for DS-SS systems.
Part I of the book, consisting of three chapters, focuses on chaos
at code level. Chapter 2 provides an introduction to spread spectrum communications, highlighting the key performance issues for DS-CDMA. Chapter 3 deals with chaos-based asynchronous DS-CDMA systems. Chapter 4 discusses information sources using chaotic dynamics, also addressing briefly the use of chaos in encryption.
At signal level, continuous-time chaotic systems can be used to generate wideband carriers for digital modulation schemes. Part II of the book, consisting of five chapters, is concerned with chaos at signal level. Chapter 5 provides an overview of digital communications. Chapter 6 focuses on chaotic modulation schemes, highlighting the problems associated with coherent detection of chaotic transmissions. The best digital chaotic modulation scheme in the literature is FM-DCSK. Chapter 7 analyzes the performance of slow- and fast-frequency-hopping
variants of FM-DCSK in multipath environments. Chapter 8 discusses noise filtering in chaos-based communications. Chapter 9 addresses statistical analysis and design strategies for chaotic systems.
The three chapters in Part III are concerned with chaos at the hardware level. Chapter 10 provides an introduction to applications and architectures for chaotic integrated circuits. Chapter 11 focuses on chaos-based noise generation in silicon. Chapter 12 is concerned with robustness issues for chaos generators
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