The recent approval granted by the Federal Communications Commission (FCC) for the use of ultra-wideband signals for vehicular radar applications has provided a gateway for the introduction of these ...sensors in the commercial arena as early as 2004. However, the rules governing the allowable spectral occupancy create significant constraints on the sensors' operation. This is further complicated by the variety of applications that these sensors are being required to fulfill. A review of the motivation for the development of these sensors is followed by a discussion of the consequent implications for waveform design and limitations on system architecture. Other practical considerations such as available semiconductor technology, packaging, and assembly techniques are reviewed, and results are presented for conventional surface-mount plastic packages illustrating their usefulness in the greater than 20-GHz frequency range. Suitable antenna technology for wide-band transmission is presented that is compliant with the specific restrictions stipulated in the FCC ruling. Finally, all of these considerations are combined with the presentation of a compatible integrated-circuit-based transceiver architecture. Measured results are presented for several critical circuit components including a +12-dBm driver amplifier for the transmitter, an RF pulse generator that can produce sub-1-ns pulses at a carrier frequency of 24 GHz, and a single-chip homodyne in-phase/quadrature down-conversion receiver that has a cascaded noise figure of less than 7 dB. All circuit components are fabricated in SiGe.
Muscle traction and bone metabolism are functionally linked and co‐regulated by a series of factors. Although a role for steroid hormones was hypothesized, a clear definition of the bone–muscle ...interconnection still lacks. To investigate this relationship, we studied bone metabolism, muscle activity, and salivary steroid hormones profile in relation with the physical effort across a cycling stage race, a model of effort in absence of load. Nine pro‐cyclists were recruited; body weight and power output/energy expenditure were recorded. Diet was kept constant. Saliva was collected at days −1, 4, 8, 12, 14, 19, and 23; blood and urine were collected at days −1, 12, and 23. Salivary steroid hormones cortisol, dehydroepiandrosterone (DHEA), testosterone, and estradiol, serum lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and creatine kinase (CK) activities, plasma sclerostin, and urinary calcium and phosphorous were measured. Cortisol remained constant, testosterone decreased at day 4, and estradiol and DHEA firstly increased and then returned to basal levels. Hormone concentrations were not correlated with plasma volume shifts. LDH, CK, AST, sclerostin, and urinary calcium and phosphorous increased. DHEA and estradiol correlated with the physical effort and the bone‐muscular markers. A relationship between muscle activity, in absence of load, and bone resorption emerged under a putative regulation by DHEA and estradiol.
The impact of a soccer match on parameters related to protein catabolism and renal function was evaluated in male players.
Blood was collected before and immediately after a 90 minutes soccer match ...from 19 athletes of two first division teams in Brazil. Red blood cells (RBC), hemoglobin (Hb), hematocrit (Ht), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC), ammonia, uric acid, urea and creatinine were analyzed. The modification of plasma volume was calculated, and biochemical values were corrected for this change. Urea/creatinine ratio and equations to estimate the glomerular filtration rate (eGFR) were used to assess kidney function.
Plasma volume decreased from pre- to post-match. Post-match values higher than the pre-match ones were observed for RBC, Hb and Ht, as a consequence of plasma volume decrease. An increase in ammonia and creatinine concentrations post-match in comparison with pre-match values was registered, without changes in uric acid and urea levels. A reduction in urea/creatinine ratio and in eGFR was observed post-match, suggesting a decrease of renal function.
A soccer match induced alterations in parameters linked to renal function and protein metabolism in male athletes. Particular attention should be paid in the monitoring of the ammonia concentration as an indicator of metabolic activity and energy requirement during prolonged exercise.
The evolution of regulation on chemical substances (i.e. REACH regulation) calls for the progressive substitution of toxic chemicals in formulations when suitable alternatives have been identified. ...In this context, the method of Hansen solubility parameters was applied to identify an alternative solvent less toxic than methylene chloride used in a microencapsulation process. During the process based on a multiple emulsion (W/O/W) with solvent evaporation/extraction method, the solvent has to dissolve a polymer, poly(ɛ-caprolactone) (PCL), which forms a polymeric matrix encapsulating or entrapping a therapeutic protein as the solvent is extracted. Therefore the three partial solubility parameters of PCL have been determined by a group contribution method, swelling experiments and turbidimetric titration. The results obtained allowed us to find a solvent, anisole, able to solubilize PCL and to form a multiple emulsion with aqueous solutions. A feasibility test was conducted under standard operating conditions and allowed the production of PCL microspheres.
To describe clinical and electrophysiological features in critically ill paediatric patients. Acquired neuromuscular weakness due to critical illness polyneuropathy (CIP)- which could develop during ...a severe illness requiring intensive care- has been rarely described in childhood, but it’s likely to occur more often than previously thought. A case series of critically ill neonates and children admitted and hospitalized for more than 1 week into Paediatric Intensive Care Unit (PICU) was observed prospectively. Selected clinical and laboratory parameters were evaluated. Conduction velocities studies were performed during the first week, and then repeated during the second, third and fourth week in order to detect sign of CIP. Clinically muscle weakness could not be easily evaluated in critical ill neonates and sensory loss is often difficult to assess in children and especially in those sedated or intubated. CIP is less common in children than in adult, but early electrophysiological investigations could help to detect this condition or to discover rare neuromuscular diseases, as very early onset hereditary polyneuropathy. We propose electrophysiological examination as an available method to detect CIP in childhood -in order to avoid unnecessary diagnostic procedures- and a screening tool in studies of critically ill children with implications for the diagnosis and management of paediatric intensive care survivors.
To recognize different type of thalidomide-related neuropathy (TRN) reviewing electrophysiologic data. We evaluated the follow-up of nerve conductions studies of 58 children affected by ...immune-mediated pathologies who had received doses ranging from 25 to 100 mg/day of thalidomide. 40 of 58 patients (69%) developed the electrophysiological findings of axonal neuropathy: 31 (53%) had pure sensory and 7 (12%) had sensory-motor neuropathy, while 2 (3.4%) had motor axonal neuropathy. Sural sensory nerve action potential (SNAP) and peroneal compound muscle action potential (CMAP) amplitudes were more prominently reduced compared to SNAPs and CMAPs obtained from the upper extremities and CMAPs from tibial nerve. Peroneal CMAP amplitude at lower limit at baseline evaluation was found in patients who developed motor neuropathy. We recorded a trend to increased incidence of TRN if thalidomide cumulative dose was >20 g except for pure motor neuropathy. Timely dose reduction or withdrawal of thalidomide can lead to improvement electrophysiological data in up to one years; however, in some cases, neuropathy is irreversible. Our results suggest that thalidomide induces a length-dependent axonal neuropathy, dose dependent if sensory and not if purely motor. The patient must be studied before treatment and monitored closely to prevent irreversible consequences.
To evaluate if duration of distal compound muscle action potential duration (DCMAPD) could represent a sensitive parameter in clinical practice to add to established electrophysiological diagnostic ...criteria in paediatric chronic inflammatory demyelinating polyneuropathy (CIDP) and its rule in patient’s follow-up. We retrospectively reviewed records of 8 children affected by CIDP (6/8 possible CIDP, 2/8 confirmed CIDP) according to established diagnostic criteria of the 88th ENMC International Workshop (2000), before consideration of DCMAPD prolongation. Patients were studied with EMG equipment with low-cut filter settings ⩽10 Hz. Using adult cut-offs to define DCMAPD prolongation it was present in 8/8 patients for peroneal nerve, in 6/8 for median nerve and in all five patients in which we recorded tibial nerve. During follow-up time clinical worsening corresponded always to a greater DCMAPD prolongation compared with other electrophysiological parameters (amplitude, distal latency and nerve conduction velocity). Appropriate evaluation of DCMAPD appears an essential criterion to consider in assessing suspected CIDP and to support clinical worsening in follow-up, which may be helpful in limiting extensiveness and duration of electrophysiological testing, thereby reducing patient discomfort, especially in children.
Calcium and phosphate are essential for cell functions, and their serum concentrations result from the balance between intestinal absorption, bony storage, and urinary excretion. Fibroblast growth ...factor 23 (FGF23), expressed by osteocytes and osteoblasts, acts in the kidney, leading to hypophosphatemia and low 1,25‐dihydroxycholecalciferol synthesis, but suppresses parathyroid function. The aim of this study was to explore the effects of a high‐energy demanding cycling race on this bone–kidney–parathyroid axis. We studied nine cyclists during the 2011 Giro d'Italia stage race. Pre‐analytical and analytical phases followed academic and anti‐doping recommendations. Serum parathyroid hormone (PTH), 25(OH)D, total calcium, inorganic phosphorus, and plasma FGF23 were measured on days −1, 12, and 22 and corrected for changes in plasma volume. Dietary calcium and phosphorus, anthropometric parameters (height, weight, and body mass index) and indexes of metabolic effort (net energy expenditure, power output) were recorded. Dietary calcium and phosphorus intakes were kept at the same levels throughout the race. Twenty‐five (OH)D, PTH, and calcium concentrations remained stable. FGF23 increased 50% with a positive correlation with the indexes of metabolic effort and, consequently, phosphorous decreased, although only in the first half. The strong metabolic effort acts on the bone–kidney–parathyroid system, and the rise in FGF23 plasma concentration might be aimed at maintaining calcium and phosphorus homeostasis.
The most frequent method of intraoperative motor tract monitoring now in widespread use is referred to as transcranial electric stimulation (TES) applied to the motor cortex recordings of reliable ...muscle motor evoked responses (MEPs). While monitoring of MEPs is well established in adults, its use and reliability in the pediatric population are debated. Overall, TES is considered a safe method. Between November 2013, and February 2015, at G. Gaslini Institute we performed 100 procedures (80 neurosurgical and 20 scoliosis procedures) (age range, 1 month and 20 days to 20 yr) with intraoperative motor tract monitoring. 14 of the surgeries were performed in children who were younger than 1 year of age. TES was performed to record MEP from abductor brevis pollicis, tibialis anterior (TA) and/or abductor hallucis muscles. The standard anesthesia regimen consisted of propofol, and remifentanil. There were no complications related to this technique. There was an exponential, systematic reduction in the latency of MEP with age, especially for lower limb within 3 months of age, less noticeable until one year of age. The adult-type response was present by 2 years. The most significant maturation of corticospinal tract responses to TES takes place during the first 3 months of life.
To evaluate the role of median and tibial nerve SEPs for foramen magnum and lumbar stenosis assessment in achondroplasic children. We reviewed SEPs recorded in 60 achondroplasic patients aged from 21 ...days to 17 years, followed-up from 2007. Forty-two of our patients underwent to neurosurgical intervention for cervical (30/42) and lumbar (13/42) decompression. We analyzed peak latencies of P37 for lower limbs, N11, N13, P14 and N20 and the interpeak latencies (IPLs) N13-N20 for upper limbs, related to 5 age groups (<1 year, ⩾1–3, ⩾3–5, ⩾5–9, ⩾9 years) and height. The peak latencies of P37, N11, N13 and P14 progressively increased with age. The peak latencies of N20 decreased exponentially with age during the first three years of age then increased with height after the age of 9 years (U-shaped). The IPLs N13-N20 decreased exponentially with age. The cortical waveforms P37 were often very broad in the youngest subjects and sometimes difficult to measure. In our patients, the N20 latencies are affected by age and height by opposing factors, but no P37. The earlier impairment of tibial than median nerve SEPs in achondroplasic patients has to be correlated with neuroradiological findings of spinal cord compression.
