Search results for " SPECTROSCOPY"

Functional Near Infrared Spectroscopy System Validation for Simultaneous EEG-FNIRS Measurements

2019

Functional near-infrared spectroscopy (fNIRS) applied to brain monitoring has been gaining increasing relevance in the last years due to its not invasive nature and the capability to work in combination with other well–known techniques such as the EEG. The possible use cases span from neural-rehabilitation to early diagnosis of some neural diseases. In this work a wireline FPGA–based fNIRS system, that use SiPM sensors and dual-wavelength LED sources, has been designed and validated to work with a commercial EEG machine without reciprocal interference.

Reaction of 4-acylaminomethylpyridine N-oxides with phenylbutazone in the presence of acetic anhydride

1987

Muscle Oxygen Delivery in the Forearm and in the Vastus Lateralis Muscles in Response to Resistance Exercise: A Comparison Between Nepalese Porters a…

2020

Altitude ascending represents an intriguing experimental model reproducing physiological and pathophysiological conditions sharing hypoxemia as the denominator. The aim of the present study was to investigate fractional oxygen extraction and blood dynamics in response to hypobaric hypoxia and to acute resistance exercises, taking into account several factors including different ethnic origin and muscle groups. As part of the “Kanchenjunga Exploration & Physiology” project, six Italian trekkers and six Nepalese porters took part in a high altitude trek in the Himalayas. The measurements were carried out at low (1,450 m) and high altitude (HA; 4,780 m). Near-infrared spectroscopy (NIRS)-d…

Towards the Point of Care and Noninvasive Classification of Bladder Cancer from Urine Sediment Infrared Spectroscopy. Spectral differentiation of nor…

2021

Abstract Bladder cancer (BC) is the 9th cancer cause of death and one of most cost-intensive in the world. The diagnostic tools are still not at all satisfactory. Herein we evaluated the potential of infrared spectroscopy to detect molecular changes that precede and accompany the carcinogenesis in voided urine sediment. We collected 165 samples from patients being diagnosed for BC and measured them with attenuated total reflectance Fourier transformed infrared spectroscopy (ATR FTIR). Samples were primarily divided into three groups according to cytology that indicated the presence of normal, abnormal and cancer cells. ATR FTIR spectra of sediments were analyzed with the use of partial leas…

Is there a critical tissue oxygen tension for bioenergetic status and cellular pH regulation in solid tumors?

1996

Bioenergetic and metabolic status have been correlated with tissue oxygenation in murine fibrosarcomas (FSaII) of varying sizes (44-600 mm3). Ratios of beta-nucleoside triphosphates to inorganic phosphate (beta NTP/P) and phosphocreatine to inorganic phosphate (PCr/P(i)) ratios derived from 31P nuclear magnetic resonance spectroscopy (NMR) were positively correlated to median tissue O2 tension (pO2) values using O2-sensitive needle electrodes. pH declined during growth with intracellular acidosis being evident in tumors350 mm3. Whereas lactic acid formation greatly contributed to this decline in small and medium-sized tumors, adenosine triphosphate (ATP) hydrolysis and slowing down of the a…

Intracellular acidosis in murine fibrosarcomas coincides with ATP depletion, hypoxia, and high levels of lactate and total Pi

1994

Bioenergetic and metabolic status of murine FSaII tumours were evaluated using 31P MRS, acid extracts ('global' techniques) and quantitative bioluminescence ('microregional' assay). Data obtained from s.c. tumours of varying sizes (44-600 mm3) have been correlated with the oxygenation status evaluated using O2-sensitive needle electrodes. beta-NTP/Pi and phosphocreatine (PCr)/Pi ratios derived from 31P MRS were positively correlated to the median tissue pO2 values. pH declined during growth with intracellular acidosis being evident in tumours > 350 mm3. Whereas lactic acid formation greatly contributed to this decline in small- and medium-sized tumours, ATP hydrolysis and slowing down of th…

MUSCLE BIOENERGETICS IN OBESE ZUCKER RATS

1994

International audience; Abstract: The purpose of this study was to investigate the energetic metabolism in obese Zucker rats, using phosphorus nuclear magnetic resonance spectroscopy at rest and during a 2-Hz muscle stimulation and subsequent recovery. Animals were anesthetized with ketamine (150 mg/kg ip). Fed obese rats and 2-day-fasted obese rats were compared with their normally fed and 2-day-fasted lean litter mates. No differences were found between the two groups for ATP, total creatine, phosphocreatine (PCr), and intracellular pH. Starvation in lean rats resulted in a significant fall in inorganic phosphate (Pi), increased resting ADP level, and decreased PCr and ADP recovery after …

Magnetic Resonance Assessment of Left Ventricular Ejection Fraction at Any Time Post-Infarction for Prediction of Subsequent Events in a Large Multic…

2021

Background Magnetic resonance imaging (MRI) is the most accurate imaging technique for left ventricular ejection fraction (LVEF) quantification, but as yet the prognostic value of LVEF assessment at any time after ST-segment elevation myocardial infarction (STEMI) for subsequent major adverse cardiac event (MACE) prediction is uncertain. Purpose To explore the prognostic impact of MRI-derived LVEF at any time post-STEMI to predict subsequent MACE (cardiovascular death or re-admission for acute heart failure). Study Type Prospective. Population One thousand thirteen STEMI patients were included in a multicenter registry. Field Strength/Sequence 1.5-T. Balanced steady-state free precession (c…

Patent Foramen Ovale and Thromboembolic Complications

2010

The foramen ovale, an atrial septal defect which is essential in the fetal circulation, remains patent through adulthood in approximately 25% of the general population and so it represents the most common persistent abnormality of fetal origin. Patent foramen ovale (PFO) allows interatrial right-to-left blood shunting during those periods of the cardiac cycle in which the right atrial pressure exceeds the left one. An increasing number of pathological manifestations of PFO has been recently identified; among these, paradoxical systemic embolism, refractory hypoxemia in patients with right ventricular myocardium infarction or severe pulmonary disease, orthostatic oxygen desaturation in the r…

Long-term prognostic implications of revascularization in patients with known or suspected chronic coronary syndromes without ischemia in vasodilator…

2021

In this study, we evaluated the association between symptoms-guided revascularization occurred within three months following a negative vasodilator stress cardiovascular magnetic resonance (negative stress-CMR) and long-term adverse events in patients with known or suspected chronic coronary syndrome (CCS).We retrospectively evaluated 3517 patients in which the stress first-pass perfusion imaging revealed no ischemia. The primary endpoint was the composite of death, spontaneous myocardial infarction, heart failure (HF), or stroke. The association between symptoms-guided revascularization after a negative stress-CMR and the endpoint was assessed using the multivariable Cox proportional hazar…