Search results for "Light"

Effect of Color on Contrast Sensitivity with Two Different Accommodative Stimuli

1993

We studied the influence of color and accommodation on the contrast sensitivity function (CSF). At the same time, we measured the effect of axial chromatic aberration (ACA) on the CSF. The CSF's of two observers were determined using red, green, blue, and white light, at 5- and 0.5-m viewing distances. At 5 m the CSF's were measured with natural vision and also with lenses which compensated the ACA. Results show that the effect of ACA on the CSF is to reduce the sensitivity to blue with respect to the red. The difference in sensitivity between these two colors is between 50 and 150% and varies with the frequency and the subject. When the ACA is compensated the influence of the color on the …

Photobleaching effects onin vivoskin autofluorescence lifetime

2015

The autofluorescence lifetime of healthy human skin was measured using excitation provided by a picosecond diode laser operating at a wavelength of 405 nm and with fluorescence emission collected at 475 and 560 nm. In addition, spectral and temporal responses of healthy human skin and intradermal nevus in the spectral range 460 to 610 nm were studied before and after photobleaching. A decrease in the autofluorescences lifetimes changes was observed after photobleaching of human skin. A three-exponential model was used to fit the signals, and under this model, the most significant photoinduced changes were observed for the slowest lifetime component in healthy skin at the spectral range 520 …

Accelerometer-measured physical activity and sedentary time in a cohort of US adults followed for up to 13 years: The influence of removing early fol…

2020

Abstract Background Observational studies linking physical activity with mortality are susceptible to reverse causation bias from undiagnosed and prevalent diseases. Researchers often attempt to deal with reverse causation bias by excluding deaths occurring within the first 1 or 2 years from the analysis, but it is unclear if excluding deaths within this time-frame is sufficient to remove bias. Methods We examined associations between total and intensity-specific physical activity and sedentary time with all-cause mortality in a prospective cohort of 3542 individuals from the 2003–2006 NHANES cycles. In order to yield measures of association hypothesized as minimally influenced by reverse c…

Targeted Hybrid Nanocarriers as a System Enhancing the Skin Structure

2021

The skin is constantly exposed to external and internal factors that disturb its function. In this work, two nanosystems-levan nanoparticles and a surfactin-stabilized nanoemulsion were preserved (tested for microbial growth) and characterized (size, polydispersity, Zeta potential, and stability). The nanosystems were introduced in the model formulations-cream, tonic, and gel, and confirmed by TEM. The analysis showed that nanoemulsion has a spherical morphology and size 220–300 nm, while levan nanoparticles had irregular shapes independently of the use of matrix and with particle size (130–260 nm). Additionally, we examined the antiradical effect of levan nanoparticles and nanoemulsion in …

Association between diabetes and stroke subtype on survival and functional outcome 3 months after stroke: data from the European BIOMED Stroke Projec…

2004

To the Editor: Regarding the study by Megherbi et al1 performed to evaluate stroke features, prognosis, and functional outcome in patients with diabetes compared with patients without diabetes, we would like to discuss some issues of potential interest: First, the authors analyzed diabetic patients classified in accordance with WHO diagnostic criteria for diabetes used in 1993 (fasting plasma glucose >140 mg/dL), so it is probably an underestimation of the number of diabetic subjects in the 4537 consecutive patients with ischemic stroke enrolled. Perhaps if they could have classified diabetic patients in accordance with American Diabetes Association (1997)2 criteria (fasting plasma glucose …

Response by Uphaus et al to Letter Regarding Article, “NfL (Neurofilament Light Chain) Levels as a Predictive Marker for Long-Term Outcome After Isch…

2019

Serum neurofilament levels reflect outer retinal layer changes in multiple sclerosis

2021

Background: Serum neurofilament light chain (sNfL) and distinct intra-retinal layers are both promising biomarkers of neuro-axonal injury in multiple sclerosis (MS). We aimed to unravel the association of both markers in early MS, having identified that neurofilament has a distinct immunohistochemical expression pattern among intra-retinal layers. Methods: Three-dimensional (3D) spectral domain macular optical coherence tomography scans and sNfL levels were investigated in 156 early MS patients (female/male: 109/47, mean age: 33.3 ± 9.5 years, mean disease duration: 2.0 ± 3.3 years). Out of the whole cohort, 110 patients had no history of optic neuritis (NHON) and 46 patients had a previous…

Unconventional Aeronautical Investigatory Methods: The Case of Alitalia Flight AZ 112

2021

Viene svelato scientificamente la causa del disastro aereo di Montagna Longa del 5 maggio 1972 Based on unconventional air investigation techniques, this book highlights the mysterious crash of Alitalia flight AZ 112 on 5 May 1972, which killed 115 people, and was blamed solely on pilot negligence. Its findings show the cause of the disaster was not actually related to any pilot negligence, but, rather, it was the result of a criminal act. It argues that this attack was a symptom of the geopolitical tensions in Italy and Europe in that decade. Based on unconventional air investigation techniques, this book highlights the mysterious crash of Alitalia flight AZ 112 on 5 May 1972

Effective broadband refractive index retrieval by a white light optical particle counter.

2009

A new approach to retrieve the effective broadband refractive indices (nbroad,eff) of aerosol particles by a white light aerosol spectrometer (WELAS) optical particle counter (OPC) is presented. Using a tandem differential mobility analyzer (DMA)-OPC system, the nbroad,eff are obtained for both laboratory and field applications. This method was tested in the laboratory using substances with a wide range of optical properties. With the obtained nbroad,eff, WELAS aerosol size distributions can be corrected. Therefore, this method can be used for instrument calibration in both laboratory and field measurements. The retrieved effective broadband refractive indices for the scattering aerosols we…

Application of time-of-flight aerosol mass spectrometry for the online measurement of gaseous molecular iodine.

2012

Here we present a new application of a time-of-flight aerosol mass spectrometer (TOF-AMS) for the measurement of atmospheric trace gases in real-time. Usually, TOF-AMS instruments are not sensitive to gas-phase species due to the aerodynamic particle focusing inlet system which reduces the gas phase species by a factor of about 10(7) relative to the particle phase. This efficient removal of the gas phase and the resulting high relative enrichment of particles is one reason for the very high sensitivity of TOF-AMS instruments for particle phase compounds (detection limits in the sub-μg/m(3)-range for online measurements with 1 min integration time), which allows application of the instrument…