No description available.

Seminal plasma (SP) is the microenvironment of spermatozoa whose composition reflects semen quality and constitutes an excellent source for detecting non-invasive biomarkers. This study characterizes good vs. poor quality semen using seminal extracellular vesicles coupled proteins and miRNA. Fresh boar semen samples were screened, centrifuged, and SP supernatants were collected for near-infrared spectroscopy (NIRS) analysis. EVs were extracted from SP (SP-EVs), characterized, and those of extremely poor or good sperm quality groups were subjected to proteomics and small RNA sequencing. Significant differences were set for P

The flow state is a subjective experience that most people can relate to. It represents an optimal balance between skills and difficulty and is the state that people often refer to when performing their best, with phrases like: “I was in the zone” or “I was in the bubble”. The flow state has mainly been studied through its psychological and behavioral components; it is not until lately the neuroscientific aspects have been investigated. This review attempts to go through the existing literature and find potential neural signatures of the flow state. The studies indicate that flow is related to activity in the dorsolateral prefrontal cortex and putamen, but the findings are too divided to reach a conclusion.

No description available.

Nonlinear absorption of Indium Antimonide (InSb) has been studied for many years, yet due to the complexity of absorption mechanisms and experimental difficulties in the infrared, this is still a subject of research. Although measurements have been made in the past, a consistent model that worked for both picosecond and nanosecond pulse widths had not been demonstrated. In this project, temperature dependent two-photon (2PA) and free carrier absorption (FCA) spectra of InSb are measured using femtosecond, picosecond, and nanosecond IR sources. The 2PA spectrum is measured at room temperature with femtosecond pulses, and the temperature dependence of 2PA and FCA is measured at 10.6µm using a nanosecond CO2 laser giving results consistent with the temperature dependent measurements at several wavelengths made with a tunable picosecond system. Measurements over this substantial range of pulse widths give results for FCA and 2PA consistent with a recent theoretical model for FCA. While the FCA cross section has been generally accepted in the past to be a constant for the temperatures and wavelengths used in this study, this model predicts that it varies significantly with temperature as well as wavelength. Additionally, the results for 2PA are consistent with the band gap scaling (Eg-3 ) predicted by a simple two parabolic band model. Using nanosecond pulses from a CO2 laser enables the recombination rates to be determined through nonlinear transmittance measurements. Three-photon absorption is also observed in InSb for photon energies below the 2PA band edge. Prior to this work, data on three-photon absorption (3PA) in semiconductors was scarce and most experiments were performed over narrow spectral ranges, v making comparison to the available theoretical models difficult. There was also disagreement between the theoretical results generated by different models, primarily in the spectral behavior. Therefore, we studied the band gap scaling and spectra of 3PA in several semiconductors by the Z-scan technique. The 3PA coefficient is found to vary as (Eg-7 ), as predicted by the scaling rules of simple two parabolic band models. The spectral behavior, which is considerably more complex than for 2PA, is found to agree well with a recently published theory based on a fourband model.

This study of ATR-IR involved taking spectra of various silicate minerals in powder samples, finding similarities and differences in nature, and locating various bands and intensities of absorption bands for identification and classification purposes. This study is limited to 4000-300 cm-1 with major emphasis on absorptions in the 2000-300 cm-1 region.

Cerebral hemodynamics monitoring is vital in the neuroscience intensive care unit to assess brain health. Diffuse optical methods using near-infrared light, e.g., near-infrared spectroscopy (NIRS) and diffuse correlation spectroscopy (DCS), allow for non-invasive prolonged monitoring of cerebral hemoglobin oxygenation and blood flow. For patients suffering from cerebral fluid or tissue volume buildup, intracranial pressure (ICP) is monitored invasively as its elevation compromises cerebral perfusion. The critical closing pressure (CrCP) is a transcranial doppler (TCD) derived non-invasive parameter that correlates with ICP; however, its use is limited due to discomfort during extended TCD measurement. I expanded on Sutin’s preliminary study using DCS to estimate CrCP and found high correlations between DCS obtained CrCP against TCD (R2: 0.77-0.83) in stroke patients. The use of DCS to monitor CrCP is advantageous because its sensors are comfortable to wear and easy to use continuously without the need of a specialized operator. However, the low DCS signal-to-noise ratio (SNR) limits the depth sensitivity and temporal resolution of CrCP measures. Following these encouraging results, I built a low-cost wireless cerebral oximeter based on multi-distance continuous wave NIRS called FlexNIRS, which exhibits high SNR (NEP < 70 fw/Hz0.5) and high sampling rate (266 Hz). This device not only quantifies cerebral oxygenation but resolves the pulsatile blood volume signal at large source-detector separations (33 mm). Using the relationship between blood flow and volume, I augmented pulsatile DCS blood flow measurements with FlexNIRS pulsatile signals. I experimentally demonstrated the high fidelity (R2: 0.98) and > 50-fold SNR improvement of the method, resulting in a one order of magnitude increase in the temporal resolution of CrCP estimates. / 2024-06-12T00:00:00Z

Alzheimer’s Disease (AD) is a neurodegenerative disease marked by progressive neuronal cell death, leading to dementia. AD is the most common disease that results in dementia and largely affects the elderly, with five million people in the United States diagnosed with the disease as of 2015 and approximately 35 million people worldwide. Diseases resulting in dementia cost the US healthcare system an estimated $172 billion in 2010 and that cost is expected to increase as the population ages and as diagnostic techniques improve so that more people are treated (Holtzman, 2011). The disease was first reported by psychiatrist Alois Alzheimer at the onset of the 20th century, when one of his patients “suffered memory loss, disorientation, hallucinations and delusions and died at the age of 55,” then was found to have severe brain atrophy post-mortem (Cipriani, Dolciotti, Picchi, & Bonuccelli, 2011). There are palliative treatments available that marginally slow disease progression but there is currently no cure for the disease (Awasthi, Singh, Pandey, & Dwivedi, 2016). More research is needed to develop effective therapeutic strategies to combat the disease. Currently, AD cytotoxicity is believed to be caused by increased amyloid β (Aβ) peptide plaque deposition in the brain, as described by the amyloid cascade hypothesis (Barage & Sonawane, 2015). The current understanding is that oligomers of Aβ peptide lead to neuronal death through multiple mechanisms, most notably hyper-phosphorylation of the tau protein. Having a better understanding of the structural changes in the fibrillization process of Aβ will provide a broader insight into mechanisms of cell death and open new possibilities for pharmacological treatments, which is what this research intends to provide.

No description available.

No description available.