Raman-stable isotope labeling using heavy water (Raman-DO) is attracting great interest as a fast technique with various applications ranging from the identification of pathogens in medical samples to the determination of microbial activity in the environment. Despite its widespread applications, little is known about the fundamental processes of hydrogen-deuterium (H/D) exchange, which are crucial for understanding molecular interactions in microorganisms. By combining two-dimensional (2D) correlation spectroscopy and Raman deuterium labeling, we have investigated H/D exchange in bacterial cells under time dependence.
View Article and Find Full Text PDFDopamine (DA) regulates several functions in the central nervous system and its depletion is responsible for psychological disorders like Parkinson's disease. Several analytical approaches have been presented for DA detection in pathological diagnosis. SERS spectroscopy is a highly promising technique for the sensitive detection of DA.
View Article and Find Full Text PDFHematoxylin and Eosin (H&E) staining is the 'gold-standard' method in histopathology. However, standard H&E staining of high-quality tissue sections requires long sample preparation times including sample embedding, which restricts its application for 'real-time' disease diagnosis. Due to this reason, a label-free alternative technique like non-linear multimodal (NLM) imaging, which is the combination of three non-linear optical modalities including coherent anti-Stokes Raman scattering, two-photon excitation fluorescence and second-harmonic generation, is proposed in this work.
View Article and Find Full Text PDFIntroduction: Neurofilament light (NfL), chitinase-3-like protein 1 (YKL-40), and neurogranin (Ng) are biomarkers for Alzheimer's disease (AD) to monitor axonal damage, astroglial activation, and synaptic degeneration, respectively.
Methods: We performed genome-wide association studies (GWAS) using DNA and cerebrospinal fluid (CSF) samples from the EMIF-AD Multimodal Biomarker Discovery study for discovery, and the Alzheimer's Disease Neuroimaging Initiative study for validation analyses. GWAS were performed for all three CSF biomarkers using linear regression models adjusting for relevant covariates.
Anal Bioanal Chem
September 2021
Raman spectral data are best described by mathematical functions; however, due to the spectroscopic measurement setup, only discrete points of these functions are measured. Therefore, we investigated the Raman spectral data for the first time in the functional framework. First, we approximated the Raman spectra by using B-spline basis functions.
View Article and Find Full Text PDFThe combination of manifold optical imaging modalities resulting in multimodal optical systems allows to discover a larger number of biomarkers than using a single modality. The goal of multimodal imaging systems is to increase the diagnostic performance through the combination of complementary modalities, e.g.
View Article and Find Full Text PDFThis study demonstrates the development of a sensitive, specific, and quantitative peptide-based nanoprobe prototype assay for the detection of Legionellaceae in a simple way and in a short time. In this work, proteases present in the culture supernatants of Legionella spp. were used as a biomarker.
View Article and Find Full Text PDFHere, we present, to the best of our knowledge for the first time, a systematic study of utilizing 2D correlation analysis in the field of femtosecond transient absorption (fs-TA) spectroscopy. We present that the application of 2D correlation spectroscopy (2DCOS) to fs-TA spectroscopy enables a model-free means to analyze excited state kinetics, which is demonstrated on the model system [(tbbpy)Ru(dppz)] in different solvents. We show that TA-2DCOS is able to determine the number of processes contributing to the time-resolved spectral changes in fs-TA data sets, as well as extract the spectral response of these components.
View Article and Find Full Text PDFBackground: Multiple pathophysiological processes have been described in Alzheimer's disease (AD). Their inter-individual variations, complex interrelations, and relevance for clinical manifestation and disease progression remain poorly understood. We hypothesize that specific molecular patterns indicating both known and yet unidentified pathway alterations are associated with distinct aspects of AD pathology.
View Article and Find Full Text PDFAlzheimers Dement
September 2021
Introduction: This study sought to discover and replicate plasma proteomic biomarkers relating to Alzheimer's disease (AD) including both the "ATN" (amyloid/tau/neurodegeneration) diagnostic framework and clinical diagnosis.
Methods: Plasma proteins from 972 subjects (372 controls, 409 mild cognitive impairment [MCI], and 191 AD) were measured using both SOMAscan and targeted assays, including 4001 and 25 proteins, respectively.
Results: Protein co-expression network analysis of SOMAscan data revealed the relation between proteins and "N" varied across different neurodegeneration markers, indicating that the ATN variants are not interchangeable.
Label-free and gentle separation of cell stages with desired target properties from mixed stage populations are a major research task in modern biotechnological cultivation process and optimization of micro algae. The reported microfluidic sorter system (MSS) allows the subsequent investigation of separated subpopulations. The implementation of a viability preserving MSS is shown for separation of late stage 1 Haematococcus pluvialis (HP) cells form a mixed stage population.
View Article and Find Full Text PDFRaman stable isotope labeling with H, C or N has been reported as an elegant approach to investigate cellular metabolic activity, which is of great importance to reveal the functions of microorganisms in native environments. A new strategy termed Raman O-labeling was developed to probe the metabolic activity of bacteria. Raman O-labeling refers to the combination of Raman microspectroscopy with O-labeling using H O.
View Article and Find Full Text PDFExercise may be a strategy for improvement of cognitive deficits commonly present in people with idiopathic generalized epilepsies (IGE). We investigated the relationship between cognition and level of physical exercise in leisure (PEL) in people with IGE who have been seizurefree for at least 6 months (IGE-) as compared to those who have not been seizurefree (IGE+) and healthy controls (HCs). We hypothesized that higher level of physical exercise is associated with better cognitive functioning in patients with IGE and HCs, and that seizure control affects both PEL levels and cognitive functioning in patients with IGE.
View Article and Find Full Text PDFBackground: To assess the performance of plasma neurofilament light (NfL) and phosphorylated tau 181 (p-tau181) to inform about cerebral Alzheimer's disease (AD) pathology and predict clinical progression in a memory clinic setting.
Methods: Plasma NfL and p-tau181, along with established cerebrospinal fluid (CSF) biomarkers of AD pathology, were measured in participants with normal cognition (CN) and memory clinic patients with cognitive impairment (mild cognitive impairment and dementia, CI). Clinical and neuropsychological assessments were performed at inclusion and follow-up visits at 18 and 36 months.
Objective: To determine the willingness-to-pay (WTP) of family caregivers to learn care strategies for persons living with dementia (PLwD).
Design: Randomized clinical trial.
Setting: Community-dwelling PLwD and their caregivers (dyads) in Maryland and Washington, DC.
Health Res Policy Syst
March 2021
Background: Co-creation strategies, such as cooperative planning, are promising as a means to ensure that physical activity interventions address real-world problems and are tailored to the target group. This has already been validated in diverse settings. However, questions targeting the transferability of cooperative planning to new settings and the key factors influencing its success or failure remain unclear.
View Article and Find Full Text PDFGlobal dairy and swine production growth has increased significantly over the past decades, resulting in higher manure generation in certain areas and environmental concerns. Therefore, manure management is an essential focus for farmers and environmental regulators. Systematic selection of manure management practices can provide environmental benefits, but accounting for local constraints, economics and farming practices are significant challenges.
View Article and Find Full Text PDFHere we present a microscope setup for coherent anti-Stokes Raman scattering (CARS) imaging, devised to specifically address the challenges of in vivo experiments. We exemplify its capabilities by demonstrating how CARS microscopy can be used to identify vitamin A (VA) accumulations in the liver of a living mouse, marking the positions of hepatic stellate cells (HSCs). HSCs are the main source of extracellular matrix protein after hepatic injury and are therefore the main target of novel nanomedical strategies in the development of a treatment for liver fibrosis.
View Article and Find Full Text PDFPsoriasis is considered a widespread dermatological disease that can strongly affect the quality of life. Currently, the treatment is continued until the skin surface appears clinically healed. However, lesions appearing normal may contain modifications in deeper layers.
View Article and Find Full Text PDFIn recent decades, vibrational spectroscopic methods such as Raman and FT-IR spectroscopy are widely applied to investigate plasma and serum samples. These methods are combined with drop coating deposition techniques to pre-concentrate the biomolecules in the dried droplet to improve the detected vibrational signal. However, most often encountered challenge is the inhomogeneous redistribution of biomolecules due to the coffee-ring effect.
View Article and Find Full Text PDFWe demonstrate the ability of nondestructive optical imaging techniques such as second-harmonic generation (SHG), two-photon fluorescence (TPF), fluorescence lifetime imaging (FLIM), and Raman spectroscopy (RS) to monitor biochemical and mechanical alterations in tissues upon collagen degradation. Decellularized equine pericardium (EP) was treated with 50 μg/mL bacterial collagenase at 37 °C for 8, 16, 24, and 32 h. The SHG ratio (defined as the normalized ratio between SHG and TPF signals) remained unchanged for untreated EP (stored in phosphate-buffered solution (PBS)), whereas treated EP showed a trend of a decreasing SHG ratio with increasing collagen degradation.
View Article and Find Full Text PDFThe timely diagnosis of MRSA in clinical samples helps to reduce the attendant morbidity/mortality associated with infection due to the organism. The early institution of appropriate therapy or deployment of infection control protocols are dependent on a timely report from the microbiology laboratory. Various assays currently used in the identification of MRSA are associated with inherent shortcomings, thus there is a need to explore newer diagnostic frontiers that can eliminate some of these short comings at a relatively cheap, timely, specific and sensitive manner.
View Article and Find Full Text PDFIn order to meet the rising global demand for food and to ensure food security in line with the United Nation's Sustainable Development Goal 2, technological advances have been introduced in the food production industry. The organic food industry has benefitted from advances in food technology and innovation. However, there remains skepticism regarding organic foods on the part of consumers, specifically on consumers' acceptance of food innovation technologies used in the production of organic foods.
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