contrast sensitivity

A novel class of (P^N^C) pincer ligands capable of stabilizing elusive gold(III) species is reported here. Straightforward access to (P^N^C)gold(III) hydroxo, formate, and hydride complexes has been streamlined by first incorporating a cycloauration step devoid of toxic metals or harsh conditions. The resulting gold complexes exhibit remarkable stability in solution as well as in the solid state under ambient conditions, which enabled their characterization by X-ray diffraction analyses. Interestingly, the influence of the ligand allowed the preparation of gold(III)-hydrides using mild hydride donors such as H-Bpin, which contrasts with sensitive super hydrides or strong acids and cryogenic conditions employed in previous protocols...

Intrinsically disordered proteins (IDPs) that lie close to the empirical boundary separating IDPs and folded proteins in Uversky's charge-hydropathy plot may behave as "marginal IDPs" and sensitively switch conformation upon changes in environment (temperature, crowding, and charge screening), sequence, or both. In our search for such a marginal IDP, we selected Huntingtin-interacting protein K (HYPK) near that boundary as a candidate; PKIα, also near that boundary, has lower secondary structure propensity; and Crk1, just across the boundary on the folded side, has higher secondary structure propensity...

INTRODUCTION: The prevalence of heart failure with preserved ejection fraction (HFpEF) is continuously rising and predominantly affects older women often hypertensive and/or obese or diabetic. Indeed, there is evidence on sex differences in the development of HF. Hence, we studied cardiovascular performance dependent on sex and age as well as pathomechanisms on a cellular and molecular level. METHODS: We studied 15-week- and 1-year-old female and male hypertensive transgenic rats carrying the mouse Ren-2 renin gene (TG) and compared them to wild-type (WT) controls at the same age...

Conscious perception is preceded by long periods of unconscious processing. These periods are crucial for analyzing temporal information and for solving the many ill-posed problems of vision. An important question is what starts and ends these windows and how they may be interrupted. Most experimental paradigms do not offer the methodology required for such investigation. Here, we used the sequential metacontrast paradigm, in which two streams of lines, expanding from the center to the periphery, are presented, and participants are asked to attend to one of the motion streams...

Background: Intravenous (IV) contrast improves the sensitivity and specificity of injury detection in computerized tomography (CT). Its use is recommended in the workup of trauma patients by the American College of Surgeons and American College of Radiology. On May 9, 2022, the Food and Drug Administration declared a shortage of iodinated contrast due to the COVID-19 pandemic. Although the shortage has ended, the temporary lack of IV contrast forced physicians to be prudent in ordering CT scans with IV contrast...

BACKGROUND: There are important unmet clinical needs to develop cell enrichment technologies to enable unbiased label-free isolation of both single cell and clusters of circulating tumor cells (CTCs) manifesting heterogeneous lineage specificity. Here, we report a pilot study based on the microfluidic acoustophoresis enrichment of CTCs using the CellSearch CTC assay as a reference modality. METHODS: Acoustophoresis uses an ultrasonic standing wave field to separate cells based on biomechanical properties (size, density, and compressibility), resulting in inherently label-free and epitope-independent cell enrichment...

BACKGROUND: Elephant seals exhibit extreme hypoxemic tolerance derived from repetitive hypoxia/reoxygenation episodes they experience during diving bouts. Real-time assessment of the molecular changes underlying protection against hypoxic injury in seals remains restricted by their at-sea inaccessibility. Hence, we developed a proliferative arterial endothelial cell culture model from elephant seals and used RNA-seq, functional assays, and confocal microscopy to assess the molecular response to prolonged hypoxia...

PURPOSE: The present study tested the hypothesis that repeated anti-VEGF injections are associated with reduced retinal nerve fiber layer (RNFL) and minimum rim width (MRW) of the optic nerve head. PATIENTS AND METHODS: Sixty-six patients with a history of intravitreal injections due to neovascular age-related macular degeneration were included. RNFL and MRW were measured using optical coherence tomography (Spectralis OCT, Heidelberg Engineering, Heidelberg, Germany)...

PURPOSE: This study compared the predictive performance of the relative enhancement index (REI) derived from gadoxetic acid (GA)-enhanced MRI with that of the functional liver imaging score (FLIS) in estimating liver function among patients with chronic liver disease (CLD) or liver cirrhosis (LC) by validating them with the albumin-bilirubin (ALBI) grade. MATERIALS AND METHODS: We retrospectively examined 166 patients (79 women, 87 men; 57.4 years) who were diagnosed with LC or CLD and underwent GA-enhanced MRI between August 2020 and September 2023...

PURPOSE: In a preclinical study using a swine myocardial infarction (MI) model, a delayed enhancement (DE)-multi-detector computed tomography (MDCT) scan was performed using a hybrid system alongside diagnostic invasive coronary angiography (ICA) without the additional use of a contrast agent, and demonstrated an excellent correlation in the infarct area compared with histopathologic specimens. In the present investigation, we evaluated the feasibility and diagnostic accuracy of a myocardial viability assessment by DE-MDCT using a hybrid system comprising ICA and MDCT alongside diagnostic ICA without the additional use of a contrast agent...

Neurotoxic organophosphorus compounds can induce a type of delayed neuropathy in humans and sensitive animals, known as organophosphorus-induced delayed neuropathy (OPIDN). OPIDN is characterized by axonal degeneration akin to Wallerian-like degeneration, which is thought to be caused by increased intra-axonal Ca2+ concentrations. This study was designed to investigate that deregulated cytosolic Ca2+ may function downstream of mitodysfunction in activating Wallerian-like degeneration and necroptosis in OPIDN...

BACKGROUND: Performance and symptoms in completing a visual search task on a PC monitor and using a head-mounted display (HMD) were compared for different viewing conditions and between users of different ages. PATIENTS AND METHODS: Twenty-three young (M = 30 y, SD = 7 y) and 23 older (M = 52 y, SD = 5 y) participants performed a visual search task presented on a PC monitor. The task was repeated using an HMD for a near and a far virtual viewing distance...

BACKGROUND: The use of right-censored composite endpoints, such as progression-free survival, has been questioned in haemato-oncology trials due to potential bias in estimated treatment effect. This may impact the accuracy of health technology evaluations. We hypothesized that there is heterogeneity and potential sources of bias in the reporting of composite endpoints to health technology assessment (HTA) bodies. METHODS: We reviewed the submissions for reimbursement of oncology drugs in 2021 and 2022 that used a composite endpoint in the pivotal trial, after appraisal by the French HTA body...

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Luminance and spatial contrast provide information on the surfaces and edges of objects. We investigated neural responses to black and white surfaces in the primary visual cortex (V1) of mice and monkeys. Unlike primates that use their fovea to inspect objects with high acuity, mice lack a fovea and have low visual acuity. It thus remains unclear whether monkeys and mice share similar neural mechanisms to process surfaces. The animals were presented with white or black surfaces and the population responses were measured at high spatial and temporal resolution using voltage-sensitive dye imaging...

The selectivity filter of K+ channels catalyzes a rapid and highly selective transport of K+ while serving as a gate. To understand the control of this filter gate, we use the pore-only K+ channel KcvNTS in which gating is exclusively determined by the activity of the filter gate. It has been previously shown that a mutation at the C-terminus of the pore-helix (S42T) increases K+ permeability and introduces distinct voltage-dependent and K+-sensitive channel closures at depolarizing voltages. Here, we report that the latter are not generated by intrinsic conformational changes of the filter gate but by a voltage-dependent block caused by nanomolar trace contaminations of Ba2+ in the KCl solution...

The aggregation of superoxide dismutase 1 (SOD1) results in amyloid deposition and is involved in familial amyotrophic lateral sclerosis, a fatal motor neuron disease. There have been extensive studies of its aggregation mechanism. Noncanonical amino acid 5-cyano-tryptophan (5-CN-Trp), which has been incorporated into the amyloid segments of SOD1 as infrared probes to increase the structural sensitivity of IR spectroscopy, is found to accelerate the overall aggregation rate and potentially modulate the aggregation process...

Measurements of local density fluctuations are crucial to characterizing the interfacial properties of equilibrium fluids. A specific case that has been well-explored involves the heightened compressibility of water near hydrophobic entities. Commonly, a spatial profile of local fluctuation strength is constructed from the measurements of the mean and variance of solvent particle number fluctuations in a set of contiguous subvolumes of the system adjacent to the solvo-/hydrophobe. An alternative measure proposed by Evans and Stewart [J...

Intraductal T2 mapping based on a catheter receiver is proposed as a method of visualizing the extent of intraductal and periductal cholangiocarcinoma (CCA). Compared to external receivers, internal receivers provide locally enhanced signal-to-noise ratios by virtue of their lower field-of-view for body noise, allowing smaller voxels and higher resolution. However, inherent radial sensitivity variation and segmentation for patient safety both distort image brightness. We discuss simulated T2 weighted images and T2 maps, and in vitro images obtained using a thin film catheter receiver of a freshly resected liver specimen containing a polypoid intraductal tumor from a patient with CCA...

INTRODUCTION: Assessing the treatment response of glioblastoma multiforme during immunotherapy (IT) is an open issue. Treatment response assessment maps (TRAMs) might help distinguish true tumor progression (TTP) and pseudoprogression (PsP) in this setting. METHODS: We recruited 16 naïve glioblastoma patients enrolled in a phase II trial consisting of the Stupp protocol (a standardized treatment for glioblastoma involving combined radiotherapy and chemotherapy with temozolomide, followed by adjuvant temozolomide) plus IT with dendritic cells...