Spatially constrained hyperpolarized 13C MRI pharmacokinetic rate constant map estimation using a digital brain phantom and a U-Net.

Fitting rate constants to Hyperpolarized [1-C]Pyruvate (HP C13) MRI data is a promising approach for quantifying metabolism in vivo. Current methods typically fit each voxel of the dataset using a least-squares objective. With these methods, each voxel is considered independently, and the spatial relationships are not considered during fitting.

Measurement of biomechanical properties of transversely isotropic biological tissue using traveling wave expansion.

The anisotropic mechanical properties of fiber-embedded biological tissues are essential for understanding their development, aging, disease progression, and response to therapy. However, accurate and fast assessment of mechanical anisotropy in vivo using elastography remains challenging. To address the dilemma of achieving both accuracy and efficiency in this inverse problem involving complex wave equations, we propose a computational framework that utilizes the traveling wave expansion model.

Peptide nucleic acids: Recent advancements and future opportunities in biomedical applications.

Peptide nucleic acids (PNA), synthetic molecules comprising a peptide-like backbone and natural and unnatural nucleobases, have garnered significant attention for their potential applications in gene editing and other biomedical fields. The unique properties of PNA, particularly enhanced stability/specificity/affinity towards targeted DNA and RNA sequences, achieved significant attention recently for gene silencing, gene correction, antisense therapy, drug delivery, biosensing and other various diagnostic aspects. This review explores the structure, properties, and potential of PNA in transforming genetic engineering including potent biomedical challenges.

Developmental changes of skin quality from breast, back, and thigh of Pekin ducks from 1 to 6 weeks of age.

Good skin quality not only improved carcass quality but also increased consumer demand for fresh poultry meat. This study aimed to investigate the developmental changes in skin growth and quality of Pekin ducks during 1-6 weeks of age. The skin samples were collected from the breast, back, and thigh tissues of six male ducks at the end of each week.

The impact of colloid-solvent dynamic coupling on the coarsening rate of colloidal phase separation.

Phase separation, a fundamental phenomenon in both natural and industrial settings, involves the coarsening of domains over time t to reduce interfacial energy. While well-understood for simple viscous liquid mixtures, the physical laws governing coarsening dynamics in complex fluids, such as colloidal suspensions, remain unclear. Here, we investigate colloidal phase separation through particle-based simulations with and without hydrodynamic interactions (HIs).

The mechanisms of frequency tuning in gecko auditory hair cells.

We developed an isolated auditory papilla of the crested gecko to record from the hair cells and explore the origins of frequency tuning. Low-frequency cells displayed electrical tuning, dependent on Ca-activated K channels; high-frequency cells, overlain with sallets, showed a variation in hair bundle stiffness which when combined with sallet mass could provide a mechanical resonance of 1 to 6 kHz. Sinusoidal electrical currents injected extracellularly evoked hair bundle oscillations at twice the stimulation frequency, consistent with fast electromechanical responses from hair bundles of two opposing orientations, as occur in the sallets.

Environmental controls on the conversion of nutrients to chlorophyll in lakes.

Anthropogenic inputs of nitrogen and phosphorus to lakes have increased worldwide, causing phytoplankton chlorophyll concentrations to increase at many sites, with negative implications for biodiversity and human usage of lake resources. However, the conversion of nutrients to chlorophyll varies among lakes, hindering effective management actions to improve water quality. Here, using a rich global dataset, we explore how the relationship between chlorophyll-a (Chla) and nitrogen and phosphorus and inferred nutrient limitation is modified by climate, catchment, hydrology and lake characteristics.

Association between homelessness and PrEP uptake among men who have sex with men: Results from the American Men's Internet Survey, 2017-2021.

Background: Gay, bisexual, and other men who have sex with men (GBMSM) are disproportionately affected by housing insecurity across the US. This study examined the association between homelessness and uptake of pre-exposure prophylaxis (PrEP) for HIV prevention among GBMSM in the United States and investigated the modifying effect of injection drug use.

Methods: 47,750 cisgender GBMSM who participated in the American Men's Internet Survey from 2017 to 2021 and who self-reported not living with HIV were included in this secondary, cross-sectional analysis.

Mental illness and personal recovery: A narrative identity framework.

This article presents a metamorphic model to describe the manifold role of narrative identity, a person's internal life story, across the course of mental illness and personal recovery. First, early adversity and negative co-authoring may contribute to the development of a fragile life story, which itself may combine with life stressors to increase the likelihood of mental illness. Second, mental illness may negatively impact the development of narrative identity, which in turn may exacerbate the devastating effects of mental illness on daily functioning.

Estimation of the phase velocity dispersion curves for viscoelastic materials using Point Limited Shear Wave Elastography.

Ultrasound shear wave elastography (SWE) is widely used in clinical applications for non-invasive measurements of soft tissue viscoelasticity. The study of tissue viscoelasticity often involves the analysis of shear wave phase velocity dispersion curves, which show how the phase velocity varies with frequency or wavelength. In this study, we propose an alternative method to the two-dimensional Fourier transform (2D-FT) and Phase Gradient (PG) methods for shear wave phase velocity estimation.

The (in)dependence of single-cell data inferences on model constructs.

Recent developments in single-cell analysis have revolutionized basic research and have garnered the attention of the forensic domain. Though single-cell analysis is not new to forensics, the ways in which these data can be generated and interpreted are. Modern interpretation strategies report likelihood ratios that rely on a model of the world that is a simplification of it.

T-Shaped Wedge Resection of the Upper Eyelid: An Alternative to the Pentagonal Wedge.

Purpose: To report the experience with an alternative to the upper eyelid pentagonal wedge resection technique which results in improved cosmesis due to a greater alignment of incisions with relaxed skin tension lines.

Methods: A retrospective review of all patients who underwent the T-shaped wedge resection by the authors from 2009 to 2017. A horizontal eyelid crease incision is made across the upper eyelid skin.

Protocol for mitochondrial variant enrichment from single-cell RNA sequencing using MAESTER.

Single-cell RNA sequencing (scRNA-seq) enables detailed characterization of cell states but often lacks insights into tissue clonal structures. Here, we present a protocol to probe cell states and clonal information simultaneously by enriching mitochondrial DNA (mtDNA) variants from 3'-barcoded full-length cDNA. We describe steps for input library preparation, mtDNA enrichment, PCR product cleanup, and paired-end sequencing.

Luminance invariant encoding in mouse primary visual cortex.

The visual system adapts to maintain sensitivity and selectivity over a large range of luminance intensities. One way that the retina maintains sensitivity across night and day is by switching between rod and cone photoreceptors, which alters the receptive fields and interneuronal correlations of retinal ganglion cells (RGCs). While these adaptations allow the retina to transmit visual information to the brain across environmental conditions, the code used for that transmission varies.

Antigen affinity and site of immunization dictate B cell recall responses.

Protective antibodies against HIV-1 require unusually high levels of somatic mutations introduced in germinal centers (GCs). To achieve this, a sequential vaccination approach was proposed. Using HIV-1 antibody knockin mice with fate-mapping genes, we examined if antigen affinity affects the outcome of B cell recall responses.

Neuraminidase 1 regulates neuropathogenesis by governing the cellular state of microglia via modulation of Trem2 sialylation.

Neuraminidase 1 (NEU1) cleaves terminal sialic acids from sialoglycoproteins in endolysosomes and at the plasma membrane. As such, NEU1 regulates immune cells, primarily those of the monocytic lineage. Here, we examine how Neu1 influences microglia by modulating the sialylation of full-length Trem2 (Trem2-FL), a multifunctional receptor that regulates microglial survival, phagocytosis, and cytokine production.

Opposing roles of p38α-mediated phosphorylation and PRMT1-mediated arginine methylation in driving TDP-43 proteinopathy.

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder typically characterized by insoluble inclusions of hyperphosphorylated TDP-43. The mechanisms underlying toxic TDP-43 accumulation are not understood. Persistent activation of p38 mitogen-activated protein kinase (MAPK) is implicated in ALS.

Coordination and persistence of aggressive visual communication in Siamese fighting fish.

Outside acoustic communication, little is known about how animals coordinate social turn taking and how the brain drives engagement in these social interactions. Using Siamese fighting fish (Betta splendens), we discover dynamic visual features of an opponent and behavioral sequences that drive visually driven turn-taking aggressive behavior. Lesions of the telencephalon show that it is unnecessary for coordinating turn taking but is required for persistent participation in aggressive interactions.

Coordinated neuron-specific splicing events restrict nucleosome engagement of the LSD1 histone demethylase complex.

Chromatin regulatory proteins are expressed broadly and assumed to exert the same intrinsic function across cell types. Here, we report that 14 chromatin regulators undergo evolutionary-conserved neuron-specific splicing events involving microexons. Among them are two components of a histone demethylase complex: LSD1 H3K4 demethylase and the H3K4me0-reader PHF21A.

Probing the functional constraints of influenza A virus NEP by deep mutational scanning.

The influenza A virus nuclear export protein (NEP) is a multifunctional protein that is essential for the viral life cycle and has very high sequence conservation. However, since the open reading frame of NEP largely overlaps with that of another influenza viral protein, non-structural protein 1, it is difficult to infer the functional constraints of NEP based on sequence conservation analysis. In addition, the N-terminal of NEP is structurally disordered, which further complicates the understanding of its function.

ERK activation waves coordinate mechanical cell competition leading to collective elimination via extrusion of bacterially infected cells.

Epithelial cells respond to infection with the intracellular bacterial pathogen Listeria monocytogenes by altering their mechanics to promote collective infected cell extrusion (CICE) and limit infection spread across cell monolayers. However, the underlying biochemical pathways remain elusive. Here, using in vitro (epithelial monolayers) and in vivo (zebrafish larvae) models of infection with L.

Thrombotic Microangiopathy Associated with Systemic Adeno-Associated Virus Gene Transfer: Review of Reported Cases.

Complement-mediated thrombotic microangiopathy (TMA) in the form of atypical hemolytic uremic syndrome (aHUS) has emerged as an immune complication of systemic adeno-associated virus (AAV) gene transfer that was unforeseen based on nonclinical studies. Understanding this phenomenon in the clinical setting has been limited by incomplete data and a lack of uniform diagnostic and reporting criteria. While apparently rare based on available information, AAV-associated TMA/aHUS can pose a substantial risk to patients including one published fatality.

Characterization of Cutaneous Radiation Syndrome in a Mouse Model Using [18F]F- Fluorodeoxyglucose Positron Emission Tomography.

Ionizing radiation on the skin has the potential to cause various sequelae affecting quality of life and even leading to death due to multi-system failure. The development of radiation dermatitis is attributed to oxidative damage to the skin's basal layer and alterations in immune response, leading to inflammation. Past studies have shown that [18F]F-2-fluoro-2-deoxyglucose positron emission tomography-computed tomography ([18F]F-FDG PET/CT) can be used effectively for the detection of inflammatory activity, especially in conditions like hidradenitis suppurativa, psoriasis, and early atherosclerosis.

Single cell derived multicellular meristem: insights into male-to-hermaphrodite conversion and de novo meristem formation in ceratopteris.

Land plants alternate between asexual sporophytes and sexual gametophytes. Unlike seed plants, ferns develop free-living gametophytes. Gametophytes of the model fern Ceratopteris exhibit two sex types: hermaphrodites with pluripotent meristems and males lacking meristems.

Transition of Perovskite Solar Technologies to Being Flexible.

Perovskite technologies has taken giant steps on its advances in only a decade time, from fundamental science to device engineering. The possibility to exploit this technology on a thin flexible substrate gives an unbeatable power to weight ratio compares to similar photovoltaic systems, opening new possibilities and new integration concepts, going from building integrated and applied photovoltaics (BIPV, BAPV) to internet of things (IoT). In this perspective, the recent progress of perovskite solar technologies on flexible substrates are summarized, focusing on the challenges that researchers face upon using flexible substrates.