Quantifying platinum binding on protein-functionalized magnetic microparticles using single particle-ICP-TOF-MS.

This work describes an analytical procedure, single particle-inductively coupled plasma-time-of-flight-mass spectrometry (SP-ICP-TOF-MS), that was developed to determine the platinum binding efficiency of protein-coated magnetic microparticles. SP-ICP-TOF-MS is advantageous due to its ability to quasi-simultaneously detect all nuclides (7Li-242Pu), allowing for both platinum and iron (composition of magnetic microparticles) to be measured concurrently. This method subsequently allows for the differentiation between bound and unbound platinum. The 1 µm magnetic microparticles were fully characterized for their iron concentration, particle concentration, and trace element composition by bulk digestion-ICP-MS and SP-ICP-TOF-MS. The results of both approaches agreed with the certificate values. Using the single particle methodology the platinum loading was quantified to be to 0.18 ± 0.02 fg per particle and 0.32 ± 0.02 fg per particle, for the streptavidin-coated and azurin-coated microparticles, respectively. Both streptavidin-coated and the azurin-coated microparticles had a particle-platinum association of >65%. Platinum bound samples were also analyzed via bulk digestion-based ICP-MS. The bulk ICP-MS results overestimated platinum loading due to free platinum in the samples. This highlights the importance of single particle analysis for a closer inspection of platinum binding performance. The SP-ICP-TOF-MS approach offers advantages over typical bulk digestion methods by eliminating laborious sample preparation, enabling differentiation between bound/unbound platinum in a solution, and quantification of platinum on a particle-by-particle basis. The procedure presented here enables quantification of metal content per particle, which could be broadly implemented for other single particle applications.

Validation of the Wiedemann-Franz Law in Solid and Molten Tungsten above 2000 K through Thermal Conductivity Measurements via Steady-State Temperature Differential Radiometry.

We measure the thermal conductivity of solid and molten tungsten using steady state temperature differential radiometry. We demonstrate that the thermal conductivity can be well described by application of Wiedemann-Franz law to electrical resistivity data, thus suggesting the validity of Wiedemann-Franz law to capture the electronic thermal conductivity of metals in their molten phase. We further support this conclusion using ab initio molecular dynamics simulations with a machine-learned potential. Our results show that at these high temperatures, the vibrational contribution to thermal conductivity is negligible compared to the electronic component.

Aluminothermic reduction of CeO2: mechanism of an economical route to aluminum-cerium alloys.

Cerium oxide is a low-value byproduct of rare-earth mining yet constitutes the largest fraction of the rare earth elements. The reduction of cerium oxide by liquid aluminum is proposed as an energy- and cost-efficient route to produce high-strength Al-Ce alloys. This work investigated the mechanism of a multi-step reduction reaction to facilitate the industrial adaptation of the process. Differential scanning calorimetry in combination with time-resolved synchrotron diffraction data uncovered the rate-limiting reaction step as the origin of the reported temperature dependence of reduction efficiency. This is the first in situ study of a metallothermic reaction mechanism and will serve as guidance for cost- and energy efficient industrial process control.

Effects of two-step golf swing drills on rhythm and clubhead speed in competitive juniors.

Vertical and horizontal rhythms are crucial aspects of a dynamic golf swing, and the two-step swing drills (TSSD) were specifically designed to promote rhythmic unloading and loading of the legs. The purpose of this study was to evaluate the effects of a TSSD training session on the swing rhythm and clubhead speed (CHS) among competitive junior golfers (3.1 ± 4.4 hcp). The driver swings (7 swings each) of 10 competitive junior golfers (aged 15-18) were captured before and after a TSSD session consisting of four stages (lasting less than 45 minutes). Post-TSSD training, there were significant increases in CHS (p < .001), maximum unweighting (p = .006), the trail-side push (p = .009), the horizontal motion ranges of the body and pelvis (p = .005-.031), the upward/downward motion range of the body in the backswing (p = .042/.024), and the backswing/downswing angular velocity peaks of the axle-chain system (p < .033). The stepping-like leg actions primarily facilitated horizontal motion rhythm over vertical motion and unweighting over push in terms of ground interaction. These findings suggest that TSSD can serve as an effective method for developing a rhythmic and dynamic motion pattern while increasing CHS.

Mapping of uranium particles on J-type swipes with microextraction-ICP-MS.

A microextraction liquid sampling system coupled to a quadrupole inductively coupled plasma-mass spectrometer (ICP-MS) was utilized to spatially discern uranium particles, isotopically, on a cellulose-based swipe material (i.e., J-type swipe). These types of swipes are often used by the International Atomic Energy Agency (IAEA) as part of their environmental sampling program. A grid was created such that extraction locations covered the center circle (n = 34 without overlapping). Uranium (U) particulates (<20 µm) of varying U isotopic abundance and chemical form (i.e., uranyl fluoride and uranyl nitrate hexahydrate) were mechanically placed on the swipes in random locations and detected via the microextraction-ICP-MS methodology. Heat maps were subsequently generated to show the placement of the particulate with their respective intensity and isotopic determination. This detection of the uranium particulates, via isotopic determination, agreed with reference values for these materials. Additionally, depleted (235U/238U = 0.002) uranium particulates were placed directly within a clay matrix, on the swipe surface, and subjected to analysis by microextraction-ICP-MS. The mapping of the swipe demonstrated, for the first time, the employment of the microextraction-ICP-MS method for extracting sample from a complex matrix, and correctly identifying the uranium isotopic composition. This example ultimately demonstrates the utility of the methodology for detecting particles of interest in complex matrices.

Differentiating Pathologic from Physiologic Fibrinolysis: Not as Simple as Conventional Thrombelastography.

BACKGROUND: Conventional rapid-thrombelastography (rTEG) cannot differentiate fibrinolysis shutdown from hypofibrinolysis, as both of these patient populations have low fibrinolytic activity. Tissue plasminogen activator (tPA) TEG can identify depletion of fibrinolytic inhibitors, and its use in combination with rTEG has the potential to differentiate all three pathologic fibrinolytic phenotypes following trauma. We hypothesize tPA-TEG and rapid TEG (rTEG) in combination can further stratify fibrinolysis phenotypes post-injury to better stratify risk for mortality. STUDY DESIGN: Adult trauma patients (n=981) with both rTEG and tPA-TEG performed <2 hours post-injury were included. rTEG LY30 was used to initially define fibrinolysis phenotypes (Hyperfibrinolysis >3%, Physiologic 0.9-3%, Shutdown <0.9%), with Youden Index then used to define pathologic extremes of tPA-TEG LY30 [tPA sensitive (depletion of fibrinolytic inhibitors) versus resistant] resulting in 9 groups that were assessed for risk of death. RESULTS: The median NISS was 22, 21% were female, 45% had penetrating injury, and overall mortality was 13%. The tPA-TEG LY30 inflection point for increased mortality was>35.5% (tPA sensitive, OR mortality 9.2 P<0.001) and <0.3% (tPA resistance, OR mortality 6.3 p=0.04). Of the nine potential fibrinolytic phenotypes, five were associated with increased mortality. Overall, the 9 phenotypes provided a significantly better prediction of mortality than rTEG or tPA-TEG alone (AUROC=0.80 vs 0.63 and 0.75, respectively, p<0.0001). These could be condensed to three pathologic phenotypes (true hyperfibrinolysis, early fibrinolysis shutdown, and hypofibrinolysis). CONCLUSIONS: The combination of rTEG and tPA-TEG increases the ability to predict mortality and suggests patient specific strategies for improved outcome.

Cell-type-specific cis-regulatory divergence in gene expression and chromatin accessibility revealed by human-chimpanzee hybrid cells.

Although gene expression divergence has long been postulated to be the primary driver of human evolution, identifying the genes and genetic variants underlying uniquely human traits has proven to be quite challenging. Theory suggests that cell-type-specific cis-regulatory variants may fuel evolutionary adaptation due to the specificity of their effects. These variants can precisely tune the expression of a single gene in a single cell-type, avoiding the potentially deleterious consequences of trans-acting changes and non-cell type-specific changes that can impact many genes and cell types, respectively. It has recently become possible to quantify human-specific cis-acting regulatory divergence by measuring allele-specific expression in human-chimpanzee hybrid cells-the product of fusing induced pluripotent stem (iPS) cells of each species in vitro. However, these cis-regulatory changes have only been explored in a limited number of cell types. Here, we quantify human-chimpanzee cis-regulatory divergence in gene expression and chromatin accessibility across six cell types, enabling the identification of highly cell-type-specific cis-regulatory changes. We find that cell-type-specific genes and regulatory elements evolve faster than those shared across cell types, suggesting an important role for genes with cell-type-specific expression in human evolution. Furthermore, we identify several instances of lineage-specific natural selection that may have played key roles in specific cell types, such as coordinated changes in the cis-regulation of dozens of genes involved in neuronal firing in motor neurons. Finally, using novel metrics and a machine learning model, we identify genetic variants that likely alter chromatin accessibility and transcription factor binding, leading to neuron-specific changes in the expression of the neurodevelopmentally important genes FABP7 and GAD1. Overall, our results demonstrate that integrative analysis of cis-regulatory divergence in chromatin accessibility and gene expression across cell types is a promising approach to identify the specific genes and genetic variants that make us human.

Fibrinolysis Resistance After Injury Is a Risk Factor for a Hospital-Acquired Pneumonia-Like Disease Pattern.

Background: Pneumonia is associated with increased morbidity and costs in the intensive care unit (ICU). Its early identification is key for optimal outcomes, but early biomarkers are lacking. Studies suggest that fibrinolysis resistance (FR) after major abdominal surgery is linked to an increased risk of infection. Patients and Methods: Patients in a randomized controlled trial for hemorrhagic shock were evaluated for FR. Fibrinolysis resistance was quantified by thrombelastography with exogenous tissue plasminogen activator (tPA-TEG) at 24- and 48-hours post-injury and measuring LY30 (%). A receiver-operating characteristics (ROC) curve analysis was used to identify a cutoff for increased risk of pneumonia, which was then validated in ICU patients at risk for venous thromboembolism (VTE). Multivariable logistic regression was used to control for confounders. Results: Forty-nine patients in the hemorrhagic shock cohort had tPA-TEGs at 24- and 48-hours (median ISS, 27; 7% pneumonia). A composite tPA-TEG LY30 of less than 4% at 24 and 48 hours was found to be the optimal cutoff for increased risk of pneumonia. This cohort had a seven-fold increased rate of pneumonia (4% vs. 28%; p = 0.048). Eighty-eight patients in the VTE cohort had tPA-TEGs at 24 and 48 hours post-ICU admission (median ISS, 28; 6% pneumonia). The tPA-TEG LY30 of less than 4% was associated with a 10-fold increased rate of pneumonia (19% vs. 1.5%; p = 0.002). In patients with traumatic brain injury, the same association was found (33% vs. 3.2%; p = 0.006). Adjusting for confounders, the tPA-TEG persisted as a substantial risk factor for pneumonia (adjusted odds ratio [OR], 35.7; 95% confidence interval [CI], 1.9-682; p = 0.018). Conclusions: Fibrinolysis resistance quantified by tPA-TEG within 48 hours of ICU admission is associated with an increased risk of pneumonia in patients in hemorrhagic shock and those at risk for VTE. Prospective validation of the tPA-TEG LY30 optimal cutoff for pneumonia and further investigation into whether endogenous FR is a cause of an altered immunity is warranted.

Corrigendum: Iatrogenic air embolism: pathoanatomy, thromboinflammation, endotheliopathy, and therapies.

[This corrects the article DOI: 10.3389/fimmu.2023.1230049.].

Chromatin activity identifies differential gene regulation across human ancestries.

BACKGROUND: Current evidence suggests that cis-regulatory elements controlling gene expression may be the predominant target of natural selection in humans and other species. Detecting selection acting on these elements is critical to understanding evolution but remains challenging because we do not know which mutations will affect gene regulation. RESULTS: To address this, we devise an approach to search for lineage-specific selection on three critical steps in transcriptional regulation: chromatin activity, transcription factor binding, and chromosomal looping. Applying this approach to lymphoblastoid cells from 831 individuals of either European or African descent, we find strong signals of differential chromatin activity linked to gene expression differences between ancestries in numerous contexts, but no evidence of functional differences in chromosomal looping. Moreover, we show that enhancers rather than promoters display the strongest signs of selection associated with sites of differential transcription factor binding. CONCLUSIONS: Overall, our study indicates that some cis-regulatory adaptation may be more easily detected at the level of chromatin than DNA sequence. This work provides a vast resource of genomic interaction data from diverse human populations and establishes a novel selection test that will benefit future study of regulatory evolution in humans and other species.

Comparing Sensor Fusion and Multimodal Chemometric Models for Monitoring U(VI) in Complex Environments Representative of Irradiated Nuclear Fuel.

Optical sensors and chemometric models were leveraged for the quantification of uranium(VI) (0-100 µg mL-1), europium (0-150 µg mL-1), samarium (0-250 µg mL-1), praseodymium (0-350 µg mL-1), neodymium (0-1000 µg mL-1), and HNO3 (2-4 M) with varying corrosion product (iron, nickel, and chromium) levels using laser fluorescence, Raman scattering, and ultraviolet-visible-near-infrared absorption spectra. In this paper, an efficient approach to developing and evaluating tens of thousands of partial least-squares regression (PLSR) models, built from fused optical spectra or multimodal acquisitions, is discussed. Each PLSR model was optimized with unique preprocessing combinations, and features were selected using genetic algorithm filters. The 7-factor D-optimal design training set contained just 55 samples to minimize the number of samples. The performance of PLSR models was evaluated by using an automated latent variable selection script. PLS1 regression models tailored to each species outperformed a global PLS2 model. PLS1 models built using fused spectra data and a multimodal (i.e., analyzed separately) approach yielded similar information, resulting in percent root-mean-square error of prediction values of 0.9-5.7% for the seven factors. The optical techniques and data processing strategies established in this study allow for the direct analysis of numerous species without measuring luminescence lifetimes or relying on a standard addition approach, making it optimal for near-real-time, in situ measurements. Nuclear reactor modeling helped bound training set conditions and identified elemental ratios of lanthanide fission products to characterize the burnup of irradiated nuclear fuel. Leveraging fluorescence, spectrophotometry, experimental design, and chemometrics can enable the remote quantification and characterization of complex systems with numerous species, monitor system performance, help identify the source of materials, and enable rapid high-throughput experiments in a variety of industrial processes and fundamental studies.

Development of small-molecule Tau-SH3 interaction inhibitors that prevent amyloid-ß toxicity and network hyperexcitability.

Alzheimer's disease (AD) is the leading cause of dementia and lacks highly effective treatments. Tau-based therapies hold promise. Tau reduction prevents amyloid-ß-induced dysfunction in preclinical models of AD and also prevents amyloid-ß-independent dysfunction in diverse disease models, especially those with network hyperexcitability, suggesting that strategies exploiting the mechanisms underlying Tau reduction may extend beyond AD. Tau binds several SH3 domain-containing proteins implicated in AD via its central proline-rich domain. We previously used a peptide inhibitor to demonstrate that blocking Tau interactions with SH3 domain-containing proteins ameliorates amyloid-ß-induced dysfunction. Here, we identify a top hit from high-throughput screening for small molecules that inhibit Tau-FynSH3 interactions and describe its optimization with medicinal chemistry. The resulting lead compound is a potent cell-permeable Tau-SH3 interaction inhibitor that binds Tau and prevents amyloid-ß-induced dysfunction, including network hyperexcitability. These data support the potential of using small molecule Tau-SH3 interaction inhibitors as a novel therapeutic approach to AD.

Laser Ablation Plasmas and Spectroscopy for Nuclear Applications.

The development of measurement methodologies to detect and monitor nuclear-relevant materials remains a consistent and significant interest across the nuclear energy, nonproliferation, safeguards, and forensics communities. Optical spectroscopy of laser-produced plasmas is becoming an increasingly popular diagnostic technique to measure radiological and nuclear materials in the field without sample preparation, where current capabilities encompass the standoff, isotopically resolved and phase-identifiable (e.g., UO and UO2) detection of elements across the periodic table. These methods rely on the process of laser ablation (LA), where a high-powered pulsed laser is used to excite a sample (solid, liquid, or gas) into a luminous microplasma that rapidly undergoes de-excitation through the emission of electromagnetic radiation, which serves as a spectroscopic fingerprint for that sample. This review focuses on LA plasmas and spectroscopy for nuclear applications, covering topics from the wide-area environmental sampling and atmospheric sensing of radionuclides to recent implementations of multivariate machine learning methods that work to enable the real-time analysis of spectrochemical measurements with an emphasis on fundamental research and development activities over the past two decades. Background on the physical breakdown mechanisms and interactions of matter with nanosecond and ultrafast laser pulses that lead to the generation of laser-produced microplasmas is provided, followed by a description of the transient spatiotemporal plasma conditions that control the behavior of spectroscopic signatures recorded by analytical methods in atomic and molecular spectroscopy. High-temperature chemical and thermodynamic processes governing reactive LA plasmas are also examined alongside investigations into the condensation pathways of the plasma, which are believed to serve as chemical surrogates for fallout particles formed in nuclear fireballs. Laser-supported absorption waves and laser-induced shockwaves that accompany LA plasmas are also discussed, which could provide insights into atmospheric ionization phenomena from strong shocks following nuclear detonations. Furthermore, the standoff detection of trace radioactive aerosols and fission gases is reviewed in the context of monitoring atmospheric radiation plumes and off-gas streams of molten salt reactors. Finally, concluding remarks will present future outlooks on the role of LA plasma spectroscopy in the nuclear community.

Novel Calibration Approach for Monitoring Aerosol Hydrogen Isotopes Using Laser-Induced Breakdown Spectroscopy for Molten Salt Reactor Off-Gas Streams.

Online monitoring is a key challenge for the continued development of molten salt reactor (MSR) technology. Laser-induced breakdown spectroscopy (LIBS) has previously been demonstrated to be a viable tool for monitoring aerosolized species and noble gases in real time, but the ability to discern varying isotopes in these streams has not yet been investigated for MSR applications. Tritium will form in MSRs from ternary fission and from (n,α)-reactions occurring in lithium-containing salts. This study compares three spectrometers of varying resolutions and types for measuring hydrogen isotope shifts in LIBS spectra of wetted filter paper. For each spectrometer, multivariate models were built (i.e., principal component regression, partial least squares regression, and multivariate curve resolution) to quantify the isotope ratio. The top models were then modified and corrected to apply the models to aerosol samples with varying isotope ratios. This novel calibration strategy offers an 82% reduction in volume of the calibration samples needed and is a more viable pathway for calibrating deployable LIBS systems. Lastly, this calibration model was compared with an all-aerosol trained model for monitoring hydrogen isotopes during a real-time test where the protium/deuterium ratio, along with representative salt species (i.e., lithium, sodium, and potassium) were adjusted dynamically. Results of this test validated the predictive capabilities of the transferred model and highlighted the capabilities of LIBS for real-time monitoring of MSR effluent streams.

Combination of aspirin and rosuvastatin for reduction of venous thromboembolism in severely injured patients: a double-blind, placebo-controlled, pragmatic randomized phase II clinical trial (The STAT Trial).

INTRODUCTION: Venous thromboembolism (VTE) remains a significant source of postinjury morbidity and mortality. Beta-hydroxy beta-methylglutaryl-CoA (HMG-CoA) reductase inhibitors (rosuvastatin) significantly reduced pathologic clotting events in healthy populations in a prior trial. Furthermore, acetylsalicylic acid (ASA) has been shown to be noninferior to prophylactic heparinoids for VTE prevention following orthopedic surgery. We hypothesized that a combination of rosuvastatin/ASA, in addition to standard VTE chemoprophylaxis, would reduce VTE in critically ill trauma patients. METHODS: This was a double-blind, placebo-controlled, randomized trial, evaluating VTE rates in two groups: ASA + statin (Experimental) and identical placebos (Control). Injured adults, 18-65 years old, admitted to the surgical intensive care unit without contraindications for VTE prophylaxis were eligible. Upon initiation of routine VTE chemoprophylaxis (i.e. heparin/heparin-derivatives), they were randomized to the Experimental or Control group. VTE was the primary outcome. RESULTS: Of 112 potentially eligible patients, 33% (n = 37, median new injury severity scale = 27) were successfully randomized, of whom 11% had VTEs. The Experimental group had no VTEs, while the Control group had 6 VTEs (4 PEs and 2 DVTs) in 4 (22%) patients (P = 0.046). The Experimental treatment was not associated with any serious adverse events. Due to the COVID-19 pandemic, the study was interrupted at the second interim analysis at <10% of the planned enrollment, with significance declared at P < 0.012 at that stage. DISCUSSION: The combination of ASA and rosuvastatin with standard VTE prophylaxis showed a favorable trend toward reducing VTEs with no serious adverse events. An appropriately powered phase III multicenter trial is needed to further investigate this therapeutic approach. LEVEL OF EVIDENCE: Level II, Therapeutic.

Rb2Ln[Si2O6]F (Ln = Y, Eu-Lu): Flux Synthesis, Structure Determination, and DFT-Calculated Formation Enthalpies of a Series of Mixed-Anion Rare Earth Cyclosilicates.

A new series of mixed-anion alkali rare earth silicate fluorides with composition Rb2Ln[Si2O6]F (Ln = Y, Eu-Lu) has been synthesized via an alkali chloride/fluoride eutectic flux synthetic route. All synthesized compositions crystallize in the tetragonal space group P42/mnm with a 3D framework consisting of LnO4F2 octahedra, tetrasilicate rings, and 1D channels containing alkali metals. A combination of powder X-ray diffraction, single-crystal X-ray diffraction, and luminescence emission spectroscopy was performed to characterize the reaction products. In addition, density functional theory (DFT) calculations were utilized to calculate the 0 K formation enthalpies of the synthesized phases and of hypothetical trivalent actinide analogues to probe the likelihood of the successful synthesis of such trivalent transuranic containing phases, specifically Am and Cm, in the future.

A new tissue-agnostic microfluidic device to model physiology and disease: the lattice platform.

To accurately phenocopy human biology in vitro, researchers have been reducing their dependence on standard, static two-dimensional (2D) cultures and instead are moving towards three-dimensional (3D) and/or multicellular culture techniques. While these culture innovations are becoming more commonplace, there is a growing body of research that illustrates the benefits and even necessity of recapitulating the dynamic flow of nutrients, gas, waste exchange and tissue interactions that occur in vivo. However, cost and engineering complexity are two main factors that hinder the adoption of these technologies and incorporation into standard laboratory workflows. We developed LATTICE, a plug-and-play microfluidic platform able to house up to eight large tissue or organ models that can be cultured individually or in an interconnected fashion. The functionality of the platform to model both healthy and diseased tissue states was demonstrated using 3D cultures of reproductive tissues including murine ovarian tissues and human fallopian tube explants (hFTE). When exogenously exposed to pathological doses of gonadotropins and androgens to mimic the endocrinology of polycystic ovarian syndrome (PCOS), subsequent ovarian follicle development, hormone production and ovulation copied key features of this endocrinopathy. Further, hFTE cilia beating decreased significantly only when experiencing continuous media exchanges. We were then able to endogenously recreate this phenotype on the platform by dynamically co-culturing the PCOS ovary and hFTE. LATTICE was designed to be customizable with flexibility in 3D culture formats and can serve as a powerful automated tool to enable the study of tissue and cellular dynamics in health and disease in all fields of research.

Iatrogenic air embolism: pathoanatomy, thromboinflammation, endotheliopathy, and therapies.

Iatrogenic vascular air embolism is a relatively infrequent event but is associated with significant morbidity and mortality. These emboli can arise in many clinical settings such as neurosurgery, cardiac surgery, and liver transplantation, but more recently, endoscopy, hemodialysis, thoracentesis, tissue biopsy, angiography, and central and peripheral venous access and removal have overtaken surgery and trauma as significant causes of vascular air embolism. The true incidence may be greater since many of these air emboli are asymptomatic and frequently go undiagnosed or unreported. Due to the rarity of vascular air embolism and because of the many manifestations, diagnoses can be difficult and require immediate therapeutic intervention. An iatrogenic air embolism can result in both venous and arterial emboli whose anatomic locations dictate the clinical course. Most clinically significant iatrogenic air emboli are caused by arterial obstruction of small vessels because the pulmonary gas exchange filters the more frequent, smaller volume bubbles that gain access to the venous circulation. However, there is a subset of patients with venous air emboli caused by larger volumes of air who present with more protean manifestations. There have been significant gains in the understanding of the interactions of fluid dynamics, hemostasis, and inflammation caused by air emboli due to in vitro and in vivo studies on flow dynamics of bubbles in small vessels. Intensive research regarding the thromboinflammatory changes at the level of the endothelium has been described recently. The obstruction of vessels by air emboli causes immediate pathoanatomic and immunologic and thromboinflammatory responses at the level of the endothelium. In this review, we describe those immunologic and thromboinflammatory responses at the level of the endothelium as well as evaluate traditional and novel forms of therapy for this rare and often unrecognized clinical condition.

Allele-specific expression reveals genetic drivers of tissue regeneration in mice.

In adult mammals, skin wounds typically heal by scarring rather than through regeneration. In contrast, "super-healer" Murphy Roths Large (MRL) mice have the unusual ability to regenerate ear punch wounds; however, the molecular basis for this regeneration remains elusive. Here, in hybrid crosses between MRL and non-regenerating mice, we used allele-specific gene expression to identify cis-regulatory variation associated with ear regeneration. Analyzing three major cell populations (immune, fibroblast, and endothelial), we found that genes with cis-regulatory differences specifically in fibroblasts were associated with wound-healing pathways and also co-localized with quantitative trait loci for ear wound-healing. Ectopic treatment with one of these proteins, complement factor H (CFH), accelerated wound repair and induced regeneration in typically fibrotic wounds. Through single-cell RNA sequencing (RNA-seq), we observed that CFH treatment dramatically reduced immune cell recruitment to wounds, suggesting a potential mechanism for CFH's effect. Overall, our results provide insights into the molecular drivers of regeneration with potential clinical implications.

Development and in-vivo validation of a portable phosphorescence lifetime-based fiber-optic oxygen sensor.

Oxygenation is a crucial indicator of tissue viability and function. Oxygen tension ([Formula: see text]), i.e. the amount of molecular oxygen present in the tissue is a direct result of supply (perfusion) and consumption. Thus, measurement of [Formula: see text] is an effective method to monitor tissue viability. However, tissue oximetry sensors commonly used in clinical practice instead rely on measuring oxygen saturation ([Formula: see text]), largely due to the lack of reliable, affordable [Formula: see text] sensing solutions. To address this issue we present a proof-of-concept design and validation of a low-cost, lifetime-based oxygen sensing fiber. The sensor consists of readily-available off-the shelf components such as a microcontroller, a light-emitting diode (LED), an avalanche photodiode (APD), a temperature sensor, as well as a bright in-house developed porphyrin molecule. The device was calibrated using a benchtop setup and evaluated in three in vivo animal models. Our findings show that the new device design in combination with the bright porphyrin has the potential to be a useful and accurate tool for measuring [Formula: see text] in tissue, while also highlighting some of the limitations and challenges of oxygen measurements in this context.