Reactive Conditions Research Articles

Browns Creek mine, Blayney, NSW—a transtensional strike-slip fault-hosted Au–Cu skarn deposit

The Browns Creek Au–Cu skarn is restricted to a 50 m-wide fault zone developed in an interbedded sequence of Upper Ordovician mafic Blayney Volcanics and Cowriga Limestone Member adjacent to the mid-Silurian (434–425 Ma) Carcoar Granodiorite. The mineralised skarns are hosted within and controlled by the Mount David/4000E Fault zone, a dextral transtensional strike-slip fault that in cross-section has the form of a negative flower structure. This is consistent with components of dextral strike-slip motion recorded on regional faults likely guiding magma emplacement during the Benambran Orogeny. The skarns comprise a barren Stage 1 prograde pyroxene–garnet–wollastonite–anorthite assemblage followed by Stage 2 hornblende–biotite–epidote–magnetite–Fe–Cu–As sulfide skarn. These are overprinted by the strongly mineralised Stage 3 retrograde epidote–andradite garnet–chlorite Cu–Au skarn containing the bornite–chalcopyrite–chalcocite–gold ore, when probable magmatic-dominated hydrothermal fluids were channelled through the previously skarned strike-slip fault system that had become a permeable fault zone. Stage 4 sheeted vein-hosted prehnite–epidote–chlorite Au–Cu skarn formed when the strike-slip fault subsequently failed in tension to form gold-rich vertical extensional veins. Conditions for extensional fault reactivation and vein formation are discussed in terms of reshear criteria and fluid overpressure. The age of the mineralisation is constrained by late-stage monzonitic dykes that both crosscut and are themselves skarned by stages 3 and 4 assemblages. These co-magmatic dykes were dated at ca 435–425 Ma, which closely corresponds with the age of the Carcoar Granodiorite itself. Stable and radiogenic isotopes indicate that hydrothermal fluids associated with prograde and retrograde skarns are within the range for magmatic fluids with some mixing with fluids of meteoric origin during later stages of mineralisation. The Browns Creek Au–Cu skarn is typical of Au-skarns worldwide and is linked to mid-Silurian magmatism at a late stage in the Benambran Orogeny.

Is It Time to Assess T Cell Clonality by Next-Generation Sequencing in Mature T Cell Lymphoid Neoplasms? A Scoping Review

Background: T cell clonality is commonly assessed in the diagnostic work-up of mature T cell lymphoid neoplasms. Although fragment-length polymerase chain reaction (FL-PCR) assays are most widely used, next-generation sequencing (NGS) of the TRG and TRB genes is increasingly being used to assess T cell clonality. Objective: The present work is a scoping review of studies that assessed T cell clonality by NGS for diagnostic purposes, including only studies that provided integrated clinicopathologic diagnoses in comparing FL-PCR and NGS assays to evaluate if it is preferable to use NGS-based assays for T cell clonality evaluation in diagnostic pathology. Methods: Papers published from 1992 to 3 August 2024 were searched in PubMed. Twenty-nine cohort studies and five instructive case reports, published from 2013–2024 from the USA, UK, Europe, and Australia that provided integrated clinicopathologic diagnoses and used NGS to evaluate T cell clonality in clinical specimens from patients with mature T cell neoplasms and related non-neoplastic and neoplastic diseases were included, with additional relevant studies. Results: Ten (34.4%) of the 29 cohorts included clinical samples from patients having various cutaneous and non-cutaneous T cell malignancies, related neoplasms, and reactive conditions; 2 (6.8%) studies focused on T cell prolymphocytic leukemia, 16 (55%) on cutaneous T cell lymphoma, and one on pediatric pityriasis lichenoides. Eleven (38%) of the 29 cohort studies compared NGS with FL-PCR assays in 908 clinical samples. Eight (72.7%) of the 11 studies compared TRG FL-PCR with TRG NGS (n = 5), TRB NGS (n = 2), and TRG NGS and TRB NGS (n = 1); the remaining three compared EuroClonality/BIOMED-2 FL-PCR (TRG and TRB) with TRG NGS (n = 1), TRB NGS (n = 1), and the EuroClonality-NGS DNA capture assay (n = 1). TRB NGS was used in 16 (55%) of 29, TRG NGS in 6 (20.6%) of 29, and both TRG and TRB NGS in 7 (24%) of 29. Two (6.8%) of the 29 studies compared TRB NGS with flow cytometric immunophenotyping assays for Vβ and T cell receptor β constant region 1. One additional study compared long-read sequencing with NGS for TRG and TRB rearrangements. Conclusions: NGS is highly specific and sensitive for assessing T cell clonality. NGS precisely tracks unique rearranged sequences, which FL-PCR cannot. NGS findings for clonality must be interpreted in the context of all clinicopathologic and immunophenotypic findings, like FL-PCR. With such interpretations, NGS is much preferable to FL-PCR for evaluating T cell clonality for diagnostic purposes. It is necessary to reduce costs, increase accessibility, and educate providers about NGS for clonality evaluation. TRB NGS has been primarily assessed in the peripheral blood and skin, whereas TRG NGS has also been evaluated in formalin-fixed and non-cutaneous fresh lymphoid tissues. TRG NGS performed better than TRB NGS in comparative studies.

A theoretical and experimental study of phase formation in Ti–CuO powder mixtures under reactive sintering conditions

A thermokinetic model of composite synthesis from Ti and CuO powders is suggested. The numerical modeling leads to nonequilibrium composition of the product that qualitatively agrees with the experimental data.

Intrinsic Coexistence of Miscibility and Segregation in Gold-Silver Nanoalloys.

Bimetallic nanoparticles are used in numerous applications in catalysis, plasmonics or fuel cell technology. The addition of the second metal to the nanoparticles allows enhancing and fine-tuning their properties by choosing their composition, size, shape and environment. However, the crucial additional parameter of chemical structure within the particle is difficult to predict and access experimentally, even though segregated core-shell structures and random alloys can have drastically different physicochemical properties. This is highlighted by the vast literature on the most studied bimetallic system, gold-silver, for which the controversy on whether gold and silver are miscible on the nanoscale or segregate persists. Here, these contradictions are solved by determining quantitatively the coexistence of an alloyed core and a 1-2nm thick shell with gradual silver enrichment as the chemical ground state structure. Chemical reactions with the environment and meta-stable structures are furthermore identified as responsible for the contradictions in the literature. This method is applicable to other multi-metallic systems, provides benchmark input for theoretical models, and forms the basis for studying chemical rearrangements under reactive conditions in catalysis.

Effect of reactive extrusion processing conditions on the production of potato-resistant starch and its use as an additive in yogurt.

Starch has multiple uses in the food industry as a stabilizer, adhesive, gelling agent, thickener, and water retention agent. Nonetheless, native starch presents limitations that restrict its applications. Thus, starch can be chemically modified by reactive extrusion (REX) to overcome these disadvantages. Additionally, resistant starch (RS) can be obtained by REX and used as an additive to improve the nutritional quality and physicochemical properties of foods. Hence, this research aimed to determine the optimal processing conditions of REX to obtain RS with an adequate degree of substitution (DS) for use as an additive in yogurt. Potato starch was modified with sodium trimetaphosphate and sodium tripolyphosphate. The effects of extrusion temperature (ET=90.00-160.00°C) and moisture content (MC=18.00-30.00%) on the physicochemical properties (water absorption, solubility index, color, and DS) of extrusion-phosphated potato starch (EPPS) were studied. A single-screw laboratory extruder and a central composite rotatable design were employed. Natural yogurt was prepared with EPPS and conventionally phosphorylated starch, and their physicochemical and sensory properties were evaluated. EPPS showed a higher percentage of RS, which can be attributed to mechanical damage and loss of crystallinity due to REX and the formation of phosphodiester bonds and cross-linking. The optimization analysis identified the best processing conditions (107.40°C ET and 30.00% MC) to obtain EPPS with high RS and WAI values and a DS=0.02. This study demonstrated that ET and MC during REX are crucial for obtaining starch with a high percentage of RS. Adding RS obtained through REX improved the yogurt's physicochemical properties and enhanced its sensory characteristics.

Leveraging Machine Learning Potentials for In-Situ Searching of Active sites in Heterogeneous Catalysis.

This Perspective explores the integration of machine learning potentials (MLPs) in the research of heterogeneous catalysis, focusing on their role in identifying in situ active sites and enhancing the understanding of catalytic processes. MLPs utilize extensive databases from high-throughput density functional theory (DFT) calculations to train models that predict atomic configurations, energies, and forces with near-DFT accuracy. These capabilities allow MLPs to handle significantly larger systems and extend simulation times beyond the limitations of traditional ab initio methods. Coupled with global optimization algorithms, MLPs enable systematic investigations across vast structural spaces, making substantial contributions to the modeling of catalyst surface structures under reactive conditions. The review aims to provide a broad introduction to recent advancements and practical guidance on employing MLPs and also showcases several exemplary cases of MLP-driven discoveries related to surface structure changes under reactive conditions and the nature of active sites in heterogeneous catalysis. The prevailing challenges faced by this approach are also discussed.

Optimization of the Parameters for Developing the Buffer Layer By Reactive Magnetron Sputtering in Order to Increase the Performance of a SOFC

Solid oxide cells (SOCs) are electrochemical devices operating at high temperature. This technology can directly convert fuel into electricity (fuel cell mode – SOFC) or electricity into fuel (electrolysis mode – SOEC). In recent years, the interest on SOCs has grown significantly thanks to the need of massive and low-cost production of H2, and their capability of reversible operation.The main objectives still remaining for these electrochemical cells are to enhance their initial performances and to increase their durability. The key parameters are obviously the choice of the materials chosen for the functional electrodes, the electrolyte or the barrier layer, but also the microstructures of each layers. It’s well know that the performances could be improved by decreasing the thickness layers, in particular for the electrolyte and the barrier layer which induce additionnal resistances or by increasing their quality (density for instance). The reference cell, used for this study, consists of Ni-YSZ for the hydrogen electrode, YSZ for the electrolyte, GDC for the barrier layer and LSCF for the oxygen electrode. This cell is produced by screen printing and tape casting;During this work, the production of the GDC barrier layer by physical deposition and more particularly by magnetron cathode sputtering in reactive conditions was studied. The GDC thin film was produced from a metallic target of cerium with 10 atomic % of gadolinium; This layer must have many qualities such as good adhesion, resistant in the conditions of synthesis of the other layers of the cell as well as in the conditions of use, covering, and thin to limit its resistance.The influence of the operating conditions in PVC on the quality of the GDC barrier layer will be discussed such as the bias voltage of the sample holder, the regulation system, the working pressure, etc. for all the synthesis conditions of the SEM observations of raw samples and after heat treatments will be presented; Then, the selected synthesis protocol will be carried out on a reference half-cell (Ni-YSZ/YSZ) and a reference electrode will be deposited using the same method as the reference cell; Electrochemical performance in electrolysis configuration over a temperature range of 700 to 800°C with different flow rate ranges.

Structure Sensitivity and Catalyst Restructuring for CO2 Electro-Reduction on Copper

Cu is the most promising metal catalyst for CO2 electroreduction (CO2RR) to multi-carbon products, but the structure sensitivity of the reaction and the stability versus restructuring of the catalyst surface under reaction conditions are still controversial. Here, atomic scale simulations of surface energies and reaction pathway kinetics supported by experimental evidence unveil that CO2RR does not take place on perfect planar Cu(111) and Cu(100) surfaces but rather on steps or kinks defects, and that these planar surfaces tend to restructure in reaction conditions to the active stepped surfaces. By combining basin hopping global sampling and grand canonical density functional theory, we show that the extremely low CO coverage on (111) and (100) surfaces, originating from sluggish CO2 conversion and unfavorable CO binding, limits the ability of these surfaces to reduce CO2 to multi-carbon products. Steps and kinks at surfaces, despite the lack of decrease in C-C coupling barriers on these sites, exhibit a significant increase in activity arising from beneficial CO2 activation and higher CO coverage. Notably, the square motifs adjacent to defects, not the defects themselves, are the active sites for CO2RR via synergistic effect. In addition, the strong binding of CO on defective sites acts as a thermodynamic driving force for the restructuring of planar surfaces to active stepped terminations under reactive conditions. We evaluate these mechanisms against experiments of CO2RR on UHV-prepared ultraclean Cu surfaces. Overall, our findings highlight the structural sensitivity in steering CO2RR and elucidate the origin of in situ restructuring of Cu catalysts during the reaction. We furthermore feature that the active sites for CO2RR are created under reaction conditions.

Mixing-controlled compression ignition of ethanol using exhaust rebreathe at a low-load operating condition—Single cylinder experiments in a heavy-duty diesel engine

As pollutant emissions regulations in the heavy-duty sector become further stringent, the energy requirements in this sector continue to increase. Due to the high-power density and operating period requirements within this sector, full electrification is challenging. A viable solution to meet the stringent requirements for criteria pollutant and greenhouse gas (GHG) emissions is the use of low carbon renewable fuels. Low carbon renewable fuels are desirable due to their lower carbon content per unit energy compared to conventional fossil diesel fuel. However, implementing some low carbon renewable fuels in the heavy-duty sector poses challenges due to their low reactivity and the prevalent mixing-controlled compression ignition (MCCI) combustion strategy. Because of this, ignition assistance is needed to ignite low reactive renewable fuels in MCCI. This work investigates the use of a variable valve actuation (VVA) strategy, exhaust rebreathe, as an ignition assistance method to ignite pure fuel grade ethanol (E98) in MCCI. Exhaust rebreathe utilizes the hot combustion products from the previous cycle by reinducing the exhaust back into the cylinder during the intake stroke from a secondary exhaust valve event. The reinduction of exhaust into the cylinder increases the in-cylinder bulk gas temperature aiding in the ignitability of the low reactive fuel. The exhaust rebreathe strategy as an ignition assistance method is investigated in this work by conducting single cylinder engine experiments on a heavy-duty diesel engine fueled with E98. Exhaust pressure is varied for the exhaust rebreathe strategy to achieve combustion characteristics with E98 similar to diesel at a low-load, high engine speed operating condition. Additionally, an elevated intake air temperature strategy is implemented to compare to the exhaust rebreathe strategy as another form of ignition assistance with the objective to induce heat in-cylinder prior to combustion without the presence of diluent. Furthermore, zero-dimensional (0D) constant pressure chemical kinetic simulations are conducted to evaluate the most reactive conditions for ethanol to achieve ignition delay times similar to n-heptane. The experimental results demonstrate that at a high speed, low load condition—the elevated intake air temperature strategy with ethanol requires 120°C intake temperature to yield an ignition delay similar to diesel. When accounting for the energy required to heat the intake air, the brake thermal efficiency is 40% lower than the diesel baseline. On the contrary, the exhaust rebreathe strategy with an exhaust pressure of 1.5 bar-a, is able to achieve the same ignition delay with an MCCI combustion process but maintain a brake thermal efficiency within 5% of the baseline diesel engine.

Covalent Modification of Protein by Chemical Probe in Living Cells for Structural and Interaction Studies.

Cellular activities are predominantly carried out by proteins that can dynamically adopt different structural conformations and differentially interact with other biomolecules according to cellular needs. Chemical probes are small molecules used to selectively interact and modulate the activities of specific proteins to study their functions such as the validation of potential drug targets. The remarkable performance of AlphaFold algorithms in the prediction of protein structures has pivoted interest toward elucidating the intracellular dynamics of protein structural conformation where covalent modification of proteins by chemical probes could be used to shed light upon. However, due to the barrier to entry by cell membrane and the general unfavorable reactive conditions of the intracellular environment, most studies using reactive chemical probes are still conducted on purified proteins and cell lysates. Nevertheless, recent progresses have been made in designing chemical probes with improved membrane permeability, stability and reactivity. This paper surveys the literature on recent advancements in membrane-permeable chemical probes and their applications with protein mass spectrometry for the intracellular studies of protein structural conformations and biomolecular interactions.

Structure Equation Model for Costs and Benefits of Distribution Pipe Rehabilitation in Reactive Maintenance

Some water distribution pipe networks were constructed several decades ago and have been damaged. The old pipe network has experienced many leaks and should be rehabilitated. In old cities like Jakarta, with high leak rates (1.6 leaks/km/year), pipeline network managers must frequently repair leaks or perform reactive maintenance. Far too many pipes need to be rehabilitated compared to the available budget. This research will develop an optimization model for selecting rehabilitated pipes under reactive maintenance conditions, which has never been performed before. The selection of pipe segments to be rehabilitated must be optimal to obtain maximum benefits using minimum costs. The variables that influence rehabilitation costs and benefits and the relationship between these variables need to be known to optimize the selection. The influencing variables and their model structure were obtained from literature reviews and surveys of respondents with sufficient experience in water pipe network management. These influential variables have varying characteristics. Data processing and analysis uses the confirmatory factor analysis (CFA) method with a formative–formative measurement model. In total, 22 variables were found to be valid and significantly influenced the cost and benefits of rehabilitation. The analysis results are a structural model of the relationship between variables that influence the costs and benefits of rehabilitation in reactive maintenance with a limited budget, which can be used to optimize rehabilitation models.

Using an ensemble Kalman filter method for a soil nitrogen transport model in the real rice field

The overuse of nitrogen fertilizer in rice field of China leads to nitrogen loss and serious water pollution, so it is vital to accurately predict soil nitrogen transport in rice field. But the prediction errors of soil nitrogen transport are great due to complex chemical and reactive conditions and uncertain parameters in real rice fields. In this study, a prediction model of soil nitrogen transport in a rice field was established via modifying the HYDRUS-1D source code, and a data assimilation method called the ensemble Kalman filtering (EnKF) was coupled, based on the observed NH4+-N and NO3–-N concentrations at different depths in a real rice field. Study results for two different protocols of assimilating observed NH4+-N and NO3–-N concentrations simultaneously and separately were compared. It indicated the predictions accuracy of NH4+-N and NO3–-N concentrations was improved significantly via the EnKF method, and the former protocol is better than the latter. Moreover, for the latter protocol, observations of NO3–-N concentrations were more efficient than NH4+-N to improve the predictions accuracy of NH4+-N and NO3–-N concentrations at different depths. Inversed parameters of urea hydrolysis, NH4+-N volatilization, soil adsorption of NH4+-N, nitrification and denitrification increased over time. On the whole, the inversed model parameters were more stable at deep soil than shallow soil, which were different at different depths. With soil depths increase, parameters of the NH4+-N adsorption and NO3–-N denitrification increased, while parameters of urea hydrolysis, NH4+-N volatilization and nitrification decreased. This study improved the model predictions accuracy and inversed the model parameters, revealing the mechanism of nitrogen loss in real rice fields, which can provide scientific basis to reduce serious environmental problems caused by the overuse of nitrogen fertilizer.

Burner and Flame Transfer Matrices of Jet-Stabilized Flames: Influence of Jet Velocity and Fuel Properties

Abstract To achieve the decarbonization of electrical power generation, gas turbines need to be upgraded to combust high-hydrogen content fuels reliably. One of the main challenges in this upgrade is the burner design. A promising burner concept for a high-hydrogen fuel mixture are jet burners, which are highly flashback resistant thanks to their high bulk velocity. Due to its nonacoustically compact extension and the presence of hydrogen in the fuel mixture, new challenges arise in assessing the (thermo)acoustic response of this burner design. A burner transfer matrix (BTM) and the flame transfer function (FTF) or transfer matrix (FTM) are typically measured with the multimicrophone method (MMM) to assess the performance of new burner types in relation to thermoacoustic stability. With the switch toward hydrogen, the fuel/air mixture is significantly altered in its properties regarding the speed of sound and density, which are of fundamental importance for acoustic waves propagation and their reconstruction via the MMM, as highlighted in recent work. In this work, we extend this discussion by studying the influence of the gas composition within the burner when measuring BTMs, and its indirect effect on the assessment of FTFs. Experimentally, we achieve this by adapting the preheating temperature during the measurement of the BTM with a nonreactive mixture in order to match the speed of sound of the hydrogen–air mixture required to flow in the burner under reactive conditions. Additionally, we present an analytical model for the jet burner transfer matrix, which is validated against the experimental data. Since the BTM is fundamental for the assessment of the FTM and FTF, the propagation of the error of changing fuel mixtures in the burner is evaluated. The influence of the variation in reactant composition of the BTM on the FTM assessment is noticeable, particularly in the gain of the FTFs. Furthermore, the influence of the total mass flow and, thus, the bulk flow velocity on the FTF is analyzed.

Numerical modeling of acoustic scattering characteristic with wavenumber domain admittance

A conversion from the wavenumber domain acoustic reflection coefficient to the wavenumber domain acoustic admittance is formulated to deal with the acoustic reflection properties of arbitrary materials in numerical simulation. This method, which can represent arbitrary reflection directional properties, is an extended reactive boundary condition modelling method based on a spatial Fourier transform over the boundary surface. The advantages are that it is computationally inexpensive because it does not need to consider the interior of the material in the analysis, and that it can handle reflection characteristics obtained from actual measurements, etc. From the results of applying the wavenumber domain acoustic admittance to the numerical analysis, it has been confirmed that the proposed method can handle not only the specular reflection component, but also when arbitrary scattering components are included, or when the main reflection direction is changed from the specular reflection direction.

EVALUATION OF CARBONATED PRODUCT FROM MINERAL CARBONATION OF MINING WASTE FOR CARBON SEQUESTRATION

Mining operations generate significant quantities of waste containing alkaline earth silicates, which are valuable for carbon sequestration. Hence, the goal of this study is to assess the possibility of using mining waste to store carbon through a process of mineral carbonation. The study tested mineral carbonation under low reactivity conditions, including ambient pressure and low temperature, to evaluate the effect of pH levels on process efficiency. The samples were discovered to have an alkaline pH, suggesting that they were suitable for mineral carbonation reactions from the beginning. The carbonation process of the mineral was conducted at different pH levels of 8, 10, and 12. The findings showed that the carbonation efficiency was approximately 3%, with the highest level observed at pH 12. Through thermogravimetric analysis, it was observed that there was a multi stage transformation of minerals, which indicated the formation of carbonates containing iron and magnesium. The process captured approximately 33 and 39 g of CO2/kg. The process indicates that mine waste can be used as a source material for mineral carbonation, as demonstrated by the formation of iron and calcium carbonate products. This research demonstrates that mine waste has the potential for long-term carbon storage, offering a beneficial method for waste management and carbon capture strategies.

SIMULATION HEATING PROCESS FOR WEAKLY REACTIVE COAL IN THE HORIZONTAL REACTOR

In this study results of the active medium parameters influence formed by hot air on the thermal heating process of weakly reactive coal from the formation «Maikubensk 3B» for the extraction of additional heat are represented. In the course of the research the regularities of the hygroscopic moisture and volatile combustible substances release for the obtaining additional heat have been determined. Optimal temperature ranges of the stage heating taking into account thermal destruction of coal in the temperature range from 20 C to 600 C, the main steps of the insulated heating process, the moisture content gradient propagation lines and dependence of the heat transfer and mass transfer coefficients on the temperature and the humidity during the thermal heating process in the horizontal coal heating reactor. The results show that it is possible to release volatile combustible gases with a gradual increase of temperatures in the obtained mode. The heating mode comprises a pre-heating stage with hydroscopic moisture release, in the temperature range from 20 C to 105 C, the stage of isothermal heating in the temperature range from 105 C to 400 C and the phase of flame-free combustion in the temperature range from 400 C to 600 C with the temperature rise above the set value. Process simulation was carried out in the Comsol Multiphisics software environment for the weakly reactive coal real-world heating conditions. Keywords: coal heating, weakly reactive coal, isothermal heating, step-by-step heating, Lagrange method, non-liner equation, non-stationary process.

Fatal Moans and Bones in Crohn's: A Case of Heterotopic Mesenteric Ossification.

Heterotopic mesenteric ossification (HMO) represents a rare reactive condition characterized by abnormal bone formation within the mesentery. HMO's etiology remains enigmatic, with proposed triggers including trauma-induced metaplasia or bone fragment dislodgment from other sites during abdominal surgery. With fewer than 100 documented cases in the literature, much about this condition remains unknown. In this report, we present a notable case of HMO in a 43-year-old man with a history of severe Crohn's disease and multiple abdominal surgeries. Following a period of unresponsiveness at home, he was admitted to the intensive care unit, where he received palliative care due to a poor prognosis. An autopsy revealed mature, benign bone fragments within the mesentery, alongside severe dehydration, likely exacerbated by decreased oral intake and medication cessation related to his ostomy. Although antemortem imaging revealed HMO, it was misattributed to contrast versus calcification. This case underscores the importance of clinician awareness regarding HMO, particularly its potential implications in inflammatory bowel disease. Early recognition and interdisciplinary collaboration among radiologists, pathologists, and clinicians are paramount in optimizing patient outcomes. Further research is warranted to elucidate this intriguing pathology's pathogenesis and best management strategies.

The independent effects of hydrostatic pressure and hypercapnic breathing during water immersion on ventilatory sensitivity and cerebrovascular reactivity.

Head-out water immersion (HOWI) induces ventilatory and hemodynamic changes, which may be a result of hydrostatic pressure, augmented arterial CO2 tension, or a combination of both. We hypothesized that the hydrostatic pressure and elevated CO2 tension that occur during HOWI will contribute to an augmented ventilatory sensitivity to CO2 and an attenuated cerebrovascular reactivity to CO2 during water immersion. Twelve subjects [age: 24 ± 3 yr, body mass index (BMI): 25 ± 3 kg/m2] completed HOWI, waist water immersion with CO2 (WWI + CO2), and WWI, where a rebreathing test was conducted at baseline, 10, 30, and 60 min, and postimmersion. End-tidal pressure of carbon dioxide ([Formula: see text]), minute ventilation, expired gases, blood pressure, heart rate, and middle cerebral artery blood velocity were recorded continuously. [Formula: see text] increased throughout all visits (P ≤ 0.011), was similar during HOWI and WWI + CO2 (P ≥ 0.264), and was greater during WWI + CO2 versus WWI at 10, 30, and 60 min (P < 0.001). When HOWI vs. WWI + CO2 were compared, the change in ventilatory sensitivity to CO2 was different at 10 (0.59 ± 0.34 vs. 0.06 ± 0.23 L/min/mmHg; P < 0.001), 30 (0.58 ± 0.46 vs. 0.15 ± 0.25 L/min/mmHg; P < 0.001), and 60 min (0.63 ± 0.45 vs. 0.16 ± 0.34 L/min/mmHg; P < 0.001), whereas there were no differences between conditions for cerebrovascular reactivity to CO2 (P ≥ 0.163). When WWI + CO2 versus WWI were compared, ventilatory sensitivity to CO2 was not different between conditions (P ≥ 0.642), whereas the change in cerebrovascular reactivity to CO2 was different at 30 min (-0.56 ± 0.38 vs. -0.30 ± 0.25 cm/s/mmHg; P = 0.010). These data indicate that during HOWI, ventilatory sensitivity to CO2 increases due to the hydrostatic pressure, whereas cerebrovascular reactivity to CO2 decreases due to the combined effects of immersion.NEW & NOTEWORTHY Although not fully elucidated, the ventilatory and hemodynamic alterations during water immersion appear to be a result of the combined effects of immersion (i.e., elevated [Formula: see text], central hypervolemia, increased cerebral perfusion, increased work of breathing, etc.). Our findings demonstrate that an augmented ventilatory sensitivity to CO2 during immersion may be due to the hydrostatic pressure across the chest wall, whereas an attenuated cerebrovascular reactivity to CO2 may be due to the combined effects of immersion.

(Invited) In Situ x-Ray Diffraction Studies of the Atomic Structure and Charge Distribution at the Electrochemical Interface

The presence of specifically adsorbed anions can significantly affect the electrochemical reactivity of a metal electrode which is of major interest for galvanic deposition, etching, corrosion and electrocatalysis. In-situ surface x-ray diffraction has enabled an atomic/molecular-level understanding of the interface under reactive conditions, including its potential and time dependence, to be developed. While information about the atomic structure of the electrode surface in electrochemical in-situ cells has been widely investigated, insight into the charge distribution and the structure of the electrolyte at the interface is still lacking. Advances in these directions offer possibilities in elucidating atomic scale models of the electrochemical interface and thus will help to establish structure-stability-reactivity relationships.A fundamental understanding of the nature of the charge transfer, especially the influence of the applied potential and the screening by the electrolyte, is a major goal in electrochemistry to better understand electrochemical processes and charge transfer during adsorption and deposition. [1]Thus, combining x-ray spectroscopy and x-ray diffraction to gain site specific information about the charge distribution at buried interfaces is a promising tool. [2,3]Examples of how the use of surface x-ray scattering techniques can help to characterize electrochemical interfaces in-situ in order to link, structure, reactivity and stability will be presented. [4-5] Advances in these directions offer possibilities in elucidating atomic scale models of the electrochemical interface and thus will help to establish structure-stability-reactivity relationships and to understand growth kinetics and electrochemical phase formation.

Mesothelioma: molecular pathology and biomarkers.

Diffuse mesotheliomas are characterized by recurrent genomic alterations involving tumor suppressors and epigenetic regulators such as BAP1, CDKN2A, MTAP, and NF2. Depending on the differential diagnosis as informed by histologic assessment, one can apply the appropriate immunohistochemical and/or molecular panels to reach the correct pathologic diagnosis, sometimes even in cases with limited tissues. Biomarkers aid in the diagnosis of mesothelioma in the following scenarios: 1)For atumor that is overtly malignant, how can one distinguish mesothelioma from other tumors? 2)For amesothelial proliferation, how can one distinguish mesothelioma from areactive process? To distinguish mesotheliomas from carcinomas, at least two positive and two negative markers are currently recommended. To distinguish sarcomatoid mesothelioma from pleomorphic carcinoma, even more markers-and sometimes molecular testing-are needed. To distinguish mesothelioma from reactive mesothelial conditions, useful immunohistochemical biomarkers include BAP1, MTAP, and merlin, which serve as surrogates for the corresponding gene mutation status. In patients with unusual clinical history, for tumors with apeculiar microscopic appearance, and/or in cases with an equivocal immunophenotypic profile, molecular testing can help to exclude mimics and to confirm the pathologic diagnosis.