Min Time Period Research Articles

Assessment of Thermal Management Using a Phase-Change Material Heat Sink under Cyclic Thermal Loads

Phase-change materials (PCMs) are widely used in the thermal management of electronic devices by effectively lowering the hot end temperature and increasing the energy conversion efficiency. In this article, numerical studies were performed to understand how temperature instability during the periodic utilization of electronic devices affects the heat-dissipation effectiveness of a phase-change material heat sink embedded in an electronic device. Firstly, three amplitudes of 10 °C, 15 °C, and 20 °C for fixed periods of time, namely, 10 min, 20 min, and 40 min, respectively, were performed to investigate the specific effect of amplitude on the PCM melting rate. Next, the amplitude was fixed, and the impact of the period on heat sink performance was evaluated. The results indicate that under the 40 min time period, the averaged melting rate of PCMs with amplitudes of 20 °C, 15 °C, and 10 °C reaches the highest at 19 min, which saves 14 min, 10 min, and 8 min, respectively, compared with the constant input of the same melting rate. At a fixed amplitude of 20 °C, the PCM with a period of 40 min, 20 min, and 10 min has the highest averaged melting rate at 6 min, 11 min, and 19 min, saving the heat dissipation time of 3 min, 8 min, and 14 min, respectively. Overall, it was observed that under identical amplitude conditions, the peak melting rate remains consistent, with longer periods resulting in a longer promotion of melting. On the other hand, under similar conditions, larger amplitude values result in faster melting rates. This is attributed to the fact that the period increases the heat flux output by extending the temperature rise, while the amplitude affects the heat flux by adjusting the temperature.

Operation time and clinical outcomes for open infrarenal abdominal aortic aneurysms to remain stable in the endovascular era.

Endovascular aortic repair (EVAR) has become a routine procedure worldwide. Ultimately, the increasing number of EVAR cases entails changing conditions for open surgical repair (OSR) regarding patient selection, complexity, and surgical volume. This study aimed to assess the time trends of open abdominal aortic aneurysm (AAA) repair in a high-volume single center in Austria over a period of 20 years, focusing on the operation time and clinical outcomes. A retrospective analysis of all patients treated for infrarenal AAAs with OSR or EVAR between January 2000 and December 2019 was performed. Infrarenal AAA was defined as the presence of a >10-mm aortic neck. Cases with ruptured or juxtarenal AAAs were excluded from the analysis. Two cohorts of patients treated with OSR at different time periods, namely, 2000-2009 and 2010-2019, were assessed regarding demographical and procedure details and clinical outcomes. The time periods were defined based on the increasing single-center trend toward the EVAR approach from 2010 onward. A total of 743 OSR and 766 EVAR procedures were performed. Of OSR cases, 589 were infrarenal AAAs. Over time, the EVAR to OSR ratio was stable at around 50:50 (p = 0.488). After 2010, history of coronary arterial bypass (13.4% vs. 7.2%, p = 0.027), coronary artery disease (38.1% vs. 25.1%, p = 0.004), peripheral vascular disease (35.1% vs. 21.3%, p = 0.001), and smoking (61.6% vs. 34.3%, p < 0.001) decreased significantly. Age decreased from 68 to 66 years (p = 0.023). The operation time for OSR remained stable (215 vs. 225 min, first vs. second time period, respectively, p = 0.354). The intraoperative (5.8% vs. 7.2%, p = 0.502) and postoperative (18.3% vs. 20.8%, p = 0.479) complication rates also remained stable. The 30-day mortality rate did not change over both time periods (3.0% vs. 2.4%, p = 0.666). Balanced EVAR to OSR ratio, similar complexity of cases, and volume over the two decades in OSR showed stable OSR time without compromise in clinical outcomes.

Phytochemical Screening and Pharmacological Evaluation of the Methanolic Extract of Cissus Elongata Roxb. Leaves

This study evaluates the pharmacological activity of the methanolic extract of Cissus elongata Roxb. leaves. Dried leaves of C. elongata were extracted with methanol. The crude extract was then tested to identify the presence of different phytoconstituents. To evaluate the pharmacological effects of this plant- analgesic, anti-diarrheal, anti-inflammatory and antipyretic, tests were conducted using animal models. Analgesic activity was evaluated by an acetic acid-induced writhing test, formalin-induced paw-licking test paw-licking immersion test. Castor oil-induced anti-diarrheal test was performed to evaluate anti-diarrheal activity. Xylene-induced ear edema and brewer’s yeast-induced pyrexia test were performed to investigate anti-inflammatory and antipyretic activity respectively. Phytochemical screening revealed the presence of carbohydrates, tannins, fat, and fixed oil. In writhing test, the extract showed 45.68±3.99 % and 52.28±1.67 % inhibition of writhing at a dose of 200 mg/kg and 400 mg/kg respectively whereas it was 73.09±1.01 % for the standard drug compared to the control group. In the formalin-induced paw-licking test, the percentage inhibition of licking by both doses of the extract was more in the delayed phase than in the acute phase. In the tail immersion test, 200 mg/kg dose didn’t show a significant effect but 40 0mg/kg showed significant (*P&lt;0.05 vs. control) analgesic activity at 30 min, 60 min and 120 min time periods. In an anti-diarrheal study, 400 mg/kg dose showed (68.42±0.87 % inhibition of diarrhea) almost similar anti-diarrheal effect as the standard drug loperamide HCl (71.05±0.58 %). In xylene induced ear edema test, both doses of the extract showed little anti-inflammatory effect compared to the standard drug but both doses showed significant (*P&lt;0.05 vs. control) reduction in body temperature in the antipyretic study.

DEVELOPMENT AND PERFORMANCE ANALYSIS OF Ni–15Cr2O3–5TiO2 AND Ni–15Al2O3–5TiO2 HVOF COATINGS IN EROSIVE FLY ASH SLURRY

This study is focused on improving the mechanical properties and slurry erosion resistance of traditional Ni–20Al2O3 and Ni–20Cr2O3 thermal spray coatings by reducing the 5% of Al2O3 and Cr2O3, respectively, and addition of 5% TiO2 feedstock in both coatings. Thermal sprayed powders were thermally sprayed on SS-420 substrates with high-velocity oxy-fuel (HVOF) method. A lab-scale pot tester was used to conduct the wear testing at low rotating speeds of 750, 1000, 1250, and 1500 rpm. To create severe accelerated conditions, a high mass flux (35–50 wt.%) of fly ash particles was used. Multi-sized fly ash slurries ranging from [Formula: see text][Formula: see text][Formula: see text]m to 250[Formula: see text][Formula: see text]m were used during the experiments to evaluate the impact of particle size fraction on the erosion over a 30–120 min time-period. Coatings’ surface characterization was done to examine more about their composition. According to the findings, the addition of 5% TiO2 powder to both Ni–15%Al2O3 and Ni–15%Cr2O3 coatings significantly improved their wear resistance of SS-420. This occurred because of the enhancement of hardness as well as brittleness by 5% TiO2 in matrix of Ni–15%Cr2O3 and Ni–15%Al2O3 coatings. Moreover, TiO2 particles aid in strengthening of Cr2O3 and Al2O3 reinforcements and the binding with matrix. Also, the results showed that Ni–15Cr2O3–5TiO2 coating showed superior wear resistance compared to Ni–15Al2O3–5TiO2 coating.

Dual Delivery of Cyclosporin A and Etodolac Using Polymeric Nanocapsules in a Rabbit Eye Model: Ocular Biodistribution and Pharmacokinetic Study.

Purpose: Commercially available eye drops are loaded only with a single drug. By using the polymeric nanocapsules, dual delivery of 0.05% w/w cyclosporin A (CsA) and 0.2% w/w etodolac (Edc) was achieved. An ultraperformance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method was developed for determining simultaneously the biodistribution and pharmacokinetic profile of CsA and Edc in ocular tissues. Methods: After one single drop instillation of nanocapsules into healthy right eyes of rabbits, the eyeballs were enucleated at 5, 15, 30, 60, and 90 min time periods to separate the 5 different ocular tissues. A liquid/liquid extraction method was used for ocular sample extraction using darunavir as internal standard. Using 3 diverse conditions such as bench-top, autosampler, and freeze-thaw, the stability of the analytes at 3 quality control samples in ocular tissues was also checked. Results: Intra- and interday precisions for both CsA and Edc in multiple ocular tissues were <10.32%, and the accuracy was <11.98%. The % bias and % RSD values for CsA and Edc were found within the acceptable limit of ±15%. The highest Cmax values were attained in cornea for both the drugs at 60 min postinstillation time point. Despite molecular size and structural differences, both CsA and Edc after liberation from nanocapsule drops can permeate into the tissues of the anterior as well as posterior segments of the eye. Conclusion: The biodistribution and pharmacokinetic data might help and strengthen our understanding of synergetic anti-inflammatory activity of CsA and Edc from nanocapsules after its ocular topical application for managing keratoconjunctivitis sicca.

Reduction of Water Color in a Spinning Disc Reactor

In this study, spinning disc (SD) technology was successfully applied to a synthetic water to remove its color. The preliminary data performed in a regular mixing system using a potential adsorptive material, i.e., double-layered hydroxide of a ZnAlLDH type, did not provide a significant decrease (no more than 10–15%) in the water color content. Thus, ZnAlLDH (2 g/L) was added to the synthetic water containing 50 mg/L Rosso Remazol RB dye that was subsequently fed onto the spinning disc. The SD efficiency was investigated at four different water-supplying flow rates (5.76, 6.00, 7.44 and 8.16 L/h) and four different disc rotational speeds (100, 250, 500 and 800 rpm). The best color removals of 44.39%, 41.14% and 42.70% were obtained at 6 L/h and 250 rpm, 6 L/h and 500 rpm and 5.76 L/min and 800 rpm, respectively, in only a 50 min working time period. In addition, for a relatively low color concentration in water (~30 mg/L dye) and at the lowest electric power consumption, Fenton oxidation was performed in the SD setup for a more advanced color removal of 62.54% within a 50 min time period. Furthermore, two other materials, titanium and aluminium oxides, underwent similar investigations in the SDR setup, and the obtained results were comparatively discussed. The FTIR spectra of each solid material before and after the SD technology application were used to appreciate the dye-retention performance of each material used. The obtained results indicated that the spinning disc technology correlated with the tested materials could significantly improve the water color (over 40% color reduction), this level of color reduction being higher than that obtained following a coagulation–flocculation test (20–28% color reduction), an ion exchange (25–30% color removal) or a sand filtration step (15–20%) applied to the same dye-based water sample. A further increase in color removal could be achieved by using an additional oxidative step (more than 65% color reduction).

The Bacterial Disinfection of Water Using a Galloping Piezoelectric Wind Energy Harvester

In this study, a method for the bacterial disinfection of drinking water in the water storage systems based on the electric potential generated from a piezoelectric wind energy harvester is presented. First, an efficient galloping piezoelectric wind energy harvester is designed by adding curve- shaped attachments to the bluff body of the harvester. The simulated output voltage of the harvester is validated by performing different sets of experiments on an open environment. Later, the output voltage of the harvester is enhanced, using copper oxide nanowires (CuONWs) grown perpendicular to the surface of the center copper wire. The enhanced electric field is able to disinfect the bacterial water in a 25 min time period. The bacterial removal log efficiency of 2.33 is obtained with a supplied rms voltage of 0.1 V from the harvester. The findings of this study will help to provide alternate means to water treatment that are efficient, reliable, and also free from disinfection by-products.

(Digital Presentation) Time-Resolved Operando XAS of FexNi100-XOy Electrocatalysts for the Oxygen Evolution Reaction Reveals Temporal Shift in Ni K-Edge during Ni2+/3+ Redox Reaction

FexNi100-xOy electrocatalysts have become a focus for alkaline water electrolysis and the oxidative half reaction of oxygen evolution. Under alkaline conditions, the oxygen evolution reaction (OER) can be promoted by non-precious metal oxide and hydroxide electrocatalysts. In particular, electrocatalyst compositions from first row late transition metals such as iron, nickel, manganese, and cobalt have emerged as some of the most active catalysts for the OER, and the role of iron has been identified as key within multi-metallic compositions. In our research, we have focused specifically on the iron-nickel bimetallic composition and have developed synthesis methods to be able to control the bimetallic composition, surface chemistry, and three-dimensional morphology of a suite of FexNi100-xOy nanoparticle electrocatalysts. With this subset of highly-active FexNi100-xOy nanoparticle electrocatalysts, we have recently been focused on operando x-ray absorption spectroscopy (XAS) studies to understand how the chemistry of the iron and nickel species within these nanocatalysts changes as a result of exposure to the electrochemical environment. This talk will focus on a set of operando data obtained with a quick scan detector at beamline 9-3 at SSRL, where we were able to capture temporal, dynamic changes to the nickel chemistry as a function of applied voltage in the Faradaic region of the OER. Specifically, we have captured the change in the Ni K-edge that occurs as a result of the voltage stepping through the Ni redox reaction, where the Ni species in our electrocatalyst oxidizes from a 2+ to a 3+/4+ oxidation state. This redox reaction is associated with a phase transition from Ni(OH)2 to NiOOH. Our measurements were able to obtain 90 s scans during a 15 min time period of measurement, where we find that the Ni redox reaction and phase transition occurs during the first 10 minutes of measurement. Modeling of the extended x-ray absorption fine structure (EXAFS) region suggests that both Ni – O and Ni – M (M = metal) scattering path atomic pairs undergo a compression in distance. Further, the time scale of the phase transition suggests that the Ni redox reaction is mass transport limited. In this talk, I will discuss these results and present our analysis of the time-resolved x-ray absorption spectroscopy data.

Schumann resonance data processing programs and four-year measurements from Sierra Nevada ELF station

In this work, we present to the scientific community the measurements taken during four years, from March 2013 to February 2017 inclusive, by the Extremely Low Frequency Sierra Nevada station, Spain, together with the data processing programs developed in Python (version 3.8) to extract the Schumann resonance (SR) parameters (i.e., amplitudes, resonant frequencies, resonance widths) in 10 min time periods from these records. The measurements correspond to the voltage induced by the atmospheric electromagnetic field at the north-south and east-west oriented magnetometers of the station. The process comprises four stages. The spectrum, calibrated in the frequency band ranging from 6 Hz to 25 Hz, is obtained at the first stage using the Welch method with Hann windows. The second step eliminates the anthropogenic noise generated by different undesired sources. Next, a non-linear fit of the measured spectrum combining Lorentzian functions together with a linear term is carried out in order to identify the presence of SRs and quantitatively characterize them. This third step is carried out using the Python package Lmfit, which implements the Levenberg-Marquad algorithm. Finally, a compact and easy-to-read output is generated at the fourth stage, using the power of the Numpy arrays and the npz format. In addition, four Jupyter notebooks with the description of the code and the possibility of their use in interactive mode are presented as supplementary material with this paper.

Renewable energy based freshwater production utilizing reverse osmosis desalination

ABSTRACT The ever-increasing need for fresh water sources puts pressure on researchers to seek new freshwater generation solutions. Amongst them, renewable energy-based applications are attracting increasing interest due to their environmentally friendly nature. In this study, a new approach is proposed that combines renewable energy production system with the reverse osmosis desalination plant. Especially for offshore locations, one of the main problems is to access both energy and fresh water sources. In this study, the wave energy conversion system is used in order to provide a clean energy source for a reverse osmosis desalination-based plant solution. The wave energy converter system is modeled with consideration of a set of irregular sea wave elevation data. The proposed controller of the wave energy converter system adjusts the tuning parameters of the power take-off unit to optimize the operation of the system. The captured power from wave energy conversion system is utilized to produce fresh water from the reverse osmosis-based desalination model. The simulation results indicate that for 20 min time period, the produced water levels in the storage tanks are about 54.8 m3, 97.6 m3, 110.6 m3, and 193.3 m3 for DS1, DS2, DS3, and DS4, respectively. While, one of the main problems to be solved is the mismatch between the produced power by the renewable energy-based system and the required power consumed by the desalination plant. The proposed approach presented in this study indicates that the operation of the two systems in combined manner can be much more feasible solution as it is a very much environmentally friendly and an effective solution.

Enhanced erosion resistance of cement-treated bricks using multiple biological surface treatments

Water erosion can deteriorate cement-treated bricks. The goal of this study was to investigate the use of multiple biological surface treatments (BSTs) on cement-treated bricks to enhance their resistance to water erosion. Calcite crystals were precipitated on the surface of cement-treated sand bricks by the microbial-induced calcite precipitation (MICP) technique. Multiple BSTs with MICP were used to enhance the properties of the cement-treated bricks further. The experimental results showed that, after a single BST, the flexural strength of the cement-treated bricks increased from 500 kPa to 750 kPa and the compressive strength increased from 3000 kPa to 4000 kPa. Erosion and water absorption were reduced by 71.2% and 16.3%, respectively. Compared with cement-treated bricks without any BST, the cement-treated bricks with triple MICP BSTs showed increases of nearly 140% and 100% in peak flexural and compressive strength, respectively. In addition, the triple BSTs resulted in 32% less water absorption compared with cement-treated samples without any BST. The surface of cement-treated bricks with triple BSTs was found to resist accelerated erosion over a 60 min time period. Overall, the results showed that BST can strengthen the erosion resistance of cement-treated bricks.

Controlled functionalisation of graphene oxide using ethylene diamine: a one‐pot synthesis approach for chromium sorption

Introduction of ethylene diamine into the layers of graphene oxide was achieved through direct compounding method. Graphene oxide intercalated with ethylene diamine was characterised by Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermo gravimetric analysis (TGA) and scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM-EDX) techniques. The efficiency of the material in adsorbing chromium was evaluated through batch scale studies by optimising parameters like pH, concentration and contact time. The material renders a monolayer adsorption capacity of 69.93 mg/g, at pH 1 within 60 min time period for a minimal dosage of 0.05 g. The ethylene diamine modified graphene oxide thus appeals to be a promising adsorbent for environmental applications.

Mechanical Activation on Bioleaching of Chalcopyrite: A New Insight

Mechanical activation as a means of accelerating the mineral dissolution may play an important role in chalcopyrite bioleaching. In the present work, the mechanical activation by ball-milling with 10 min, 30 min, 60 min, 90 min, 120 min and 180 min time periods of bioleaching of chalcopyrite was studied, and then evaluated by a Density Functional Theory (DFT) calculation. The results showed that the specific surface area increased sharply in the very beginning of mechanical activation and then increased slowly until the agglomeration of the particles occurred, while the chalcopyrite lattices increased with the mechanical activation. The reaction activity analyzed by cyclic voltammetry (CV) increased slowly in 30 min, increased quickly in the following 90 min, and then decreased, while the hydrophobicity analyzed by contact angles of the chalcopyrite after activation showed less of a change. The results showed that after 15 days of bioleaching, the Cu leaching by Sulfobacillus thermosulfidooxidans (S. thermosulfidooxidans) increased from 9.39% in the 0 min of mechanical activation to 87.41% in the 120 min of mechanical activation, and the copper leaching rate increased by about 78%. The DFT results provide solid proof that the activated chalcopyrite can be adsorbed more easily by cells with higher adsorption energies and stronger bonds.

Impact of the adsorbent material on volatile metabolites during in vitro and in vivo bio-sampling

The increased attraction of biological volatile compounds has opened the route to a wide variety of sampling techniques, amongst which trap tubes packed with adsorbent materials are commonly used. Many types of adsorbent materials are available and the choice of the adsorbent can impact the obtained results in untargeted analysis. Therefore, a proper combination of the adsorbent material and the sample is necessary to increase the robustness and reproducibility of biological studies. In this study, the sampling performance of thermal desorption tubes with six common adsorbent material combinations, i.e., Tenax® TA, Tenax® TA/Carbopack™ B, Tenax® TA/Sulficarb, Tenax® TA/Carbograph™ 5TD, Tenax® TA/Carbograph™ 1TD/Carboxen® 1003, and Carboxen® 1016/Carbograph™ 5TD, was evaluated in two different setups: in vitro and in vivo sampling. The in vitro setup consisted of the headspace dynamic extraction of spiked serum, and a mixture of 19 standards was evaluated in terms of response and reproducibility. The in vivo setup consisted into two parts: the first one was based the evaluation of the standard mixture, which was flash-vaporised into Tedlar® bags containing exhaled breath; the second part was based on the longitudinal monitoring of breath metabolites originating from a beverage intake (i.e., brewed coffee), over a 90 min time period. The tubes were all desorbed and analysed in a comprehensive two-dimensional gas chromatography system coupled to a high-resolution time-of-flight mass spectrometer (GC × GC-HR ToF MS). In both sampling setups, the widest analytes coverage and the overall best extraction yield on the selected compounds were obtained using Tenax® TA, followed by Tenax® TA/Carbopack™ B. Tenax® TA provided the highest sampling reproducibility with 12 %RSD, 10 %RSD and <5 %RSD of the response during the experiments using the in vitro setup, the in vivo setup, and during the longitudinal tracking, respectively.

Interplay of Adsorption, Supersaturation and the Presence of an Absorptive Sink on Drug Release from Mesoporous Silica-Based Formulations.

Mesoporous silica-based formulations of poorly soluble drugs may exhibit incomplete drug release due to drug remaining adsorbed on the silica surface. The goal of this study was (1) to evaluate the adsorption tendency of atazanavir from aqueous solution onto mesoporous silica (SBA-15) and (2) to determine if the drug release from mesoporous silica formulations was promoted by the presence of an absorptive compartment during dissolution testing. Atazanavir (ATZ) formulations with different drug loadings were prepared by incipient impregnation. The solid-state properties of the formulations were analyzed by X-ray diffraction (XRD), differential scanning calorimetry (DSC), infrared spectroscopy and thermogravimetric analysis. Drug release was compared for closed compartment versus absorptive dissolution testing at gastric and intestinal pH. XRD and DSC showed that all formulations were amorphous. Infrared spectra indicated intermolecular interactions between silanol groups in SBA-15 and carbonyl groups in atazanavir. Nanoconfinement of drug in silica mesopores was suggested by thermal analysis. Closed compartment dissolution testing showed incomplete drug release, largely due to theadsorption tendency of ATZ. However, coupled dissolution-absorption studies showed complete release over a 240min time period. This suggested that the depletion of drug in the dissolution medium due to drug diffusion across the membrane promotes drug release. Drug release was further improved when the formulation was first added to fasted state gastric pH conditions followed by pH-shift to intestinal conditions, which was attributed to the higher solubility of atazanavir at low pH. However, ATZ mesoporous silica formulations showed a poorer overall absorption behavior relative to a polymer-based amorphous solid dispersion formulation. This study highlights that absorptive dissolutionconditions promote drug desorption from the silica surface and hence, enhance drug release. Further, the influence of solution pH on drug release underscores the need to consider how variations in physiological conditions may impact the performance of mesoporous silica-based formulations. Graphical Abstract Drug release and adsorption tendency in the absence and presence of an absorptive sink during dissolution testing.

Type 1 Diabetes Results in Significant Purinergic Receptor Remodeling in Podocytes

P2 (purinergic) receptors have been proposed to be potential viable targets for the treatment of various cardiovascular and renal disorders. Previous studies in our lab have demonstrated that the predominant purinergic signaling pathway in healthy podocytes is through P2Y1 metabotropic receptors. It was also reported that expression of purinergic receptors in different tissues, including kidney, is dynamic and might be changed under pathological conditions such as diabetic nephropathy. We hypothesized that prolonged type 1 diabetes (T1D) would result in substantial changes to podocyte purinergic calcium signaling and result in a transition from predominantly metabotropic signaling through P2Y1 to increased ionotropic signaling through P2X receptors. To do this we utilized the established T1D model of streptozocin‐injected Dahl Salt Sensitive (SS) rats, and measured intracellular calcium ([Ca2+]i) signaling in podocytes from their freshly isolated glomeruli. We determined that in comparison to non‐diabetic rats, which have a rapid elevation of [Ca2+]i levels in response to ATP (40 μM) that returns to baseline within 2 min, podocytes from T1D rats had reduced peak response amplitudes (0.53 ± 0.04 vs. 0.34±0.02, p&lt;0.001). Furthermore, podocytes of glomeruli isolated from diabetic rats had prolonged sustained elevation of [Ca2+]i level, which was not observed in non‐diabetic rats. Additionally, we used P2 specific antagonists to determine which receptors resulted in the altered calcium response curve in T1D podocytes. We found that pharmacological inhibition of P2X7 and P2X4 (10 μM A438079 and 5‐BDBD, respectively) altered the calcium curve dynamics, but did not significantly reduce the total [Ca2+]i level over a 5 min time period, as determined by area under the curve (AUC) measurements. Similarly, inhibition of P2Y1 (1 μM MRS2500) changed the [Ca2+]i curve response, but did not reduce the AUC. Combining both P2X7 and P2X4 inhibitors reduced the AUC; however, did not completely eliminate podocyte purinergic signaling (51.42 ± 5.52 vs 30.39 ± 5.00). Combined inhibition of P2X7, P2X4, and P2Y1 resulted in the near complete elimination of [Ca2+]i release in response to ATP (AUC, 51.42 ± 5.52 vs 10.57 ± 2.56, p&lt;0.001). These results demonstrate that T1D increases ionotropic purinergic signaling in podocytes; however, does not eliminate metabotropic signaling. These studies establish the potential for targeting both P2X4 and P2X7 for therapeutic intervention in T1D.Support or Funding InformationNational Institutes of Health grants T32 HL134643 and R35 HL135749, and Department of Veteran Affairs I01 BX004024

Non‐invasive Targeted Gastric Vagal Complex Stimulation: Preliminary in Human Cutaneous Measures of Gastric Slow Wave Function

Gastric slow wave abnormalities have been associated with upper gastrointestinal motility disorders. Invasive studies in humans have described normal and abnormal propagation of the gastric slow wave, and recent non‐invasive studies have shown that multi‐electrode cutaneous measures of gastric slow wave function correlate with symptom severity in patients with gastroparesis and functional dyspepsia (Gharibans et al, Clinical Gastroenterology and Hepatology, 2019). Invasive Neurostimulation of gastric Vagal complexes are thought to result in satiety (Abiliti, Transcend), anti‐nausea (Entera) and general weight loss (vBLOC), but effects of invasive neuromodulation on gastric motility are not clear. Our group developed: 1) a wearable non‐invasive electrogastrography (EGG) device that reliably records gastric slow wave function and 2) a new non‐invasive targeted gastric Vagus nerve stimulation (ntG‐VNS) system. The challenge is to further develop a combined ntG‐VNS/EGG system that may be used as a tool to probe Gastric disease states, and eventually diagnose and or treat gastric motility disorders.MethodsA 10 lead ambulatory high resolution electrogastrogram (AHR‐EGG) system for ambulatory use (Gharibans et al, Scientific Reports, 2018) was used to record gastric myolectric activity cutaneously (Fig 1A). The gastric proximal fundus was visualized at a depth of 2cm using a Butterfly high frequency transducer at 1–5MHz (Fig 1b) and guided stimulator electrode placement. After fundus localization ntG‐VNS was applied inferior to the lower sternum with 2 (0.5 inch) disk electrodes 0.5 inch apart in rostral caudal orientation (Fig 1A) utilizing short pulsed intermittent stimulation for 14 minutes during simultaneous EGG. Cutaneous recordings were sampled at 250Hz, filtered below 0.15Hz and down‐sampled to 1Hz. Artifact rejection methods as described in (Gharibans et al, Scientific Reports, 2018) were next applied, followed by median filtering of the 0.05Hz power derived from spectrograms across all electrodes to derive EGG power. Baseline activity was derived from percentiles of power across the recording, and was subtracted to derive normalized EGG power to be used for subsequent analysis.ResultsEGG power prior to nTG‐VNS showed a center frequency of .0493 Hz (Fig 2A). Post nTG‐VNS EGG showed highly significant reduction of slow wave power (Fig 2B), below the baseline pre‐stimulation levels.ConclusionntG‐VNS immediately abolishes gastric slow wave propagation as measured by non‐invasive AHR‐EGG over a 14 min time period. Taken together, targeted non‐invasive gastric vagus nerve stimulation technology may prove to be a valuable human research tool, focused on improving our fundamental understanding of gastric motility vagal reflexes.Support or Funding InformationThis work was in part supported by the U.S. Department of Health and Human Services, Biological Advanced Research and Development Authority, BARDA: (75A50119C00038)Figure 1Figure 2

Rice and wheat yield and soil potassium changes in response to potassium management in two soil types

The soil non-exchangeable potassium (K) pool contributes significantly to meeting crop K requirements. The objective of this study was to determine wheat and rice grain yield responses to different concentrations of sodium tetraphenylboron (NaTPB) extractable non-exchangeable K in soils. A field experiment was conducted over a period of 4 years using three K application strategies in soils with high (JY) and low (GD) levels of non-exchangeable K. In both soils, rice yield was unaffected by K application during the 4-year study period. However, in GD soil, wheat was unable to produce grains without K additions (0 K) during the fourth wheat season. In JY soil, wheat grain yield decreased only in the 0 K (by 11%) compared with the recommended K application during the fourth wheat season. Different responses in wheat between the two soils indicated that NaTPB-non-exchangeable K better represented the soil K supplying capacity than it did exchangeable K. Lower amounts of non-exchangeable K extracted by NaTPB in GD soil were mainly due to lower amounts extracted during the 0–5 s and 5–10 min time periods. Straw retention alone resulted in negative K balances, with 100 kg K ha−1 yr−1 in JY soil and 95 kg ha−1 yr−1 in GD soil. In conclusion, recommended K application combined with NaTPB-K monitoring would be useful for sustaining crop yield and soil K fertility among different soils in rice–wheat cropping systems.

Generation of coherent broadband high photon flux continua in the XUV with a sub-two-cycle fiber laser.

High harmonic sources can provide ultrashort pulses of coherent radiation in the XUV and X-ray spectral region. In this paper we utilize a sub-two-cycle femtosecond fiber laser to efficiently generate a broadband continuum of high-order harmonics between 70 eV and 120 eV. The average power delivered by this source ranges from > 0.2 µW/eV at 80 eV to >0.03 µW/eV at 120 eV. At 92 eV (13.5 nm wavelength), we measured a coherent record-high average power of 0.1 µW/eV, which corresponds to 7 · 109 ph/s/eV, with a long-term stability of 0.8% rms deviation over a 20 min time period. The presented approach is average power scalable and promises up to 1011 ph/s/eV in the near future. With additional carrier-envelop phase control even isolated attosecond pulses can be expected from such sources. The combination of high flux, high photon energy and ultrashort (sub-) fs duration will enable photon-hungry time-resolved and multidimensional studies.

Labile Heme Aggravates Renal Inflammation and Complement Activation After Ischemia Reperfusion Injury.

Background: Ischemia reperfusion injury (IRI) plays a major role in solid organ transplantation. The length of warm ischemia time is critical for the extent of tissue damage in renal IRI. In this experimental study we hypothesized that local release of labile heme in renal tissue is triggered by the duration of warm ischemia (15 vs. 45 min IRI) and mediates complement activation, cytokine release, and inflammation.Methods: To induce IRI, renal pedicle clamping was performed in male C57BL/6 mice for short (15 min) or prolonged (45 min) time periods. Two and 24 h after experimental ischemia tissue injury labile heme levels in the kidney were determined with an apo-horseradish peroxidase assay. Moreover, renal injury, cytokines, and C5a and C3a receptor (C5aR, C3aR) expression were determined by histology, immunohistochemistry and qPCR, respectively. In addition, in vitro studies stimulating bone marrow-derived macrophages with LPS and the combination of LPS and heme were performed and cytokine expression was measured.Results: Inflammation and local tissue injury correlated with the duration of warm ischemia time. Labile heme concentrations in renal tissue were significantly higher after prolonged (45 min) as compared to short (15 min) IRI. Notably, expression of the inducible heme-degrading enzyme heme oxygenase-1 (HO-1) was up-regulated in kidneys after prolonged, but not after short IRI. C5aR, the pro-inflammatory cytokines IL-6 and TNF-α as well as pERK were up-regulated after prolonged, but not after short ischemia times. Consecutively, neutrophil infiltration and up-regulation of pro-fibrotic cytokines such as CTGF and PAI were more pronounced in prolonged IRI in comparison to short IRI. In vitro stimulation of macrophages with LPS revealed that IL-6 expression was enhanced in the presence of heme. Finally, administration of the heme scavenger human serum albumin (HSA) reduced the expression of pro-inflammatory cytokines, C3a receptor and improved tubular function indicated by enhanced alpha 1 microglobulin (A1M) absorption after IRI.Conclusions: Our data show that prolonged duration of warm ischemia time increased labile heme levels in the kidney, which correlates with IRI-dependent inflammation and up-regulation of anaphylatoxin receptor expression.