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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,081 records · Page 60
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Domain Wall Patterning and Giant Response Functions in Ferrimagnetic Spinels

Abstract The manipulation of mesoscale domain wall phenomena has emerged as a powerful strategy for designing ferroelectric responses in functional devices, but its full potential is not yet realized in the field of magnetism. This work shows a direct connection between magnetic response functions in mechanically strained samples of Mn 3 O 4 and MnV 2 O 4 and stripe‐like patternings of the bulk magnetization which appear below known magnetostructural transitions. Building off previous magnetic force microscopy data, a small‐angle neutron scattering is used to show that these patterns represent distinctive magnetic phenomena which extend throughout the bulk of two separate materials, and further are controllable via applied magnetic field and mechanical stress. These results are unambiguously connected to the anomalously large magnetoelastic and magnetodielectric response functions reported for these materials, by performing susceptibility measurements on the same crystals and directly correlating local and macroscopic data.

36 MATERIALS SCIENCE↗
DOE OSTI2018

Distinct progression pattern of susceptibility MRI in the substantia nigra of Parkinson's patients

Abstract Background: Susceptibility MRI may capture Parkinson's disease‐related pathology. This study delineated longitudinal changes in different substantia nigra regions. Methods: Seventy‐two PD patients and 62 controls were studied at both baseline and after 18 months with MRI. R2* and quantitative susceptibility mapping values from the substantia nigra pars compacta and substantia nigra pars reticulata were calculated. Mixed‐effects models compared controls with PD or PD subgroups having different disease durations: early (<1 year), middle (<5 years, middle‐stage PD), and late (>5 years, late‐stage PD). Pearson's correlation assessed associations between imaging and clinical measures. Results: At baseline, R2* and quantitative susceptibility mapping were higher in both the substantia nigra pars compacta and substantia nigra pars reticulata in all PD patients (group effect, P ≤ 0.003). Longitudinally, the substantia nigra pars compacta R2* showed a faster increase in PD compared with controls (time × group, P = 0.002), whereas quantitative susceptibility mapping did not ( P = 0.668). The substantia nigra pars reticulata R2* and quantitative susceptibility mapping did not differ between PD and controls (time × group, P ≥ 0.084), although both decreased longitudinally (time effect, P ≤ 0.004). Baseline substantia nigra pars compacta R2* was higher in all PD subgroups (group, P ≤ 0.006), but showed a significantly faster increase only in later‐stage PD (time × group, P < 0.0001) that correlated with changes in nonmotor symptoms ( r = 0.746, P = 0.002). Baseline substantia nigra pars reticulata quantitative susceptibility mapping was higher in middle‐stage PD and later‐stage PD (group, P ≤ 0.002), but showed a longitudinal decrease (time × group, P = 0.004) only in later‐stage PD that correlated with changes in motor signs ( r = 0.837, P < 0.001). Conclusion: Susceptibility MRI revealed distinct patterns of PD progression in the substantia nigra pars compacta and substantia nigra pars reticulata. The different patterns are particularly clear in later‐stage patients. These findings may resolve past controversies and have implications in the pathophysiological processes during PD progression. © 2018 International Parkinson and Movement Disorder Society

Du, Guangwei↗
DOE OSTI2015

A prediction of dislocation‐free CdTe/CdS photovoltaic multilayers via nano‐patterning and composition grading

Abstract Defects in multilayered films have long been a performance‐limiting problem for the semiconductor industry. For instance, CdTe/CdS solar cell efficiencies have had significant improvement in the past 15years or more without addressing the problem of high misfit dislocation densities. Overcoming this stagnation requires a fundamental understanding of interfacial defect formation. Herein, we demonstrate a new first principles‐based CdTe bond‐order approach that enables efficient molecular dynamics to approach the fidelity of density functional theory. Stringent quantum‐mechanical verification and experimental validation tests reveal that our new approach provides an accurate prediction of defects that earlier methods cannot. Using this new capability, we show that misfit dislocations in CdTe/CdS multilayers can be significantly reduced via nano‐patterning and composition grading and more importantly, dislocation‐free multilayers naturally arise when the pattern dimension is reduced below 90nm. Our predictive methods are generally applicable to other materials, highlighting a rational approach towards low‐defect semiconductor films. Copyright © 2015 John Wiley & Sons, Ltd.

Zhou, Xiao Wang↗
DOE OSTI2017

Tungsten Diselenide Patterning and Nanoribbon Formation by Gas‐Assisted Focused‐Helium‐Ion‐Beam‐Induced Etching

A gas‐assisted focused‐helium‐ion beam‐induced etching (FIBIE) process is introduced, which accelerates direct‐write patterning of WSe 2 relative to standard ion milling. The etching process utilizes the XeF 2 precursor molecule to provide a chemical assist for enhanced material removal relative to ion sputtering. The FIBIE process enables high‐fidelity patterning of WSe 2 with doses 5× lower than standard He + milling. This enables the formation of high‐resolution WSe 2 nanoribbons with dimensions less than 10 nm. The WSe 2 nanoribbons demonstrate high Raman anisotropy and nanoribbon electrical measurements are reported for the first time. The normalized on‐currents of field‐effect transistors reveal that the electron and hole currents are both suppressed and scale with the nanoribbon width, with the electron transport experiencing more degradation. However, on‐currents of nanoribbons created by the FIBIE process remain orders of magnitude greater than nanoribbons formed by standard He + milling. Scanning transmission electron microscopy and complementary Monte Carlo ion–solid simulations reveal that the reduced currents are partially due to ion‐induced damage in the WSe 2 .

Stanford, Michael G.↗
DOE OSTI2019

Predictive role of PI-RADSv2 and ADC parameters in differentiating Gleason pattern 3 + 4 and 4 + 3 prostate cancer

Purpose: To compare the predictive roles of qualitative (PI-RADSv2) and quantitative assessment (ADC metrics), in differentiating Gleason pattern (GP) 3 + 4 from the more aggressive GP 4 + 3 prostate cancer (PCa) using radical prostatectomy (RP) specimen as the reference standard. Methods: We retrospectively identified treatment-naïve peripheral (PZ) and transitional zone (TZ) Gleason Score 7 PCa patients who underwent multiparametric 3T prostate MRI (DWI with b value of 0,1400 and where unavailable, 0,500) and subsequent RP from 2011 to 2015. For each lesion identified on MRI, a PI-RADSv2 score was assigned by a radiologist blinded to pathology data. A PI-RADSv2 score ≤ 3 was defined as “low risk,” a PI-RADSv2 score ≥ 4 as “high risk” for clinically significant PCa. Mean tumor ADC (ADC{sub T}), ADC of adjacent normal tissue (ADC{sub N}), and ADC{sub ratio} (ADC{sub T}/ADC{sub N}) were calculated. Stepwise regression analysis using tumor location, ADC{sub T} and ADC{sub ratio}, b value, low vs. high PI-RADSv2 score was performed to differentiate GP 3 + 4 from 4 + 3. Results: 119 out of 645 cases initially identified met eligibility requirements. 76 lesions were GP 3 + 4, 43 were 4 + 3. ADC{sub ratio} was significantly different between the two GP groups (p = 0.001). PI-RADSv2 score (“low” vs. “high”) was not significantly different between the two GP groups (p = 0.17). Regression analysis selected ADC{sub T} (p = 0.03) and ADC{sub ratio} (p = 0.0007) as best predictors to differentiate GP 4 + 3 from 3 + 4. Estimated sensitivity, specificity, and accuracy of the predictive model in differentiating GP 4 + 3 from 3 + 4 were 37, 82, and 66%, respectively. Conclusions: ADC metrics could differentiate GP 3 + 4 from 4 + 3 PCa with high specificity and moderate accuracy while PI-RADSv2, did not differentiate between these patterns.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Radiological patterns of secondary sclerosing cholangitis in patients after lung transplantation

Purpose: The purpose of this study was to investigate the radiological patterns of secondary sclerosing cholangitis (SSC) following lung transplantation. Methods: Fifty-five patients underwent abdominopelvic CT before and after lung transplantation for end stage pulmonary disease. Nine patients underwent MR cholangiopancreatography (MRCP). The radiological patterns of biliary abnormalities (location, bile duct dilatation with stricture, beaded appearance, and biliary casts/sludge), laboratory data (serum total bilirubin and alkaline phosphatase), and patient survival rates were evaluated. SSC was diagnosed when there were newly developed biliary abnormalities with cholestasis after lung transplantation. Potential perioperative risk factors pertaining to SSC were analyzed. Patient survival rates with or without SSC were compared. Results: Six of the 55 patients showed imaging and laboratory findings of SSC after lung transplantation. Multifocal dilatation and stricture involved the intrahepatic (6 of 6, 100%), hilar (4 of 6, 66.7%), and extrahepatic bile duct (1 of 6, 16.7%). On CT, the lesions presented as multifocal small cyst-like lesions along the bile duct course. On MRCP, the lesions showed beaded appearance with mild duct dilatation. Preoperative mechanical ventilation and bilateral lung transplantation were associated with SSC (p < 0.05). The median survival of patients with SSC was 4.6 months. Conclusion: Lung transplantation can induce SSC similar to SSC in critically ill patients, and result in worse clinical outcomes than in patients without SSC. Multifocal small cyst-like lesions along the intrahepatic bile duct on CT and beaded appearance on MRCP are suggestive findings of SSC in patients with cholestasis after lung transplantation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2017

An Ensemble Method for Classifying Regional Disease Patterns of Diffuse Interstitial Lung Disease Using HRCT Images from Different Vendors

We propose the use of ensemble classifiers to overcome inter-scanner variations in the differentiation of regional disease patterns in high-resolution computed tomography (HRCT) images of diffuse interstitial lung disease patients obtained from different scanners. A total of 600 rectangular 20 × 20-pixel regions of interest (ROIs) on HRCT images obtained from two different scanners (GE and Siemens) and the whole lung area of 92 HRCT images were classified as one of six regional pulmonary disease patterns by two expert radiologists. Textual and shape features were extracted from each ROI and the whole lung parenchyma. For automatic classification, individual and ensemble classifiers were trained and tested with the ROI dataset. We designed the following three experimental sets: an intra-scanner study in which the training and test sets were from the same scanner, an integrated scanner study in which the data from the two scanners were merged, and an inter-scanner study in which the training and test sets were acquired from different scanners. In the ROI-based classification, the ensemble classifiers showed better (p < 0.001) accuracy (89.73%, SD = 0.43) than the individual classifiers (88.38%, SD = 0.31) in the integrated scanner test. The ensemble classifiers also showed partial improvements in the intra- and inter-scanner tests. In the whole lung classification experiment, the quantification accuracies of the ensemble classifiers with integrated training (49.57%) were higher (p < 0.001) than the individual classifiers (48.19%). Furthermore, the ensemble classifiers also showed better performance in both the intra- and inter-scanner experiments. We concluded that the ensemble classifiers provide better performance when using integrated scanner images.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Optimizing human activity patterns using global sensitivity analysis

Implementing realistic activity patterns for a population is crucial for modeling, for example, disease spread, supply and demand, and disaster response. Using the dynamic activity simulation engine, DASim, we generate schedules for a population that capture regular (e.g., working, eating, and sleeping) and irregular activities (e.g., shopping or going to the doctor). We use the sample entropy (SampEn) statistic to quantify a schedule’s regularity for a population. We show how to tune an activity’s regularity by adjusting SampEn, thereby making it possible to realistically design activities when creating a schedule. The tuning process sets up a computationally intractable high-dimensional optimization problem. To reduce the computational demand, we use Bayesian Gaussian process regression to compute global sensitivity indices and identify the parameters that have the greatest effect on the variance of SampEn. Here we use the harmony search (HS) global optimization algorithm to locate global optima. Our results show that HS combined with global sensitivity analysis can efficiently tune the SampEn statistic with few search iterations. We demonstrate how global sensitivity analysis can guide statistical emulation and global optimization algorithms to efficiently tune activities and generate realistic activity patterns. Finally, though our tuning methods are applied to dynamic activity schedule generation, they are general and represent a significant step in the direction of automated tuning and optimization of high-dimensional computer simulations.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2019

Intensity and daily pattern of passenger vehicle use by region and class in China: estimation and implications for energy use and electrification

Given the explosive growth of the passenger vehicle market and energy demands in China, research on vehicle-use intensity and driver-travel patterns is critical for better assessing travel demand and its implications for alternative fuel vehicles, energy security, and environmental policies. This study attempts to estimate annual vehicle kilometers traveled (AVKT) per privately-owned passenger vehicle and their daily distance patterns by vehicle class and geographic region. The data sample from a survey consists of 169,292 privately owned passenger vehicles, made by 177 car manufacturers during 2003–2018, running in 82 cities from 27 provincial regions. The log-transformed average AVKT is estimated to be 12,377 km with 95% probability ranging from 5490 to 28,579 km. The investigation reveals that vehicles from South China have the highest AVKT at 13,320 km. Generally, vehicles in small cities have higher AVKT than in big cities, except AVKT of tier 1 cities being higher. Another trend is that more expensive or larger vehicles tend to be driven more. A model is fitted for estimating AVKT based on region, city type, automaker, price range, and certain vehicle features including class and age. Data of daily commuting distances in recent years are also analyzed. The average daily commuting distances typically range from 21 to 28 km. Using the validated Gamma distribution method, daily distance distributions are specified for different regions. It is found that 99% of the daily driving distance is no more than 88.0–112.0 km, depending on region. Utility factors of plug-in electric vehicles are also estimated to be much higher than those based on driving data in the USA. Finally, these findings suggest global mitigations strategies on vehicle fuel use, electrification, and greenhouse gases should consider vehicle-use intensity at the regional level.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2019

Image encryption and watermarking combined dynamic chaotic hopping pattern with double random phase encoding DRPE

In modern civilization information, security is a crucial problem. Image encryption and watermarking can effectively protect information from unauthorized access. This paper introduces a new vigorous symmetric optical image encryption and watermarking technique. This technique depends on a novel dynamic delay chaotic hopping pattern (DDCHP) combined with double random phase encoding (DRPE). To get a robust watermark image, the plain image is first watermarked with a binary secret message using a new chaotic hopping pattern (CHP) and then encrypted using a DRPE system that is controlled by double random independent keys generated with double DDCHP. In this symmetric cryptosystem, three different chaotic maps are used to enlarge the key space of the proposed cryptosystem against brute-force attack and overcome the linearity and vulnerable of the classical DRPE. The system keys are hypersensitive and their initial parameters are selected carefully. Security scrutiny proves the efficiency of the suggested cryptosystem. Therefore, the obtained simulation results prove that the cryptosystem is robust enough against the known attacks, such as statistical attack (uniform histograms of different encrypted images, correlation coefficients between the plain and the encrypted image is as low as 5.46 × 10{sup −6}), differential attack (99.99% NPCR and 38.6% UACI), brute force attack (large enough key space), and entropy attack. Moreover, the robustness of the watermark (secret message) is proved due to the solidity of CHP. The proposed approach can be used in different implementations like secure military communications, e-finance, e-healthcare, authenticated multimedia broadcasting, etc.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2023

Investigation of Raster Pattern Spacing and Direction for Friction Stir Additive Manufacturing of Al-5083

Friction stir additive manufacturing (FSAM) is a sheet-lamination based additive manufacturing technique. In addition to the traditional factors that govern the friction stir process-structure-property relationship, the processing history is convoluted by the in-plane raster pattern and repeated thermal cycling from subsequent layers. This can lead to complex thermal gradients within the workpiece and reprocessing of material. Here, this work aims to understand the impact of raster pattern spacing and direction on the microstructure and properties during friction stir additive manufacturing of Al-5083. Control of the raster spacing can lead to an increase in hardness of up to 18% from the base material and defect-free joining. These results are then directly demonstrated at the component-scale for FSAM of Al-5083.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Application and evaluation of a pattern-based building energy model calibration method using public building datasets

Building performance simulation has been adopted to support decision making in the building life cycle. An essential issue is to ensure a building energy simulation model can capture the reality and complexity of buildings and their systems in both the static characteristics and dynamic operations. Building energy model calibration is a technique that takes various types of measured performance data (e.g., energy use) and tunes key model parameters to match the simulated results with the actual measurements. This study performed an application and evaluation of an automated pattern-based calibration method on commercial building models that were generated based on characteristics of real buildings. A public building dataset that includes high-level building attributes (e.g., building type, vintage, total floor area, number of stories, zip code) of 111 buildings in San Francisco, California, USA, was used to generate building models in EnergyPlus. Monthly level energy use calibrations were then conducted by comparing building model results against the actual buildings' monthly electricity and natural gas consumption. The results showed 57 out of 111 buildings were successfully calibrated against actual buildings, while the remaining buildings showed opportunities for future calibration improvements. Enhancements to the pattern-based model calibration method are identified to expand its use for: (1) central heating, ventilation and air conditioning (HVAC) systems with chillers, (2) space heating and hot water heating with electricity sources, (3) mixed-use building types, and (4) partially occupied buildings.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2018

Apical sparing pattern of left ventricular myocardial {sup 99m}Tc-HMDP uptake in patients with transthyretin cardiac amyloidosis

Background: A decreased longitudinal strain in basal segments with a base-to-apex gradient has been described in patients with cardiac amyloidosis (CA). Objectives: Aim was to investigate the left ventricular (LV) regional distribution of early-phase {sup 99m}Tc-Hydroxymethylene diphosphonate ({sup 99m}Tc-HMDP) uptake in patients with transthyretin-related cardiac amyloidosis (TTR-CA). Methods: All patients underwent a whole-body planar {sup 99m}Tc-HMDP scintigraphy acquired at 10-min post-injection (early-phase) followed by a thorax SPECT/CT. The segmental uptake (expressed as % of maximal myocardial HMDP uptake) was investigated on the AHA 17-segment model and 3-segment model (basal, mid-cavity, apical). Results: Sixty-one TTR-CA patients were included of whom 29 were wild-type (wt-TTR-CA) and 32 had hereditary TTR-CA (m-TTR-CA). Early myocardial {sup 99m}Tc-HMDP uptake occurred in all TTR-CA. In all patients, segmental analysis of the LV myocardial distribution of {sup 99m}Tc-HMDP uptake showed an increased median uptake (interquartile range) in basal/mid-cavity segments compared to the lowest median uptake of apical segments (respectively, 79% [72%-86%] vs. 72% [64%-81%]; P < 10{sup −6}). This pattern was similar in wt-TTR-CA group (78% [70%-84%] vs. 70% [61%-81%]; P < 10{sup −6}), in m-TTR-CA group (80% [74%-86%] vs. 73 [66%-82%]; P < 10{sup −7}) and remained constant independently of the TTR mutation subtype with P ranging 10{sup −5} to 0.03. Conclusions: Early-phase myocardial scintigraphy identified regional distribution of {sup 99m}Tc-HMDP uptake characterized by a base-to-apex gradient, corroborating echocardiographic, and cardiac magnetic resonance findings. This apical sparing pattern was similar across TTR-CA and TTR mutation subtypes.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2021

Domain patterns and super-elasticity of freestanding BiFeO 3 membranes via phase-field simulations

Super-elasticity of functional ferroelectric oxides offers promises for integrating ferroelectric films into flexible electronics. However, super-elastic deformation is a complex phenomenon related to possibly multiple concurrent mechanisms. Fundamentally understanding how multiple mechanisms contribute to the super-elasticity of ferroelectric oxides is crucial to realizing their potential flexible electronic applications. In this study, we employ phase-field simulations to model the dynamics of ferroelectric domain patterns of freestanding BiFeO 3 membranes to understand the origin of their super-elasticity under substantial bending deformation (5% strain). It is demonstrated that both a reversible Rhombohedral-Tetragonal (R-T) phase transition and a nearly reversible domain evolution of BiFeO 3 membranes contribute to accommodating the large deformation and thus their super-elasticity. The dynamics of domain evolution also reveal the formation of an exotic ferroelectric vortex and polarization rotation before the phase transition. We constructed a diagram of phases and domain patterns as a function of the membrane thickness and bending angle, which allows one to readily predict the emergence of T phase and ferroelectric vortex in bent BFO membranes. These results not only provide fundamental understanding of mesoscale super-elastic mechanisms but also reveal exotic domain states of ferroelectric membranes.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Emergence of complex-regular eutectic patterns in Al–Ge: Observations from correlative nano-imaging

Eutectic solidification exemplifies nonequilibrium pattern formation, making it a well-studied moving boundary problem. Yet the mechanisms behind the formation of complex-regular microstructures – particularly in highly anisotropic systems with a significant volume fraction of a faceted phase – remain poorly understood. Our understanding of such systems is made complicated by the nonlinear interface kinetics and unique growth dynamics characteristic of faceted phases. To address these challenges, we investigate a model Al–Ge eutectic system, where the faceted Ge phase constitutes a substantial volume fraction (~0.35) and where the two solid phases arrange into so-called “fishbone” or “feather” complex-regular patterns. Using synchrotron-based x-ray nano-imaging and nanotomography with high spatial resolution (22 nm per pixel), we capture in real-time the evolution of the solid–liquid interfaces and the resulting three-dimensional microstructures in this faceted/non-faceted eutectic system. By integrating these observations with electron backscattered diffraction, we elucidate the crystallographic biases on the solidification process and the mechanisms driving the formation of such complex-regular microstructures. These findings inform a new growth model for irregular eutectics in (near-)symmetrical phase diagrams, offering insight on advanced microstructural design and processing strategies. More broadly, we demonstrate how interfacial curvature is generated in irregular eutectic alloys and how it depends on the volume fraction of the faceted phase.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Influence of scan pattern and geometry on the microstructure and soft-magnetic performance of additively manufactured Fe-Si

The influence of geometry and scan pattern on the microstructure evolution and magnetic performance of additively manufactured Fe-3Si components was investigated. To reduce eddy current losses, novel geometries were designed and built and the microstructure and properties of these samples were characterized. The laser scan pattern was shown to strongly influence both the as-built grain structure and strength of the crystallographic texture, resulting in measurable changes in the as-built magnetic performance. In thin wall samples, heat treatment resulted in an increase in the maximum relative magnetic permeability and decrease in power losses in most samples, consistent with grain growth. However, decreases in the spacing between thin walls to increase the stacking factor of the cross-section was shown to result in unwanted electrical shorting between walls and an increase in eddy current losses. Compared to simple parallel plate construction and a mesh structure, a novel cross-section design based on the Hilbert space filling curve was found to produce the lowest power losses. The mechanisms behind these results were explored using a combination of heat conduction and electromagnetic simulations, providing a route for future component and process optimization.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Self-aligned concentrating immersion-lens arrays for patterning and efficiency recovery in scaffold-reinforced perovskite solar cells

In contrast to existing silicon, CIGS, and multi-junction cells that exhibit remarkable mechanical durability, perovskite solar cells have been shown to delaminate when subjected to the mechanical loads that occur during processing and field exposures, limiting their potential as a reliable solar technology. Mechanical reinforcement is thus essential for durable and reliable perovskite technologies. One current strategy to overcome the thermomechanical fragility of perovskite solar cells is to extrinsically shield them by introducing reinforcing scaffolds which partition the cell into many distinct microcells, but improvements in mechanical stability coincide with a reduced device efficiency due to parasitic absorption by the scaffold. We address this reduced efficiency by integrating concentrating immersion-lens arrays (CILAs) into scaffold-reinforced solar cells. These scaffolds are lithographically patterned by a maskless process, in which ultraviolet light is used to pattern the scaffolds through the CILAs, ensuring self-alignment and optical contact with the microcells. Perovskite devices are deposited into the microcells, and during operation, light is concentrated into the microcells and away from the insulating scaffolds, resulting in mechanically resilient solar cells with efficiencies comparable to planar devices. The CILAs also exhibit passive tracking of incident light—verified experimentally and with ray-tracing simulations—which is critical for optimal power output as the sun moves across the sky during the day. The simplicity of the fabrication process and the efficiency of the resulting scaffolded devices show that a lens-integrated scaffold-reinforced structure is a potential pathway to high-performance, robust, commercially viable perovskite solar cells.

14 SOLAR ENERGY↗
DOE OSTI2018

Distinct notch signaling expression patterns between nucleoside and nucleotide analogues treatment for hepatitis B virus infection

Highlights: • Notch signaling inhibited by nucleoside analogues treatment under HBV infection. • Upregulation of Notch signaling after nucleotide analogues administration. • Reduction of Foxp3 expression by both nucleotide and nucleoside analogues treatment. • Activation of phosphorylated mTORC2–Akt cascade after nucleotide analogue treatment. Nucleos(t)ide analogues therapies are currently approved for the treatment of chronic hepatitis B virus (HBV) infection, which effectively suppress HBV replication and correlate with the anti-HBV-specific immune response. Notch signaling serves pleiotropic roles in the immune system that also contribute to virus-specific immunity. In this study, we assessed Notch signal-related gene expression after administrating nucleoside or nucleotide analogues to HBV-replicating cells and clinical liver tissues. We found distinct Notch signaling expression patterns under nucleos(t)ide analogues therapies, with high expression for nucleotide analogues (adefovir pivoxil or tenofovir disoproxil fumarate) and low expression for nucleoside analogues (lamivudine or entecavir) in the presence of HBV infection. Furthermore, activation of mammalian target of rapamycin (mTOR)-Akt (Ser473) phosphorylation was also observed after nucleotide analogue treatment. In conclusion, nucleoside and nucleotide analogues displayed different patterns of Notch signaling activity under HBV infection, and the induction of mTORC2-Akt (Ser473) phosphorylation may contribute to nucleotide analogues-mediated Notch signaling activation.

60 APPLIED LIFE SCIENCES↗