Phase Pattern Research Articles

GLONASS-K2 signal analysis

K2 is a new generation of GLONASS satellites that provides code division multiple access (CDMA) signals in the L1, L2 and L3 frequency bands in addition to legacy L1 and L2 signals based on frequency division multiple access (FDMA) modulation. The first GLONASS-K2 satellite was launched in August 2023 and started signal transmission in early September 2023. Based on measurements with a 30-m high-gain antenna, spectral characteristics of the various signal components are described and relative power levels are identified. A 3 dB (L1) to 4 dB (L2) higher total power is determined for the CDMA signal compared to the legacy FDMA signal and an equal power of the open service and secured CDMA signal components is found. The ranging code of the L2 channel for service information, which has not been publicly disclosed so far, is identified as a Gold code sequence consistent with the data channel of the L1 open service CDMA signal. The high-gain antenna measurements are complemented by tracking data from terrestrial receivers that enable a first assessment of user performance. An up to 50% improvement in terms of noise and multipath performance is demonstrated for the new L1 and L2 CDMA signals in comparison with their legacy counterpart, but no obvious differences between the different binary phase-shift keying and binary offset carrier modulations of the data and pilot components of these signals could be identified for the test stations. Triple-frequency carrier phase observations from L1, L2, and L3 CDMA signals exhibit good consistency at the noise and multipath level, except for small variations that can be attributed to slightly different antenna phase patterns on the individual frequencies. Overall, the new CDMA signals are expected to notably improve and facilitate precise point positioning applications once fully deployed across the GLONASS constellation.

In silico investigation of the formation of multiple intense zebra stripes using extending domain

We perform an in silico investigation of the formation of multiple intense zebra stripes by extending the domain with an appropriate extending speed. The common zebra has alternating dark and light stripes, creating a two phase pattern. However, some Equus burchelli zebras have an intermediate gray color stripe situated between the dark and light stripes. To numerically investigate the formation of multiple intense zebra stripes, we first find the equilibrium state of the governing system in the one-dimensional (1D) static domains using various frequency modes. After finding the equilibrium state for the governing system in the 1D static domains, we stack a numerical data. Then, we load the stacked numerical data to use as an initial state for finding the growth rate that forms the multiple intense zebra stripe formation in the 1D extended domains. Next, convergence experiments are conducted to verify the convergence of the numerical method for the governing system. Finally, numerical simulations are performed to confirm the formation of multiple intense zebra stripes in two-dimensional extending domains and on evolving curved surfaces.

Simple and robust 3D MINFLUX excitation with a variable phase plate

MINFLUX has achieved extraordinary resolution in superresolution imaging and single fluorophore tracking. It is based on localizing single fluorophores by rapid probing with a patterned beam that features a local intensity minimum. Current implementations, however, are complex and expensive and are limited in speed and robustness. Here, we show that a combination of an electro-optical modulator with a segmented birefringent element such as a spatial light modulator produces a variable phase plate for which the phase can be scanned on the MHz timescale. Bisected or top-hat phase patterns generate high-contrast compact excitation point-spread functions for MINFLUX localization in the x, y, and z-direction, respectively, which can be scanned across a fluorophore within a microsecond, switched within 60 microseconds and alternated among different excitation wavelengths. We discuss how to compensate for non-optimal performance of the components and present a robust 3D and multi-color MINFLUX excitation module, which we envision as an integral component of a high-performance and cost-effective open-source MINFLUX.

Symmetry and complexity: a Lie symmetry method to bifurcation, chaos, multistability and soliton solutions of the nonlinear generalized advection-diffusion-reaction equation

This paper deals with the complexities of nonlinear dynamics within the nonlinear generalized advection-diffusion-reaction equation, which describes intricate transport phenomena involving advection, diffusion, and reaction processes occurring simultaneously. Through the utilization of the Lie symmetry approach, we thoroughly examine this proposed model, transforming the partial differential equation into an ordinary differential equation using similarity reduction techniques to facilitate a more comprehensive analysis. Exact solutions for this transformed equation are derived employing the extended simplest equation method and the new extended direct algebraic method. To enhance understanding, contour plots along with 2D and 3D visualizations of solutions are employed. Additionally, we explore bifurcation and chaotic behaviors through a qualitative analysis of the model. Phase portraits are meticulously scrutinized across various parameter values, offering insights into system behavior. The introduction of an external periodic strength allows us to utilize various tools including time series, 3D, and 2D phase patterns to discern chaotic and quasi-periodic behaviors. Furthermore, a multistability analysis is conducted to examine the impacts of diverse initial conditions. These findings underscore the efficacy and practicality of the proposed methodologies in evaluating soliton solutions and elucidating phase dynamics across a spectrum of nonlinear models, offering novel perspectives on intricate physical phenomena

Single-frame double-grating interferometry with two inherent-phase-shifted interferograms.

In this work, we introduce a novel self-referencing, common-path, double-grating interferometry method for studying slowly varying phase samples. Two plane wave diffraction orders of the gratings, namely (0,+1) and (+1,0), with a certain phase difference, interfere with each other in a single frame. When a phase sample is applied in the middle of the impinging beam, two simultaneous inherent phase-shifted interferograms are generated on either side of the interference pattern. In one interferogram, the sample phase is added to (0,+1), while in the second one, the sample phase is added to (+1,0). Consequently, the phase of the first interferogram increases by the amount of the sample phase, while in the second interferogram, it decreases by the same amount. Without a phase sample, both interferograms have uniform intensity and value since the two interfering beams have the same phase difference in both patterns. We observe that the intensity changes in the two interferograms due to the phase sample, depending on the initial phase difference between the two interfering beams, can be equal or unequal, and in certain circumstances, they can be even complementary. We introduce a specific phase difference between the interfering orders by precisely controlling the separation between two diffraction gratings. This allows us to extract the sample's phase information from the resulting pair of interferograms. This setup enables us to obtain the sample phase without applying an additional phase shift(s) between the interfering beams. The method was applied to a thermal lens induced in a nonlinear liquid sample containing absorbent nanoparticles. The proposed method is characterized by its simplicity, accuracy, and insensitivity to vibrations, making it well-suited for analyzing dynamic samples with millimeter scales, such as nearly transparent organisms. The theory, simulations, and experimental results presented in this paper are found to be consistent. Unlike conventional methods, our approach does not necessarily require a reference interferogram. Additionally, when the absolute value of phase changes over the sample area and time is less than π, the raw phase pattern precisely matches the reconstructed phase pattern of the sample, eliminating the need for a phase-reconstructing algorithm. The phase pattern can be accurately calculated from the interferograms using an arcsine function without needing a fast Fourier transform. Compared to Fourier-based methods, the phase extraction process for each frame in our approach is 60 times faster. As a result, this technique operates in real-time for |φ(x, y;t) | < π.

Cognitive driven gait freezing phase detection and classification for neuro-rehabilitated patients using machine learning algorithms

BackgroundThe significance of diagnosing illnesses associated with brain cognitive and gait freezing phase patterns has led to a recent surge in interest in the study of gait for mental disorders. A more precise and effective way to characterize and classify many common gait problems, such as foot and brain pulse disorders, can improve prognosis evaluation and treatment options for Parkinson patients. Nonetheless, the primary clinical technique for assessing gait abnormalities at the moment is visual inspection, which depends on the subjectivity of the observer and can be inaccurate. Research questionThis study investigates whether it is possible to differentiate between gait brain disorder and the typical walking pattern using machine learning driven supervised learning techniques and data obtained from inertial measurement unit sensors for brain, hip and leg rehabilitation. MethodThe proposed method makes use of the Daphnet freezing of Gait Data Set, consisted of 237 instances with 9 attributes. The method utilizes machine learning and feature reduction approaches in leg and hip gait recognition. ResultsFrom the obtained results, it is concluded that among all classifiers RF achieved highest accuracy as 98.9 % and Perceptron achieved lowest i.e. 70.4 % accuracy. While utilizing LDA as feature reduction approach, KNN, RF and NB also achieved promising accuracy and F1-score in comparison with SVM and LR classifiers. SignificanceIn order to distinguish between the different gait disorders associated with brain tissues freezing/non-freezing and normal walking gait patterns, it is shown that the integration of different machine learning algorithms offers a viable and prospective solution. This research implies the need for an impartial approach to support clinical judgment.

Assessing a semi-empirical model performance to predict the wetting patterns in subsurface drip irrigation

ContextBecause of the complexity of soil water distribution, accurate prediction of wetting pattern is not easily accessible and this has led to a inefficiency in some proposed models in the literature. These models do not consider the hydraulic characteristics of the irrigation system and are developed solely on the basis of the water volume or infiltration rate, soil hydrodynamic properties, and other conditions of the percolation environment. ObjectiveDue to the importance of the estimation of wetting front beneath Subsurface Drip Irrigation (SDI) laterals, a semi-empirical model using easily accessible data of the SDI system is proposed to predict the wetting patterns in both distribution and redistribution phases. The aforementioned model has been developed based on a novel approach that couples the governing equations of the lateral hydraulics with empirical equations derived by dimensional analysis. MethodsTo develop the model and evaluate its performance, three 16-mm drip line pipes with 0.2, 0.4, and 0.5 m emitter spacing, and 2–5 l/h discharge were placed at 0.20 m depth in a soil box filled with clay loam soil. Water was applied for 3 hours at 50, 100, and 150 kPa operating pressures, and the wetting patterns’ geometries were measured in each lateral after 1, 2, 3, and 24 h. The performance of the model was then assessed and compared with that of three other models. Results and conclusionThe result demonstrated that the proposed model provides the most accurate estimations of the wetting depths and widths. RMSE and MAE statistical indexes of the wetting depth were 0.001–0.002 m and 0.004–0.009 m, respectively, whereas those associated with the wetting width were 0.001–0.003 m and 0.005–0.016 m, respectively. These values resulted in the lowest error when compared with the corresponding obtained from other well-known models. Consequently, the model allows acceptable predictions of the wetting patterns using accessible hydraulic parameters of the SDI system. SignificanceUniquely, the results of the lateral hydraulic analysis were applied to determine the wetting front dimensions in this study. Also, the results demonstrated that the model was successful in wetting pattern prediction beneath the lateral as a line source. While other models usually are used to estimate the wetting front around a point source.

How is postoperative pain after hip and knee replacement managed? An analysis of two large hospitals in Australia

BackgroundMultimodal analgesia regimens are recommended for the postoperative period after hip and knee replacement surgeries. However, there are no data on practice patterns for analgesic use in the immediate postoperative period after hip and knee replacements in Australia.ObjectivesTo describe analgesic prescribing patterns in the inpatient postoperative phase for patients undergoing hip and knee replacement.MethodsRetrospective study of electronic medical record data from two major hospitals in Sydney, Australia. We identified analgesic medication prescriptions for all patients aged 18 years and older who underwent hip or knee replacement surgery in 2019. We extracted data on pain medications prescribed while in the ward up until discharge. These were grouped into distinct categories based on the Anatomical Therapeutic Chemical classification. We described the frequency (%) of pain medications used by category and computed the average oral morphine equivalent daily dose (OMEDD) during hospitalisation.ResultsWe identified 1282 surgeries in 1225 patients. Patients had a mean (SD) age of 69 (11.8) years; most (57.1%) were female. Over 99% of patients were prescribed opioid analgesics and paracetamol during their hospital stay. Most patients (61.4%) were managed with paracetamol and opioids only. The most common prescribed opioid was oxycodone (87.3% of patients). Only 19% of patients were prescribed nonsteroidal anti-inflammatories (NSAIDs). The median (IQR) average daily OMEDD was 50.2 mg (30.3–77.9).ConclusionWe identified high use of opioids analgesics as the main strategies for pain control after hip and knee replacement in hospital. Other analgesics were much less frequently used, such as NSAIDs, and always in combination with opioids and paracetamol.

Multi-scale population analysis unit construction method considering scene feature variability and long/short-term patterns in spatiotemporal population activities

ABSTRACT Differences in the spatial scale and component elements of urban scenes affect the analysis of spatiotemporal changes in population distribution (PD) patterns. Fixed scales and geometric forms constrained previous analyses of PD and spatiotemporal changes, which neglected the realistic characteristics of urban scenarios. These limitations hinder the ability to capture the diversity and spatiotemporal representation of PD patterns across multiple spatial scales. This study developed a multi-spatial scale population analysis unit (PAU) construction method considering the scenario heterogeneity and long/short-term patterns of spatiotemporal population changes (PC). Initially, we decompose the multi-scale changes in population time series patterns and their relationships with scene features along the temporal dimension to analyze the primary and secondary factors. Starting from the temporal characteristics of the PD and PC, we established a validation and correction method for the factors. Finally, combined with a multi-feature clustering method, a multi-scale PAU construction method driven by scene feature factors is proposed. Experiments were conducted at different spatial scales in both routine and emergent scenarios. The results indicated that this method can help to obtain more homogeneous analysis regions and enhance the stability and phase pattern representations of changes in PDs, thereby improving the interpretability of analytical results.

Triplet Excited State Mechanistic Study of meso‐Substituted Methylthio Bodipy Derivative: Time‐Resolved Optical and Electron Paramagnetic Resonance Spectral Studies

AbstractUnderstanding the intersystem crossing (ISC) mechanism of organic compounds is essential for designing new triplet photosensitizers. Herein, we investigated the ISC mechanism of a heavy atom‐free Bodipy derivative with thiomethyl substitution (S−BDP). A long‐lived triplet state was observed with nanosecond transient absorption spectroscopy with lifetime of 7.5 ms in a polymer film and 178 μs intrinsic lifetime in fluid solution, much longer as compared with what was previously reported (apparent triplet lifetime=15.5 μs). Femtosecond transient absorption studies retrieved an ISC time constant of ∼3 ns. Time‐resolved electron paramagnetic resonance (TREPR) indicated a special triplet electron spin polarization phase (ESP) pattern (a, e, a, e, a, e) for S−BDP, different from the ESP (e, e, e, a, a, a) typical for the spin‐orbital coupling (SOC) mechanism. This indicates that the electron spin selectivity of the ISC of S−BDP is different from that of the normal SOC effect in iodo‐Bodipy. Simulations of the TREPR spectra give a zero‐field‐splitting D parameter of −2257 MHz, much smaller as compared to the reference 2,6‐diiodo‐Bodipy (D=−4380 MHz). The computed SOC matrix elements (0.28–1.59 cm−1) and energy gaps for the S1/Tn states suggest that the energy matching between the S1 and T2/T3 states (supported by the largest kISC ∼109 s−1) enhances the ISC for this compound.

Single shot depth-resolved imaging through dynamic turbid media

Guide star assisted wavefront shaping techniques have been exploited for focusing and imaging through turbid media by addressing a scatter inverse pattern. However, the turbid medium is required to be steady before finding the proper correction pattern, which limits applications in focusing and imaging through dynamic media, such as turbid water or blood. This study proposes a holography-based dual-polarization computational wavefront shaping method for imaging objects at variant depths behind dynamic turbid media. The orthogonal polarized output speckles of a point source (considered as a guide star) and an object are simultaneously recorded in holograms in separate regions of a single CCD camera. The holograms of the point source and object are subjected to the same distortion regardless of whether the media is static or dynamic. The hologram of the point source is used to determine the correction phase pattern for the distortion, while that of the object is used to record the complex scattered wavefront of the object. To reconstruct a clear object image, the wavefront of the scattered object is digitally corrected using the correction phase pattern and is then transferred to the image plane by calculating the transmission of the angular spectrum. Benefiting from the autofocusing feature of digital holography, objects at different depths can be recovered from a single shot hologram pair. The potential applications of the proposed method in diverse dynamic scattering media are demonstrated by imaging through a moving diffuser, turbid water, and pig blood with optical depth beyond 10.

Spatiotemporal variations in eco-environmental quality and responses to drought and human activities in the middle reaches of the Yellow River basin, China from 1990 to 2022

The middle reaches of the Yellow River basin (MYRB) are among the regions most severely affected by soil erosion globally. It has always held a pivotal role in soil and water conservation and ecological restoration efforts in China. Nonetheless, in the face of recurrent drought occurrences and growing human intervention, there have been notable alterations in the eco-environmental quality (EEQ) within the MYRB. However, the influences of drought and human intervention on the EEQ of MYRB remain unclear. In this study, the remote sensing ecological index (RSEI) was applied to quantify the spatiotemporal changes in EEQ and the contributions of drought and land use type transitions to EEQ in the MYRB from 1990 to 2022. The results showed that the EEQ in the MYRB fluctuated significantly and exhibited a weak overall improvement trend over the past 33 years. The proportion of good and excellent grades for EEQ significantly improved, while the proportion of poor and fair grades significantly decreased, especially in the northern regions. The trend of changes in EEQ follows a phased pattern. During the periods of 1990–2002 and 2011–2022, an improving trend is observed, while the period of 2003–2010 shows no significant change in EEQ. Drought had the strongest influence on the EEQ from 2003 to 2010, followed by that from 1990 to 2002, and had a lesser impact in the period from 2011 to 2022. The EEQ was primarily positively influenced by spring, autumn and winter droughts and negatively affected by summer droughts, especially in arid grassland and unused land areas. The EEQ in the MYRB improved primarily during the initial and final phases of the ecological projects, with a lesser impact from drought. The increase in EEQ during the initial phases of ecological project implementation was less noticeable, and drought significantly affected EEQ during this period.

Analysis of the shear-driven flow in a scale model of a phase separator: Validation of a coupled CFD approach using experimental data from a physical model

The effect of shear stress at the interface between a flowing gaseous phase and a liquid-filled cavity, a scenario commonly found in flue gas/slag phase separators, is investigated in this study. This effect is frequently disregarded in computational fluid dynamics (CFD) simulations within metallurgy, primarily due to its limited influence on the motion of liquids (e.g., slag, liquid metal) when compared to other factors such as stirring by natural convection or bubbling. This study was undertaken to investigate shear-driven flow in a 1:4 scale model of a phase separator in which a flue gas stream coming from a furnace is mobilizing the flow of a slag melt. To cover a wide range of operating conditions, silicone oil with varying viscosities (20, 50, and 70 cSt) was considered for mimicking viscous slag. Additionally, different volumetric airflow rates (18, 27, and 36 m3/h) were considered to simulate the flue gas flow. Particle image velocimetry (PIV) measurements were conducted on the model. The experimental results were utilized to validate computationally efficient, coupled steady-state simulations of the system. Notably, the steady-state simulations, requiring approximately one hour of CPU time, demonstrated a computation time decrease of two magnitudes compared to conventional Volume of Fluid (VOF) modeling. A stable, laminar flow pattern of the liquid phase with surface velocities of up to approximately 30 mm/s was observed for the case with the lowest oil viscosity and the highest airflow rate, while a steady, turbulent flow was observed in the gas phase. Conversely, the lowest surface velocities, measuring around 5 mm/s, were recorded and calculated for the scenario with the highest oil viscosity and the lowest airflow rate. It was noted that velocities increased proportionally with the airflow rate but exhibited a disproportionate relationship with oil viscosity. The prediction of velocity magnitudes by the steady-state CFD model was highly accurate, with only minor discrepancies observed between the measured and calculated flow patterns. In summary, valuable insights into the often-overlooked shear stress effects at the phase boundary in gaseous-liquid flow over a cavity are provided by our study.

Phase Pattern Formation in Grain Boundaries.

In this Letter we derive conditions that predict the existence of two-phase periodic-pattern grain boundary structures that are stable against coarsening. While previous research has established that elastic effects can lead to phase pattern formation on crystal surfaces, the possibility of stable grain boundary structures composed of alternating grain boundary phases has not been previously analyzed. Our theory identifies the specific combination of grain boundary and materials properties that enable the emergence of patterned grain boundary states and shows that the dislocation content of grain boundary phase junctions, absent in surface phenomena, weakens the stability of the patterned structures. The predictions of the theory are tested using a model copper grain boundary that exhibits multiple phases and two-phase pattern formation. We discuss how, similarly to surfaces, elastic effects associated with grain boundary phase junctions have profound implications for how grain boundary phases transform.

Abstract PO2-07-01: Predicted Circadian-related Transcription Factors in Human Breast Cell Lines–A key to understanding breast cancer pathology?

Abstract Studies show that disrupted circadian clocks are associated with breast and other forms of cancer. However, the pathways and cell processes linking broken circadian clocks to breast cancer are still mostly unknown. In this study, we conducted a reanalysis of mRNA expression in breast cell lines, specifically MCF10a (a fibrocystic cell line) and MCF7 (a metastatic adenocarcinoma cell line). To achieve this, we utilized microarray data obtained from Gutierrez et al. in 2016, specifically the datasets GSE76370, GSE76368, and GSE76369. First, Metacycle, an R statistical package employing a cosine fitting algorithm, was used to identify circadian-oscillations in mRNA expression from both cell lines. MetaCycle (Wu et al., 2016) analysis produced an amplitude, phase, and period value for each circadian gene. Following the analysis, we conducted principal component analysis on the Metacycle output to identify any outlier genes. Subsequently, hierarchical clustering analysis was employed to group these outlier genes based on their oscillating expression levels, with the purpose of identifying clusters that exhibited similar period and phase patterns. We hypothesized that genes found in the same cluster would share common transcription factors that would drive and synchronize the expression of those genes. We tested this hypothesis and found that genes with the same circadian pattern did indeed share common transcription factor binding sites, using Ciiider 3.0 (Gearing et al, 2019), an internet-based tool for predicting and analyzing transcription factor binding sites. We found 96 genes grouped into 6 clusters for MCF10a, and 92 genes grouped into 6 for MCF7 cell lines. Arid3A binding sites were highly enriched across MCF7 and MCF10a. In MCF10a, where circadian oscillations were more pronounced, Sox5 binding sites were highly enriched for cluster 1, Meis1 was enriched for cluster 2, and Arid3A was enriched in clusters 3-6, in combination with other transcription factors. In MCF7, a different set of genes showed circadian-like oscillating expression patterns. However, these different genes showed enrichment of Arid3A across all clusters. Since Arid3A binding sites were found in genes involved in all of the MCF7 clusters, and found in four of the six clusters in MCF10a, further work is needed in understanding the additional regulatory mechanisms that shift the phase and period of the oscillations of these groups of genes. In addition, more work needs to be done to study the role of these transcription factors in cancer progression and basic cell processes. Most of these transcription factors are known to be related to breast or other forms of cancer. Though this list is not complete, some of the more enriched transcription factor binding sites include Arid3A, Meis1, Znf354c, in MCF10a and in MCF7 they include Arid3A, Znf354c, Nfatc2, and Ahr:Arnt. The most enriched transcription factor amongst these circadian-like genes is Arid3A. Arid3A is an H3K9me3 demethylase and may impact regulation of other genes through demethylation. Suppression of Arid3A is associated with leukemia. Meis1 is also implicated in leukemia and tumor growth, as well as sleep disorders. Arnt splice variants are also associated with breast cancer. Future research is needed to determine if these transcription factors are important for circadian-like control. Our in silico results suggest that genes found in the same clusters share their respective transcription factors that regulate the expression of these circadian-like genes. Citation Format: Yocanxóchitl Perfecto-Avalos, Janice Yoo, Cinthya Saravia Heyman, Princess Jemeala Deranamie, John Tran, Sean-Patrick Scott. Predicted Circadian-related Transcription Factors in Human Breast Cell Lines–A key to understanding breast cancer pathology? [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-07-01.

Pregnancy Rates in Frozen-Thawed Embryos Derived from Donor Oocytes According To the Mid-Luteal Phase Endometrial Echo Pattern

Background: Previous studies have found a lower live delivered pregnancy rate (LDPR) when women have a triple-line (TL) endometrial echo pattern in mid-luteal phase in natural cycles, but not specifically when a donor oocyte was used. Objective: To determine if failure of progression of a triple line (TL) sonographic endometrial echo pattern despite supplemental progesterone (P) support in the luteal phase is associated with a LDPR following frozen embryo transfer (FET) where the embryos were derived from donor oocytes. Study Design/Materials and Methods: A retrospective review was performed over a twenty-year period of all FET cycles performed in women ≤ age 42 and women ≥ age 43 when the oocyte source was a fresh donor oocyte. All women were on the same regimen of maximum P where 100 mg of P in oil plus vaginal P once there was adequate endometrial thickness. All FETs occurred on day three. The live delivered pregnancy rates were determined and compared according to whether a TL echo pattern, isoechogenic (IE), or homogenic hyperechogenic (HH) was found on the seventh day of taking P. Results: No matter what age, the TL pattern was uncommon (&lt;5%). Women aged &gt; 43 showed a non-significant trend of about a 33% reduction in LDPRs if they continued with a TL pattern into mid-luteal phase. Conclusion: Identifying a TL mid-luteal echo pattern may help to identify a potential correctable reason for failure to conceive following transfer of embryos derived from younger donors in a small minority of women aged &gt; 43.

Acoustic Wave-Induced FeRh Magnetic Phase Transition and Its Application in Antiferromagnetic Pattern Writing and Erasing.

We explore the FeRh magnetic phase transition (MPT) and magnetic phase domain (MPD) with the introduction of surface acoustic waves (SAWs). The effects of the SAW pulses with different pulse widths and powers on resistance-temperature loops are investigated, revealing that the SAW can reduce the thermal hysteresis. Meanwhile, the SAW-induced comb-like antiferromagnetic (AFM) phase domains are observed. By changing the pulse width and SAW frequency, we further realize a writing-erasing process of the different comb-like AFM phase domains in the mixed-phase regime of the cooling transition branch. Resistance measurements also display the repeated SAW writing-erasing and the nonvolatile characteristic clearly. MPT paths are measured to demonstrate that short SAW pulses induce isothermal MPT and write magnetic phase patterns via the dynamic strain, whereas long SAW pulses erase patterns via the acoustothermal effect. The Preisach model is introduced to model the FeRh MPT under the SAW pulses, and the calculated results correspond well with our experiments, which reveals the SAW-induced energy modulation promotes FeRh MPT. COMSOL simulations of the SAW strain field also support our results. Our study not only can be used to reduce the thermal hysteresis but also extends the application of the SAW as a tool to write and erase AFM patterns for spintronics and magnonics.

1Hβ chemical shift-based phase modulated NMR methods for fast identification of amino acid types in proteins

Here we report two phase modulated NMR experiments: PM-2D HN(CACBHB) and PM-2D HN(HB), that use 1Hβ chemical shifts to rapidly identify amino acid type in proteins. The magnetization on the 1Hβ spins during the experiments is allowed to evolve for a fixed evolution period that results in phase modulation (positive or negative) of the cross peaks corresponding to various amino acid residues on their 2D HN projections, resembling a typical 2D [1H–15N]-HSQC spectrum. All amino acids except glycine can be categorized into three discernible groups based on their 1Hβ chemical shifts, resulting in unique phase patterns at different fixed evolution periods for 1Hβ, thus facilitating their identification. Remarkably, the PM-2D HN(HB) stands out among all amino acid type identification NMR techniques for its applicability with cost-effective and most routinely employed 15N-labeled protein samples for NMR studies. Furthermore, when combined effectively with the 13Cβ chemical shift-based phase modulated NMR method (PM-2D HN(CACB)), these methods resolved the identification of large groups of amino acids into relatively smaller groups. Moreover, these techniques can accelerate the sequence-specific sequential resonance assignment (SSRA) process and would help in fast tracking of assigned NMR signals exhibiting chemical shift perturbation on the 2D [1H–15N]-HSQC spectrum of proteins during various experiments (e.g., temperature change, pH change, and protein or ligand or cofactor binding) as well as in site-directed mutagenesis.

Structural Study of Nematogenic Compound 5OS5

The S-(4-pentylphenyl) 4-(pentyloxy)benzothioate, forming the nematic phase, is investigated by X-ray diffraction in temperatures between 263 K and 365 K, with the support of differential scanning calorimetry and polarizing optical microscopy. The microscopic observations show changes within the solid state, while X-ray diffraction does not indicate any transitions between the crystal phases. The Rietveld refinement shows that the crystal phase formed from the melt is the same monoclinic crystal phase with the P21/c space group as reported for a single crystal grown from an ethanol solution. The temperature dependence of the unit cell parameters in the 263–335 K range is determined and the coefficients of thermal expansion are obtained. The unit cell expands on heating along the longer ac-diagonal and b-axis while, along the shorter ac-diagonal, a very small shrinkage occurs. The diffraction patterns of the liquid crystalline nematic phase indicate the formation of dimers via hydrogen bonding. Density functional theory calculations (def2TZVPP basis set, B3LYP-D3(BJ) correlation-exchange functional) are applied for geometry optimization of an isolated molecule and selected dimers.

Nonlocal Elasticity Yields Equilibrium Patterns in Phase Separating Systems

Recent experiments demonstrated the emergence of regular mesoscopic patterns when liquid droplets form in an elastic gel after cooling. These patterns appeared via a continuous transition and were smaller in stiffer systems. We capture these observations with a phenomenological equilibrium model describing the density field of the elastic component to account for phase separation. We show that local elasticity theories are insufficient, even if they allow large shear deformations. Instead, we can account for key observations using a nonlocal elasticity theory to capture the gel’s structure. Analytical approximations unveil that the pattern period is determined by the geometric mean between the elastocapillary length and a nonlocality scale. Our theory highlights the importance of nonlocal elasticity in soft matter systems, reveals the mechanism of this mesoscopic pattern, and will improve the engineering of such systems. Published by the American Physical Society 2024