Phase Selection Research Articles

Dual states based reinforcement learning for fast MR scan and image reconstruction

Incomplete phase encoding with few phases is an effective under-sampling manner of fast Magnetic Resonance (MR) scan. The key is how to choose important slice-specific phases. Reinforcement Learning (RL) is powerful for sequential decision-making and therefore is feasible for slice-specific phase selection. Existing RL-based methods employ time-consuming reconstruction-oriented Deep Neural Networks (DNN) to generate/transit states from which phase selection and reward computation are performed. The advantage is that the selected phases and the corresponding partial k-space data match the DNN for image reconstruction. The disadvantage lies in the impossibility of deciding/selecting a phase in as short as several milliseconds required in the timings of a typical pulse sequence. To simultaneously keep the matching advantage and avoid the inefficiency disadvantage, we propose a dual-state-based RL framework. A visible Parameter-Free (PF) state obtained by inverse Fast Fourier transform and a hidden DNN state obtained by applying a time-consuming reconstruction-oriented DNN on the visible state are called dual states. Visible states are used as input of phase decision networks and hidden states are used for computing reward to evaluate the decision networks. Because the time-consuming hidden states are merely involved in training process and only efficient visible states are computed in inference process, the proposed method is very efficient. Moreover, we demonstrate that incorporating the phase-indicator vector (containing sequentially selected phases) as an additional input to the transformer used for reconstructing from undersampled MR images can significantly improve image reconstruction accuracy. Experiments on fastMRI dataset demonstrate effectiveness and efficiency of the proposed method.

Prognostic Effect of Performance Status on Outcomes of Patients with Colorectal Cancer Receiving First-Line Chemotherapy: A Meta-analysis.

Performance status (PS) is a variable derived from the assessment of a patient's functional status, originally proposed to predict drug toxicity. However, despite its characteristic of being subjective and unidimensional, it has become one of the most important prognostic variables for patients with metastatic colorectal cancer (mCRC). In light of the considerable progressive prolongation of median overall survival (OS) of patients with mCRC, it is unclear whether PS continues to be a valid prognostic factor. This article aims to perform a meta-analysis to verify the current prognostic role of PS. A search on two databases of prospective trials of first-line chemotherapy in mCRC patients, published in English from 1991 to 2020, was done by predefined criteria. After the selection of phase III trials evaluating the prognostic role of PS, a meta-analysis has been performed. Thirteen trials were included in the meta-analysis. They reported a reduction in the risk of death with a PS 0 compared to a PS 1 or more (HR 0.63, CI 0.54-0.72; 13 studies), which was confirmed for the comparison between PS 0 and PS 1. However, the study found significant heterogeneity (Q = 68.10; p-value < 0.001) and high-grade inconsistency (I2 = 82.38%). Therefore, to explore the reasons for the heterogeneity, a univariate meta-regression was performed, which suggested a possible moderating activity for liver metastases and timing of metastasis. PS is a reliable prognostic factor for patients with mCRC receiving first-line chemotherapy but is poorly evaluated in phase III trials.

Topical delivery of seriniquinone for treatment of skin cancer and fungal infections is enabled by a liquid crystalline lamellar phase

Seriniquinone (SQ) was initially described by our group as an antimelanoma drug candidate and now also as an antifungal drug candidate. Despite its promising in vitro effects, SQ translation has been hindered by poor water-solubility. In this paper, we described the challenging nanoformulation process of SQ, which culminated in the selection of a phosphatidylcholine-based lamellar phase (PLP1). Liposomes and nanostructured lipid carriers were also evaluated but failed to encapsulate the compound. SQ-loaded PLP1 (PLP1-SQ) was characterized for the presence of sedimented or non-dissolved SQ, rheological and thermal behavior, and irritation potential with hen's egg test on the chorioallantoic membrane (HET-CAM). PLP1 influence on transepidermal water loss (TEWL) and skin penetration of SQ was assessed in a porcine ear skin model, while biological activity was evaluated against melanoma cell lines (SK-MEL-28 and SK-MEL-147) and C. albicans SC5314. Despite the presence of few particles of non-dissolved SQ (observed under the microscope 2 days after formulation obtainment), PLP1 tripled SQ retention in viable skin layers compared to SQ solution at 12 h. This effect did not seem to relate to formulation-induced changes on the barrier function, as no increases in TEWL were observed. No sign of vascular toxicity in the HET-CAM model was observed after cutaneous treatment with PLP1. SQ activity was maintained on melanoma cells after 48 h-treatment (IC50 values of 0.59–0.98 µM) whereas the minimum inhibitory concentration (MIC) against C. albicans after 24 h-treatment was 32-fold higher. These results suggest that a safe formulation for SQ topical administration was developed, enabling further in vivo studies.

Phase Selection and Microstructure Evolution in Laser Additive Manufactured Ni-Based Hardfacing Alloy Bush

Phase Selection and Microstructure Evolution in Laser Additive Manufactured Ni-Based Hardfacing Alloy Bush

A First-in-Human, Phase 1 Study to Assess the Pharmacodynamic Properties of Single-Dose Iptacopan (CLNP023X2101)

Introduction: Iptacopan is a first-in-class, oral, selective inhibitor of factor B, a key component of the complement system alternative pathway (AP). Inhibition of the complement system represents a potential mechanism for treatment of several diseases including paroxysmal nocturnal hemoglobinuria and atypical hemolytic uremic syndrome. Here, we report the exploratory pharmacodynamics of single doses of iptacopan from part 1 of the phase 1 study (CLNP023X2101) in healthy participants. Methods: CLNP023X2101 was a randomized, non-confirmatory, first-in-human assessment of iptacopan in healthy participants. Part 1 was a participant-blinded, placebo-controlled, single-ascending dose (SAD) study. SADs ranged from 5 mg to 400 mg in 56 participants across 7 cohorts. Eight participants per cohort were randomized to receive a single oral dose of iptacopan or placebo in a 3:1 ratio. Inhibition of terminal complex activity of the complement system was assessed using the Wieslab assay which was based on the in vitro formation of the C5b-9 complex, triggered by AP activation. Other soluble biomarkers measured were plasma fragment Bb, a biomarker of AP activation generated by the cleavage of Factor B, and plasma sC5b-9. Results: Demographic data were similar across the treatment groups. Most participants were men with a median age of 45 years. Iptacopan led to dose-dependent suppression of the AP activity as measured by the Wieslab assay ( Figure 1). Following administration, &amp;gt;81% reduction of the AP activity (compared with baseline) was observed at 2 hours post-dose for all dose groups except the 5-mg dose group. Duration of sustained inhibition of AP activity was dose-dependent. Greater than 80% inhibition of the AP activity compared with baseline was maintained beyond 12 hours after 200-mg and 400-mg doses. Wieslab values returned to baseline levels after 48 hours post dose except for the 200-mg and 400-mg cohorts. The decrease in Bb levels from baseline was observed at 2 hours post-dose in all groups and was sustained until 12 hours post-dose before returning to baseline levels by 48 hours ( Figure 2). In the 200-mg and 400-mg cohorts, Bb levels plateaued until 24 hours post-dose and similarly returned to baseline by 48 hours. In contrast, no significant change in Bb level was seen in participants receiving placebo. A trend to decreased sC5b-9 levels was observed until 6 hours post-dose in most cohorts (≥25 mg). Conclusions: Iptacopan achieved rapid, substantial, and sustained dose-dependent suppression of AP activity at 2 hours post-dose for all doses &amp;gt;5 mg. Further validating this result, the decrease in Bb levels at 2 hours post-dose was maintained until 12 hours post-dose, with doses ≥100 mg showing sustained inhibition beyond 12 hours. These pharmacodynamic findings of single-dose iptacopan were part of the rationale for dose selection in clinical Phase 2 and 3 studies contributing to the evidence of 200 mg twice daily being the appropriate dose.

Hplc Method Development and Validation for the Simultaneous Estimation of Pitavastatin and Telmisartan

Method validation of both the compounds was done on the basis of ICH guidelines. Validation by HPLC method the wavelength was selected at the isobestic point at which the two drugs can be detected using UV detectors. The selected wavelength was 250nm. Optimized liquid chromatographic condition was obtained by performing many trials for the selection of mobile phase and column, for the separation of Pitavastatin &amp; Telmisartan. The method development was conducted with C18, 250 × 4.6 mm, 5µm particle size, Phenomenex with the flow rate of 1.0mL/min. the optimized mobile phase conditions were Acetonitrile and 10mM Ammonium acetate buffer containing 0.1% formic acid in the ratio of 65:35 v/v. Data of Simultaneous shows retention time for Pitavastatin 5.408 &amp; Telmisartan was 7.183. The method found to be linear, accurate, rugged and robust for validated parameters. The linearity range was determined by external standard calibration method in the concentration range of 10μg/ml to 60μg/ml. The amount of recovery was calculated as 98% – 101% and it was observed that all the values are within the limits. Further the precision of the method was confirmed by the repeatable analysis of sample. The results were found to be precise due to low values of the %RSD. It indicated that the method has good precision. Limit of quantification for Pitavastatin &amp; for Telmisartan 1.554μg/ml and 4.709μg/ml respectively. Similarly limit of detection for Pitavastatin &amp; for Telmisartan 0.647μg/ml and 1.959μg/ml respectively. In the robustness study %RSD obtained for change of flow rate and wavelength and ruggedness for change of analyst was found to be below 2, which was within the acceptance criteria. So, simple, sensitive, accurate, precise RP- HPLC methods were developed and validated for the simultaneous estimation of Pitavastatin &amp; Telmisartan.

Effect Of Young Coconut Water Concentration On Bud Chip Germination Phase On Several Parts Of SugarCane (Saccharum Officinarum L.) Stems

The germination phase of sugarcane is a pivotal stage crucial for successful cultivation. Seeds derived from six to eight-month-old gardens, obtained from protrusions of sugarcane stems, are employed. These seeds exhibit characteristics of dormant buds, contributing to their suitability for germination. A single sugarcane stem typically harbors a minimum of 13 buds, and the selection of seeds with 2-8 eyes per spike is customary among farmers. However, excessive bud usage may lead to abnormal seed growth, underscoring the importance of careful selection. The study employs the rase cage test system, dividing the sugarcane stem into upper, middle, and bottom sections to determine the optimal bud quantity in each treatment. The research investigates the response of different parts of sugarcane bud chip stems to varying concentrations of coconut water growth regulator during germination. Utilizing a factorial randomized block design, the study comprises two factors: Bud chip (BA: Upper Stem, BT: Middle Stem, BB: Bottom Stem) and coconut water growth regulator concentration (Z1: 25%, Z2: 50%, Z3: 75%, Z4: 100%). Positive control involves Agrogibb at a concentration of 120 ppm, with all treatments soaked for six hours. Conducted at the Indonesian Sugar Plantation Research Center on January 10, 2023, the study reveals that the BBZ1 treatment significantly affects the observed parameter of shoot emergence, with an average of 8.1 days. Conversely, the BAZ1 treatment exhibits the fastest and most efficient shoot emergence, with an average of 5.1 days, outperforming other treatments. These findings underscore the importance of careful selection and treatment in the germination phase for optimal sugarcane productivity.

Correction: Modeling Phase Selection and Extended Solubility in Rapid Solidified Alloys

Correction: Modeling Phase Selection and Extended Solubility in Rapid Solidified Alloys

Toward understanding the microstructure characteristics, phase selection and magnetic properties of laser additive manufactured Nd-Fe-B permanent magnets

Nd-Fe-B permanent magnets play a crucial role in energy conversion and electronic devices. The essential magnetic properties of Nd-Fe-B magnets, particularly coercivity and remanent magnetization, are significantly influenced by the phase characteristics and microstructure. In this work, Nd-Fe-B magnets were manufactured using vacuum induction melting (VIM), laser directed energy deposition (LDED) and laser powder bed fusion (LPBF) technologies. The microstructure evolution and phase selection of Nd-Fe-B magnets were then clarified in detail. The results indicated that the solidification velocity (V) and cooling rate (R) are key factors in the phase selection. In terms of the VIM-casting Nd-Fe-B magnet, a large volume fraction of the α-Fe soft magnetic phase (39.7 vol.%) and Nd2Fe17B x metastable phase (34.7 vol.%) are formed due to the low R (2.3 × 10−1 °C s−1), whereas only a minor fraction of the Nd2Fe14B hard magnetic phase (5.15 vol.%) is presented. For the LDED-processed Nd-Fe-B deposit, although the Nd2Fe14B hard magnetic phase also had a low value (3.4 vol.%) as the values of V (<10−2 m s−1) and R (5.06 × 103 °C s−1) increased, part of the α-Fe soft magnetic phase (31.7 vol.%) is suppressed, and a higher volume of Nd2Fe17B x metastable phases (47.5 vol.%) are formed. As a result, both the VIM-casting and LDED-processed Nd-Fe-B deposits exhibited poor magnetic properties. In contrast, employing the high values of V (>10−2 m s−1) and R (1.45 × 106 °C s−1) in the LPBF process resulted in the substantial formation of the Nd2Fe14B hard magnetic phase (55.8 vol.%) directly from the liquid, while the α-Fe soft magnetic phase and Nd2Fe17B x metastable phase precipitation are suppressed in the LPBF-processed Nd-Fe-B magnet. Additionally, crystallographic texture analysis reveals that the LPBF-processed Nd-Fe-B magnets exhibit isotropic magnetic characteristics. Consequently, the LPBF-processed Nd-Fe-B deposit, exhibiting a coercivity of 656 kA m−1, remanence of 0.79 T and maximum energy product of 71.5 kJ m−3, achieved an acceptable magnetic performance, comparable to other additive manufacturing processed Nd-Fe-B magnets from MQP (Nd-lean) Nd-Fe-B powder.

Shear and delamination behaviour of basal planes in Zr3AlC2 MAX phase studied by micromechanical testing

The mechanical properties of layered, hexagonal-structured MAX phases often show the combined merits of metals and ceramics, making them promising material candidates for safety critical applications. While their unique mechanical performance largely arises from the crystal structure, the effect of chemistry on the properties of these materials remains unclear. To study this, here we employed two in situ electron microscope small-scale testing approaches to examine the micromechanical properties of Zr3AlC2, and compared the results with the properties of Ti3SiC2: we used micropillar compression tests to measure basal slip strength, and double cantilever beam splitting tests to evaluate fracture energy for basal plane delamination. We observed distinct and systematic differences in these measured properties between Zr3AlC2 and Ti3SiC2, where Zr3AlC2 appeared to be stronger but more brittle at the microscale, and discussed the implications of the results in the selection, design, and engineering of MAX phases for targeted engineering applications.

Modeling Phase Selection and Extended Solubility in Rapid Solidified Alloys

Modeling Phase Selection and Extended Solubility in Rapid Solidified Alloys

An improved high-impedance fault identification scheme for distribution networks based on kernel extreme learning machine

In distribution networks, high-impedance faults (HIFs) occur frequently and have a harmful impact on the distribution network. However, fault detection and fault phase selection of HIFs are challenging due to weak fault characteristics. Therefore, this paper proposes an improved HIF identification scheme based on a kernel extreme learning machine (KELM) that can sensitively identify HIFs and select the fault phase by adaptively extracting the weak fault characteristics. First, a fault feature extraction strategy based on discrete wavelet decomposition (DWT) and the Hilbert–Huang transform (HHT) is proposed to obtain multiple features that describe the weak fault characteristics of HIFs. Second, an XGBoost-based fault feature selection scheme is proposed for screening with sensitive characterization of HIFs. Next, a sensitive and accurate HIF identification scheme based on the improved learning algorithm (KELM) is proposed to enable accurate and sensitive HIF detection and phase selection. Finally, numerical simulations based on PSCAD/EMTDC and MATLAB were carried out, which reveals the effectiveness and accuracy of the proposed HIF identification scheme. Compared with the traditional HIF identification scheme, the proposed method exhibits conciseness and correctness.

Unveiling the Structural Characteristics of Intergrowth Zeolites Synthesized in the Presence of Isopropylimidazolium-Based Cations and Fluoride Anions.

Here, we present the synthesis of RTH/ITE and MEL/MFI intergrowth zeolites using 2-isopropylimidazolium-based cations as organic structure-directing agents (OSDAs) in concentrated fluoride media and their local structural properties. Phase selectivity in the synthesis of zeolite intergrowths was found to differ according to the concentration of OSDA cations and fluoride anions in the synthesis mixture as well as to the type of OSDA employed. Molecular modeling results suggest that the crystallization of intergrowth zeolites in fluoride media may be kinetically rather than thermodynamically controlled, as in ordered zeolites. Cs-corrected STEM analysis of MEL/MFI crystals synthesized at HF/OSDA = 2.0 in the presence of 2-isopropyl-1,3-dipropylimidazolium ions as an OSDA indicates the existence of previously unobserved MEL-MFI intergrowth along the [100] direction, leading to a partial blockage of MEL 10-ring channels.

Interface Response Functions for multicomponent alloy solidification—An application to additive manufacturing

The near-rapid solidification conditions during additive manufacturing can lead to selection of non-equilibrium phases. Sharp interface models via interface response functions have been used earlier to explain the microstructure selection under such solidification conditions. However, most of the sharp interface models assume linear superposition of contributions of alloying elements without considering the non-linearity associated with the phase diagram. In this report, both planar and dendritic Calphad coupled sharp interface models have been implemented and used to explain the growth-controlled phase selection observed at high solidification velocities relevant to additive manufacturing. The implemented model predicted the growth-controlled phase selection in multicomponent alloys, which the other models with linear phase diagram could not. These models are calculated for different steels and the results are compared with experimental observations.

Observation of atomically displacive transformation out of the boundary-reconstructive phase competition

During the phase transitions, diverse states evolve with multiplex phenomena arising from the critical competition. In this study, a displacive martensitic transformation with a lattice shear distortion was unexpectedly observed at the reconstructive phase boundary that usually connects multiple phases without crystallographic relation, in a Ni–Co–Mn–V all-d-metal Heusler alloy system. Experiments and theoretical calculations suggest that the parent phase becomes increasingly unstable when approaching the phase boundary. The lattice-distorted transformation with moderate first-order nature survives due to the critical phase competition from the structural frustration, in which the comparable energy and the diminished formation preference of different phases emerge. In this critical state, the phase selection including the martensitic transformation can be tuned by external fields such as rapid cooling, annealing, and magnetic field. Our research reveals a novel manner to destabilize the parent phase, through which one could attain new functional materials based on the phase transitions.

Faulted phase selection multicriteria algorithm implemented in generic hardware for centralized P&C in smart grids

The integration of devices based on renewable energies and power electronics makes it necessary to rethink some of the methods used for protection and control in distribution and transmission grids. The difference between short circuit current contributions from renewable and conventional generators may affect protection system operation. Fault phase selection is one of the elements to be analyzed under renewable generation scenarios due to its importance in protection functions such as distance protection.The digitization of substations presents new opportunities in control and protection systems, such as functionality increase, reliability improvement, cost reduction of the installation and capacity for remote maintenance. This paper proposes a multi-criteria fault phase selection algorithm developed to be implemented in digital substations. The proposed faulted phase algorithm combines the results provided by four independent protection algorithms and has been designed to be applied in transmission power systems. Depending on the electrical variables measured in each event, quality criteria are defined to consider the strengths and weaknesses of each independent algorithm. The proposed algorithm has been implemented and tested on the centralized protection and control platform called EPICS, obtaining very satisfactory results.

Solidification behavior and microstructure of Ag–Cu eutectic alloy at different sub-rapid cooling rates

The microstructures of rapidly solidified Ag-39.9 at. % Cu eutectic alloys have been widely studied, while the research between microstructures and sub-rapid cooling rates is still lacking. Ag-39.9 at. % Cu eutectic alloy was solidified in quartz crucibles under different conditions. The alloy that was melted and in-situ cooled in a quartz crucible to room temperature solidified into eutectic dendrites composed of regular lamellae. The alloy that was melted and injection cast into a quartz crucible solidified into equiaxed eutectic colonies with primary α-Ag phase embedded. If the quartz crucible was further immersed in a gallium-indium liquid, a new spherical eutectic colony structure was found, with anomalous eutectic or primary α-Ag phase at the central part and a “ring” of coarse lamellar eutectic structure separating the eutectic colony into two parts. It is demonstrated that the cooling rate influences not only the primary phase selection and eutectic lamellar spacing, but also the eutectic nucleation and growth mode.

Solid-source metal-organic MBE for elemental Ir and Ru films

Thin films of elemental metals play a very important role in modern electronic nano-devices as conduction pathways, spacer layers, spin-current generators/detectors, and many other important functionalities. In this work, by exploiting the chemistry of solid metal-organic source precursors, we demonstrate the molecular beam epitaxy synthesis of elemental Ir and Ru metal thin films. The synthesis of these metals is enabled by thermodynamic and kinetic selection of the metal phase as the metal-organic precursor decomposes on the substrate surface. Film growth under different conditions was studied using a combination of in situ and ex situ structural and compositional characterization techniques. The critical role of substrate temperature, oxygen reactivity, and precursor flux in tuning film composition and quality is discussed in the context of precursor adsorption, decomposition, and crystal growth. Computed thermodynamics quantifies the driving force for metal or oxide formation as a function of synthesis conditions and changes in chemical potential. These results indicate that bulk thermodynamics are a plausible origin for the formation of Ir metal at low temperatures, while Ru metal formation is likely mediated by kinetics.

Ensiling alfalfa of foreign selection with experimental biological preparations

The article considers the results of a laboratory study of the use of experimental preparations Inoculant 1 and Inoculant 2, containing live bacteria and their combinations, in the preparation of silage from the green mass of alfalfa of foreign selection in the budding phase. The mass fraction of moisture, crude protein (CP), crude fiber (CF), as well as the concentration of the mass fraction of organic acids (lactic, acetic and butyric) were determined. The positive influence of the consortium of microorganisms in the preservation of nutrients and energy of the finished silage has been established. Elevated indicators of dry matter and metabolic energy in experimental samples were revealed, the concentration of which is significantly higher than the control ones in terms of dry matter - by 1.55 and 1.69%, in terms of metabolic energy - by 2.60 and 1.38%.

Phase selectivity and environmental stability of 612‐aluminate synthesized by sintering Co‐precipitated precursor

AbstractThe environmental stability of barium calcium aluminate for impregnated cathodes is significant for storing impregnants and fabricating thermionic cathodes. In this work, two types of phase structures are obtained in the 612‐type aluminate. The Ba3CaAl2O7 single‐phase structure is obtained if the crucible is uncovered after sintering for 300 min at 1200°C. In contrast, the Ba3Al2O6 and BaCO3 dual‐phase structure is achieved by suppressing the solid‐state reaction by covering the crucible and reducing the sintering duration to 75 min. The dual‐phase sample exhibits superior environment stability to the single‐phase one when exposed to moist air. The reason could be attributed to the smaller specific surface area and total pore volume of the dual‐phase sample due to the incomplete liberty of gases in sintering. Because of their identical compositions, the cathodes impregnated with different sintered phases possess comparable electron emission capacities. This work provides an effective process to synthesize 612‐aluminate with good environmental stability and emissive capacity.