Resurrected and Tunable Conductivity and Ferromagnetism in the Secondary Growth La0.7Ca0.3MnO3 on Transferred SrTiO3 Membranes.

To avoid the epitaxy dilemma in various thin films, such as complex oxide, silicon, organic, metal/alloy, etc., their stacking at an atomic level and secondary growth are highly desired to maximize the functionality of a promising electronic device. The ceramic nature of complex oxides and the demand for accurate and long-range-ordered stoichiometry face severe challenges. Here, the transport and magnetic properties of the La0.7Ca0.3MnO3 (LCMO) secondary growth on single-crystal freestanding SrTiO3 (STO) membranes are demonstrated. It has been experimentally found that on an only 10 nm thick STO membrane, the LCMO can offer a bulk-like Curie temperature (TC) of 253 K and negative magnetoresistance of -64%, with a weak dependence on the thickness. The resurrected conductivity and ferromagnetism in LCMO confirm the advantages of secondary growth, which benefits from the excellent flexibility and transferability. Additionally, this study explores the integration strategy of complex oxides with other functional materials.

Current-Induced Magnetization Switching in Light-Metal-Oxide/Ferromagnetic-Metal Bilayers via Orbital Rashba Effect.

The orbital angular momentum (OAM) generation as well as its associated orbital torque is currently a matter of great interest in spin-orbitronics and is receiving increasing attention. In particular, recent theoretical work predicts that the oxidized light metal Cu can serve as an efficient OAM generator through its surface orbital Rashba effect. Here, for the first time, the crucial current-induced magnetic-field-free in-plane magnetization reversal is experimentally demonstrated in CoFeB/CuOx bilayers without any heavy elements. We show that the critical current density can be comparable to that of strong spin-orbit coupling systems with heavy metals (Pt and Ta) and that the magnetization reversal mechanism is governed by coherent rotation in the grains through the second-harmonic and magneto-optical Kerr effect measurements. Our results indicate that light metal oxides can play an equally important role as heavy metals in magnetization reversal, broadening the choice of materials for engineering spintronic devices.

Enhanced oxygen evolution reaction via the tunability of spin polarization and electronic states in a flexible van der Waals membranous catalyst.

The response of the magnetic field and strain engineering in an electrochemical process, such as the oxygen evolution reaction (OER), not only provides a strategy for enhancing catalytic performance through external fields and mechanical stress but also serves as a platform for revealing the functionality of multiple degrees of freedom in catalysts. The perovskite transition metal oxide (TMO) thin film with precise stoichiometry and lattice ordering enables atomic-level catalysis mechanisms in various electrochemical processes, thereby facilitating the design and engineering of promising catalysts. However, the perplexing dominance of spin in an OER process is still a puzzle due to the strong correlation between transition metal d and oxygen p orbitals. In this study, we utilized La0.7Sr0.3MnO3 (LSMO) manganite as a ferromagnetic OER catalyst, which was directly deposited onto a flexible mica substrate. By subjecting LSMO to a tensile stress, we observed an enhanced OER, and the OER performance of LSMO improved by 30% with a +0.2% strain due to the weakened chemisorption of Mn-O. Moreover, it has been observed that the OER performance can be improved by approximately 87%, while the overpotential can be reduced by around 22% through the combination of a 5 kOe magnetic field and +0.2% strain. The OER performance of LSMO changed by ∼153% under 4% strain and 5 kOe magnetic field. Our experiments indicate that the primary source of the observed magnetic response is derived from the triplet state of O2, in which spin-polarized d and oxygen p orbitals decrease the spin potential within OER. This study provides experimental evidence for understanding the spin degree and electronic state regulation in the OER process, thereby facilitating further design and engineering of flexible magnetic electrochemistry catalysts with promising potential.

The modulated oxygen evolution reaction performance of LaFeO3 with abundant electronic structures via a design of stoichiometry offset.

Transition metal oxides have been widely employed as electrocatalysts in various electrochemical processes such as oxygen evolution reaction (OER) owing to their designable adsorption/desorption ability of water intermediates by engineering their electronic structures. However, the coexistence of multiple chemical valences of the transition metal always hides the realization of the functional active phase in OER. In this study, we have performed the OER measurements on LaFeO3 (LFO) catalysts to reveal the complex relationships between 3d electronic structure and its OER responses; herein, several electronic statuses, including t42ge2g (S = 2), t52ge1g (S = 1), or t62ge0g (S = 0) of Fe ions, can be dominantly achieved by the design of stoichiometry offset in LFO. It is found that the current density of LFO at 1.9 V shows a volcanic dependence on the oxygen content. After the comprehensive characterization of Fe and oxygen ions in LFO by X-ray photoelectron spectroscopy and magnetic hysteresis measurements, we have found the OH- adsorption capacity and exchange interaction of Fe ions jointly determine the OER performance. Our research provides a stepwise evolution of the multiple spin states in LFO, and their subsequent OER responses are demonstrated, which can benefit the fundamental understanding of the link between 3d electronic structure and OER performance and the design for further promising transition metal oxide catalysts.

Maternal pre-pregnancy BMI, MTHFR polymorphisms, and the risk of adverse pregnancy outcomes in pregnant women from South China: a retrospective cohort study.

BACKGROUND: Increasing evidence suggests an association between maternal pre-pregnancy body mass index (pre-BMI) and adverse pregnancy outcomes. However, the effects of methylenetetrahydrofolate reductase (MTHFR) polymorphisms on these relationships require further investigation. This study aimed to investigate whether the relationship between pre-BMI and the risk of adverse pregnancy outcomes was influenced by MTHFR gene polymorphisms. METHODS: A total of 5614 mother-fetus pairs were included in the study. The odds ratios (OR) of adverse pregnancy complications, including gestational diabetes mellitus (GDM), gestational hypertension (GHT), cesarean delivery (CS), and premature rupture of membranes (PROM), were estimated using adjusted logistic regression models and subgroup analysis. RESULTS: Pregnant women with higher pre-BMI values were positively related to the risk of GDM, GHT, and CS. In the subgroup analysis, underweight BMI was associated with a decreased risk of CS and GDM in pregnant women with the MTHFR A1298C AA or C677T CC genotype, while overweight/obese BMI was associated with an increased risk of GDM and CS in different MTHFR variants. Moreover, pregnant women with MTHFR A1298C AC + CC or C667T CC were found to have an increased risk of GHT in the MTHFR A1298C AA or C667T CT + TT genotype. A remarkable association was observed between the obesity group with MTHFR A1298C AC + CC (OR = 6.49, CI: 2.67-15.79) and the overweight group with the C667T CC genotype (OR = 4.72, CI: 2.13-10.45). CONCLUSIONS: MTHFR gene polymorphisms exert a modifying effect on the association between maternal pre-BMI and the risk of GHT, CS, and GDM. Pregnant women with a high pre-BMI with specific MTHFR genotypes should be considered for GHT development.

Strain Modified Oxygen Evolution Reaction Performance in Epitaxial, Freestanding, and Van Der Waals Manganite Thin Films.

In perovskite complex oxides, the strain has been established as a promising approach for tuning the oxygen evolution reaction (OER) performance by the manipulated electronic structure and interaction/coupling. In this study, we have employed rigid epitaxial, flexible freestanding, and van der Waals La2/3Sr1/3MnO3 (LSMO) to investigate the strain effects on OER, which are different in stress strength and range via lattice mismatch and curvature change. It was found that the OER performances as a function of strain exhibited volcano and monotonous trends in rigid and flexible LSMO, respectively. The findings suggest that distinguished oxygen activation energy in varied lattice fields also plays a crucial role in the epitaxial LSMO in contrast to the pure strain effect in the flexible LSMO. Our results not only fundamentally clarify the effort of strain but also technologically provide an effective route to engineer the electronic structure for modified OER performance by perovskite complex oxides.

[Determination of quinoxalines veterinary drug residues in food products of animal origin by high performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method for simultaneous determination of olaquindox, quinoxaline-2-carboxylic acid, 3-methyl-quinoxaline-2-carboxylic acid in food products of animal origin. METHODS: Samples were extracted with ethyl acetate-0.1 mol/L sodium dihydrogen phosphate(1∶9, V/V) solution in water bath at 40 ℃, purified by solid phase extraction column(olaquindox uses HLB SPE cartridge, quinoxaline-2-carboxylic acid and 3-methyl-quinoxaline-2-carboxylic acid use MAX SPE cartridge), evaporated by concentrator, and dissolved by mobile phase. The supernatant was separated on Agilent ZORBAX SB-C_(18) column(2.1 mm×50 mm, 1.8 m), using 0.2% formic acid solution methanol solution as mobile phase, and then detected by HPLC-MS/MS using multiple reaction monitoring(MRM) in positive ionization mode. RESULTS: The linear range for olaquindox、quinoxaline-2-carboxylic acid and 3-methyl-quinoxaline-2-carboxylic acid were 2.5-100 µg/L, r & gt; 0.9990.The average recoveries were 72.6%-90.5% and the precisions were 3.2%-13.1%(n=6). The detection limits for olaquindox、quinoxaline-2-carboxylic acid and 3-methyl-quinoxaline-2-carboxylic acid were 0.08 µg/kg. CONCLUSION: The method is specific, sensitive, easy, fast and suitable for the confirmation and quantification of olaquindox、quinoxaline-2-carboxylic acid、3-methyl-quinoxaline-2-carboxylic acid in food products of animal origin.

The diagnostic value of (1,3)-ß-D-glucan alone or combined with traditional inflammatory markers in neonatal invasive candidiasis.

BACKGROUND: Asymptom of invasive candidiasis (IC) and low positive rate of blood culture lead to delay diagnose of neonatal infection. Serum (1,3)-ß-D-glucan (BDG) performs well in adult IC, but its use in neonatal IC is unclear. We evaluated the use of BDG, procalcitonin (PCT), high-sensitive C-reactive protein (hsCRP) or platelet count (PC) in neonatal IC. METHODS: We collected the data of neonates admitted to our institute. Eighty neonates were enrolled, and divided into IC group, bacterial infection (BI) group and control (CTRL) group. We analyzed the difference of these indicators between groups, and generated Receiver operator characteristic (ROC) curve. The value of BDG in antifungal therapy efficacy assessment was also investigated. RESULTS: The BDG level was higher in IC group compared with BI and CTRL group. C. albicans lead to significant increase of BDG compared with C. parapsilosis. IC group had highest hsCRP level and lowest PC. PCT level was similar between groups. ROC showed that BDG or hsCRP performs well in neonatal IC, the optimal cut-off for BDG was 13.69 mg/ml. Combined BDG with hsCRP, PCT and PC increased diagnostic value. Serum BDG level was decreased during antifungal treatment. CONCLUSION: Serum BDG performs well in identification of neonatal IC and in monitoring the antifungal therapy efficacy.

Rapid identification of Brucella sepsis/osteomyelitis in a 6-year old febrile patient with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry directly from positive blood culture: a case report.

BACKGROUND: Brucella is high-consequence pathogen and one of the most common seen laboratory- acquired infection pathogens. Quick and accurate detection of the pathogen will be of great important to reducing laboratory- acquired infection. Traditional biomedical reaction based method is time consumption, and mass spectrometry based method greatly reduces time consumption in pathogen identification. In the case presented here, we shared our experience in identification of Brucella directly from positive blood culture with mass spectrometry based method. CASE PRESENTATION: The patient is a 6-year boy with a history of three weeks fever accompanied with sweating and a pain at right patella. The patient also has a history of thalassemia and blood transfusion was performed previously admitted to our hospital. Two bottles of marrow culture and one bottle of blood culture were positive, and direct mass spectrometry from positive culture material revealed Brucella infection within 1 h. CONCLUSION: Clinical characters and laboratory findings of the patient presented here might help clinician in non-endemic region to made suspected brucellosis diagnose. Our experience in rapid identification of Brucella from positive blood culture with MALDI-TOF SP could help preventing laboratory-acquired infection of Brucella.

The Effect of Polar Fluctuation and Lattice Mismatch on Carrier Mobility at Oxide Interfaces.

Since the discovery of two-dimensional electron gas (2DEG) at the oxide interface of LaAlO3/SrTiO3 (LAO/STO), improving carrier mobility has become an important issue for device applications. In this paper, by using an alternate polar perovskite insulator (La0.3Sr0.7) (Al0.65Ta0.35)O3 (LSAT) for reducing lattice mismatch from 3.0% to 1.0%, the low-temperature carrier mobility has been increased 30 fold to 35,000 cm(2) V(-1) s(-1). Moreover, two critical thicknesses for the LSAT/STO (001) interface are found, one at 5 unit cells for appearance of the 2DEG and the other at 12 unit cells for a peak in the carrier mobility. By contrast, the conducting (110) and (111) LSAT/STO interfaces only show a single critical thickness of 8 unit cells. This can be explained in terms of polar fluctuation arising from LSAT chemical composition. In addition to lattice mismatch and crystal symmetry at the interface, polar fluctuation arising from composition has been identified as an important variable to be tailored at the oxide interfaces to optimize the 2DEG transport.

Ultrathin BaTiO3-based ferroelectric tunnel junctions through interface engineering.

The ability to change states using voltage in ferroelectric tunnel junctions (FTJs) offers a route for lowering the switching energy of memories. Enhanced tunneling electroresistance in FTJ can be achieved by asymmetric electrodes or introducing metal-insulator transition interlayers. However, a fundamental understanding of the role of each interface in a FTJ is lacking and compatibility with integrated circuits has not been explored adequately. Here, we report an incisive study of FTJ performance with varying asymmetry of the electrode/ferroelectric interfaces. Surprisingly high TER (∼400%) can be achieved at BaTiO3 layer thicknesses down to two unit cells (∼0.8 nm). Further our results prove that band offsets at each interface in the FTJs control the TER ratio. It is found that the off state resistance (R(Off)) increases much more rapidly with the number of interfaces compared to the on state resistance (ROn). These results are promising for future low energy memories.

COP1, the negative regulator of ETV1, influences prognosis in triple-negative breast cancer.

BACKGROUND: ETS variant 1 (ETV1) and E3 ubiquitin ligase constitutive photomorphogenetic 1 (COP1) have been proposed to be a pair of oncogene and tumor suppressor. However, the co-existing status of ETV1 and COP1 in triple-negative breast cancer (TNBC) and their predictive role in determining the patient's outcome are uncertain. METHODS: We examined the abundance of COP1 and ETV1 proteins and their clinicopathologic significance in archival TNBC tissues from 105 patients by tissue microarray. The potential function link between COP1 and ETV1 was observed in MDA-MB-231 cells by cell proliferation, invasion and migration assays. RESULTS: ETV1 expression was higher in TNBC tissues compared to normal tissues, while COP1 was lower. ETV1 expression was negatively associated with COP1 abundance in TNBCs. Overexpression of COP1 led to significant reduction of ETV1 in MDA-MB-231 cells, and suppressed the cells migration and invasion. Rescue of ETV1 expression in the presence of COP1 notably regained the cells behaviors. ETV1-positive group was associated with a markedly poor overall survival. Meanwhile, we had observed favourable prognosis in COP1-positive cases for the first time. Multivariate analysis showed that COP1 together with ETV1 were independent risk factors in the prognosis of TNBC patients. CONCLUSIONS: COP1 might be a tumor suppressor by negative regulating ETV1 in patients with TNBCs. COP1 and ETV1 are a pair of independent predictors of prognosis for TNBC cases. Thus, targeting them might be a potential strategy for personalized TNBC treatment.

Gas-Phase-Induced Engineering for Fabrication of 3D Hierarchical Porous Nickel and Its Application toward High-Performance Supercapacitors.

Commercial nickel foam (NF), which is composed of numerous interconnected ligaments and hundred-micron pores, is widely acknowledged as a current collector/electrode material for catalysis, sensing, and energy storage applications. However, the commonly used NF often does not work satisfactorily due to its smooth surface and hollow structure of the ligaments. Herein, a gas-phase-induced engineering, two-step gaseous oxidation-reduction (GOR) is presented to directly transform the thin-walled hollow ligament of NF into a three-dimensional (3D) nanoporous prism structure, resulting in the fabrication of a unique hierarchical porous nickel foam (HPNF). This 3D nanoporous architecture is achieved by utilizing the spontaneous reconstruction of nickel atoms during volume expansion and contraction in the GOR process. The process avoids the involution of acid-base corrosion and sacrificial components, which are facile, environmentally friendly, and suitable for large-scale fabrication. Furthermore, MnO2 is electrochemically deposited on the HPNF to form a supercapacitor electrode (HPNF/MnO2). Because of the fully open structure for ion transport, superhydrophilic properties, and the increased contact area between MnO2 and the current collector, the HPNF/MnO2 electrode exhibits a high specific capacitance of 997.5 F g-1 at 3 A g-1 and remarkable cycling stability with 99.6% capacitance retention after 20000 cycles in 0.1 M Na2SO4 electrolyte, outperforming most MnO2-based supercapacitor electrodes.

Giant Electroresistance in Ferroelectric Tunnel Junctions via High-Throughput Designs: Toward High-Performance Neuromorphic Computing.

Ferroelectric tunnel junctions (FTJs) have been regarded as one of the most promising candidates for next-generation devices for data storage and neuromorphic computing owing to their advantages such as fast operation speed, low energy consumption, convenient 3D stack ability, etc. Here, dramatically different from the conventional engineering approaches, we have developed a tunnel barrier decoration strategy to improve the ON/OFF ratio, where the ultrathin SrTiO3 (STO) dielectric layers are periodically mounted onto the BaTiO3 (BTO) ferroelectric tunnel layer using the high-throughput technique. The inserted STO enhances the local tetragonality of the BTO, resulting in a strengthened ferroelectricity in the tunnel layer, which greatly improves the OFF state and reduces the ON state. Combined with the optimized oxygen migration, which can further manipulate the tunneling barrier, a record-high ON/OFF ratio of ∼108 has been achieved. Furthermore, utilizing these FTJ-based artificial synapses, an artificial neural network has been simulated via back-propagation algorithms, and a classification accuracy as high as 92% has been achieved. This study screens out the prominent FTJ by the high-throughput technique, advancing the tunnel layer decoration at the atomic level in the FTJ design and offering a fundamental understanding of the multimechanisms in the tunnel barrier.

Ultralow Strain-Induced Emergent Polarization Structures in a Flexible Freestanding BaTiO3 Membrane.

The engineering of ferroic orders, which involves the evolution of atomic structure and local ferroic configuration in the development of next-generation electronic devices. Until now, diverse polarization structures and topological domains are obtained in ferroelectric thin films or heterostructures, and the polarization switching and subsequent domain nucleation are found to be more conducive to building energy-efficient and multifunctional polarization structures. In this work, a continuous and periodic strain in a flexible freestanding BaTiO3 membrane to achieve a zigzag morphology is introduced. The polar head/tail boundaries and vortex/anti-vortex domains are constructed by a compressive strain as low as ≈0.5%, which is extremely lower than that used in epitaxial rigid ferroelectrics. Overall, this study c efficient polarization structures, which is of both theoretical value and practical significance for the development of next-generation flexible multifunctional devices.

Multi-Label Classification With Dual Tail-Node Augmentation for Drug Repositioning.

Due to the lengthy and costly process of new drug discovery, increasing attention has been paid to drug repositioning, i.e., identifying new drug-disease associations. Current machine learning methods for drug repositioning mainly leverage matrix factorization or graph neural networks, and have achieved impressive performance. However, they often suffer from insufficient training labels of inter-domain associations, while ignore the intra-domain associations. Moreover, they often neglect the importance of tail nodes that have few known associations, which limits their effectiveness in drug repositioning. In this paper, we propose a novel multi-label classification model with dual Tail-Node Augmentation for Drug Repositioning (TNA-DR). We incorporate disease-disease similarity and drug-drug similarity information into k-nearest neighbor ( kNN) augmentation module and contrastive augmentation module, respectively, which effectively complements the weak supervision of drug-disease associations. Furthermore, before employing the two augmentation modules, we filter the nodes by their degrees, so that the two modules are only applied to tail nodes. We conduct 10-fold cross validation experiments on four different real-world datasets, and our model achieves the state-of-the-art performance on all the four datasets. We also demonstrate our model's capability of identifying drug candidates for new diseases and discovering potential new links between existing drugs and diseases.

A New Insight into the Singlet Oxygen Mechanism for Photodynamic Therapy.

Modern photodynamic therapy has been built on the mechanism of the interaction between the photosensitizer (porphyrin derivatives) and oxygen to produce singlet oxygen, which relies on energy transfer from the triplet excited state (T1) of porphyrin to the excited state of oxygen. In this process, the energy transfer from the singlet excited state (S1) of porphyrin to oxygen is believed to be not pronounced as the rapid decay of S1 and the large energy mismatch. Here, we have evidenced the existence of an energy transfer between S1 and oxygen, which can contribute to the production of singlet oxygen. For hematoporphyrin monomethyl ether (HMME), the Stern-Volmer constant of S1 (KSV') is 0.023 kPa-1, according to the oxygen concentration-dependent steady fluorescence intensities. In addition, fluorescence dynamic curves of S1 under various oxygen concentrations have also been measured through ultrafast pump probe experiments to further verify our results.

Magnetic Field-Enhanced Oxygen Evolution Reaction via the Tuneability of Spin Polarization in a Half-Metal Catalyst.

The magnetic field response of an electrochemistry process, such as the oxygen evolution reaction (OER), provides not only a strategy for enhanced catalytic activity by applying an external field but also a platform for revealing the functionality of the multiple degrees of freedom of the catalyst. However, the mechanism of the magnetic field tuneable OER is controversial. The strong correlation between the d and p orbitals of transition metal and oxygen still puzzles the dominant role of spin in an OER process. Here in this study, we have employed the manganite La0.7Sr0.2Ca0.1MnO3 as the ferromagnetic OER catalyst, which has a ferromagnetic/paramagnetic transition (TC) around the room temperature. It is found that the overpotential can be reduced by ∼18% after applying a 5 kOe magnetic field. Furthermore, this magnetic field can trigger a further improvement of the OER performance, and it demonstrates a strong temperature dependence which is incongruent with its magnetoresistive behavior. So our experiments suggest that the observed magnetic response originates dominantly from the triplet state of the O2, where the spin-polarized d and oxygen p orbitals lower the Gibbs free energy for every reaction step in OER. This study offers experimental evidence on comprehending the spin degree in the OER process, meanwhile benefiting the further design and engineering of the promising magnetic electrochemistry catalysts.

Enhanced OER Performance and Dynamic Transition of Surface Reconstruction in LaNiO3 Thin Films with Nanoparticles Decoration.

In an electrocatalytic process, the cognition of the active phase in a catalyst has been regarded as one of the most vital issues, which not only boosts the fundamental understanding of the reaction procedure but also guides the engineering and design for further promising catalysts. Here, based on the oxygen evolution reaction (OER), the stepwise evolution of the dominant active phase is demonstrated in the LaNiO3 (LNO) catalyst once the single-crystal thin film is decorated by LNO nanoparticles. It is found that the OER performance can be dramatically improved by this decoration, and the catalytic current density at 1.65 V can be enhanced by ≈1000% via ≈109 cm-2 nanoparticle adhesion after extracting the contribution of surface enlargement. Most importantly, a transition of the active phase from LNO to NiOOH via surface reconstruction with the density of LNO nanoparticles is demonstrated. Several mechanisms in terms of this active phase transition are discussed involving lattice orientation-induced change of the surface energy profile, the lattice oxygen participation, and the A/B-site ions leaching during OER cycles. This study suggests that the active phases in transition metal-based OER catalysts can transform with morphology, which should be corresponding to distinct engineering strategies.

Extreme Enhanced Curie Temperature and Perpendicular Exchange Bias in Freestanding Ferromagnetic Superlattices.

Most recently, the freestanding of an epitaxial single-crystal oxide has been greatly developed to its fundamental concerns and the possibility of integration with metal, two-dimensional, and organic materials for more promising functionalities. In an artificial ferromagnetic oxide heterostructure and superlattice, the release of the substrate constraint can induce a reasonable transformation of the magnetic structure because the change of the lattice field occurs. In this study, we have comprehensively investigated the evolution of magnetic properties of (La0.7Ca0.3MnO3/SrRuO3)n [(LCMO/SRO)n] ferromagnetic superlattices while they are epitaxially on SrTiO3 and freestanding. It is found that the Curie temperature and the perpendicular exchange bias of the freestanding superlattices exhibit extreme sensitivity to the interface number and the thickness of LCMO and SRO, which can maximumly reach ∼293 K and ∼1150 Oe. These enhanced and bulk-beyond magnetic behaviors originate from the interfacial magnetic transition from ferromagnetic to antiferromagnetic via the charge reconstruction with the assistance of strain. Our study provides not only a reference for designing a high-performance flexible ferromagnetic architectural superlattice but also a deep understanding of the interfacial effect in freestanding ferromagnetic heterostructures benefiting flexible spintronics.