Dislocation Majorana bound states in iron-based superconductors.

We show that lattice dislocations of topological iron-based superconductors such as FeTe1-xSex will intrinsically trap non-Abelian Majorana quasiparticles, in the absence of any external magnetic field. Our theory is motivated by the recent experimental observations of normal-state weak topology and surface magnetism that coexist with superconductivity in FeTe1-xSex, the combination of which naturally achieves an emergent second-order topological superconductivity in a two-dimensional subsystem spanned by screw or edge dislocations. This exemplifies a new embedded higher-order topological phase in class D, where Majorana zero modes appear around the "corners" of a low-dimensional embedded subsystem, instead of those of the full crystal. A nested domain wall theory is developed to understand the origin of these defect Majorana zero modes. When the surface magnetism is absent, we further find that s± pairing symmetry itself is capable of inducing a different type of class-DIII embedded higher-order topology with defect-bound Majorana Kramers pairs. We also provide detailed discussions on the real-world material candidates for our proposals, including FeTe1-xSex, LiFeAs, ß-PdBi2, and heterostructures of bismuth, etc. Our work establishes lattice defects as a new venue to achieve high-temperature topological quantum information processing.

The experiences of children and adolescents with cancer returning to school: A qualitative meta-synthesis.

BACKGROUND: Returning to school can be challenging for children and adolescents with cancer who have been absent for a long time. As there is little known about the return to school experience of children and adolescents with cancer, this meta-synthesis aimed to describe the experiences of children and adolescent cancer patients as they return to school. METHODS: Seven English databases and three Chinese databases were searched from inception to March 14, 2023. The Joanna Briggs Institute Qualitative Assessment and Review Instrument (JBI-QARI) was used to appraise study quality. Data were synthesized using the Thomas and Harden thematic and content analysis method. RESULTS: Twelve qualitative studies met the inclusion criteria and were analyzed into meta-synthesis. Data synthesis led to constructing four analytical themes and twelve sub-themes. The four major themes constructed were:benefits to school re-entry, barriers to school re-entry, motivators to school re-entry and the adaptation process after returning to school. CONCLUSION: Children and adolescents with cancer were willing to return to education and can adapt to school life over time. But they were faced with challenges, including physical, psychological, and social barriers. Appropriate measures need to be taken to reduce those barriers. IMPLICATIONS TO PRACTICE: Findings can be used to inform future research and interventions to support a successful return to education for children and adolescents with cancer. Healthcare providers should address the needs of children and adolescents at different stages and actively work with schools, hospitals and families to help childhood cancer survivors successfully return to school.

Topological superconducting vortex from trivial electronic bands.

Superconducting vortices are promising traps to confine non-Abelian Majorana quasi-particles. It has been widely believed that bulk-state topology, of either normal-state or superconducting ground-state wavefunctions, is crucial for enabling Majorana zero modes in solid-state systems. This common belief has shaped two major search directions for Majorana modes, in either intrinsic topological superconductors or trivially superconducting topological materials. Here we show that Majorana-carrying superconducting vortex is not exclusive to bulk-state topology, but can arise from topologically trivial quantum materials as well. We predict that the trivial bands in superconducting HgTe-class materials are responsible for inducing anomalous vortex topological physics that goes beyond any existing theoretical paradigms. A feasible scheme of strain-controlled Majorana engineering and experimental signatures for vortex Majorana modes are also discussed. Our work provides new guidelines for vortex-based Majorana search in general superconductors.

Relationship between cognitive emotion regulation strategies and coronary heart disease: an empirical examination of heart rate variability and coronary stenosis.

OBJECTIVE: Despite longstanding interest in emotion regulation and cardiovascular health, limited studies have investigated the relationship between cognitive emotion regulation (CER) strategies and coronary heart disease (CHD) using objective measures of heart rate variability (HRV) and coronary stenosis. This study aimed to objectively explore the associations between CER strategies and both HRV and coronary stenosis and provide empirical evidence for the relationship between emotion regulation and CHD. METHODS: Questionnaires on CER strategies were distributed to 251 CHD patients and 250 healthy persons. HRV and coronary stenosis were measured for CHD respondents using the 24-h dynamic electrocardiogram and coronary angiography, respectively. RESULTS: CHD patients with low HRV/severe stenosis used maladaptive emotion regulation more frequently and adaptive emotion regulation less frequently. Various maladaptive emotion regulation strategies (e.g. acceptance, rumination, putting into perspective) were positively associated with lower HRV and coronary stenosis severity, while adaptive emotion regulation strategies (e.g. positive refocusing, refocusing on planning) were negatively associated with lower HRV and coronary stenosis severity. CONCLUSIONS: Patients with more serious diseases exhibited increased maladaptive emotion regulation, which was associated with lower HRV and severe coronary stenosis. Further, adaptive emotion regulation was associated with higher HRV and moderate coronary stenosis.

The Psychological Adaptation Process in Chinese Parent Caregivers of Pediatric Leukemia Patients: A Qualitative Analysis.

BACKGROUND: Psychological stresses caused by caring for pediatric leukemia patients can affect their parent caregivers' health. How these stressors are successfully managed determines how well these caregivers adapt to the illness situation over time. Previous studies suggest that caregivers will adapt gradually to the adverse consequences of caring for their child with a long-term illness. However, studies of the psychological adaptation process of family caregivers of children with leukemia are limited. OBJECTIVE: The aim of this study was to study the psychological adaptation process of the parent caregivers of pediatric leukemia patients. METHODS: In this qualitative study, we interviewed 32 caregivers of children with leukemia in China. Data were collected through semistructured interviews and analyzed using the content analysis method. RESULTS: The psychological adaptation process in caregivers of pediatric leukemia patients seems to involve 5 stages: initial devastation, accumulation of hope, fluctuation in feelings, integration, and psychological adaptation. Significant emotional changes were observed at each stage. CONCLUSIONS: This study identified commonalities in the psychological adaptation process experienced by caregivers of children with leukemia in the Chinese social and cultural context. It also characterized the different emotions that the caregivers had in the 5 stages of adaptation. In addition, our research identified the possible psychological interventions at different stages. IMPLICATIONS FOR PRACTICE: The study described the adaptation process of Chinese parents of children with leukemia. The findings of this study will help nurses identify main coping resources, controllable intervention factors, and the timing of intervention for these caregivers of children with leukemia.

Competing Vortex Topologies in Iron-Based Superconductors.

In this Letter, we establish a new theoretical paradigm for vortex Majorana physics in the recently discovered topological iron-based superconductors (TFeSCs). While TFeSCs are widely accepted as an exemplar of topological insulators (TIs) with intrinsic s-wave superconductivity, our theory implies that such a common belief could be oversimplified. Our main finding is that the normal-state bulk Dirac nodes, usually ignored in TI-based vortex Majorana theories for TFeSCs, will play a key role of determining the vortex state topology. In particular, the interplay between TI and Dirac nodal bands will lead to multiple competing topological phases for a superconducting vortex line in TFeSCs, including an unprecedented hybrid topological vortex state that carries both Majorana bound states and a gapless dispersion. Remarkably, this exotic hybrid vortex phase generally exists in the vortex phase diagram for our minimal model for TFeSCs and is directly relevant to TFeSC candidates such as LiFeAs. When the fourfold rotation symmetry is broken by vortex-line tilting or curving, the hybrid vortex gets topologically trivialized and becomes Majorana free, which could explain the puzzle of ubiquitous trivial vortices observed in LiFeAs. The origin of the Majorana signal in other TFeSC candidates such as FeTe_{x}Se_{1-x} and CaKFe_{4}As_{4} is also interpreted within our theory framework. Our theory sheds new light on theoretically understanding and experimentally engineering Majorana physics in high-temperature iron-based systems.

Dynamical symmetry indicators for Floquet crystals.

Various exotic topological phases of Floquet systems have been shown to arise from crystalline symmetries. Yet, a general theory for Floquet topology that is applicable to all crystalline symmetry groups is still in need. In this work, we propose such a theory for (effectively) non-interacting Floquet crystals. We first introduce quotient winding data to classify the dynamics of the Floquet crystals with equivalent symmetry data, and then construct dynamical symmetry indicators (DSIs) to sufficiently indicate the inherently dynamical Floquet crystals. The DSI and quotient winding data, as well as the symmetry data, are all computationally efficient since they only involve a small number of Bloch momenta. We demonstrate the high efficiency by computing all elementary DSI sets for all spinless and spinful plane groups using the mathematical theory of monoid, and find a large number of different nontrivial classifications, which contain both first-order and higher-order 2+1D anomalous Floquet topological phases. Using the framework, we further find a new 3+1D anomalous Floquet second-order topological insulator (AFSOTI) phase with anomalous chiral hinge modes.

Anomalous Floquet Chiral Topological Superconductivity in a Topological Insulator Sandwich Structure.

We show that Floquet chiral topological superconductivity arises naturally in Josephson junctions made of magnetic topological insulator-superconductor sandwich structures. The Josephson phase modulation associated with an applied bias voltage across the junction drives the system into the anomalous Floquet chiral topological superconductor hosting chiral Majorana edge modes in the quasienergy spectrum, with the bulk Floquet bands carrying zero Chern numbers. The bias voltage acts as a tuning parameter enabling novel Floquet topological quantum phase transitions driving the system into a myriad of exotic Majorana-carrying Floquet topological superconducting phases. Our theory establishes a new paradigm for realizing Floquet chiral topological superconductivity in solid-state systems, which should be experimentally directly accessible.

CaFtsH06, A Novel Filamentous Thermosensitive Protease Gene, Is Involved in Heat, Salt, and Drought Stress Tolerance of Pepper (Capsicum annuum L.).

Harsh environmental factors have continuous negative effects on plant growth and development, leading to metabolic disruption and reduced plant productivity and quality. However, filamentation temperature-sensitive H protease (FtsH) plays a prominent role in helping plants to cope with these negative impacts. In the current study, we examined the transcriptional regulation of the CaFtsH06 gene in the R9 thermo-tolerant pepper (Capsicum annuum L.) line. The results of qRT-PCR revealed that CaFtsH06 expression was rapidly induced by abiotic stress treatments, including heat, salt, and drought. The CaFtsH06 protein was localized to the mitochondria and cell membrane. Additionally, silencing CaFtsH06 increased the accumulation of malonaldehyde content, conductivity, hydrogen peroxide (H2O2) content, and the activity levels of superoxide dismutase and superoxide (·O2-), while total chlorophyll content decreased under these abiotic stresses. Furthermore, CaFtsH06 ectopic expression enhanced tolerance to heat, salt, and drought stresses, thus decreasing malondialdehyde, proline, H2O2, and ·O2- contents while superoxide dismutase activity and total chlorophyll content were increased in transgenic Arabidopsis. Similarly, the expression levels of other defense-related genes were much higher in the transgenic ectopic expression lines than WT plants. These results suggest that CaFtsH06 confers abiotic stress tolerance in peppers by interfering with the physiological indices through reducing the accumulation of reactive oxygen species, inducing the activities of stress-related enzymes and regulating the transcription of defense-related genes, among other mechanisms. The results of this study suggest that CaFtsH06 plays a very crucial role in the defense mechanisms of pepper plants to unfavorable environmental conditions and its regulatory network with other CaFtsH genes should be examined across variable environments.

Intrinsic Time-Reversal-Invariant Topological Superconductivity in Thin Films of Iron-Based Superconductors.

We establish quasi-two-dimensional thin films of iron-based superconductors (FeSCs) as a new high-temperature platform for hosting intrinsic time-reversal-invariant helical topological superconductivity (TSC). Based on the combination of Dirac surface state and bulk extended s-wave pairing, our theory should be directly applicable to a large class of experimentally established FeSCs, opening a new TSC paradigm. In particular, an applied electric field serves as a "topological switch" for helical Majorana edge modes in FeSC thin films, allowing for an experimentally feasible design of gate-controlled helical Majorana circuits. Applying an in-plane magnetic field drives the helical TSC phase into a higher-order TSC carrying corner-localized Majorana zero modes. Our proposal should enable the experimental realization of helical Majorana fermions.

Momentum space toroidal moment in a photonic metamaterial.

Berry curvature, the counterpart of the magnetic field in the momentum space, plays a vital role in the transport of electrons in condensed matter physics. It also lays the foundation for the emerging field of topological physics. In the three-dimensional systems, much attention has been paid to Weyl points, which serve as sources and drains of Berry curvature. Here, we demonstrate a toroidal moment of Berry curvature with flux approaching to π in judiciously engineered metamaterials. The Berry curvature exhibits a vortex-like configuration without any source and drain in the momentum space. Experimentally, the presence of Berry curvature toroid is confirmed by the observation of conical-frustum shaped domain-wall states at the interfaces formed by two metamaterials with opposite toroidal moments.

Inversion-Protected Higher-Order Topological Superconductivity in Monolayer WTe_{2}.

Monolayer WTe_{2}, a centrosymmetric transition metal dichacogenide, has recently been established as a quantum spin Hall insulator and found superconducting upon gating. Here we study the pairing symmetry and topological nature of superconducting WTe_{2} with a microscopic model at mean-field level. Surprisingly, we find that the spin-triplet phases in our phase diagram all host Majorana modes localized on two opposite corners. Even when the conventional pairing is favored, we find that an intermediate in-plane magnetic field exceeding the Pauli limit stabilizes an unconventional equal-spin pairing aligning with the field, which also hosts Majorana corner modes. Motivated by our findings, we obtain a recipe for two-dimensional superconductors featuring "higher-order topology" from the boundary perspective. Generally, a superconducting inversion-symmetric quantum spin Hall material whose normal-state Fermi surface is away from high-symmetry points, such as gated monolayer WTe_{2}, hosts Majorana corner modes if the superconductivity is parity-odd. We further point out that this higher-order phase is an inversion-protected topological crystalline superconductor and study the bulk-boundary correspondence. Finally, we discuss possible experiments for probing the Majorana corner modes. Our findings suggest superconducting monolayer WTe_{2} is a playground for higher-order topological superconductivity and possibly the first material realization for inversion-protected Majorana corner modes without utilizing proximity effect.

Möbius Insulator and Higher-Order Topology in MnBi_{2n}Te_{3n+1}.

We propose MnBi_{2n}Te_{3n+1} as a magnetically tunable platform for realizing various symmetry-protected higher-order topology. Its canted antiferromagnetic phase can host exotic topological surface states with a Möbius twist that are protected by nonsymmorphic symmetry. Moreover, opposite surfaces hosting Möbius fermions are connected by one-dimensional chiral hinge modes, which offers the first material candidate of a higher-order topological Möbius insulator. We uncover a general mechanism to feasibly induce this exotic physics by applying a small in-plane magnetic field to the antiferromagnetic topological insulating phase of MnBi_{2n}Te_{3n+1}, as well as other proposed axion insulators. For other magnetic configurations, two classes of inversion-protected higher-order topological phases are ubiquitous in this system, which both manifest gapped surfaces and gapless chiral hinge modes. We systematically discuss their classification, microscopic mechanisms, and experimental signatures. Remarkably, the magnetic-field-induced transition between distinct chiral hinge mode configurations provides an effective "topological magnetic switch".

Associations Between Quality of Life, Psychosocial Well-being and Health-Related Behaviors Among Adolescents in Chinese, Japanese, Taiwanese, Thai and the Filipino Populations: A Cross-Sectional Survey.

Health-related behaviors during adolescence have lifelong impacts. However, there are unclear areas regarding the associations between health-related quality of life and demographic characteristics, as well as physical and psychosocial indicators. The aim of this study was to examine the associations between quality of life and body weight, sleep outcome, social support by age, and cohabitants, given that income, self-esteem, lifestyle, emotional, social and behavioral problems were taken into account among adolescents in East and Southeast Asia. A cross-sectional survey was conducted in Zhengzhou of China, Hong Kong, Kansai region of Japan, Taipei of Taiwan, Bangkok of Thailand and Manila of the Philippines between 2016 and 2017 among 21,359 urban adolescents aged between 9 and 16. The results showed that adolescents who had better self-esteem and control of emotions and behaviors had much higher level of perceived quality of life. Those who were overweight or obese, sleepy in the daytime, and not living with parents had worse quality of life compared with those who were not. In conclusion, psychosocial well-being should have a higher priority in the promotion of quality of life among Asian adolescents. Nevertheless, further studies are required to explore the differences in perceived quality of life between genders and countries.

Relationship between resilience and insomnia among the middle-aged and elderly: mediating role of maladaptive emotion regulation strategies.

This study aimed to investigate the relationships between cognitive emotion regulation (CER) strategies, resilience, and insomnia and the underlying mechanism that explains the relationships. Six hundred and fifty-three middle-aged and old people recruited from community service centers in Henan province completed questionnaires related to CER strategies, resilience, and insomnia. Results showed refocus on planning and positive reappraisal negatively predicted insomnia, and catastrophising, rumination and self-blame positively predicted insomnia. Moreover, maladaptive emotion regulation strategies (especially catastrophising) mediated the relationship between resilience and insomnia. The findings suggest the middle-aged and elderly with insomnia tended to employ maladaptive emotion regulation strategies and had lower resilience. Maladaptive emotion regulation strategies buffered the positive effect of resilience on sleep.

A novel gene, CaATHB-12, negatively regulates fruit carotenoid content under cold stress in Capsicum annuum.

BACKGROUND: Carotenoids, the secondary metabolites terpenoids, are the largest factors that form the fruit color. Similar to flavonoids, they are not only safe and natural colorants of fruits but also play a role as stress response biomolecules. METHODS: To study the contribution of the key genes in carotenoids biosynthesis, fruit-color formation, and in response to cold stress, we characterized the key regulatory factor CaATHB-12 from the HD-ZIP I sub-gene family members in pepper. RESULTS: Cold stress enhanced carotenoid accumulation as compared with the normal condition. CaATHB-12 silencing through virus-induced gene silencing changed the fruit color by regulating the carotenoid contents. CaATHB-12 silencing increased the antioxidant enzyme activities in the fruits of pepper, exposed to cold stress, whereas CaATHB-12 overexpression decreased the activities of antioxidant enzymes in the transgenic Arabidopsis lines, exposed to cold stress, suggesting that CaATHB-12 is involved in the regulation of cold stress in the pepper fruits. CONCLUSION: Our research will provide insights into the formation of fruit color in pepper and contribution of CaATHB-12 in response to cold stress. Further study should be focused on the interaction between CaATHB-12 and its target gene.

Higher-Order Topology and Nodal Topological Superconductivity in Fe(Se,Te) Heterostructures.

We show, theoretically, that a heterostructure of monolayer FeTe_{1-x}Se_{x}-a superconducting quantum spin Hall material-with a monolayer of FeTe-a bicollinear antiferromagnet-realizes a higher order topological superconductor phase characterized by emergent Majorana zero modes pinned to the sample corners. We provide a minimal effective model for this system, analyze the origin of higher order topology, and fully characterize the topological phase diagram. Despite the conventional s-wave pairing, we find a rather surprising emergence of a novel topological nodal superconductor in the phase diagram. Featured by edge-dependent Majorana flat bands, the topological nodal phase is protected by an antiferromagnetic chiral symmetry. We also discuss the experimental feasibility, the estimation of realistic model parameters, and the robustness of the Majorana corner modes against magnetic and potential disorder. Our work provides a new experimentally feasible high-temperature platform for both higher order topology and non-Abelian Majorana physics.

Helical Hinge Majorana Modes in Iron-Based Superconductors.

Motivated by recent experiments on FeTe_{1-x}Se_{x}, we construct an explicit minimal model of an iron-based superconductor with band inversion at the Z point and nontopological bulk s_{±} pairing. While there has been considerable interest in Majorana zero modes localized at vortices in such systems, we find that our model-without any vortices-intrinsically supports 1D helical Majorana modes localized at the hinges between (001) and (100) or (010) surfaces, suggesting that this is a viable platform for observing "higher-order" topological superconductivity. We provide a general theory for these hinge modes and discuss their stability and experimental manifestation. Our work indicates the possible experimental observability of hinge Majorana modes in iron-based topological superconductors.

A valley valve and electron beam splitter.

Developing alternative paradigms of electronics beyond silicon technology requires the exploration of fundamentally new physical mechanisms, such as the valley-specific phenomena in hexagonal two-dimensional materials. We realize ballistic valley Hall kink states in bilayer graphene and demonstrate gate-controlled current transmission in a four-kink router device. The operations of a waveguide, a valve, and a tunable electron beam splitter are demonstrated. The valley valve exploits the valley-momentum locking of the kink states and reaches an on/off ratio of 8 at zero magnetic field. A magnetic field enables a full-range tunable coherent beam splitter. These results pave a path to building a scalable, coherent quantum transportation network based on the kink states.

Crystalline Symmetry-Protected Majorana Mode in Number-Conserving Dirac Semimetal Nanowires.

One of the cornerstones for topological quantum computations is the Majorana zero mode, which has been intensively searched in fractional quantum Hall systems and topological superconductors. Several recent works suggest that such an exotic mode can also exist in a one-dimensional (1D) interacting double-wire setup even without long-range superconductivity. A notable instability in these proposals comes from interchannel single-particle tunneling that spoils the topological ground state degeneracy. Here we show that a 1D Dirac semimetal (DSM) nanowire is an ideal number-conserving platform to realize such Majorana physics. By inserting magnetic flux, a DSM nanowire is driven into a 1D crystalline-symmetry-protected semimetallic phase. Interaction enables the emergence of boundary Majorana zero modes, which is robust as a result of crystalline symmetry protection. We also explore several experimental consequences of Majorana signals.