Anomalous Long-Distance Coherence in Critically Driven Cavity Magnonics.

Developing quantum networks necessitates coherently connecting distant systems via remote strong coupling. Here, we demonstrate long-distance coherence in cavity magnonics operating in the linear regime. By locally setting the cavity near critical coupling with traveling photons, nonlocal magnon-photon coherence is established via strong coupling over a 2-m distance. We observe two anomalies in this long-distance coherence: first, the coupling strength oscillates twice the period of conventional photon-mediated couplings; second, clear mode splitting is observed within the cavity linewidth. Both effects cannot be explained by conventional coupled-mode theory, which reveals the tip of an iceberg of photon-mediated coupling in systems under critical driving. Our Letter shows the potential of using critical phenomena for harnessing long-distance coherence in distributed systems.

Non-Hermitian control between absorption and transparency in perfect zero-reflection magnonics.

Recent works in metamaterials and transformation optics have demonstrated exotic properties in a number of open systems, including perfect absorption/transmission, electromagnetically induced transparency, cloaking or invisibility, etc. Meanwhile, non-Hermitian physics framework has been developed to describe the properties of open systems, however, most works related to this focus on the eigenstate properties with less attention paid to the reflection characteristics in complex frequency plane, despite the usefulness of zero-reflection (ZR) for applications. Here we demonstrate that the indirectly coupled two-magnon system not only exhibits non-Hermitian eigenmode hybridization, but also ZR states in complex frequency plane. The observed perfect-ZR (PZR) state, i.e., ZR with pure real frequency, is manifested as infinitely narrow reflection dips (~67 dB) with infinite group delay discontinuity. This reflection singularity of PZR distinguishes from the resonant eigenstates but can be adjusted on or off resonance with the eigenstates. Accordingly, the absorption and transmission can be flexibly tuned from nearly full absorption (NFA) to nearly full transmission (NFT) regions.

Coherent Microwave Emission of Gain-Driven Polaritons.

By developing a gain-embedded cavity magnonics platform, we create a gain-driven polariton (GDP) that is activated by an amplified electromagnetic field. Distinct effects of gain-driven light-matter interaction, such as polariton auto-oscillations, polariton phase singularity, self-selection of a polariton bright mode, and gain-induced magnon-photon synchronization, are theoretically studied and experimentally manifested. Utilizing the gain-sustained photon coherence of the GDP, we demonstrate polariton-based coherent microwave amplification (∼40 dB) and achieve high-quality coherent microwave emission (Q>10^{9}).

[Factors associated with malnutrition in infants with congenital heart disease within one year after surgery].

Objective: To explore the risk factors of malnutrition in infants with congenital heart disease within one year after surgery. Methods: This retrospective cohort study selected 502 infants with congenital heart disease who underwent surgical treatment in Guangzhou Women and Children's Medical Center from February 2018 to January 2019. Their basic information and clinical data were analyzed, and their nutrition status after the surgery was followed up by questionnaire survey. Weight-for-age Z score (WAZ)≤-2 one year after operation was defined as malnutrition group, and WAZ>-2 was non-malnutrition group. The perioperative indicators and complementary food advancement were compared between the two groups by chi-square test, t-test, and Kruskal-Wallis test. The risk factors of malnutrition were analyzed by Logistic regression. Results: A total of 502 infants were selected, including 301 males and 201 females, with the age of 4.1 (2.0, 6.8) months. There were 90 cases in malnutrition group and 412 cases in non-malnutrition group. The body length and weight at birth in the malnutrition group were lower than those in the non-malnutrition group ((47.8±3.8) vs. (49.3±2.5) cm, (2.7±0.6) vs.(3.0±0.5) kg, both P<0.001). The proportion of paternal high school education or above and the proportion of family per capita income of 5 000 yuan or above in the malnutrition group were lower than those in the non-malnutrition group ((18.9% (17/90) vs. 30.8% (127/412), 18.9% (17/90) vs. 33.7% (139/412), both P<0.05). Compared to the non-malnutrition group, the proportion of complex congenital heart disease in the malnutrition group was higher (62.2% (56/90) vs. 47.3% (195/412), P<0.05). The postoperative mechanical ventilation time, postoperative intensive care unit (ICU) stay time, postoperative hospital stay, total length of ICU stay and total hospital stay in the malnutrition group were significantly longer than those in non-malnutrition group (all P<0.05). The proportion of egg and fish supplementation over 2 times/week within one year after the surgery was also lower in the malnutrition group (both P<0.05). Logistic regression analysis showed that mother's weight at delivery (OR=0.95,95%CI 0.91-0.99), the pre-operative WAZ≤-2 (OR=6.04, 95%CI 3.13-11.65), the complexity of the cardiac disease (OR=2.23, 95%CI 1.22-4.06), the hospital stay after the surgery over 14 days (OR=2.61, 95%CI 1.30-5.26), the types of complementary food<4 (OR=2.57, 95%CI 1.39-4.76), and the frequency of meat and fish<2 times/week (OR=2.11, 95%CI 1.13-3.93) were the risk factors associated with malnutrition within one year after the surgery. Conclusion: Mother's weight at delivery pre-operative nutritional status, complexity of cardiac disease, postoperative hospital stay, types of daily supplements and frequency of fish are risk factors associated with malnutrition within one year after surgery in children with congenital heart disease.

Interferometric control of magnon-induced nearly perfect absorption in cavity magnonics.

The perfect absorption of electromagnetic waves has promoted many applications, including photovoltaics, radar cloaking, and molecular detection. Unlike conventional methods of critical coupling that require asymmetric boundaries or coherent perfect absorption that require multiple coherent incident beams, here we demonstrate single-beam perfect absorption in an on-chip cavity magnonic device without breaking its boundary symmetry. By exploiting magnon-mediated interference between two internal channels, both reflection and transmission of our device can be suppressed to zero, resulting in magnon-induced nearly perfect absorption (MIPA). Such interference can be tuned by the strength and direction of an external magnetic field, thus showing versatile controllability. Furthermore, the same multi-channel interference responsible for MIPA also produces level attraction (LA)-like hybridization between a cavity magnon polariton mode and a cavity photon mode, demonstrating that LA-like hybridization can be surprisingly realized in a coherently coupled system.

Hybrid perfect metamaterial absorber for microwave spin rectification applications.

Metamaterials provide compelling capabilities to manipulate electromagnetic waves beyond the natural materials and can dramatically enhance both their electric and magnetic fields. The enhanced magnetic fields, however, are far less utilized than the electric counterparts, despite their great potential in spintronics. In this work, we propose and experimentally demonstrate a hybrid perfect metamaterial absorbers which combine the artificial metal/insulator/metal (MIM) metamaterial with the natural ferromagnetic material permalloy (Py) and realize remarkably larger spin rectification effect. Magnetic hot spot of the MIM metamaterial improves considerably electromagnetic coupling with spins in the embedded Py stripes. With the whole hybridized structure being optimized based on coupled-mode theory, perfect absorption condition is approached and an approximately 190-fold enhancement of spin-rectifying photovoltage is experimentally demonstrated at the ferromagnetic resonance at 7.1 GHz. Our work provides an innovative solution to harvest microwave energy for spintronic applications, and opens the door to hybridized magnetism from artificial and natural magnetic materials for emergent applications such as efficient optospintronics, magnonic metamaterials and wireless energy transfer.

Unconventional Singularity in Anti-Parity-Time Symmetric Cavity Magnonics.

By engineering an anti-parity-time (anti-PT) symmetric cavity magnonics system with precise eigenspace controllability, we observe two different singularities in the same system. One type of singularity, the exceptional point (EP), is produced by tuning the magnon damping. Between two EPs, the maximal coherent superposition of photon and magnon states is robustly sustained by the preserved anti-PT symmetry. The other type of singularity, arising from the dissipative coupling of two antiresonances, is an unconventional bound state in the continuum (BIC). At the settings of BICs, the coupled system exhibits infinite discontinuities in the group delay. We find that both singularities coexist at the equator of the Bloch sphere, which reveals a unique hybrid state that simultaneously exhibits the maximal coherent superposition and slow light capability.

[Study on the relationship between EPHX1 gene polymorphism and antioxidant capacity in patients with chronic obstructive pulmonary disease].

Objective: To explore the difference of mRNA, protein expression levels and the indexes of peripheral blood antioxidant capacity in peripheral blood lymphocytes of different EPHX1 genotypes in chronic obstructive pulmonary disease(COPD). Methods: A case-control study was conducted to collect peripheral blood samples of 220 stable chronic COPD patients with smoking history and 230 healthy smokers (control group) from October 2016 to February 2018 in the First Affiliated Hospital of Kunming Medical University, and the genetic testing was carried out according to the operation instructions of BigDye Terminator v1.1 DNA Sequencing Kit. Based on their EPHX1 exon 3 and exon 4 polymorphism status, the EPHX1 was classified into 4 groups, i. e., normal activity, slow activity, extremely slow activity and fast activity. Then COPD patients were allocated to either a slow activity group (slow and very slow activity) or a fast activity group (normal and fast activity) according to EPHX1 genotype and gene activity. The expression of EPHX1 mRNA and protein in peripheral blood lymphocytes were detected by qRT-PCR and Western blot, and indexes of serum antioxidant capacity was detected by corresponding kits. Results: (1)The 2(-ΔΔCt) of the control group was 1.000, and the 2(-ΔΔCt) of the COPD group was 1.052±0.023. There was no significant difference in the level of EPHX1 mRNA expression between the two groups (t=1.992 P=0.865). The level of EPHX1 mRNA expression in the slow activity group was not different significantly compared to that in the fast-active group (1.053±0.023 vs 1.048±0.021, t=1.133, P=0.260). (2)The level of EPHX1 protein expression by Western blot analysis showed that the EHPX1/GAPDH gray ratio was not different significantly between the COPD group and the control group (0.613±0.089 vs 0.602±0.075, t=0.805, P=0.422). The level of EPHX1 protein expression in the slow activity group was not significantly different compared to that in the fast activity group (0.606±0.088 vs 0.622±0.092, t=-0.786 P=0.434). (3)There were significant differences in indexes of antioxidant capacity between the control group and the COPD group (P<0.05). There were significant differences in indexes of antioxidant capacity between the slow activity group and the fast activity group of COPD patients (P<0.05). Conclusions: The different antioxidant capacity of COPD patients with different EPHX1 genotypes may be related to the polymorphism of EPHX1 gene affecting the activity of microsomal epoxidase, but not to the level of EPHX1 mRNA and protein expression.

Nonreciprocity and Unidirectional Invisibility in Cavity Magnonics.

We reveal the cooperative effect of coherent and dissipative magnon-photon couplings in an open cavity magnonic system, which leads to nonreciprocity with a considerably large isolation ratio and flexible controllability. Furthermore, we discover unidirectional invisibility for microwave propagation, which appears at the zero-damping condition for hybrid magnon-photon modes. A simple model is developed to capture the generic physics of the interference between coherent and dissipative couplings, which accurately reproduces the observations over a broad range of parameters. This general scheme could inspire methods to achieve nonreciprocity in other systems.

Analysis of Characteristics and Relevant Factors of 1 340 Cases of Intentional Injury Cases in Southwest China.

ABSTRACT: Objective To investigate the characteristics and patterns of factors such as victims' information, injury tools and time of occurrence of intentional injury cases in southwest China. Methods One thousand three hundred and forty intentional injury cases from several places in southwest China from 2014 to 2016 assessed as minor injury level Ⅱ and above had been randomly selected. Data on victims' information, motives, injury tools, sites of occurrence, time of occurrence, injured parts and degrees of injury were classified and gathered, and then association analyses of motives and types of injury tools as well as degrees of injury and injury tools were made. Results Most of the victims were young adults between 20-50 years （65.2%）, male （82.3%）, rural household registration （62.8%）; the motives were mainly dispute （45.8%）. Injury tools were mostly blunt （54.6%） or sharp （36.0%）. Specifically, injuries were mostly made bare-handed （36.9%） and by cutting tools （33.2%）; the cases mainly occurred in public areas （59.0%）. Cases occurred more frequently in January （11.3%）, February （13.1%）, March （11.6%） and from 22：00 to 01：00 every night. Injuries mainly involved the craniofacial region. The wounds were mainly assessed as minor injury level Ⅱ （61.6%）. There was statistical significance in the difference of types of injury tools among cases with different motives （P<0.05）. There was statistical significance in the difference of the distribution of injury tools among cases with different degrees of injury （P<0.05）. Conclusion The occurrence of intentional injury cases in southwest China has potential patterns and relevant influencing factors. Prevention and analysis of such cases need to be comprehensively considered from the aspects such as victims' information, injury tools and time of occurrence.

Analogue of dynamic Hall effect in cavity magnon polariton system and coherently controlled logic device.

Cavity magnon polaritons are mixed quasiparticles that arise from the strong coupling between cavity photons and quantized magnons. Combining high-speed photons with long-coherence-time magnons, such polaritons promise to be a potential candidate for quantum information processing. For harnessing coherent information contained in spatially distributed polariton states, it is highly desirable to manipulate cavity magnon polaritons in a two-dimensional system. Here, we demonstrate that tunable cavity magnon polariton transport can be achieved by strongly coupling magnons to microwave photons in a cross-cavity. An analog to the dynamic Hall effect has been demonstrated in a planar cavity spintronic device, where the propagation of cavity-magnon-polaritons is deflected transversally due to hybrid magnon-photon dynamics. Implementing this device as a Michelson-type interferometer using the coherent nature of the dynamic Hall and longitudinal signals, we have developed a proof-of-principle logic device to control the amplitude of cavity-magnon-polaritons by encoding the input microwave phase.

Level Attraction Due to Dissipative Magnon-Photon Coupling.

We report dissipative magnon-photon coupling caused by the cavity Lenz effect, where the magnons in a magnet induce a rf current in the cavity, leading to a cavity backaction that impedes the magnetization dynamics. This effect is revealed in our experiment as level attraction with a coalescence of hybridized magnon-photon modes, which is distinctly different from level repulsion with mode anticrossing caused by coherent magnon-photon coupling. We develop a method to control the interpolation of coherent and dissipative magnon-photon coupling, and observe a matching condition where the two effects cancel. Our work sheds light on the so-far hidden side of magnon-photon coupling, opening a new avenue for controlling and utilizing light-matter interactions.

Pure red cell aplasia with t-cell large granular lymphocytic leukemia.

Pure red cell aplasia (PRCA) develops as a result of erythroid precursors failing to reach maturity in the bone marrow, which eventually leads to anemia. Here we present a case of a 64-year-old Asian male with a medical history of colorectal adenocarcinoma who had been treated with 6 cycles of oxaliplatin and capecitabine four years ago. The patient was diagnosed with PRCA and T-cell large granular lymphocyte leukemia.

Effect of magnetization boundary condition on cavity magnon polariton of YIG thin film.

Motivated by recent studies of cavity magnon polariton (CMP), we extended a previous theoretical work to generalize microwave transmission calculation with various magnetization boundary condition of YIG thin film embedded in cavity. It is found that numerical implementation given in this paper can be easily applied to other magnetization boundary condition and extended to magnetic multilayers. Numerical results show that ferromagnetic resonance mode of microwave transmission spectrum, which is absent in previous calculation, can be recovered by altering the pinning condition of surface spins. The demonstrated reliability of our theory opens attractive perspectives for studying CMP of thin film with complicated surface magnetization distribution and magnetic multilayers.

Bistability of Cavity Magnon Polaritons.

We report the first observation of the magnon-polariton bistability in a cavity magnonics system consisting of cavity photons strongly interacting with the magnons in a small yttrium iron garnet (YIG) sphere. The bistable behaviors emerged as sharp frequency switchings of the cavity magnon polaritons (CMPs) and related to the transition between states with large and small numbers of polaritons. In our experiment, we align, respectively, the [100] and [110] crystallographic axes of the YIG sphere parallel to the static magnetic field and find very different bistable behaviors (e.g., clockwise and counter-clockwise hysteresis loops) in these two cases. The experimental results are well fitted and explained as being due to the Kerr nonlinearity with either a positive or negative coefficient. Moreover, when the magnetic field is tuned away from the anticrossing point of CMPs, we observe simultaneous bistability of both magnons and cavity photons by applying a drive field on the lower branch.

Cooperative polariton dynamics in feedback-coupled cavities.

The emerging field of cavity spintronics utilizes the cavity magnon polariton (CMP) induced by magnon Rabi oscillations. In contrast to a single-spin quantum system, such a cooperative spin dynamics in the linear regime is governed by the classical physics of harmonic oscillators. It makes the magnon Rabi frequency independent of the photon Fock state occupation, and thereby restricts the quantum application of CMP. Here we show that a feedback cavity architecture breaks the harmonic-oscillator restriction. By increasing the feedback photon number, we observe an increase in the Rabi frequency, accompanied with the evolution of CMP to a cavity magnon triplet and a cavity magnon quintuplet. We present a theory that explains these features. Our results reveal the physics of cooperative polariton dynamics in feedback-coupled cavities, and open up new avenues for exploiting the light-matter interactions.

Primary diffuse large B-cell lymphoma of the frontal sinus.

Primary frontal sinus lymphoma is a rare disease, with the presenting symptoms that are secondary to the tumor mass effect and often misleading. Here we describe the case of a 43-year-old male patient who presented with a 4-week history of a gradually enlarging painful diffuse swelling over the right frontal sinus region. We report the clinical presentation, differential diagnosis and treatment of the case. We also reviewed the available literature on the diffuse large B-cell lymphoma in the frontal sinus region. The article emphasizes the importance of early recognition of this rare disease.

Epstein-Barr virus-encoded LMP1 increases miR-155 expression, which promotes radioresistance of nasopharyngeal carcinoma via suppressing UBQLN1.

OBJECTIVE: Epstein-Barr virus (EBV)-encoded latent membrane protein (LMP1) can drive aberrant expression of miR-155 in nasopharyngeal carcinoma (NPC). In this study, we investigated the regulation of miR-155 expression over UBQLN1 and studied their effects on radio-sensitivity of NPC. MATERIALS AND METHODS: MiR-155, LMP1 and ubiquilin-1 expression were measured in 40 cases of NPC cases. The regulative role of miR-155 over UBQLN1 was investigated using a dual luciferase assay, qRT-PCR and Western blot analysis. The effect of miR-155-UBQLN1 axis on radio-sensitivity was explored using loss-and-gain study. The activation of PI3K/Akt pathway and the expression change of some important genes regulating cell cycle, cell proliferation and epithelial-to-mesenchymal transition (EMT) were measured. RESULTS: MiR-155 was significantly increased in radio-resistant NPC tissues and was negatively correlated to ubiqulin-1 expression. LMP1 overexpression led to significantly higher miR-155 expression. MiR-155 had two binding sites with 3'UTR of UBQLN1 and could decrease it expression. MiR-155 overexpression increased survival fraction of CNE-2 cells after exposure to 6 Gy and decreased cell apoptosis. It also partly abrogated the inhibiting effect of UBQLN1. Through decreasing ubiqulin-1, miR-155 changed the cell cycle to a more radio-resistant model. The miR-155-UBQLN1 axis affected the activation of PI3K/Akt pathway in NPC cells and changed the expression of some important genes regulating the cell cycle, cell proliferation and EMT. CONCLUSIONS: This study found that aberrant miR-155 expression driven by LMP1 can modulate radio-sensitivity of the NPC cell at least partly through targeting UBQLN1.

Enrichment of regulatory T-cells in blood of patients with multidrug-resistant tuberculosis.

OBJECTIVE: To measure the percentage of regulatory T-cells (Treg) and the expression of signalling molecules in these cells from the peripheral blood of patients with multidrug-resistant tuberculosis (MDR-TB). DESIGN: Patients with drug-susceptible tuberculosis (S-TB), MDR-TB and healthy controls (HCs) were recruited into the study. Levels of CD4(+)CD25(+)Foxp3(+) Treg cells from peripheral blood, and programmed death-1 (PD-1), cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) and inducible costimulatory (ICOS) molecule expression in the cells were measured using flow cytometry. Suppression mediated by Treg cells was assessed in carboxyfluorescein succinimidyl ester (CFSE) based suppression assays with autologous CD4(+)CD25(-) T-effector (Teff) cells. RESULTS: Presence of Mycobacterium tuberculosis resulted in a higher proportion of Treg cells in S-TB patients than in HCs, and even higher levels in MDR-TB patients. Moreover, Treg cells in MDR-TB patients constitutively expressed high-level PD-1, CTLA-4 and ICOS. In addition, when cultured with activated CD4(+)CD25(-) Teff cells, Treg cells potently suppressed proliferation of Teff cells. CONCLUSIONS: The high level of Treg cells found in the peripheral blood of tuberculosis patients may partly explain the poor immune response against M. tuberculosis, and could be a marker of MDR-TB.