Giant Magnon-Polaron Anomalies in Spin Seebeck Effect in Double Umbrella-Structured Tb_{3}Fe_{5}O_{12} Films.

We report a giant hysteretic spin Seebeck effect (SSE) anomaly with a sign reversal at magnetic fields much stronger than the coercive field in a (001)-oriented Tb_{3}Fe_{5}O_{12} film. The high-field SSE enhancement reaches 4200% at approximately 105 K over its weak-field value and presents a nonmonotonic dependence on temperature. The unexpected high-field hysteresis of SSE is found to be associated with a magnetic transition of double-umbrella spin texture in TbIG. Nearly parallel dispersion curves of magnons and acoustic phonons around this neoteric transition are supported by theoretical calculations, leading to a high density of field-tuned magnon polarons and consequently an extraordinarily large SSE. Our study provides insight into the evolution of magnon dispersions of double-umbrella TbIG and could potentially boost the efficiency of magnon-polarons SSE devices.

Role of Magnon-Magnon Scattering in Magnon Polaron Spin Seebeck Effect.

The spin Seebeck effect (SSE) signal of magnon polarons in bulk-Y_{3}Fe_{5}O_{12} (YIG)/Pt heterostructures is found to drastically change as a function of temperature. It appears as a dip in the total SSE signal at low temperatures, but as the temperature increases, the dip gradually decreases before turning to a peak. We attribute the observed dip-to-peak transition to the rapid rise of the four-magnon scattering rate. Our analysis provides important insights into the microscopic origin of the hybridized excitations and the overall temperature dependence of the SSE anomalies.

Disorder-order transformation and significant dislocation motion cooperating with a surprisingly large hysteretic magnetic transition in a nickel-bisdithiolene spin system.

The compound [4'-CF3bzPy][Ni(mnt)2] (1) (where 4'-CF3bzPy = 1-(4'-(trifluoromethyl)benzyl)pyridinium and mnt(2-) = maleonitriledithiolate) was synthesized and displays a magnetic bistability with a surprisingly large thermal hysteresis loop (~49 K). X-ray crystallographic studies reveal that in the high-temperature (HT) phase the anions and cations form mixed stacks, with alternating anion dimers (AA) and cation dimers (CC) in an ...AACCAACC... fashion along the crystallographic a + b direction, and disordered CF3 groups in the cations are aligned into a molecular layer parallel to the crystallographic (001) plane. However, in the low-temperature (LT) phase, the c-axis length of the unit cell is roughly doubled, and the asymmetric unit switches from one [4'-CF3bzPy][Ni(mnt)2] pair in the HT phase to two [4'-CF3bzPy][Ni(mnt)2] pairs. Most interestingly, the CF3 group in the cations becomes ordered, and the conformation of one of two crystallographically different cations changes significantly. A dislocation motion between the neighboring molecular layers emerges as well. The analyses of the magnetic susceptibilities and the density functional theory calculations suggest that the antiferromagnetic exchange interaction within one of two types of [Ni(mnt)2]2(2-) dimers in the LT phase is much stronger than that within the [Ni(mnt)2]2(2-) dimer in the HT phase. The lattice reorganization during this phase transition is proposed to be responsible for the wide thermal hysteresis loop.

Chiral fermion reversal in chiral crystals.

In materials chiral fermions such as Weyl fermions are characterized by nonzero chiral charges, which are singular points of Berry curvature in momentum space. Recently, new types of chiral fermions beyond Weyl fermions have been discovered in structurally chiral crystals CoSi, RhSi and PtAl. Here, we have synthesized RhSn single crystals, which have opposite structural chirality to the CoSi crystals we previously studied. Using angle-resolved photoemission spectroscopy, we show that the bulk electronic structures of RhSn are consistent with the band calculations and observe evident surface Fermi arcs and helical surface bands, confirming the existence of chiral fermions in RhSn. It is noteworthy that the helical surface bands of the RhSn and CoSi crystals have opposite handedness, meaning that the chiral fermions are reversed in the crystals of opposite structural chirality. Our discovery establishes a direct connection between chiral fermions in momentum space and chiral lattices in real space.

Organic solid fluorophores regulated by subtle structure modification: color-tunable and aggregation-induced emission.

Organic solid fluorophores with a tunable emission color have been widely applied in multiple areas. However, rational design and efficient crafting of these fluorophores from a simple core skeleton is still a formidable challenge because of the undesirable concentration quenching emission effect. Herein, we present the development of two series of organic solid fluorophores based on a backbone of p-bis(2,2-dicyanovinyl)benzene. Notably, the introduction of either non-aromatic or aromatic substituents provides fluorophores with a tunable emission color. Moreover, the fluorophores with aromatic substituents exhibit additional unique optical phenomena, such as aggregation-induced emission, polymorphism-dependent emission, and reversible mechanochromic luminescence.

Serum Cystatin C can detect impaired graft function early after renal transplantation.

OBJECTIVES: To study the significance of Cystatin C (Cys C) in early detection of the graft function after renal transplantation. MATERIAL: The concentrations of Cys C, Blood urea nitrogen (BUN), Serum creatinine (SCr), and glomerular filtration rate (GFR) were measured. According to the results of the post-transplantation GFR; Seventy renal post-transplanted patients were assigned into 3 groups: group A (31 cases with the normal range of the renal function, GFR≥90 ml/min/1.73 m(2)), group B (27 cases with Scr<133 µmol/L and 60

Inverse relationship between apolipoprotein A-I and cerebral white matter lesions: a cross-sectional study in middle-aged and elderly subjects.

BACKGROUND: Apolipoprotein A-I (apoA-I), the major protein for high density lipoprotein, is essential for reverse cholesterol transport. Decreased serum levels of apoA-I have been reported to correlate with subcortical infarction and dementia, both of which are highly related to white matter lesions (WMLs). However, the association between apoA-I and WMLs has never been investigated. In this study, we sought to investigate the association between apoA-I and the presence of WMLs in middle-aged and elderly subjects. METHODS: Consecutive patients aged 50 years and older of our department were prospectively enrolled in this study (n = 1282, 606 men and 676 women, 65.9 ± 9.4 years). All participants underwent MRI scans to assess the presence and severity of WMLs. Multivariate logistic regression analyses were performed to examine the association of apoA-I with WMLs. RESULTS: Patients with WMLs were older and showed significantly higher proportion of male sex, hypertension, diabetes mellitus, previous stroke, and coronary heart disease whereas levels of total cholesterol, high density lipoprotein cholesterol, and apoA-I were lower. After adjustment for potential confounders, the lowest apoA-I quartile was independently associated with an increased risk of WMLs (odds ratio: 1.87, 95% confidence interval: 1.29-2.72). In sex-specific analyses, this relationship was observed only in women. CONCLUSIONS: Our findings demonstrated that apoA-I was inversely associated with the presence of WMLs in middle-aged and elderly subjects. This results suggest that therapies which increase apoA-I concentration may be beneficial to reduce the risk of WMLs, dementia and stroke.

A low-dimensional molecular spin system with two steps of magnetic transitions and liquid crystal property.

A low-dimensional compound [C(6)-Apy][Ni(mnt)(2)] (1, where mnt(2-) = maleonitriledithiolate, C(6)-Apy(+) = 4-amino-1-hexylpyridinium) has been designed and synthesized, which has layer arrangement of anions and cations and shows two steps of magnetic transitions. The low temperature magnetic transition has an uncommon hysteresis loop, while the crystal structure investigations disclosed no structural transition with the magnetic transition. The high temperature magnetic transition exhibits two remarkable features: (1) it synchronously occurs with a crystalline-to-mesophase transition in the first heating process and (2) the structural changes that accompany the solid-mesophase transition are irreversible. A diamagnetic and isostructural compound, [C(6)-Apy][Cu(mnt)(2)], is further characterized by structure, DSC and POM techniques, which revealed also the existence of an irreversible crystalline-to-mesophase transition in the same temperature interval of [C(6)-Apy][Ni(mnt)(2)]. Therefore, the high-temperature magnetic transition in 1 is driven by release of the structural strains, but not magnetoelastic interactions. The mesophase exhibits the characteristic of smectic A phase, and the alkyl chain melting in the cation layers probably lead to the formation of mesophase. It is noticeable that the finding of a mesophase occurring in a hexyl hydrocarbon chain molecular system is in contrast to a suggested rule that at least a dodecyl chain is required. Our results will shed a light on the design and preparation of a new low-dimensional molecular system combining magnetic transition and liquid crystal properties.

A multicomponent recognition and separation system established via fluorescent, magnetic, dualencoded multifunctional bioprobes.

Accurate and rapid recognition and separation of multiple types of biological targets such as molecules, cells, bacteria or viruses from complex sample mixtures is of great importance for a wide range of diagnostic and therapeutic strategies. To achieve this goal, a set of fluorescent, magnetic, dual-encoded multifunctional bioprobes has been constructed by co-embedding different-sized quantum dots and varying amounts of γ-Fe(2)O(3) magnetic nanoparticles into swollen poly(styrene/acrylamide) copolymer nanospheres. The dual-encoded bioprobes, which possessed different photoluminescent property and magnetic susceptibility, were proven to be capable of simultaneously recognizing and separating multiple components from a complex sample when three kinds of lectins were used as the targets. The lectins were separated with high efficiency and kept their bioactivity during the process. Compared to the conventional batchwise separation, this method does not require a large number of sequential reaction steps, which is economical of time and can be very reagent-saving. By combining the multiplexing capability of quantum dots with the superparamagnetic properties of iron oxide nanoparticles, this dual-encoded technique is expected to open new opportunities in high-throughput and multiplex bioassays, such as cell sorting, proteomical and genomical applications, drug screening etc.

Asymmetric organocatalytic formal double-arylation of azomethines for the synthesis of highly enantiomerically enriched isoindolines.

Isoindoline derivatives with high enantiomeric purity (up to 98% ee) have been accessed by formal double arylation of azomethines.