Understanding the correlation between orbital degree of freedom, lattice-striction and magneto-dielectric coupling in ferrimagnetic Mn1.5Cr1.5O4.

Dielectric anomaly observed in cubic Mn1.5Cr1.5O4around ferrimagnetic ordering temperature (TN) suggests a possible magneto-dielectric coupling in the system. This report confirms the presence of a weak but significant magneto-dielectric coupling in the system. Theab initiocalculations show a band gap of around 1.2 eV, with Fermi-level closer to the conduction band. The major features of conduction band nearest to the Fermi-level correspond todxzandd3z2-r2orbitals of Mn3+ion. Temperature-dependent neutron diffraction results show a rapid decay in structural parameters (lattice-striction and transition metal-oxygen bond length) aroundTN.We confirmed that these changes in structural parameters atTNare not related to structural transition but the consequences of orbital-ordering of Mn3+. The rapid decay in transition metal-oxygen bond length under internal magnetism of the system shows that magnetism could certainly manipulate the electric dipole moment and hence the dielectric constant of the system. Magneto-striction acts as a link between magnetic and dielectric properties.

Magnetic glassy state at low spin state of Co3+ in EuBaCo2O5+δ (δ = 0.47) cobaltite.

The magnetic glassy state is a fascinating phenomenon, which results from the kinetic arrest of the first order magnetic phase transition. Interesting properties, such as metastable magnetization and nonequilibrium magnetic phases, are naturally developed in the magnetic glassy state. Here, we report magnetic glass property in the low spin state of Co3+ in EuBaCo2O5+δ (δ = 0.47) cobaltite at low temperature (T < 60 K). The measurements of magnetization under the cooling and heating in unequal fields, magnetization relaxation and thermal cycling of magnetization show the kinetic arrest of low magnetization state below 60 K. The kinetically arrested low temperature magnetic phase is further supported through the study of isothermal magnetic entropy, which shows the significant entropy change. The present results will open a new window to search the microscopic relation between the spin state transitions and the kinetic arrest induced magnetic glassy phenomena in complex materials.

[A multi-center clinical retrospective study on the therapeutic effect of endoscopic myringoplasty].

Objective: To analyze the therapeutic effect of endoscopic myringoplasty. Methods: A retrospective analysis of 523 patients with chronic otitis media who underwent endoscopic myringoplasty between June 2016 and June 2017 in eight tertiary hospitals in China. Among all the patients, 256 were male and 267 were female, aged from 18 to 68 years old. The grafts used to repair the tympanic membrane were all tragus cartilage-perichondrium complex. All patients were followed up at 1 month, 3 months, 6 months, 9 months, and 12 months after surgery, at least 3 months. The closure rate of tympanic membrane perforation by different factors, the hearing results, and the incidence of postoperative complications were analyzed. SPSS 21.0 software was used to analyze the data. Results: Three months after operation, the closure rates of anterior, inferior, posterior and subtotal perforation were 92.4% (109/118), 94.9% (93/98), 95.6% (129/135), and 89.0% (153/172) respectively, the difference was not statistically significant (χ(2)=5.779, P=0.123). The closure rates of small, medium and large perforations were 100.0% (82/82), 93.7% (178/190) and 89.2% (224/251) respectively. The difference was statistically significant (χ(2)=10.927, P=0.004). The closure rates of dry ear and wet ear tympanic membrane perforation were 93.1% (392/421), 90.2% (92/102), the difference was not statistically significant (χ(2)=1.011, P=0.915). The preoperative pure tone audiometry(PTA) was (38.4±5.3) dBHL, while, the 3-month postoperative PTA was (25.1±5.7) dBHL. The difference was statistically significant (t=39.079, P<0.001). The preoperative air bone gap (ABG) was (22.4±4.3) dB, while 3 months postoperative ABG was (9.1±3.8) dB. The difference was statistically significant (t=53.004, P<0.001). Of all 523 patients, 14 (2.7%) had middle ear infection, 8 (1.5%) had dislocated tympanic membrane, 12 (2.3%) had parageusia, 35 (6.7%) had tinnitus, 28 (5.4%) had hearing loss, 26 (5.0%) had vertigo,33 (6.3%) had reperforation, 2 (0.4%) had secondary cholesteatoma, and none had facioplegia. Conclusions: Endoscopic myringoplasty is a safe and effective surgical method with good postoperative outcome.

[Different anthropometric indices and incident risk of hypertension in elderly population: a prospective cohort study].

Objective: To explore the relationship between anthropometric indices and the incident risk of hypertension, compare novel anthropometric indices with traditional indices in hypertension prediction and establish hypertension prediction models among elderly Chinese. Methods: A total of 27 009 retirees from the Dongfeng Motor Corporation were recruited at baseline in 2008 and the first follow-up was conducted in 2013. After the exclusion of participants less than 60 years old, participants with hypertension, coronary heart disease, stroke, cancer, and those with missing data, a total of 6 784 elderly participants were enrolled in this study. A multivariate logistic regression model was used to analyze the relationship between traditional anthropometric indices, body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), novel anthropometric indices, visceral adiposity index (VAI), body shape index (ABSI), body roundness index (BRI), and the incident risk of hypertension. Meanwhile, a multivariate logistic regression model was used to establish hypertension prediction models. Receiver operating characteristic (ROC) curve was applied to compare the prediction ability of different models. Results: A total of 1 787 incident cases of hypertension were identified, with the incidence of hypertension about 27.59%. Significant positive associations were detected between BMI, WC, WHtR, VAI, BRI and the incident risk of hypertension after adjusting for potential confounders (all P values<0.05). In men, the OR (95%CI) (upper tertile vs lower tertile) was 1.45 (1.22-1.73) for VAI, and 1.86 (1.55-2.23) for BRI. In women, the OR (95% CI) (upper tertile vs lower tertile) was 1.55 (1.22-1.96) for VAI, and 1.60 (1.27-2.01) for BRI. For ABSI, no significant association was observed in either men (OR (95%CI): 1.07 (0.90-1.28)) or women (OR (95%CI): 1.03 (0.82-1.29), both P values >0.05). The basic hypertension prediction model included age, drinking (only in men), education status (only in men), systolic blood pressure (SBP), diastolic blood pressure (DBP), and fasting blood glucose levels. Based on the basic prediction model, BMI (in men: AUC=0.697) and BRI (only in men: AUC=0.696) improved area under ROC curve (AUC) significantly (P<0.05). BMI was the strongest predictor in both men (AUC=0.697) and women (AUC=0.685) in the extended model. Conclusion: Significant positive associations were detected between BMI, WC, WHtR, VAI, BRI and the incident risk of hypertension among elderly Chinese. BMI was the strongest predictor in hypertension prediction model compared with other anthropometric indices.

[Outcomes of same-day bilateral endoscopic tympanoplasty].

Objective:To investigate the feasibility of simultaneous bilateral endoscopic for tympanoplasty in patients with bilateral chronic suppurative otitis media. Method:Fifteen patients (30 ears) with bilateral chronic suppurative otitis media who underwent bilateral endoscopic transcanal tympanoplasty on the same day were enrolled in this study. The ear with worse-hearing was selected as the first operation side, the contralateral ear as the second one. The operation group consisted of 22 ears of Type 1 tympanoplasty, 5 ears of Type 2 tympanoplasty and 3 ears of Type 3 tympanoplasty. All second sides(15 ears) underwent Type 1 tympanoplasty. The cartilage-perichondrium graft was harvested from the tragal of the first side and was cut in two halves which could be used for the both sides. The graft success and hearing improvement were evaluated at the postoperative 6th month according to the follow up results of the endoscopic image and the pure-tone audiometry. Result:The graft take rate was 96.7%(27/30) without any retraction pockets or displaced grafts. The graft take rate of the first side was 93.3%(14/15), and the one of the second side was 100.0%(15/15). The average air conduction thresholds were (50.9±9.1) dB HL preoperatively and (32.0±6.0) dB HL postoperatively(P<0.01). The average air-bone gap overall improved from (30.2±7.9) dB HL preoperatively to (13.7±6.0) dB HL postoperatively(P<0.01). Conclusion:Bilateral same-day endoscopic tympanoplasty are safe and cost effective in appropriately selected patients. It can offer favorable out-comes in selected patients with chronic suppurative otitis media.

[Application of ICMM Occupational Health Risk Assessment Modelin evaluation of occupational risk of a lead-acid battery enterprise].

Objective: ICMM occupational health risk assessment model was be used to evaluate the risk of a lead-acid battery enterprise. Methods: In November 2016, a lead-acid battery company in Jiangsu Province was selected as the research object. Based on the occupational health survey data and occupational hazard assessment reports, the ICMM risk assessment model was used to conduct occupational health risks in eight key positions of a lead-acid battery enterprise. The risk assessment results was verified by actual test results. Results: In the quantitative assessment model, the occupational health risk assessment results for the castings and welding positions exposed to lead smoke, and the occupational health risk assessment results for the grinding and dividing positions exposed to lead dust existed unacceptable risks. The occupational health risk assessment results for the ball-milled and plated positions exposed to lead dust existed tolerable risks. The occupational health risk assessment results for the lead-plated and soldered positions exposed to sulphuric acid pastes and acids existed potential risks. In qualitative evaluation matrix method, the occupational health risk assessment results for the castings and welding positions exposed to lead smoke, and the occupational health risk assessment results for the grinding and dividing positions exposed to lead dust existed high risks, the occupational health risk assessment results for other four key positions were considered to be with low risks. Conclusion: The key control points for lead smoke in this enterprise were castings and welding positions; The key control points for lead dust were the grinding and separating brush positions. The quantitative assessment model and the qualitative assessment matrix method in the ICMM model were consistent with the actual test results in the eight health risk assessments of occupational hazards in key positions. Therefore, the method could be applied to the assessment of occupational health risks of the lead-acid battery enterprise. According to the results of the assessment, improvements could be made to high-risk positions and the concentration of occupational hazards in high-risk posts could be reduced to better protect the health of workers.

Antisite disorder driven spontaneous exchange bias effect in La(2-x)Sr(x) CoMnO6 (0 ⩽ x ⩽ 1).

Doping at the rare-earth site by divalent alkaline-earth ions in perovskite lattice has witnessed a variety of magnetic and electronic orders with spatially correlated charge, spin and orbital degrees of freedom. Here, we report an antisite disorder driven spontaneous exchange bias effect as a result of hole carrier (Sr(2+)) doping in La(2-x)Sr(x)CoMnO6 (0 < x < 1) double perovskites. X-ray diffraction and Raman spectroscopy have evidenced an increase in disorder with the increase of Sr content up to x = 0.5 and thereby a decrease from x = 0.5 to 1. X-ray absorption spectroscopy has revealed that only Co is present in the mixed valence of Co(2+) and Co(3+) states with Sr doping to compensate the charge neutrality. Magnetotransport is strongly correlated with the increase of antisite disorder. The antisite disorder at the B-site interrupts the long-range ferromagnetic order by introducing various magnetic interactions and instigates reentrant glassy dynamics, phase separation and canted type antiferromagnetic behavior with the decrease of temperature. This leads to a novel magnetic microstructure with unidirectional anisotropy that causes a spontaneous exchange bias effect that can be tuned with the amount of antisite disorder.

[A clinical analysis for sudden sensorineural hearing loss withcontralateral sensorineural hearing loss].

Objective:To analyze the clinical characteristics and prognosis,and to learn the impact factors of patients with sudden sensorineural hearing loss with contralateral sensorineural hearing loss(SSHLwCSHL).Method:Clinical data of 63 cases of patients with SSHLwCSHL were analyzed systematically,including all the clinical manifestations,audiologic characteristics and the effect assessment,and compared with that of unilateral sudden sensorineural hearing loss(USSHL) and bilateral sudden sensorineural hearing loss(BSSHL).Base on those,we summarized comprehensively the development and prognosis characteristics of the disease.Result:The incidence of SSHLwCSHL was 8.3 percent of overall patients with SSNHL.SSHLwCSHL occurs more commonly in male patients,with more vertigo,diabetes mellitus,and lipid panel abnormalities compared with other groups.Hearing curve and the degree of hearing loss of the prevalence ear of SSHLwCSHL was statistically significant difference with USSHL(P<0.05).Most common reason of the contralateral hearing loss was sudden sensorineural hearing loss(49%),and 59% patients of SSHLwCSHL suffered hearing loss of other ear after 2-10 years after contralateral hearing loss.The total effective rate was 14.3%,1 in 63 patients cured,1 excellence and 6 effective.The total effective rate was 9.5% in patients with severe or profound sensorineural hearing loss in the contralateral ear,which was lower than that of patients with moderate and moderately severe sensorineural hearing loss in the contralateral-ear(P=0.021).Conclusion:SSHLwCSHL has complex condition.The prognosis for improvement is poor.Recognition of similarities and differences between bilateral and unilateral SSNHL can help in counseling and managing the patients.

Unexpected observation of splitting of skyrmion phase in Zn doped Cu2OSeO3.

Polycrystalline (Cu1-xZnx)2OSeO3 (0≤x≤0.2) samples were synthesized using solid-state reaction and characterized by X-ray diffraction (XRD). The effect of Zn doping upon saturation magnetization (MS) indicates that the Zn favors to occupying Cu(II) square pyramidal crystallographic site. The AC susceptibility (χ'ac) was measured at various temperatures (χ'ac-T) and magnetic field strengths (χ'ac-H). The Zn doping concentration is found to affect greatly the M-T and χ'ac-T. The skyrmion phase has been inferred from the χ'ac-H data, and then indicated within the H-T phase diagrams for various Zn doping concentrations. The striking and unexpected observation is that the skyrmion phase region becomes split upon Zn doping concentration. Interestingly, second conical boundary accompanied by second skyrmion phase was also observed from dχ'ac/dH vs. H curves. Atomic site disorder created by the chemical doping modulates the delicate magnetic interactions via change in the Dzyaloshinskii-Moriya (DM) vector of distorted Cu(II) square pyramidal, thereby splitting of skyrmion phase might occur. These findings illustrate the potential of using chemical and atomic modification for tuning the temperature and field dependence of skyrmion phase of Cu2OSeO3.

Structural, transport and optical properties of (La0.6Pr0.4)0.65Ca0.35MnO3 nanocrystals: a wide band-gap magnetic semiconductor.

(La0.6Pr0.4)0.65Ca0.35MnO3 system has been synthesized via a sol-gel route at different sintering temperatures. Structural, transport and optical measurements have been carried out to investigate (La0.6Pr0.4)0.65Ca0.35MnO3 nanoparticles. Raman spectra show that Jahn-Teller distortion has been decreased due to the presence of Ca and Pr in A-site. Magnetic measurements provide a Curie temperature around 200 K and saturation magnetization (MS) of about 3.43µB/Mn at 5 K. X-ray photoemission spectroscopy study suggests that Mn exists in a dual oxidation state (Mn(3+) and Mn(4+)). Resistivity measurements suggest that charge-ordered states of Mn(3+) and Mn(4+), which might be influenced by the presence of Pr, have enhanced insulating behavior in (La0.6Pr0.4)0.65Ca0.35MnO3. Band gap estimated from UV-Vis spectroscopy measurements comes in the range of wide band gap semiconductors (∼3.5 eV); this makes (La0.6Pr0.4)0.65Ca0.35MnO3 a potential candidate for device application.

A preliminary evaluation of the surgery to reconstruct thoracic breathing in patients with high cervical spinal cord injury.

STUDY DESIGN: A prospective study. OBJECTIVES: To evaluate the effect of the surgery to reconstruct thoracic breathing in patients with high cervical spinal cord injury (CSCI). SETTING: China Rehabilitation Research Center, Beijing, China. METHODS: The posterior ribs (from the fifth to the eighth) were suspended on the inferior angle of the scapula on each side using titanium cables, as well as muscles and myofascial tissue in the subscapular area. After the surgery, the patients were trained for synchronous contraction of the trapezius and diaphragm muscles, and electromyography (EMG) was performed to evaluate the synchronization. The clinical symptoms and pulmonary function were assessed within 1 week before surgery and at 2, 12 and 24 postoperative weeks. RESULTS: Six patients with complete high CSCI received rib suspension surgery 84±26.7 days after spinal cord injury. Before the surgery, all of the patients presented with weakened cough, retention of respiratory secretions and dyspnea, while these symptoms alleviated postoperatively. The vital capacity (VC) was enhanced to be 1680±282 ml at 2 weeks after the surgery, compared with 1085±92 ml (P=0.013). The EMG showed a synchronous muscle electrical activity between the trapezius muscles and diaphragm during deep breaths. CONCLUSION: The rib suspension surgery partially restored the thoracic breathing of the patients with high CSCI, thereby improving VC, cough and expectoration.

Formation of hydrides in (Ti(1-x)Zr(x))Co(2.00) (0 < x < 1) pseudobinary alloys.

The exposure of (Ti(1-x)Zr(x))Co(2.00) intermetallic alloys to hydrogen at high pressure caused (Ti(1-x)Zr(x))Co(2.00) (x = 0.50-0.90) hydrides in the alloy. The crystalline structural, electronic, and magnetic properties of parent alloys and of their hydrides were determined by using XRD (X-ray powder diffraction) and XAS (X-ray absorption spectrometry) and by the use of SQUID (a superconducting quantum interference device). Hydrogenation did not alter the crystal structure of the parent alloy, but it did increase the volume of the unit cell. An in situ Co K-edge XAS study of the hydride revealed that the valence state of Co increased during discharge (which is the release of hydrogen from the hydride). Hydrogenation of the parent alloy also reduced the magnetic moment. A possible mechanism of discharge for the hydride is also proposed.

Influence of cytoskeletal structure and mechanics on epithelial cell injury during cyclic airway reopening.

Although patients with acute respiratory distress syndrome require mechanical ventilation, these ventilators often exacerbate the existing lung injury. For example, the cyclic closure and reopening of fluid-filled airways during ventilation can cause epithelial cell (EpC) necrosis and barrier disruption. Although much work has focused on minimizing the injurious mechanical forces generated during ventilation, an alternative approach is to make the EpC less susceptible to injury by altering the cell's intrinsic biomechanical/biostructural properties. In this study, we hypothesized that alterations in cytoskeletal structure and mechanics can be used to reduce the cell's susceptibility to injury during airway reopening. EpC were treated with jasplakinolide to stabilize actin filaments or latrunculin A to depolymerize actin and then exposed to cyclic airway reopening conditions at room temperature using a previously developed in vitro cell culture model. Actin stabilization did not affect cell viability but significantly improved cell adhesion primarily due to the development of more numerous focal adhesions. Surprisingly, actin depolymerization significantly improved both cell viability and cell adhesion but weakened focal adhesions. Optical tweezer based measurements of the EpC's micromechanical properties indicate that although latrunculin-treated cells are softer, they also have increased viscous damping properties. To further investigate the effect of "fluidization" on cell injury, experiments were also conducted at 37 degrees C. Although cells held at 37 degrees C exhibited no changes in cytoskeletal structure, they did exhibit increased viscous damping properties and improved cell viability. We conclude that fluidization of the actin cytoskeleton makes the EpC less susceptible to the injurious mechanical forces generated during cyclic airway reopening.

Electronic structure of pyrochlore Cd(2)Re(2)O(7).

Detailed band structure calculations have been performed for Cd(2)Re(2)O(7) in high-, middle- and low-temperature (T) phases. The calculations are based on the observed lattice structures from x-ray diffraction measurements. The spin-orbit interaction is incorporated self-consistently in both the generalized gradient approximation (GGA) and the GGA plus Hubbard U (GGA+U) approaches. It is found that the on-site U has negligible effects on the Re 5d band structures; therefore both the GGA and GGA+U Re 5d band energies agree well with the observed O K-edge x-ray absorption spectroscopy (XAS) spectrum, whereas the Cd 4d band energy observed from photoemission spectroscopy can only be correctly reproduced by GGA+U calculations, indicating the relatively itinerant Re 5d and localized Cd 4d electrons. On the other hand, the spin-orbit coupling gives rise to nontrivial spin and orbital magnetic moments for the middle- T phase. Most unexpectedly, we found that the low- T phase exhibits quasi-two-dimensional Fermi surfaces. The calculated carrier numbers for the three phases are, at least qualitatively, consistent with the measured Hall coefficient.

High-field magnetization of a two-dimensional spin frustration system, Ni(5)(TeO(3))(4)X(2) (X = Br, Cl).

The high-field magnetization, M(H), of Ni(5)(TeO(3))(4)X(2) (X =  Br, Cl) was measured by using a pulse magnet. These compounds have a two-dimensional crystal structure and a distorted Kagome spin frustrated system which is built from the Ni(2+) ions (S = 1). The Néel transition temperatures are T(N)∼28 and 23 K for X =  Br and Cl, respectively. When TT(N), the field-dependent magnetization curves behave like a monotonically increasing straight line up to 55 T. The H(c) value is close to those obtained in previous spin resonance studies in which a model of a spin-flop scenario was proposed to explain the field-dependent resonance spectra. With the earlier model a further transition at around 23 T was predicted; however, our observations did not show any plateau behaviors, saturation or other anomalies up to 55 T, suggesting that the further transition possibly exists in a much higher field region.

Strain-induced effects on antiferromagnetic ordering and magnetocapacitance in orthorhombic HoMnO(3) thin films.

We investigated the magnetic and ferroelectric properties of c-axis oriented orthorhombic phase HoMnO(3) (o-HMO in Pbnm symmetry setting) thin films grown on Nb-doped SrTiO(3)(001) substrates. The o-HMO films exhibit an antiferromagnetic ordering near 42 K, irrespective of the orientation of the applied field. However, an additional magnetic ordering occurring around 35 K was observed when the field was applied along the c-axis of o-HMO, which was absent when the field was applied in the ab-plane. The magnetocapacitance measured along the c-axis showed that although there is evidence of dielectric constant enhancement when the temperature is below 35 K the expected abrupt change in dielectric constant appears at a much lower temperature and reaches maximum around 13.5 K, indicating that the low-temperature c-axis polarization might be related to the ordering of the Ho(3+) moment. The lattice constant analyses using x-ray diffraction and the observation of a slight magnetization hysteresis suggest that the weak second magnetic transition along the c-axis at 35 K might be more relevant to the strain-induced effect on antiferromagnetism.

Structural and optical studies of high dielectric constant (Na(0.5)A(0.5))Cu(3)Ti(4)O(12) (A = La and Bi).

We report x-ray powder diffraction and temperature-dependent infrared reflectivity measurements of (Na(0.5)La(0.5))Cu(3)Ti(4)O(12) and (Na(0.5)Bi(0.5))Cu(3)Ti(4)O(12) in order to investigate the origin of their lower room-temperature dielectric constants in comparison with the giant value of CaCu(3)Ti(4)O(12). Substituting Ca with Na/La or Na/Bi is found to decrease all Ti-O-Ti angles by the TiO(6) octahedra tilts, resulting in an increase of the local structural disorder on the Na/La and Na/Bi compounds. Further, several infrared-active phonon modes show a broadening in their linewidths, reflecting that the coherency in these vibrational modes is degraded by disorder. Additionally, the lowest-frequency mode of the Ca material is observed to strengthen dramatically at low temperatures, but to a lesser extent in the Na/La and Na/Bi compounds. These results suggest the important role of the local structural disorder on the anomalous low-frequency dielectric response in these materials.

Viscoelasticity of aqueous telechelic poly(ethylene oxide) solutions: relaxation and structure.

We present a rheology study of associating polymers. The associating polymers are telechelic, composed of a water-soluble backbone (polyethylene oxide) terminated by hydrophobic moieties (C16H33). In aqueous solutions, these polymers self-assemble to form micellar structures. Above a critical concentration, approximately 1 wt % of polymer, bridging between the micelles forms a transient network. Traditionally, the viscoelastic response of these polymeric solutions has been described using the Maxwell model. In this work we measure the viscoelastic properties over an extended frequency range (0.01-6000 Hz) using microrheology, and show that at high frequencies the rheology behaves as the square root of the oscillation frequency. To fit the data, we use a combination of the Maxwell model and the Rouse model. The Maxwell model accounts for the hydrophobic associations between the polymeric micelles, and the Rouse model accounts for the microscopic dynamics of the individual micelles.