Search

The behavior of a one-dimensional system, with two potential minima separated by a barrier coupled to a small set of oscillators is studied. The results show that close coupling to a small heat bath provides a mechanism for ' internal friction'.

OBJECTIVE: To explore the expression pattern and diagnostic value of microRNA-122 (miRNA-122) in childhood Kawasaki disease (KD). PATIENTS AND METHODS: A total of 150 children with KD were included in the KD group. During the same period, 150 children with respiratory infection complicated with fever and without myocardial involvement were included in the control group. Serum level of miRNA-122 in children with acute phase of KD and those in the control group was detected. The relationship between serum level of miRNA-122 and clinical features of KD was analyzed by Pearson correlation test. ROC curves were depicted to assess the diagnostic value of miRNA-122 in KD. RESULTS: Serum level of miRNA-122 was higher in the KD group than controls. In the acute phase of KD, the serum level of miRNA-122 was positively correlated to CRP and NT-proBNP, while negatively correlated to the sodium level. The specificity and sensitivity of miRNA-122 in diagnosing KD was 78.67% and 84.67%, respectively (AUC=0.8861, cut-off value=2.905). CONCLUSIONS: Serum level of miRNA-122 is significantly enhanced in the acute phase of KD, and highly expressed miRNA-122 is related to systematic inflammation. MiRNA-122 may be used as a diagnostic hallmark of KD. [ABSTRACT FROM AUTHOR]

The structure of human interleukin-1β (hIL-1β) has a nonpolar 'hydrophobic' cavity that, in three independent crystal structures[1], appears to be empty. On the basis of nuclear magnetic resonance (NMR) data, [...]

Selecting drip emitters with excellent anti-clogging performance (AP) is vital to ensure the safe operation of drip irrigation systems. However, previous researchers have not reached a consensus on emitter selection and evaluation standards based on emitter AP. In this study, eight types of flat emitters were selected as experimental objects, and highsand surface water was used as the water source to test the AP of emitters with three experimental treatments. The emitter total coefficient of evaluation index (ETEI) was applied to analyze the relative differences in AP of the emitters, and then the mechanism leading to those differences was explored. The results indicated that there were significant variations in AP among different emitters, and four evaluation indices had good consistency in evaluating emitter AP. Small-discharge emitters showed good anti-clogging ability. Emitters with large cross-section average velocity (v), not just with high discharge (Q), should be identified as having excellent AP. The combination of emitter structural parameters, mainly width-depth ratio (W/D), relative radius (A1/2/L), and flow path length (L), made significant differences in the v of emitters under the same operating conditions. Higher v caused a significant linear decrease in key clogging components, such as solid particles (SD), CaCO3 and MgCO3 precipitates (C-MP), extracellular polymeric substances (EPS), and microbial activity (MA), of the clogging material inside the emitter. This study provides a reference for the selection and development of emitter products with high-efficiency AP. [ABSTRACT FROM AUTHOR]

In order to elucidate pressure-induced second superconducting phase (SC-II) in AxFe2−ySe2 (A = K, Rb, Cs, and Tl) having an intrinsic phase separation, we perform a detailed highpressure magnetotransport study on the isoelectronic, phase-pure (Li1−xFex)OHFe1−ySe single crystals. Here we show that its ambient-pressure superconducting phase (SC-I) with a critical temperature Tc ≈ 40 K is suppressed gradually to below 2 K and an SC-II phase emerges above Pc ≈ 5 GPa with Tc increasing progressively to above 50 K up to 12.5 GPa. Our high-precision resistivity data uncover a sharp transition of the normal state from Fermi liquid for SC-I to non-Fermi liquid for SC-II phase. In addition, the reemergence of high-Tc SC-II is found to accompany with a concurrent enhancement of electron carrier density. Without structural transition below 10 GPa, the observed SC-II with enhanced carrier density should be ascribed to an electronic origin presumably associated with pressure-induced Fermi surface reconstruction. [ABSTRACT FROM AUTHOR]

Floral nectar can affect the fitness of insect-pollinated plants, through both attraction and manipulation of pollinators. Self-incompatible insect-pollinated plants receive more insect visits than their self-compatible relatives, and the nectar of such species might face increased risk of infestation by pathogens carried by pollinators than self-compatible plants. Proteins in nectar (nectarins) play an important role in protecting the nectar, but little is known regarding nectarins in self-incompatible species., The nectarins from a self-incompatible and insect-pollinated leguminous crop, Canavalia gladiata, were separated using two-dimensional electrophoresis and analysed using mass spectrometry. The predominant nectarin gene was cloned and the gene expression pattern investigated using quantitative real-time PCR. Chitinolytic activity in the nectar was tested with different substrates., The C. gladiata nectar proteome only has one predominant nectarin, an acidic class III chitinase (CaChi3). The full-length CaChi3 gene was cloned, coding for a protein of 298 amino acids with a predicted signal peptide. CaChi3 is very similar to members of the class III chitinase family, whose evolution is dominated by purifying selection. CaChi3 was expressed in both nectary and leaves. CaChi3 has thermostable chitinolytic activity according to glycol-chitin zymography or a fluorogenic substratem but has no lysozyme activity., Chitinase might be a critical protein component in nectar. The extremely simple nectar proteome in C. gladiata disproves the hypothesis that self-incompatible species always have more complex nectar proteomes. Accessibility of nectar might be a significant determinant of the evolutionary pressure to develop nectar defence mechanisms. [ABSTRACT FROM AUTHOR]

Ni0·25-xMgxCu0·3Zn0·45Fe2O4 (for x = 0, 0·05, 0·1, 0·2 and 0·25) ferrites have been synthesised by NaOH coprecipitation method. The X-ray diffraction patterns of these ferrites confirmed the formation of the single phase spinel structure. The lattice constant was found to increase with Mg content obeying Vegard's law. The crystallite size of these samples varies from 13·2 to 16·4 nm. The bulk density ρB decreases with increasing Mg concentration. And scanning electron microscopy images show no obvious differences among all samples with different Mg concentration. With increasing Mg content, the initial permeability monotonously increases while the cutoff frequency fr gradually decreases, which agrees well with Snoek's law. Moreover, saturation magnetisation Ms and the Curie temperature Tc continuously decrease with increasing Mg content but no noticeable variation in quality factor Q with Mg content is observed. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: Pulmonary arterial hypertension (PAH) is a major cause of morbidity and mortality among patients with congenital heart disease (CHD). Earlier diagnosis of PAH would be of great benefit for the estimation of the CHD, the grasp of the indications for surgery and prognosis. PATIENTS AND METHODS: We assessed the diagnostic accuracy of Doppler echocardiography (D-ECHO) in detecting PAH in patients with CHD and the value of estimation about ventricular morphology and function of PAH-CHD patients. 123 CHD patients evaluated for suspected PAH were prospectively recruited. D-ECHO was performed and estimated right ventricular systolic pressure (RVSP) was measured to screen for PAH. Subsequently, pulmonary hemodynamic parameters were measured by right heart catheterization (RHC) for definitive diagnosis of PAH. RESULTS: RHC identified 66/123 (54%) patients with PAH. The noninvasive cut-point was: estimated right ventricular systolic pressure (RVSP) > 36.5 mm Hg by D-ECHO. D-ECHO classified 107 subjects correctly (sensitivity 89.4%, specificity 84.2%). The area under receiver-operating characteristic curve (AUC) was 0.96 for D-ECHO. A positive significant correlation (r = 0.853, p < 0.01) was found between RVSP measured by D-ECHO and systolic pulmonary arterial pressure (sPAP) measured by RHC. In addition, D-ECHO showed higher RVSP, left ventricular internal diameter (LV), right atrial diameter (RA), right ventricular internal diameter (RV), left ventricular end-diastolic diameter (EDD), left ventricular diastolic end-diastolic volume (EDV) and mitral velocity A wave (AMV) values in the PAH-CHD group than in the CHD group (p < 0.05). CONCLUSIONS: D-ECHO is not only an important noninvasive diagnostic technique for PAH- CHD patients, but also a tool which can indicate the ventricular remodeling and diastolic dysfunction induced by PAH to some extent. [ABSTRACT FROM AUTHOR]

The inter/extrapolation accuracy of the cubic polynomial method has been improved by optimizing three frequency samples for frequency-sweeping in the method of moments (MoM). In the method, the frequency samples are optimized by minimizing the global maximum of the polynomial component at the stationary points and two terminal points of the frequency band. The optimal frequency samples can be expressed as analytical forms of the two terminal points. Numerical examples are presented to validate the proposed method through comparison with the Padé approximation. [ABSTRACT FROM AUTHOR]