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YCoronary artery bypass surgery has been the accepted treatment for left main coronary artery disease for over 50 years. Balloon angioplasty was later used then abandoned because of deaths likely due to restenosis or thrombotic occlusion. However, rapid innovations in drug-eluting stent designs leading to more biocompatible thin strut platforms with optimal drug elution profiles and further advances in modern pharmacotherapy involving potent P2Y(12) inhibitors combined with utilization of intracoronary imaging and physiologic assessment for procedural planning and optimization have transformed percutaneous interventions into successful alternatives to coronary artery bypass graft surgery (CABG) in selected LM anatomic territories. Herein, we provide an evidence-based practical guide on how to approach and perform LM percutaneous interventions (PCI). (C) 2020 Elsevier Inc. All rights reserved.

We report the synthesis of Bi0.9La0.1Fe0.95Mn0.05O3 (BLFMO) films with enhanced multiferroic properties and without second phase using Ba0.7Sr0.3Ti0.95Co0.05O3 (BSTCO) film as a buffer layer. Sol–gel processes were used to prepare the crystallized BLFMO/BSTCO films, in which magnetic domains were observed and no impurity phase was detected. We found that the buffer layer could effectively enhance the saturation magnetization and retentivity values of the BLFMO films, and especially the magnetic coercive field of these bilayer films was significantly stronger than that of the BLFMO films without buffer layers.

First-principles calculations are used to study KNbO3:Y ultrathin film. The conducting two-dimensional electron gas (2DEG) is found in KNbO3:Y film, whereas SrTiO3:Y superlattice is insulating [Science 331, 886 (2011)]. The carrier density of 2DEG of KNbO3:Y film is twice that of LaTiO3/SrTiO3 superlattice, which is in agreement with the theoretical results of KNbO3:La superlattice. It is found that the charge densities of different monolayers are modulated by the polarization effect of KNbO3. We predict that 2DEG may be in other rare-earth atoms-doped KNbO3 film.

The adsorption of CO2 on K1−yNayTa1−xNbxO3 (KNTN) surface terminations has been studied using density functional theory. The preferred adsorption sites are found to be the Na O bridge site on the K(Na)O-termination and O top site on the Ta(Nb)O2-termination. In the most favorable configurations, the CO2 molecule is bent and the C O bonds are elongated, indicating the CO2 activation. After adsorption, the band gap of the surface is enlarged, relevant to the electrons density redistribution. The results illustrate that the electronic structure of KNTN surface is sensitive with CO2 adsorption. The results provide fundamental insight into the CO2 adsorption mechanism on KNTN surface and potential application on gas sensing.

We present a density functional theory study of water adsorption on K1−yNayTa1−xNbxO3 (KNTN) surface terminations. The adsorption configuration and energy are determined and the bond formation between water molecule and KNTN surface are investigated by analysis of difference electron density and partial density of states. Our calculations reveal that the energetically favorable configurations for water monomer adsorption is at the K–Na bridge site on the K(Na)O-termination and the Nb top site on the Ta(Nb)O2-termination. With the coverage increasing, the water–surface interaction per water molecule decreases because of the formation of interwater hydrogen bonds, whereas the surface geometry becomes more roughness. The variation of bandgap for water adsorbed KNTN surface is also studied. We find that the interaction between water and surface would lead to a bandgap increase of KNTN surface, which is correlated to the electrons density redistribution.

We performed a bioinformatic analysis of the microarray data on the gene expression profiles of degenerative intervertebral disc cells after exposure to tumor necrosis factor-α (TNF-α) to uncover the key genes that were differentially expressed between cells with and without exposure, and to explore the related signaling pathways and interaction networks, providing clues for future investigations on the molecular mechanisms of disc degeneration.The microarray data for degenerative intervertebral disc cells after stimulation with TNF-α were downloaded from a public database, the GEO (Gene Expression Omnibus), in order to identify the genes that were differentially expressed between untreated degenerative disc cells and those stimulated with TNF-α, and then analyses of the gene ontology, signaling pathways and interaction networks for the differentially expressed genes were conducted using the DAVID, STRING and other online tools.A total of 753 differentially expressed genes were found in the degenerative annulus fibrosus disci intervertebralis cells after stimulation with TNF-α, including 458 upregulated genes and 295 downregulated genes. The Gene Ontology annotation analysis showed that these differentially expressed genes were mainly associated with the extracellular matrix, damage reactions, inflammatory reactions, and the regulation of apoptosis. A signaling pathway analysis showed that these differentially expressed genes were mainly involved in the interactions of cytokines, apoptosis, NOD-like receptors, chemokines, and other signal transduction pathways. The interaction network analysis indicated that JUN, CCL3, ANHK and other genes may play key roles in intervertebral disc degeneration.The bioinformatic analysis of the gene expression profiles of degenerative intervertebral disc cells stimulated with TNF-α showed that CCL3 and other genes may play a role in the development of the disc degeneration induced by inflammatory reactions. This suggests that bioinformatics methods can be used to identify potential therapeutic target genes, and to provide new insight into intervertebral disc degeneration.

The magnetic and structural properties of atomic-scale [Fe/Pt]18 and [Fe/Pt/Ag]18 multilayer films annealed at 350 and 400°C have been investigated. The results indicate that, by introducing thin Ag addition layers, the ordering temperature of FePt with nominal 7.4-nm thickness (excluding Ag thickness) can be significantly reduced to 350°C, at which a relatively large coercivity is achieved. When annealing temperature increases to 400°C, the atomic-scale [Fe/Pt]18 and [Fe/Pt/Ag]18 multilayer films show (001) orientation. The reduced diffusion length of atoms in atomic-scale multilayer films and an enhanced atomic diffusion coefficient produced by Ag doping led to the low-temperature ordering and (001) orientation of L10 FePt phase.

Lead zirconate titanate (PZT) thin films are deposited on platinized silicon substrate by sol–gel process. The crystal structure and surface morphology of PZT thin films are characterized by X-ray diffraction and atomic force microscopy. Depth-sensing nanoindentation system is used to measure mechanical characteristics of PZT thin films. X-ray diffraction analyses confirm the single-phase perovskite structures of all PZT thin films. Nanoindentation measurements reveal that the indentation modulus and hardness of PZT thin films are related with the grain size and crystalline orientation. The increases of the indentation modulus and hardness with grain size are observed, indicating the reverse Hall–Petch effect. Furthermore, the indentation modulus of (1 1 1)-oriented PZT thin film is higher than those of (1 0 0)- and random-oriented films. The consistency between experimental data and numerical results of the effective indentation moduli for fiber-textured PZT thin films using Voigt–Reuss–Hill model is obtained.

In this paper, the optimal finite impulse response (OFIR) with embedded unbiasedness (EU) filter is derived by minimizing the mean square error (MSE) subject to the unbiasedness constraint for discrete time-invariant state-space models. Un like the OFIR filter, the OFIR-EU filter does not require the initial conditions. In terms of accuracy, the OFIR-EU filter occupies an intermediate place between the UFIR and OFIR filters. With a two-state harmonic model, we show that the OFIR-UE filter has higher immunity against errors in the noise statistics and better robustness against temporary model uncertainties than the OFIR and Kalman filters.

The microstructure of a laser treated Al18B4O33w/2024Al composite has been investigated using transmission electron microscope (TEM), low-angle (glancing angle) X-ray diffraction (XRD) techniques. Various surface microstructures were observed in the laser treated composite. The Al18B4O33 whisker on the surface of the composite was decomposed during laser surface melting, various decomposition products were studied in the laser treated composite. Eutectic phases and the precipitation in the matrix of the composite with laser-treated were observed. The main phases detected in the molten zone were aluminum and decomposition products Al2O3. The effect of laser treatment on the hardness of the composite was also examined. A surface hardness of 400 Hv was noted.

A series of experiments of strain modulations in heterostructures of SrTiO3/LaAlO3 and LaAlO3/SrTiO3 perovskite thin films fabricated by laser molecular beam epitaxy (L-MBE) were performed to study the effect of the compressive stress and tensile stress on the growth and microstructure of the films. The growth process of the films was in-situ monitored by reflective high-energy electron diffraction (RHEED). The morphology of the films was studied by ex-situ atomic force microscopy (AFM). We demonstrated that the compressive stress-induced self-organized SrTiO3 films deposited on LaAlO3 (100) single crystal substrates exhibited a periodic well-ordered ripple-shaped structure, forming a unique nanopatterning tool to fabricate 1D/2D arrays of confined nanostructures (i.e., islands and wires). Small angle X-ray scattering technique was employed to investigate the superstructure. Symmetric satellite peaks were observed, which also revealed the well-aligned self-organized structures. In contrast, the similar superstructure was not observed during the growth of the tensile stress-induced LaAlO3 films on SrTiO3 substrates. Based on the experimental data, the compressive stress was estimated as the main reason of the self-organized growth. A growth model about the formation mechanisms of compressive stress-induced nanostructure was put forward and systematical kinetics elucidations about the growth processes were also discussed to illustrate the effects of different stresses on the growth and microstructures of the films.

The surface roughness and residual stress development in Fe–N thin films prepared by compound technology—combining magnetron sputtering with plasma based ion implantation were investigated by means of atomic force microscope and synchrotron radiation. The results indicate that the grain size of the thin film increases with the increasing of nitrogen ion implantation time, and the state of residual stress is related closely to the formation mechanism of thin films. With the nitrogen ion implantation time increasing, the residual stress of the thin film changes into tensile stress from initial compressive stress, and the tensile stress decreases with the further increasing of ion implantation time.

Fe–N thin films were fabricated using a direct current magnetron sputtering process assisted by a radio-frequency (rf) field. The effect of the rf field on the phase composition of the films was investigated. The results indicate that with the assistance of the rf field, various kinds of iron nitrides can be obtained in the films, including α′-Fe–N, α″-Fe16N2, ξ-Fe2N, e-Fe3N, and γ″-FeN with ZnS structure. It was found that the rf field greatly benefits the formation of iron nitrides in the Fe–N films.

Iron nitride films were deposited by dc magnetron sputtering using an Ar/N2 gas mixture. The structure, roughness, and surface morphology of the films were investigated using x-ray diffraction, grazing incidence x-ray scattering (GIXS), and atomic force microscopy (AFM). It was found that the morphologies and structures of the films were influenced by the N2 fraction. The perpendicular fluctuations in the height h(x,t) of the surface were also analyzed by AFM and GIXS in the light of dynamical scaling approach. The surfaces of the films typically exhibited self-affining structures both in space and in time. The two dependent nontrivial exponents, roughness exponent α and growth exponent β, were determined. For the iron nitride films grown at N2 fraction of 5%, 10%, and 30%, α≈0.65, 0.56, and 0.39, and β≈0.53±0.02, 0.38±0.02, and 0.29±0.03, respectively. The scaling relationship α+α/β≈2 is obeyed in all samples, which is in agreement with Kardar–Parisi–Zhang universality. The discrepancies between the theoretical foundations of dynamic scaling and experimental results have been discussed as well.

A method has been developed and proven using highly focused acoustic beams that allows for the rapid reconstruction of scattering coefficients of a thin anisotropic plate immersed in liquid. In a single bistatic coordinate scan, nearly the entire range of wave number within the spatial and temporal frequency bandwidth of the transducer can be reconstructed. This paper also reports the development of a multiple-source complex transducer point model that includes all extrinsic factors and permits prediction of the wave number-frequency (k–f) domain result obtained from a scan of focused transducers in a pitch-catch reflection or transmission arrangement. Extensive experiments have been performed to test the method and the model and to demonstrate transducer beam effects on the k–f domain results, leading to a very efficient method for mapping major portions of the guided wave dispersion spectrum in thin-plate media. As a demonstration of the technique, an estimate of material elastic properties in an isotropic and a transversely-isotropic plate is reported, making only minimal use of the highly redundant dispersion data. Acoustic velocities inferred from these experiments show a disparity of less than 3% from contact acoustic estimates of the same parameters in either plate.

The carbon nitride films were deposited on single crystalline Si(001) and polycrystalline diamond substrates using microwave plasma chemical vapor deposition (MPCVD) with CH4+N2 as well as CH4+NH3 mixtures as the reactive gas source, respectively. Different CH4/N2 and CH4/NH3 gas ratios were tested. The results showed that carbon nitride films with different nitrogen content could more readily be obtained using a mixture of CH4/N2 rather than CH4/NH3. The films grown by different CH4/N2 ratios showed different morphology, which was revealed by scanning electron microscopy (SEM). The crystalline carbon nitride films containing silicon were realized using a CH4:N2 = 1:100 ratio. X-ray photoelectron spectroscopy (XPS), Auger electron microscopy (AES), Raman spectroscopy, and X-ray diffraction were used to characterize the composition and chemical bonding of the deposited films.

Aluminium matrix composites reinforced by silicon carbide and aluminium borate whiskers were hot rolled at 550°C, and the hot rolling behaviors of the composites were studied by scanning electronic microscope and X-ray diffraction (anti-pole figure). The results indicated that the whiskers in composite were reorientated, and some whiskers were broken during hot rolling process. The cracks in hot rolled composites may be related to the interface slide which is dependent on the interface strength of the composites. The tensile properties of hot rolled composites were also investigated.

The microstructure evolution of the Alnico8 alloy thermomagnetically treated at the temperatures of 800, 850, 865 °C was investigated by transmission electron microscope. The microstructure in both as-homogenized and thermomagnetically treated specimens consists of the rod-like Fe–Co rich phase and Ni–Al rich phase. During thermomagnetical treatment, the Fe–Co rich phase was coarsened to a certain size firstly, then split into smaller ones, which resulted in a more homogenous and finer microstructure. The result also indicates that the temperature of thermomagnetical treatment has great effect on the splitting process of Fe–Co rich phase. Based on the point of view of energy, the splitting process of Fe–Co rich phase was analyzed.

Interfaces of the Al 18 B 4 O 33w /Al composite subjected to different thermal exposure treatments were investigated by means of TEM and its tensile properties were tested. The results of observations indicated that the interfacial reaction took place in the specimens thermally exposed at 500°C for 50 h, the products of which were γ-Al 2 O 3 with the spinel structure and boron. In addition, tensile tests showed that Yong’s modulus, ultimate tensile strength as well as yield strength initially increased, then decreased with time at 500°C; however, Young’s modulus and ultimate tensile strength both had an increasing tendency with temperature for a given 10 h exposure time, but yield strength initially increased and then decreased with increasing temperature for a 10 h exposure time. Before the interfacial reaction took place, welding of the microcracks at interfaces of the starting as-squeeze cast composite was responsible for an improvement in tensile properties. However, the interfacial reaction always deteriorated the tensile properties of the Al 18 B 4 O 33w /Al composite.

The aging behavior of alumina borate whisker (Al18B4O33w/AC8A-Al) composite was examined by hardness and differential scanning calorimetry heat flow measurement. Microstructures were investigated by transmission electronic microscope. The results indicated that the interfacial reaction played an important role in the aging precipitation behavior of the composite. As the interfacial reaction between the whiskers and AC8A-Al alloy consumed the Mg atom of the matrix in the composite, the time to the peak aging of the composite was almost same as that of the AC8A-Al alloy. The free precipitation zone can be found nearby some whisker in the composite, duo to Mg content decreased in the matrix.

A 2-2-type nanostructure bilayer film of CoFe2O4/Pb(Zr0.52Ti0.48)O3 was successfully prepared on the (111)Pt/Ti/SiO2/Si substrate. The Pb(Zr0.52Ti0.48)O3 layer in the bilayer film is (111) oriented and is a mixture of tetragonal and monoclinic phases. The results from an in situ X-ray diffraction analysis of the multiferroic bilayer film under statistic magnetic field indicate that the monoclinic-tetragonal phase transition was induced by magnetostriction of the CoFe2O4 layer. A large magnetoelectric effect was obtained probably because of the different polarization directions of the tetragonal and monoclinic phases.

The precipitation behaviour of three Al-Mg-Si alloys has been studied by differential scanning calorimetry (DSC) and transmission electron microscopy. Seven exothermic peaks are usually observed in DSC thermograms of Al-Mg-Si alloys with high silicon contents. These peaks are believed to be caused by the formation of clusters of silicon and magnesium atoms, Guinier-Preston zones, small precipitates with an unknown structure, β″ phase, B′ phase, silicon precipitates and β phase. The silicon content has no obvious effect on the precipitation of β″ and B′ phases in these alloys, but it has a pronounced influence on the formation of silicon precipitates. The cold-rolling reduction before solution heat treatment is also found to affect the precipitation process appreciably.

A radiation model of millimeter wave antenna is established in this paper. The electromagnetic field distribution on the seeker antenna is calculated in MMWSS based on PO method. According the numerical results, when target is in the near-field of antenna, the characteristic of echo amplitude has an obvious effect of multi-scattering points effect.

Titanium aluminide (TiAl) is an advanced intermetallic material and is being investigated for application in turbocharger components for diesel engines. A TiAl turbocharger rotor consists of a cast TiAl turbine wheel and a Ti-alloy shaft that are joined by friction welding. Although friction welding is an established industrial process, it is still challenging to join dissimilar materials especially for brittle intermetallics. These joints are therefore required to be inspected using a nondestructive evaluation (NDE) method. In this study, synchrotron X-ray computed tomography (CT) developed at the Advanced Photon Source at Argonne National Laboratory was used for NDE characterization of friction-welded joint in three TiAl turbocharger rotors. The filtered synchrotron X-ray source has high peak energies to penetrate thick metallic materials, and the detector (imager) has high spatial resolutions to resolve small flaws. The CT inspections revealed detailed 3D crack distributions within poorly welded joints...

The SAW velocity of PMMA as a function of temperature (25-75°C) and frequency (1.0-8.0MHz) is measured by the laser generation and detection technique. From the temperature dependence of the velocity two turning points are observed, one of which may be related to the β-transition of PMMA.

Alnico alloys are of technological importance owing to their excellent magnetic stability and good comprehensive properties. Considerable interest has arisen concerning the chemical compositions of the Fe-Co and Ni-Al rich phases which evolve from the spinodal decomposition of a bcc single phase solution at high temperatures [1–5]. However, emphasis has been seldom placed on kinetics of microstructural evolution at high temperatures. Recently, we have observed the splitting of Fe-Co rich particles in Alnico8 thermomagnetically treated [6]. On the other hand, some investigations [7– 9] have shown that microstructures in some materials have been found to be of fractal characteristics. However, different structures often exhibit different fractal natures, which implies that they are formed usually by different kinetic mechanisms. To this end, in this paper, our attention is focused on development of fractal characteristics in the microstructure formed during thermomagnetic treatment, which is expected to enhance understanding of the mechanisms of the microstructural evolution in Alnico8. The chemical composition of the Alnico8 studied is as follows (at mass percentage): 33.2Co, 16.3Ni, 5.3Al, 3.6Ti, 3.0Cu, 1.5Si, 1.0Nb, bal. Fe. The bulk Alnico8 was solution treated for 50 min at 1250 ◦C and then vacuum quenched. Thin laminar samples were cut from the quenched Alnico8 and subsequently subjected to a magnetic heat treatment with a field of 270 kA m−1 perpendicular to the section plane at 800 ◦C for various times such as 1.5, 5 and 10 min, and finally vacuum quenched. Transmission electron microscope (TEM) observations were made using a JEOL 200CX microscope with an accelerating voltage of 200 kV. Small angle X-ray scattering (SAXS) performed in transmission geometry with Cu Kα radiation on a Rigaku diffractometer was employed to evaluate the spatial fractal characteristics in size and morphology of Fe-Co rich particles. Fig. 1 shows TEM micrographs of the samples thermomagnetically treated at 800 ◦C for various times. TEM images were taken with electron beams along the [001] direction. The dark and isolated areas in all TEM images corresponded to rod-like Fe-Co rich particles, the long axis of which was parallel to the [001] direction [6]. The splitting of large Fe-Co rich particles was observed in the specimens with thermomagnetic treatment for 1.5 and 5 min, respectively, as the arrows in Fig. 1a and b indicate. In Fig. 1a small particles originated from the splitting of larger ones [6]. To compare Fig. 1a with b, it is easily found that the split particles coarsened. As a result of splitting, the resultant microstructure was fine and homogenous as shown in Fig. 1c. For a fractal object, N (R) is proportional to Rdf , where N (R) represents the number of particles within a radius R around a given particle, and df is the fractal dimension [10]. Based on this, direct measurements from TEM images have been taken on Fe-Co rich particles for all samples in two-dimensional Euclidian space, which covered wide ranges of R. Logarithmic plots of N (R) versus R for all samples measured are shown in Fig. 2. Each set of data are well described by a power-law behavior, as expected for a fractal. The linear least-squares fits to the data sets give estimates of fractal dimensions for 1.5, 5 and 10 min, which are 1.941, 1.945 and 1.784, respectively. In addition, SAXS experiments were also performed on all samples with different treatments to obtain directly three-dimensional information about the fractal behavior of Fe-Co rich particles. It has been however pointed out that since a fractal object has the spatial self-similarity, the scattering intensity obeys a power-law decay: I ∼ q−p [11]. If p 3, then p= df− 2d, where d is the Euclidian space dimension 3, which is the case of a compact object with smooth or rough surface depending on the value of p. Fig. 3 shows the curves of lgI versus lgq for the samples thermomagnetically treated for various times. On the curves, there exist obvious linear regions between lgI and lgq for all samples, which also indicates clearly that Fe-Co rich particles with different sizes are self-similar and of fractal characteristic in statistical sense. The exponents p for 1.5, 5 and 10 min are 2.566, 2.687 and 1.917, respectively, which are all less than 3 and thus equivalent exactly to the fractal dimensions. The fractal dimensions 2.566 and 2.687 obtained from the SAXS data for 1.5 and 5 min are in good agreement with the theoretical dimension 2.5, which has been figured out by Meakin on the basis of the diffusion-limited aggregation (DLA) model in threedimensional space [12]. In addition, for 10 min, a fractal dimension 1.917 derived from the SAXS data is also basically in accord with the fractal dimension 1.8 calculated from the cluster-cluster aggregation (CCA) growth model reported in Reference [13]. This gives a hint that the evolution of Fe-Co rich particles for

Heart rate recovery (HRR) is an important indicator of cardiovascular health. The purpose of the present investigation is to examine the influence of sex on the relationship between HRR and other markers of cardiovascular health. Two hundred and seventy-five apparently healthy subjects participated in this study. Subjects underwent cardiopulmonary exercise testing (outcome measures: VO(2max) and HRR 1 and 2 min into recovery), lipid analysis, measurement of resting systolic and diastolic blood pressure and measurement of aortic wave velocity (AWV in m/s) via magnetic resonance. HRR both at 1 min (HRR(1)) and at 2 min (HRR(2)) were higher in males. In general, the correlation between HRR(1) and other measures of interest was weaker than that found with HRR(2) in both male and female subjects. With respect to HRR(2), the relationship with other measures of interest was stronger in the female subgroup. Specific to arterial stiffness, the correlation between HRR(2) and AWV was -0.33 and -0.46 (P0.001 for both) in male and female subgroups, respectively. The results of the present study indicate that both gender and the timing of HRR measurement influence its relationship with other important cardiovascular risk factors.

ZnAl

The interface plays a very important role in the properties of composites. One of the effects of the interface on the properties of the composite is that it may affect the load transfer from the matrix to the reinforcement. As it is well known that the Young's modulus of composites is influenced mainly by the load transfer [1, 2], the interfacial reaction has a great effect on the bonding and strength of the interface [3], which can affect the Young's modulus of the composite. Recently, a low cost aluminium matrix composite reinforced by aluminium borate whisker (AIIsB4 O33W » denoted by ABOw) has been studied by many researchers [4 8]. Although the interfacial reaction, mechanical properties and ageing behaviours of the composite have been investigated extensively, there have been few studies on the effect of the interfacial reaction on the Young's modulus of ABOw/A1 composite. This letter aims to report this effect. The ABOw/AC8A-A1 composite used was fabricated by the squeeze casting method. The volume fraction of the whisker was 25%. The composition of the matrix alloy was Si: 12.0wt%, Mg: 1.0wt%, Cu: 0.8 wt%, NJ: 1.0 wt%, AI: 85.2 wt%. To obtain different degrees of the interfacial reaction, the composites were fabricated at various temperatures: 660°C, 720°C, 760°C, 800°C and 840°C. The specimens for tensile testing were solutionized at 500 °C for 5 h then quenched into water maintained at 80 °C, to prevent the effect of precipitation on the properties of the composite. The microstructure and the interfacial reaction were studied by transmission electron microscopy (TEM). The specimens for TEM observation were thinned by the ion milling method. The Young's modulus of the composite was measured by the slope of the tensile stress-strain curves. The dependence of Young's modulus of the composites on the casting temperature is shown in Fig. 1. It can be seen that when the casting temperature is lower than 800°C, the Young's modulus of the composite increases with the casting temperature. When the casting temperature is higher that 800 °C, however, the Young's modulus of the composite decreases with increasing casting temperature. That is to say, there exists an optimal casting temperature for the Yourig's modulus of the ABOw/AC8A composite. The microstructure of the ABOw/AC8A composite was studied using TEM. As shown in Fig. 2, an

Conventional ultrasonic tests are conducted using water as a transmitting medium. Water coupled ultrasound cannot be applied to certain water‐sensitive or porous materials and is more difficult to use in the field. In contrast, air‐coupled ultrasound is non‐contact and has clear advantages over water‐coupled testing. The technology of air‐coupled ultrasound has gained maturity in recent years. Some systems have become commercially available and researchers are pursuing several different modalities of air‐coupled transduction. This paper reports our experience of applying air‐coupled ultrasound to the inspection of flaws, damage, and normal internal structures of composite parts. Through‐transmission C‐scans at 400 kHz using a focused receiver has resolution sufficient to image honeycomb cells in the sandwich core. With the transmitter and receiver on the same side of a laminate. Lamb waves were generated and used for the imaging of substructures. Air‐coupled scan results are presented for flaw detection and damage in aircraft composite structures.

Vascular endothelial growth factor (VEGF) plays a crucial role in angiogenesis and in pathological processes such as tumor growth, rheumatoid arthritis, and ocular neovascularization. A recombinant humanized monoclonal antibody (rhuMAb), rhuMAb VEGF, has been developed to inhibit the effects of VEGF in the treatment of solid tumors. Intravenous and s.c. pharmacokinetic studies were conducted in mice, rats, and cynomolgus monkeys. In addition, the tissue distribution of i.v. 125I-rhuMAb VEGF was investigated in rabbits. At a dose of approximately 10 mg/kg, the clearance of rhuMAb VEGF from the serum was 15.7 ml/day/kg in mice, 4.83 ml/day/kg in rats, and 5.59 ml/day/kg in cynomolgus monkeys, and the terminal half-life ranged from 6 to 12 days in all species. After s.c. administration, rhuMAb VEGF had a bioavailability of 69% in rats and 100% in mice and cynomolgus monkeys. Pharmacokinetic data in mice, rats, and cynomolgus monkeys were used to predict the pharmacokinetics of rhuMAb VEGF using allometric scaling in humans. The predicted serum clearance of rhuMAb VEGF in humans was 2.4 ml/day/kg and the terminal half-life was 12 days. Two hours after i.v. bolus administration of 125I-rhuMAb VEGF in rabbits, trichloroacetic acid-precipitable radioactivity was noted primarily in the plasma, with lesser amounts in highly perfused tissues such as kidneys, testes, spleen, heart, and lungs. At 48 h after dosing, trichloroacetic acid-precipitable radioactivity was noted in plasma with minimal distribution to testes, bladder, heart, lungs, and kidneys. Tissue distribution and pharmacokinetic data indicate that rhuMAb VEGF is cleared slowly and distributes to specific sites in the body.

In recent years, there has been increasing interest in nanostructured ceramic materials because of their advanced properties. The superplasticity; improved strength and toughness, higher densification rate and low sintering temperature are observed in these materials[1–4]. The sintering speed vsintering of ceramic is related to the grain size d by the expression of vsin ting ∝d-4 [2]. By adding the nano-particles of Al2O3 to conventional Al2O3, the strength, fracture toughness and thermal resistance of Al2O3 ceramic can increase[5]. Up to now, only a few researchers[6,7] have concerned about the specific heat and thermal expansion of nano- ceramics, and no report about thermal diffusivity of nano-composite has been found in literature. However, characterizations of thermal diffusivity of nanocomposite ceramics are very important for designing and preparing this kind of new materials.

Polymethyl methacrylate (PMMA) is a kind of typical amorphous polymer, whose main mechanical property is viscoelasticity that can be of great importance in materials characterization and nondestructive evaluation (NDE). On the other hand, ultrasonic NDE technique is one of the basic methods to characterize polymeric materials. By the measurements of the velocity and attenuation of the bulk waves as a function of frequency and temperature [1–3], the moduli of PMMA can be deduced and various relaxation phenomena can be investigated. However, as we know, the studies on the SAW attenuation of PMMA have not been reported. It is difficult for the contact ultrasonic method to do so because the effect of the electric transducers working in the contact way on the SAW field can not be avoided. Some disadvantages of using electronic ultrasonic method to characterize polymers, such as the measurement must be made in the immersion apparatus and the piezoelectric transducers with different frequencies must be used to obtain the attenuation spectra etc. have been overcome by the means of the laser ultrasonic technique [4,5]. The noncontact nature of the laser ultrasonic technique can also eliminate the effect of the contact measurement on the SAW field and make it convenient for the measurement at elevated temperatures. Therefore the laser ultrasonic technique is extremely suitable for the study on the attenuation of SAW.

The relationship between the incidence of ectopic pregnancy (EP) and the use of IUD was examined by the method of analytical epidemiological study. 10,843 women of child-bearing age from the west district of Beijing were investigated. The conclusions were: (1) The incidence of EP in IUD users was 0.91/1,000 women year; and the EP incidence in women not using any contraceptives was 2.23/1,000 women year. (2) The incidence of EP in women with IUD inserted within 2 years was significantly higher than that in women using IUD longer than 2 years, that is 5.64/1,000 women year and 0.47/1,000 women year respectively. (3) The probability of suffering from EP for accidental pregnancy in IUD users was 4.84%, which was much higher than that of women not using any contraceptives (0.20%). (4) The risk of EP for IUD users with pelvic inflammatory disease was 6.64 times compared to those without pelvic inflammatory disease. (5) EP was not related to previous cesarean section or induced abortion.