Issues in the High Resolution Acoustoelastic Measurement of Stress

The acoustoelastic measurement of stress is a topic with a rich history and the basic principles are well known [1]. In summary, one takes advantage of various nonlinearities which govern the elastic response of a solid, including but not limited to anharmonicities in interatomic forces, which lead to a stress dependence of the ultrasonic velocity. The basic idea, then is to precisely measure the velocity and to infer stress from a relation of the form V=Vo+Kσ where V is the measured velocity in the presence of a stress σ, Vo is the value that would have been observed in the absence of that stress, and K is known as the acoustoelastic constant.</p

The role of hypothalamic H1 receptor antagonism in antipsychotic-induced weight gain

Treatment with second generation antipsychotics (SGAs), notably olanzapine and clozapine, causes severe obesity side effects. Antagonism of histamine H1 receptors has been identified as a main cause of SGA-induced obesity, but the molecular mechanisms associated with this antagonism in different stages of SGA-induced weight gain remain unclear. This review aims to explore the potential role of hypothalamic histamine H1 receptors in different stages of SGA-induced weight gain/obesity and the molecular pathways related to SGA-induced antagonism of these receptors. Initial data have demonstrated the importance of hypothalamic H1 receptors in both short- and long-term SGA-induced obesity. Blocking hypothalamic H1 receptors by SGAs activates AMP-activated protein kinase (AMPK), a well-known feeding regulator. During short-term treatment, hypothalamic H1 receptor antagonism by SGAs may activate the AMPK—carnitine palmitoyltransferase 1 signaling to rapidly increase caloric intake and result in weight gain. During long-term SGA treatment, hypothalamic H1 receptor antagonism can reduce thermogenesis, possibly by inhibiting the sympathetic outflows to the brainstem rostral raphe pallidus and rostral ventrolateral medulla, therefore decreasing brown adipose tissue thermogenesis. Additionally, blocking of hypothalamic H1 receptors by SGAs may also contribute to fat accumulation by decreasing lipolysis but increasing lipogenesis in white adipose tissue. In summary, antagonism of hypothalamic H1 receptors by SGAs may time-dependently affect the hypothalamus-brainstem circuits to cause weight gain by stimulating appetite and fat accumulation but reducing energy expenditure. The H1 receptor and its downstream signaling molecules could be valuable targets for the design of new compounds for treating SGA-induced weight gain/obesity

Predicted predissociation linewidths in the Schumann-runge bands of O2 compared with recent high-resolution measurements

A Computerized Ultrasonic Gauging System (CUGS) has been developed to generate very precise topographical maps of the outer and inner surfaces of tubes during various stages of manufacture and life-cycle of the parts. Measurements of the tube dimensions are obtained with a resolution of 2.5 μm (10−4 inches) and accuracies of the order of 10 μm (4×10−4 inches) or better. A typical output of CUGS is an ultrasonic image, in which the horizontal and vertical axes represent the axial and angular position of the part, respectively[1]. The system is currently utilized to gauge tubes as long as 7.5 m (25 feet) resulting in the acquisition of more than 15,000,000 data points, which require up to 60 Mbytes of disk memory on a computer. A Wavelet Transform Image decomposition technique was developed for compression and processing of the ultrasonic images, resulting in a great decrease in time and resources needed to perform such operations. Waveletbased image analysis has two distinct characteristics: multiresolution and high spatial localization[2]. Multiresolution refers to the possibility of obtaining representations of the same image with different resolutions. The high spatial localization properties of the filters used for the wavelet decomposition can also be utilized for the enhancement of features such as erosion pattern without the loss of localization, a problem commonly encountered in Fourier analysis. In the application here discussed, CUGS is utilized to map the wear of the internal surface of steel tubes, before and after exposure to extreme environments involving temperature, pressure, corrosive gases and mechanical forces

Human MAD2B is essential for mutagenic DNA damage tolerance homolgous recombination and maintenance of genome stability

Thermal spraying of protective coatings has been in use since 1917 when the initial application was the spraying of zinc layers onto steel structures to prevent corrosion [1]. In the 1970’s plasma-spray technology was first used with the introduction of vacuum plasma-spraying [1]. Today, gases such as argon and nitrogen (sometimes with an additional gas such as helium or hydrogen) are often used in plasma-spray guns. In plasma-spraying an electric-arc discharge heats the gas stream to high temperature (≥ 10,000 K), turning it into a plasma. The gas exits the spray-gun at high speed (≈ 200 m/s to 600 m/s) towards the material to be coated. Material powder (often carried by a second gas stream) is injected into the plasma stream, where it melts into liquid droplets. These droplets are carried onto the target surface, where they rapidly cool (≈ 106 K/s) into solid, flat splats. A layer of material can be built up by repeated spraying of the same surface area. This high-temperature process allows for the spraying of virtually any material possessing a stable molten phase, including ceramics [2]. Further technical details and the history of plasma-spraying can be found in [1–2]