The first reactive synthesis competition (SYNTCOMP 2014)

International Journal on Software Tools for Technology Transfer - We introduce the reactive synthesis competition (SYNTCOMP), a long-term effort intended to stimulate and guide advances in the...     

Interactions between naloxone and narcotic analgesics under three schedules that induce polydipsia

The fluorescein angiographic picture of sympathetic ophthalmia is described in an instructive case, which first started at the posterior pole. In the acute phase there was a picture of an exudative process with multiple subretinal enlarging hyperfluorecent spots and some dye-pooling. The retinal vasculature was unaffected. In the healing phase a transitory involvement of the optic nerve head was observed. The cicatricial phase was characterized by a coarsening of the pigment pattern of the fundus. In addition to fluorescein angiography the degree of transitory hyperopia was an excellent indicator of the activity of the disease process.     

Neurogenic relaxation mediated by vasoactive intestinal polypeptide (VIP) in the isthmus of the human fallopian tube

The smooth musculature of the Fallopian tube is important for normal ovum transport, fertilization and implantation. Little is known about the factors controlling the motor activity of the isthmic sphincter. Studies were performed on smooth muscle preparations from the human tube in vitro. Electrical field stimulation of the nerves in the isthmic region reduced the motor activity, particularly in the circular muscle. The response was unaffected by adrenergic and cholinergic antagonists, but blocked by tetrodotoxin, suggesting a neural involvement. Vasoactive intestinal polypeptide (VIP) was considered a likely candidate for the neural mediation of this response in view of the high density of VIP-containing nerve fibres in this region, and in view of the fact that exogenous VIP causes a marked reduction of the tubal motor activity. To test whether VIP might be the endogenous mediator of this effect, nerve stimulation was carried out in the presence of large amounts of exogenous VIP in order to occupy all VIP receptors; the motor inhibitory action of VIP was counteracted by vasopressin. Under these conditions, nerve stimulation failed to reduce isthmic motor activity. This was not due to vasopressin since reduction occurred in the presence of this peptide alone. The results suggest that VIP is responsible for the neurogenic inhibition of motor activity in the isthmus region of the human Fallopian tube.     

Metal ion implantation in inert polymers for strain gauge applications

Metal ion implantation in inert polymers may produce ultra-thin conducting films below the polymer surface. These subsurface films are promising structures for strain gauge applications. To this purpose, polycarbonate substrates were irradiated at room temperature with low-energy metal ions (Cu⁺ and Ni⁺) and with fluences in the range between 1 × 10¹⁶ and 1 × 10¹⁷ ions/cm², in order to promote the precipitation of dispersed metal nanoparticles or the formation of a continuous thin film. The nanoparticle morphology and the microstructural properties of polymer nanocomposites were investigated by glancing-incidence X-ray diffraction and transmission electron microscopy (TEM) measurements. At lower fluences (<5 × 10¹⁶ ions/cm²) a spontaneous precipitation of spherical-shaped metal nanoparticles occurred below the polymer top-surface (∼50 nm), whereas at higher fluences the aggregation of metal nanoparticles produced the formation of a continuous polycrystalline nanofilm. Furthermore, a characteristic surface plasmon resonance peak was observed for nanocomposites produced at lower ion fluences, due to the presence of Cu nanoparticles. A reduced electrical resistance of the near-surface metal-polymer nanocomposite was measured. The variation of electrical conductivity as a function of the applied surface load was measured: we found a linear relationship and a very small hysteresis.     

全球烧结金属含油轴承评定

烧结金属含油轴承是当今全世界最早生产和使用最广的粉末冶金产品.以前对一种组成为中等石墨-青铜的轴承研究发现,北美制造的轴承和欧洲生产的同样产品之间有显著差异.为此,对北美、欧洲及日本提供的轴承,进行了比较详细的研究.每一地区至少提供二个生产厂商和二种不同合金的轴承试件.合金范围包括青铜、铁-铜及铁-石墨.测试结果证实了以前的发现,欧洲制造的青铜轴承和北美与日本生产的轴承不同,现在认为这是由于铜基粉末不同所致.还发现北美和日本制造的铁-石墨轴承的压溃强度不同.提出了这些研究的结果,包括证实力学性能不同的显微照片.另外,还评价了和国际标准ISO 5755有关的结论.