Synthesis and antimicrobial activity of a dihydroampicillin and a dihydrocephalexin

A dihydroampicillin (3) and a dihydrocephalexin (4) have been synthesized by condensing alpha-(cyclohexa-1, 3-dienyl)glycyl chloride with 6-aminopenicillanic acid (1) and 7-deacetoxycephalosporanic acid (2) respectively. The two antibiotics obtained show enhanced antimicrobial activity towards certain bacterial strains compared with ampicillin and cephalexin.     

Rheological and processing properties of a system consisting of a ferrite powder and a composite plasticizer

Translated from Poroshkovaya Metallurgiya, No. 5(305), pp. 11–15, May, 1988.     

Effects of a merger of a small and a large organization on members' behaviors and experiences.

11 mo after the merger of 2 local churches consisting of 419 and 961 members, 118 members formerly from the smaller church and 115 members formerly from the larger church reported their support for activities in both the prior and merged churches, and their feelings about participating in the merged church. Church support prior to the merger did not differ for the 2 groups. Results indicate that both groups declined in support after the merger, but the decline was greater for members from the small church. The small church sample felt less close, obligated, and welcome to participate in the merged church activities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Method and technique of experimental autotransplantation of a lung and a lung lobe

The authors have accumulated an experience of 350 canine autotransplantations of a lung and its lobe. The peculiarities of the operative technique are described, and special emphasis is laid on its technical details that largely determine the success of a lung autotransplantation. The described method and technique permit the performance of orthotopic autotransplantation of a whole lung and of its lobe, and of heterotopic autotransplantation of the lower lobe of the right lung into the left pleural cavity in place of a removed lower lobe or whole lung. The first stage of autotransplantation of a lung or its lobe consists in applying an atrio-venous or venous anastomosis and that of the pulmonary artery with continuous U-shaped eversion sutures, with a re-establishment of the circulation, thus reducing the period of lung ischaemia. Upon restoring the blood flow in the lung, a bronchial anastomosis is applied with interrupted or continuous sutures, and the ventilation is restored. The vascular and bronchial anastomoses are applied with synthetic suture material (Orsylon) on atraumatic needles. The extensive experience of the authors in long-term follow-up of the animals after transplantation (up to 5 years) demonstrates that the described technique and method of lung autotransplantation ensures good competence and patency of the vascular and bronchial anastomoses, without any stenoses observed in the late postoperative period. As shown by histological examinations, the inflammatory reaction around the suture material is minimal.     

Simultaneous perforation of a gastric and a duodenal ulcer

This is a case report of simultaneous perforation of a gastric and duodenal ulcer. Perusal of the literature shows the rarity of this occurrence. Consideration is given to the difficulty of handling such a case in the presence of severe generalized peritonitis and the precarious condition of the patient.     

Digital simulations of a stationary and a linear weld

A computational model was used to simulate stationary and linear gas-tungsten-arc (GTA) welds and to study the effect of surface-tension as well as arc position. The results show that the surface-tension gradient with respect to temperature is a dominating factor in determining the direction of the convective flow within the molten weld pool. Furthermore, a linear-arc movement leads to a convective pattern, which is different from that of a stationary weld.     

Matching location and color of a compound stimulus: Comparison of a food-storing and a nonstoring bird species.

Black-capped chickadees (Parus atricapillus), birds that store food, and dark-eyed juncos (Junco hyemalis), nonstoring birds, were compared in 2 operant delayed-matching-to-sample experiments. Subjects were required to remember a stimulus of a different color in a different spatial location on each trial. When spatial and color elements of the sample were placed in conflict on test trials in Experiments 1A and 1B, chickadees' first choices were controlled by the stimulus associated with the spatial location, but juncos' first choices were controlled by the spatial location and the color. In Experiment 2, each element was tested alone after exposure to the compound. Chickadees performed better on the spatial element than the color element, whereas juncos performed equally well on both elements. It is hypothesized that chickadees process spatial information at the expense of color, whereas juncos distribute their attention or memory, or both, more evenly across stimulus dimensions. This difference may be related to the chickadees' reliance on spatial information to find stored food. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Becoming a grandparent: a longitudinal study of expectations and early experiences as a function of sex and lineage

In this study the presence of glial fibrillary acidic protein (GFAP) in kidney is for the first time demonstrated in cryostat sections and cultures of isolated glomerular explants derived from rat kidneys. In double immunolabelling analysis of adult rat kidney sections using antiserum against GFAP and monoclonal antibody (mAb) against vimentin or desmin, the presence of immunoreactivity for GFAP could be observed in the glomerulus of the kidney and vascular cells situated in the peritubular space which expressed vimentin and desmin. Labelling of the sections with absorbed antiserum against GFAP completely abolished the staining in all these cells. The mAb against GFAP, clone GF12.24 which is known to label GFAP both in neural and non-neural cells, recognised its antigen only in the cells located in glomeruli. The investigations performed on early 2- or 3-day-old cultures from glomerular explants revealed different patterns of staining for GFAP in mesangial cells and podocytes: weak filamentous in mesangial cells and a strong non-filamentous perinuclear pattern in podocytes. Due to prominent perinuclear expression in podocytes GFAP may be considered as a marker of these cells. A different pattern of distribution of immunoreactivity for GFAP in podocytes and mesangial cells might be due to function-related posttranslational modifications of GFAP resulting in assembly or disassembly of GFAP filaments. The different pattern of staining for GFAP in the podocytes and mesangial cells, cells which exert a different influence on the capillaries of the glomeruli, suggests a role for GFAP in regulation of the tension and permeability of vascular walls. Previous investigations and present studies hint at GFAP as being a general marker of perivascular cells.     

Growth kinetics of a surface film during the annealing of a mixture of a metal powder and a decomposing oxide

Conclusions Equations have been derived describing the growth kinetics of surface films. Conditions have been determined under which surface films cease to be porous and become coherent. Values of the coefficient of oxygen diffusion in copper at a temperature of 850°C calculated using the equations proposed and experimental data are in good agreement with a value cited in the literature.Translated from Poroshkovaya Metallurgiya, No. 2(182), pp. 22–25, February, 1978.     

Relation between a rheological and a microscopical model of sintering

Conclusions The results obtained point to a relation between the possibility of employing the rheological model (1) for describing the viscous flow of a material and the validity of the Mackenzie equation. Two limiting cases may arise. In one of them, where pore healing in a material occurs through a mechanism of viscous change in shape of the nonporous part of the material, the Mackenzie relation (2) or its generalized variant (15) is applicable. The rheological model for an isotropic solid is described by Eq. (1). When the Nabarro-Herring diffusional creep mechanism is operative, the coefficients of viscosity are calculated with Eqs. (19) and (20).In the other limiting case the nonporous part of a material possesses no viscosity (n = ), which rules out the possibility of employing the rheological model (1) and the Mackenzie equation. To describe the kinetics of shrinkage under the action of external pressure and surface tension forces, recourse must be had to Eq. (14). The coefficients of volume viscosity for typical porous structures (one pore and an assembly of pores in a polycrystal grain and pores at grain boundaries) are given by Eqs. (22), (27), and (31).Translated from Poroshkovaya Metallurgiya, No. 3(183), pp. 31–36, March, 1978.     

也谈直线和平面投影阵的应用

针对空间解析几何中的投影与垂直问题,引入直线和平面的投影阵与投影公式,从计算空间角与距离,体积和对称以及判断直线共面等方面给出求解结论,以展示投影阵在理论推导和实际计算中的应用.     

新型张弦网壳组合结构的设计与分析

在鄂尔多斯东胜体育中心综合体育馆展厅结构设计中,提出了在张弦桁架之间设置双层网壳的新结构体系,在满足复杂建筑造型的同时,有效增加了结构的刚度和稳定性.设计了接近实际工程的基本算例,从整体模型入手,全面分析了垂跨比、初始预应力和撑杆数量变化对结构静力性能、动力性能以及用钢量的影响.依据分析结果,对不规则造型的鄂尔多斯东胜体育中心综合体育馆展厅进行设计,其中索的预应力是设计中的难点和关键,本文给出了详尽的调索方法和依据.     

Comparison of fatigue deformation and fracture in a dispersion-strengthened and a conventional nickel-base superalloy

INCONEL alloy MA 753 is a dispersion strengthened nickel-base superalloy made by mechanical alloying which combines γ’ precipitation hardening and yttria dispersion strengthening with good oxidation and sulfidation resistance. At temperatures up to 1227 K (1750°F), the fatigue strength of MA 753 is greater than that of a conventional wrought superalloy which has a composition close to that of the MA 753 matrix. Fatigue strength at elevated temperatures is strongly dependent on testing frequency. This behavior is correlated with the strain rate dependence of tensile strength. Fatigue crack initiation sites and propagation modes in MA 753 are discussed as a function of temperature and microstructure and compared to those in the conventional superalloy. The transition from transgranular to intergranular fracture mode in MA 753 occurs at a higher temperature than found in conventional nickel-base superalloys. While the γ’ precipitate controls the fatigue strength at low and intermediate temperatures, the oxide dispersoid and carbides also affect deformation in this temperature range. At elevated temperatures, fatigue deformation is controlled by the dispersoid and carbides. Trademark of The International Nickel Company, Inc.