Selective loss of peripheral blood CD45RO+ T lymphocytes correlates with increased levels of serum cytokines and endothelial cell-derived soluble cell adhesion molecules in patients with chronic idiopathic neutropenia of adults

The cause of urinary or fecal incontinence may be a complex one. A central or peripheral neurogenic lesion is frequently found to be accounting for the problem. The diagnosis should be specified by neurologic examinations and adequate neurophysiologic workup prior to any conservative or surgical treatment. Of particular expressiveness are, neurological history, both neurography of the pudendal nerve and electromyography of the external anal sphincter. Additional measures such as recording of the motor or sensory potentials, determination of reflex latencies and an electromyogram of other striated muscles of the pelvic floor may be taken as needed. Close co-operation of gynecologists, proctologists, and neurophysiologically trained neurologists will help to improve the prospects of treatment and avoid inappropriate therapeutic approaches.     

渗碳淬火零件表面磨削裂纹及其与热处理工艺的关系

渗碳淬火零件磨削后表面往往出现裂纹,即所谓的"磨削裂纹"。严格地讲,这种裂纹是在磨削过程中产生的。裂纹的形态有网状、长条状、星状等。磨削裂纹的产生与材料的内在质量、磨削工艺、热处理工艺、零件表层的性质与结构密切相关。简述了氢脆和磨削裂纹的预防问题。     

Étude hydrodynamique des lits fluidisés sous vide et sous haute température

After having analyzed the few literature results concerning fluidized beds hydrodynamics under reduced pressure, new theoretical elements are proposed which provide an estimation of the beginning and finishing fluidization velocities. Numerous experimental results(U_mfapp, U_mb, U_mp, ?_mf, ?_mb, ?_mp), obtained at 20 and 500°C, are then presented for several sub-atmospheric pressures. Finally, f& the first time, at leastto our knowledge, by high frequency recording pressure drops through the bed, the influence of pressure decreases on the hydrodynamics is accurately analyzed.     

Use of Thermophysical Properties to Select and Control Convection During Rapid Solidification of Steel Alloys Using Electromagnetic Levitation on the Space Station

A major reason to conduct solidification experiments in space is that the unique conditions accessible in reduced-gravity allow investigation of fundamental questions while limiting the influence of sedimentation or buoyancy-induced convection. When processing metallic alloys using containerless electromagnetic levitation, convection may be controlled over a wide range, spanning the laminar-turbulent transition, by proper selection of facility operating conditions. By measuring key thermophysical properties such as density, viscosity, and electrical resistivity on-orbit, the specific sample being processed may be characterized and the results used to update pre-mission magnetohydrodynamic model predictions of induced stirring within the droplet. Thus, convection becomes a controlled experimental parameter that can be applied to an investigation of how stirring influences the metastable-to-stable transformation during rapid solidification of FeCrNi alloys. For these alloys, the incubation or delay time is observed to be a weak function of undercooling and a strong function of applied convection.     

Experimental study of lateral pass width in conventional and vibrations-assisted ball burnishing

Burnishing is a mechanical finishing operation performed on workpieces to enhance their surface quality through plastic deformation. One of the main issues to understand the overall process is the behavior of the elastoplastic deformations caused by the burnishing ball on the workpiece. The first burnishing passes performed on the workpiece surface lead to its plastic strain and self-hardening, thus influencing the results of consecutive passes. Some references have studied the phenomenon of indentation, finding that there is a certain self-hardening coefficient threshold which allows to predict the presence of pile-ups at the edges of the indentation path. Nevertheless, burnishing is not a single-pass operation. On the contrary, burnishing a whole surface requires successive adjacent and/or overlapping passes, i.e., parallel passes separated consecutively a certain lateral pass width. No reference has been found in the literature defining the adequate values of the lateral pass width with regards to the pile-up effect to enhance the final topology of the burnished surface. This paper explores that influence by studying the presence of the pile-up effect after burnishing a single or several overlapping passes on two materials (aluminum and steel), by characterizing the topology of the generated path. Afterwards, two adjacent passes are performed, varying the lateral pass width, to compare the final surface roughness derived from each operation. An optimum value for the lateral pass width was found, to improve the final roughness after burnishing in different conditions and to increase the productivity of the process.     

Effects of turbulent flow on the corrosion inhibition properties of 2‐mercaptobenzimidazole

The electrochemical techniques, that is, polarization resistance (R_p) and potentiodynamic polarization curves, were used in order to determine the effect of turbulent flow on the corrosion inhibiting effect of 2‐mercaptobenzimidazole (2‐MBI) on API 5L X52 grade steel samples immersed in a 3% NaCl aqueous solution saturated with CO₂ at 60 °C. Turbulent flow conditions were controlled using a rotating cylinder electrode (RCE). An inhibition efficiency of 98% was measured at a concentration of 10 ppm of 2‐MBI at a rotation rate of 5000 rpm. This efficiency value is similar to those efficiency values measured at 25 and 40 ppm 2‐MBI and at the same rotation rate. These observations suggest that as the turbulent flow conditions increase the corrosion inhibiting effect of 2‐MBI is enhanced. 2‐MBI follows a Langmuir adsorption isotherm. The calculated values of adsorption equilibrium constant (K_ads) and adsorption free energy ($\Delta G_{{\rm ads}}^{{\rm o}} $ ) suggest that the adsorption process taking place is chemical. The polarization curves indicate that the 2‐MBI does not modify the electrochemical mechanism of the anodic (Fe dissolution) and cathodic (hydrogen evolution) reactions. It is suggested that 2‐MBI decreases the rate at which these reactions occur, blocking the active sites on the steel surface.     

Physicochemical studies of mild steel corrosion and atmospheric corrosivity mapping of Karachi: An important harbor city of modern Maritime Silk Route

This paper has reported physicochemical features of mild steel's corrosion products and provided atmospheric corrosivity maps of Karachi harbor city, drafted on the basis of spatial distribution of corrosion data from July 2018 to June 2019 at 10 different urban, industrial, and marine test sites. Exposure tests have been performed to study atmospheric corrosivity, corrosion products, and corrodants including chloride, sulfur dioxide, time of wetness (TOW), and corrosion rate as per ISO and ASTM standards. Scanning electron microscope, Fourier-transform infrared spectroscopy, and X-ray diffraction have corroborated the presence of lepidocrocite, goethite, magnetite, and quartz phases at almost all the test sites, with slight variations in their morphologies and quantities. The data analysis has revealed that TOW is a major detrimental factor to accelerate corrosion of mild steel at Karachi city. The corrosivity category of all urban and marine test sites is found in C₄–C₅ range, whereas for industrial test sites, it is found in C₃–C₅ range. Resultant corrosivity maps have shown that the prevailing atmosphere is significantly corrosive at Karachi harbor city. This study has furnished a novel product of atmospheric corrosivity map, which is the first-ever corrosivity map for Pakistan.     

二氢杨梅素的降血糖及保护肾脏损伤效果研究

以D-半乳糖为诱导剂,采用剂量递增全程腹腔注射法建立糖耐量异常动物模型。以二氢杨梅素为受试物,实验8周后,测定各实验组大鼠空腹及餐后2h血糖、胰岛素水平、尿微量白蛋白、尿素氮以及肾脏乳酸脱氢酶比活。与模型组相比,二氢杨梅素能显著降低餐后2h血糖及胰岛素水平(P<0.05),尿微量白蛋白含量及乳酸脱氢酶比活均明显降低(P<0.05),而尿素氮水平变化不明显(P>0.05)。尿微量白蛋白及乳酸脱氢酶可作为检测肾脏早期损伤的敏感指标。结果表明:二氢杨梅素可明显改善大鼠糖耐量异常状态,对肾脏早期损伤具有一定保护作用。     

Characterization of shear stress at the tool‐part interface during autoclave processing of prepreg composites

In this article, shear stress between an aluminum tool and a carbon fiber‐epoxy prepreg is characterized during cure using polymeric release agent and release film at the tool‐part interface. The effects of surface roughness, release materials, pull‐out speed, temperature, and normal force (autoclave pressure) on the shear stress are investigated using a customized friction rig. Results show that the interfacial shear stress decreases as the temperature increases and it increases as the normal force increases when using either the release film or the release agent. Additionally, changes in surface roughness from 1.35 to 0.18 μm decrease the shear stress 10–27% while the use of release agent shows a decrease between 23% and 51% in the shear stress. Furthermore, strong adhesion between the tool and the part is observed when using release agent and pull‐out speeds of 0.05 mm/min (static/dynamic friction ratio of 5.29 ± 0.19). Using the experimental data, a mathematical approach based on the Coulomb's friction model is proposed to predict the friction force at the tool‐part interface. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013