Early,Frequent, and Efficient Hemodialysis: A New Trend or Déjà Vu From the 1970s?

After more than a quarter century of dialysis, two factors are still present in dialysis treatment of chronic renal failure patients: inadequacy of technology (the artificial kidney acts as an artificial glomerulus) and inadequate use of technology in terms of dialysis initiation and frequency. This paper presents the results of two less unphysiological dialysis programs, introduced in Bologna at the beginning of the 1960s, which proved their clinical value and are now becoming trendy, at the end of this century. Features of these programs are twofold: (1) daily dialysis, which aims at making treatment more biologically suited to the patient; its validity relies on lower intra- and interdialytic osmotic fluctuations; (2) early dialysis, which aims at making the patient more biologically suited to the treatment. After more than 25 years it is evident that this treatment has fulfilled its original expectations versus late dialysis. There is a 40% improvement in survival, a 35% decrease in morbidity, and a 24% improvement in the cost/benefit ratio. This report is based on a retrospective analysis of our overall experience and clinical results of chronic hemodialysis carried out in 224 patients on early dialysis and 1210 patients on late dialysis in Bologna from 1967 to 1997. Based on this experience, the following should be regarded as particularly important indications for early dialysis: adequate dialysis facilities; symptomatic patients despite renal creatinine clearances between 15 and 20 mL/min; patients unable to comply with dietary measures; children, to allow for adequate development; patients with diabetes mellitus; candidates for renal transplantation.     

Addressed Term Rewriting Systems: Syntax, Semantics, and Pragmatics: Extended Abstract

We present a formalism called Addressed Term Rewriting Systems, which can be used to define the operational semantics of programming languages, especially those involving sharing, recursive computations and cyclic data structures. Addressed Term Rewriting Systems are therefore well suited for describing object-based languages, as for instance the family of languages called , involving both functional and object-based features.     

Advanced RBSOA analysis for advanced power BJTs

Performances of some modern power BJT's in inductive turn-off are experimentally evaluated, by means of an unclamped non-destructive method. The different instabilities exhibited are classified and their influence on device performances is discussed both in clamped and unclamped applicationsAn “Instability Map” is proposed both as a synthetic picture which eases comparison of reverse-bias performances of devices having different ratings, and as an investigation tool for linking device behaviour to its physical features.It results that RBSOA performances are not just related to lateral dimensions of the emitter, but also to metallization lay-out of the chip, which evidently influences current distribution among cells.Finally, stray elements of testing circuit which affect results of RBSOA measurements are investigated, and some suggestions are proposed in order to let measurement results become independent of testing circuit.     

Application of response surface methodology to evaluate the effect of dry‐spinning parameters on poly (ε‐caprolactone) fiber properties

Poly (ε‐caprolactone) fibers were prepared by dry‐spinning method. The effect of processing parameters on linear density, mechanical, and morphological properties of fibers was investigated using the response surface methodology (RSM). This method allowed evaluating a quantitative relationship between polymer concentrations, spinning speed, and draw ratio on the properties of the fibers. Polynomial regression model was fitted to the experimental data to generate predicted response. The results were subjected to analysis of variance to determine significant parameters. It was found that all three parameters had significant effect on linear density of fibers. Combined effect of concentration and spinning speed was observed in which the linear density of fiber was more sensitive to changes in the solution concentration at lower spinning speed. Polymer concentration had the largest influence on the mechanical properties of fibers. An average cross‐sectional radius of fibers was affected by concentration and draw ratio in opposite manner. Among all three parameters, only polymer concentration had significant effect on circularity of fiber cross sections. By applying the RSM, it was possible to obtain a mathematical model that can be used to better define processing parameters to fabricate dry‐spun PCL fiber in a more rational manner. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42113.     

The effect of processing routes on the thermal and mechanical properties of poly(urethane‐isocyanurate) nanocomposites

A systematic investigation of four processing routes was implemented so as to evaluate the thermal and mechanical properties of nanosilica (NS) reinforced poly(urethane‐isocyanurate) nanocomposites (NC). The NS dispersion in the Polmix and the Isomix routes was performed in the polyol and the isocyanate precursor, respectively. The Isopol and the Solvmix routes consisted on the dispersion of the filler after the mixing of the precursors and with the aid of solvents, respectively. The NS dispersion, fractography (SEM, TEM), flexural and tensile mechanical properties, thermogravimetric analysis and FTIR analysis of NCs was performed as a function of processing route, isocyanate index, and NS concentration. Each route produced a NC with distinct properties, which were correlated to the NS agglomeration degree and how the NS affected the thermal transitions of the HS and the relative ratio of urethane and isocyanurate chemical groups. For example, the NC prepared with the Polmix route had substantial improvements of σ_t and ε_t of around +40 and +52%, respectively and an improved thermal resistance of the Hard Segments. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42750.     

Protein Synthesis in Sub‐Micrometer Water‐in‐Oil Droplets

Water‐in‐oil (w/o) emulsions are used as a cellular model because of their unique cell‐like architecture. Previous works showed the capability of eukaryotic‐cell‐sized w/o droplets (5–50 μm) to support protein synthesis efficiently; however data about smaller w/o compartments (<1 μm) are lacking. This work focuses on the biosynthesis of the enhanced green fluorescent protein (EGFP) inside sub‐micrometric lecithin‐based w/o droplets (0.8–1 μm) and on its dependence on the compartments’ dynamic properties in terms of solute exchange mechanisms. We demonstrated that protein synthesis is strongly affected by the nature of the lipid interface. These findings could be of value and interest for both basic and applied research.     

SiC陶瓷表面Mo-Ni-Si金属化及其与Ag的润湿性研究

采用真空熔烧工艺在SiC陶瓷表面制备了三种化学成分的Mo-Ni-Si金属化涂层,研究涂层的相组成和涂层/SiC陶瓷界面的微结构。通过座滴法实验考察纯Ag在SiC陶瓷涂层上的润湿与铺展特性,分析和讨论了Ag/金属化SiC陶瓷体系的界面行为。实验结果表明,该金属化涂层主要由Mo₅Si₃, MoSi₂, Ni₂Si, NiSi₂ 和MoNiSi组成,同时随着涂层中Mo的摩尔比由20%增加至40%,位于涂层表面的具有四方结构的MoSi₂晶粒逐渐消失。Ag对Mo20-Ni32-Si48、Mo30-Ni28-Si42、Mo40-Ni24-Si36金属化SiC陶瓷在1000 oC保温30分钟后对应的最终接触角分别为45o, 79o 和 85o,该结果与Ag滴和三种Mo-Ni-Si涂层之间的相互作用密切相关。同时在润湿试验前后,在Mo-Ni-Si涂层/SiC衬底界面没有发现明显的反应层。     

Alignment of Rod‐Shaped Single‐Photon Emitters Driven by Line Defects in Liquid Crystals

Arrays of liquid crystal defects—linear smectic dislocations—are used to trap semiconductor CdSe/CdS dot‐in‐rods which behave as single‐photon emitters. Measurements of the emission diagram are combined together with measurements of the emitted polarization of the single emitters. It is shown that the dot‐in‐rods are confined parallel to the linear defects to allow for a minimization of the disorder energy associated with the dislocation cores. It is demonstrated that the electric dipoles associated with the dot‐in‐rods, tilted with respect to the rods, remain oriented in the plane including the smectic linear defects and perpendicular to the substrate, most likely due to dipole/dipole interactions between the dipoles of the liquid crystal molecules and those of the dot‐in‐rods. Using smectic dislocations, nanorods can consequently be oriented along a unique direction for a given substrate, independently of the ligands' nature, without any induced aggregation, leading as well to a fixed azimuthal orientation for the dot‐in‐rods' dipoles. These results open the way for the fine control of nanoparticle anisotropic optical properties, in particular, fine control of single‐photon emission polarization.     

A model for the devolatilization of EPDM rubber in a series of steam stripping vessels

A mathematical model was developed for the multitank stripping section of industrial ethylene propylene diene monomer (EPDM) rubber processes. Experiments were conducted to determine Henry's law coefficients and diffusivities for hexane solvent and 5‐ethylidene‐2‐norbornene (ENB) comonomer in EPDM particles. Equivalent radii for diffusion within the particles were also determined. A model was developed to predict solvent and comonomer concentrations in a single particle as it moves through a series of tanks with different operating conditions. A second, more‐complicated model was then developed to account for a continuous flow stirred tank residence time distribution for the particles in the tanks. Data from three industrial plants were used to estimate parameters and assess the models' predictive ability. Typical prediction errors are 0.90 wt % for residual hexane and 0.14 wt % for residual ENB. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2596–2606, 2014     

A polycaprolactone‐based compatibilization treatment to improve dispersion and interphase structure of silica polyurethane composites

Silica nanoparticles (SNs) were grafted with ε ‐caprolactone using an environmentally friendly approach. By using tartaric acid as a catalyst and the silanol groups as initiators, grafted nanoparticles (GNs) with organic weight fractions (w_of) within the range 0–46 wt% were synthesized. Thermogravimetric (TGA) and infrared analysis were used to measure the w_of and to corroborate the covalent bond between the SN and the caprolactone monomer. Transmission electron micrographs of the polyurethane (PU) nanocomposites based on the SN and the GN revealed that the interfacial area of the GN‐based PU increased by the reduction of agglomerate dimensions from 10 µm to around 0.1 µm. Dynamic mechanical analysis showed that the GN nanocomposites improved the storage shear modulus from 616±11 to 849±8 MPa for a GN with w_of = 16.7% and 3 wt% filler concentration. In addition, the GN particles prevented a relevant decrease of the transition temperature (T_g). Differential scanning calorimetry corroborated that GN increased the enthalpic energy associated to the physical crosslinking of the hard segments (HS). Wide‐angle X‐ray diffraction proved that the GN formed a HS structure with improved crystallinity. The thermal stability of the GN‐based PU a nanocomposite was improved by an increase of the thermal stability of the castor oil soft segments. POLYM. ENG. SCI., 54:1817–1826, 2014. © 2013 Society of Plastics Engineers