Use of the correct blank test in the determination of COD and AOX in bleached kraft mill D stage effluents

A study of four types of blank, two of which (the placebo blank and the method blank) are amenable to direct measurements and the other two [the total Youden blank (TYB) and system blank] to extrapolation, revealed the need to use a correct blank test, the TYB, in order to eliminate the constant error component. The conclusions drawn here are demonstrated for the microcoulometric determination of adsorbable organic halogen (AOX), according to Scandinavian standard SCAN-W 9:89, and in the spectrophotometric determination of chemical oxygen demand (COD) following a closed reflux spectrophotometric method. These environmental analytical parameters (AOX and COD) were determined in two different bleached kraft mill effluents: one from stage D (100% ClO2) of the bleaching sequence AOD of the elemental chlorine-free type and the other for the chlorination step, the first in the conventional sequence (D20C80)(E0)D1D2, applied to kraft pulp from Populus spp.     

Cationic liposome-nucleic acid complexes: liquid crystal phases with applications in gene therapy

Cationic liposome (CL) carriers of nucleic acids are primarily studied because of their applications in gene delivery and gene silencing with CL-DNA and CL-siRNA (short-interfering RNA) complexes, respectively, and their implications to ongoing clinical gene therapy trials worldwide. A series of synchrotron-based small-angle-x-ray scattering studies, dating back to 1997, has revealed that CL-nucleic acid complexes spontaneously assemble into distinct novel liquid crystalline phases of matter. Significantly, transfection efficiency (TE; a measure of expression of an exogenous gene that is transferred into the cell by the lipid carrier) has been found to be dependent on the liquid crystalline structure of complexes, with lamellar complexes showing strong dependence on membrane charge density (σ(M)) and non-lamellar complexes exhibiting TE behavior independent ofσ(M). The review describes our current understanding of the structures of different liquid crystalline CL-nucleic acid complexes including the recently described gyroid cubic phase of CL-siRNA complexes used in gene silencing. It further makes apparent that the long-term goal of developing optimized liquid crystalline CL-nucleic acid complexes for successful medical applications requires a comprehensive understanding of the nature of the interactions of distinctly structured complexes with cell membranes and events leading to release of active nucleic acids within the cell cytoplasm.     

Two-dimensional packing of short DNA with nonpairing overhangs in cationic liposome-DNA complexes: from Onsager nematics to columnar nematics with finite-length columns

We report the formation of liquid crystalline (LC) phases of short double-stranded DNA with nonpairing (nonsticky) overhangs, confined between two-dimensional (2D) lipid bilayers of cationic liposome-DNA complexes. In a landmark study (Science2007, 318, 1276), Nakata et al. reported on the discovery of strong end-to-end stacking interactions between short DNAs (sDNAs) with blunt ends, leading to the formation of 3D nematic (N) and columnar LC phases. Employing synchrotron small-angle X-ray scattering, we have studied the interplay between shape anisotropy-induced and DNA end-to-end interaction-induced N ordering for 11, 24, and 48 bp sDNA rods with single-stranded oligo-thymine (T) overhangs modulating the end-to-end interactions. For suppressed stacking interactions with 10-T overhangs, the volume fraction of sDNA at which the 2D isotropic (I)-to-N transition occurs for 24 and 48 bp sDNA rods depended on their length-to-width (L/D) shape anisotropy, qualitatively consistent with Onsager's theory for the entropic alignment of rigid rods. As the overhang length is reduced from 10 to 5 and 2 T for 24 and 48 bp sDNA, the N-to-I transition occurs at lower volume fractions, indicating the onset of some degree of end-to-end stacking interactions. The 11 bp sDNA rods with 5- and 10-T overhangs remain in the I phase, consistent with their small shape anisotropy (L/D ≈ 1.9) below the limit for Onsager LC ordering. Unexpectedly, in contrast to the behavior of 24 and 48 bp sDNA, the end-to-end interactions between 11 bp sDNA rods with 2-T overhangs set in dramatically, and a novel 2D columnar N phase (N(C)) with finite-length columns formed. The building blocks of this phase are comprised of 1D stacks of (on average) four 11 bp DNA-2T rods with an effective L(stacked)/D ≈ 8.2. Our findings have implications for the DNA-directed assembly of nanoparticles on 2D platforms via end-to-end interactions and in designing optimally packed LC phases of short anisotropic biomolecules (such as peptides and short-interfering RNAs) on nanoparticle membranes, which are used in gene silencing and chemical delivery.     

Synthesis of Novel Ethyl (substituted)phenyl‐4‐oxothiazolidin‐3‐yl)‐1‐ethyl‐4‐oxo‐1,4‐dihydroquinoline‐3‐Carboxylates as Potential Anticancer Agents

A series of ethyl (substituted)phenyl‐4‐oxothiazolidin‐3‐yl)‐1‐ethyl‐4‐oxo‐1,4‐dihydroquinoline‐3‐carboxylates ( 7a , 7b , 7c , 7d , 7e , 7f , 7g ) has been prepared from reactions between aminoquinolones 6 with arenealdehydes and mercaptoacetic acid. The critical intermediates, 6 a and 6b , were obtained from appropriate amines by a sequence of steps involving (i) reaction with diethylethoxymethylenemalonate, (ii) thermal cyclization in diphenyl ether, (iii) ethylation and (iv) Pd/C catalyzed reduction. New compounds 7a , 7b , 7c , 7d , 7e , 7f , 7g were fully identified and characterized by NMR (¹H and ¹³C) and specifically for 7d by X‐ray crystallography. Compounds 7b , 7c , 7d , 7e , 7f were found not to exhibit activity at 10 uM concentrations against gastric ascitis (AGP‐01), gastric adenocarcinoma kind intestinal (ACP‐02), colon (HCT‐116) and murine melanome (B16F10) cancer cells. However, none exhibited cytotoxicity against normal cells human fibroblast (MRC‐5), murine fibroblast (NIH3T3) and normal human melanocyte (Melan‐A).     

原子氧在Ru低指数面及(110),(111)台阶面上的吸附

利用原子与表面簇合物相互作用的5参数Morse势方法(简称5-MP)系统地研究了O-Ru低指数面及Ru(1120),(1121)台阶面体系,获得了吸附几何、结合能、振动频率等临界点特性,所得相关数据与实验结果非常吻合.并且通过理论计算及原子吸附态振动指纹的遗传、遗变特性预言了氧原子在Ru(1121)台阶面的吸附.本文认为氧原子在HCP晶格的金属表面上的吸附倾向于三重位.     

Long-term integrated surgery room optimization and recovery ward planning,with a case study in the Brazilian National Institute of Traumatology and Orthopedics (INTO)

This paper proposes an integrated approach for the long-term planning and surgery allocation problem with downstream constraints. It is motivated by a case study in the Brazilian National Institute of Traumatology and Orthopedics, which provides elective high complexity surgeries for patients from the Brazilian public health system. We introduce an optimization problem that designs a periodic surgery allocation schedule as well as a recovery ward utilization plan, with a view at balancing patient arrivals and releases in the long term, in such a way that all surgeries are performed in a timely manner.     

Preparation,Characterization and ex vivo Intestinal Permeability Studies of Ibuprofen Solid Dispersion

The aim of the present study was to improve the solubility and dissolution rate of ibuprofen and to evaluate, ex vivo, the intestinal permeation. Solid dispersions (SD) were prepared with Kollicoat IR^® by solvent evaporation technique in different drug:carrier ratios. The permeation intestinal of ibuprofen was evaluated by inverted intestinal sac method. The SD was characterized by solubility equilibrium, FT-IR, DSC, PXRD, SEM, and dissolution rate. The solubility, dissolution rate, and permeability were significantly greater for SD 1:2. The PXRD, SEM and DSC indicated a partial change in the crystalline state of ibuprofen. The solubility equilibrium of SD (1:2) was approximately 15 times greater than the solubility of ibuprofen. Dissolution rate enhancement was attributed to the decreased crystallinity of the ibuprofen, and increase of wettability and decrease of particle size. In conclusion, dissolution rate and intestinal permeability of ibuprofen were enhanced by the use of Kollicoat IR^® carrier in the SD formulation.     

Monoolein and chitosan gels as potential carriers of the rhBMP-2, using decortication surgical technique in Wistar rats as experimental model

The purpose of this work was to evaluate the new bone tissue, comparing two different carriers for rhBMP-2, monoolein and chitosan gels, using the decortication and nondecorticatication surgical technique in rat mandibles, evaluated by histomorphometrical method. It was used 56 male Wistar rats (300g), divided into 8 groups according to the rhBMP-2 carrier used, monoolein or chitosan gels; surgical technique, bone decortication or nondecortication; and period of time, 3 or 6 weeks until the sacrifice by perfusion. Results obtained in this study showed that the rhBMP-2/monoolein and rhBMP-2/chitosan used in this experimental model was able to induce osteogenesis, contributing to the bone healing process. The bone repair process was time dependent, so that at 6 weeks there was an improved amount of new bone in relation to 3 weeks, considered each analyzed group, and the decortication was able to expose the bone marrow and speed up the bone healing process, which was showed by histomorphometrical methods. Both of carriers were capable to adapt to the bone surgical area, according to the clinical observations, and had favorable properties in relation to protein releasing, revealed by the amount of new bone tissue found in the histological analysis.     

Effect of unilateral extraction of molar teeth on suprahyoid muscles: macroscopic and ultrastructural aspects

Anatomical and physiologic components are parts of the stomatognathic system and their interaction results in integrated functional activities. Important alterations in the masticatory system originated by dental loss affect the bone, oral mucosa and muscular function. Dental arch structures specifically designed to receive and expose teeth allow performance of their functions. But the distinction between bony and soft tissues is lost when teeth are removed since there is not a specific function to be completed. The aim of this study was to evaluate the macroscopic and ultrastructural effects of the unilateral extraction of molar teeth on the suprahyoid muscles function, using twenty young male gerbils (Meriones unguiculatus) as the experimental animal model. They were divided in experimental malocclusion (n=10) and control (n=10) groups. The experimental malocclusion group was submitted to exodontia of the left upper molars and the control group was not submitted to this procedure and served as sham-operated. For macroscopic analysis of the suprahyoid muscle, the skin was uplifted and the muscles dissected individually and removed for weight analysis according to Scherle method. The electron microscopy analysis was made in ultra thin sections of small suprahyoid muscle fragments from the experimental and control groups, examined in a Jeol 1010, 880Kv transmission electron microscope. Several micrographs at magnifications of 3000x, 6000x, 30,000x were randomly selected for the qualitative analysis of the muscle fiber ultrastructures. Sixty days after the induced unilateral occlusal alteration no macroscopic morphologic changes was detected in the suprahyoid muscles and the muscle volume differences between the right and left sides and between groups were not significant. However, in the ultrastructural analysis suprahyoid muscles showed characteristics of specific adaptation to the unilateral occlusal alteration, by the reduced density of subsarcolemmal mitochondria and the shorter and less numerous ramifications in intermyofibrilar mitochondria localized between electronlucid myofibrils. It is concluded that unilateral exodontia of all the upper left molars affect the ultrastructural morphology of suprahyoid muscle fibers.