Accelerated weathering of cementitious matrix for the development of an accelerated laboratory test of biodeterioration

Cement based materials are porous, may contain organic adjuvants, and thus possesses an important primary bioreceptivity. To preserve constructions from fungal colonization and to act efficiently against fungal biodeterioration, it is necessary to have a better understanding of biodeterioration mechanisms and its effects on materials properties. An accelerated laboratory test which allows us to compare the growth of three fungal strains and the aesthetic biodeterioration of a cementitious matrix was developed. As the surface pH of the fresh cement specimen is too high to allow fungal growth (pH ~12), accelerating weathering of the matrix, consisting of the combination of carbonation and leaching, was performed to reduce the matrix alkalinity. XRD analyses and SEM observations pointed out that the matrix surface is progressively covered by a calcium carbonate layer as the weathering increases. Results point out that the microbial growth occurs on matrix with a surface composition more like a limestone than a cementitious one.     

Three‐component terpolymers of glycidyl methacrylate with good swelling characteristics

Highly swellable glycidyl methacrylate terpolymers with styrene and a series of crosslinkers (divinyl benzene and ethylene, diethylene, and triethylene glycol dimethacrylates) were obtained by suspension polymerization. The loading capacities of the resins, their glass‐transition temperatures, and their swelling characteristics in 20 solvents were examined with respect to the monomer composition. A selected resin was modified for a cobalt–imine complex and tested as a catalyst in a model ring‐opening reaction. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Pulsed Electric Field Pretreatment for Osmotic Dehydration of Apple Tissue: Experimental and Mathematical Modeling Studies

The aim of this study was to analyze the influence of pulsed electric field pretreatment (PEF) on the osmotic dehydration of apple tissue. Osmotic dehydration was carried out in sucrose solution at 40°C and 100 rpm in a water-bath shaker. PEF pretreatment was performed using varying field strength of 5 and 10 kV/cm and 10 and 50 pulses. On the basis of electric conductivity measurement, the cell disintegration index was calculated. The course of osmotic dehydration was described by means of water loss, solid gain, weight reduction, and water content changes. Moreover, the course of the process was described by different mathematical models that are commonly used in the literature. PEF application before osmotic dehydration significantly increased water loss after 60 minutes of the process. In turn, no significant differences were found in the case of solid gain. The highest osmotic dehydration efficiency ratio (WL/SG) was noticed for samples treated by PEF at the electric field strength of 5 kV/cm and 10 pulses. The statistical analysis of mathematical modeling of the process showed the equations utilized generally exhibit a good fit to the experimental data.     

Mass spectrometric strategies for the investigation of biomarkers of illicit drug use in wastewater

The analysis of illicit drugs in urban wastewater is the basis of wastewater‐based epidemiology (WBE), and has received much scientific attention because the concentrations measured can be used as a new non‐intrusive tool to provide evidence‐based and real‐time estimates of community‐wide drug consumption. Moreover, WBE allows monitoring patterns and spatial and temporal trends of drug use. Although information and expertise from other disciplines is required to refine and effectively apply WBE, analytical chemistry is the fundamental driver in this field. The use of advanced analytical techniques, commonly based on combined chromatography—mass spectrometry, is mandatory because the very low analyte concentration and the complexity of samples (raw wastewater) make quantification and identification/confirmation of illicit drug biomarkers (IDBs) troublesome. We review the most‐recent literature available (mostly from the last 5 years) on the determination of IDBs in wastewater with particular emphasis on the different analytical strategies applied. The predominance of liquid chromatography coupled to tandem mass spectrometry to quantify target IDBs and the essence to produce reliable and comparable results is illustrated. Accordingly, the importance to perform inter‐laboratory exercises and the need to analyze appropriate quality controls in each sample sequence is highlighted. Other crucial steps in WBE, such as sample collection and sample pre‐treatment, are briefly and carefully discussed. The article further focuses on the potential of high‐resolution mass spectrometry. Different approaches for target and non‐target analysis are discussed, and the interest to perform experiments under laboratory‐controlled conditions, as a complementary tool to investigate related compounds (e.g., minor metabolites and/or transformation products in wastewater) is treated. The article ends up with the trends and future perspectives in this field from the authors’ point of view. © 2016 by The Authors. Mass Spectrometry Reviews published by Wiley Periodicals, Inc. Mass Spec Rev 37:258–280, 2018     

轮铲式挖掘机新一代驾驶室隔震系统的优化

 提出新一代驾驶室计算机辅助设计的一些观点,重点关注驾驶室隔振系统的原始设计方案,它由挖掘悬臂连同驾驶室悬臂组成。用有限元法对驾驶室动态特性进行了分析,在虚拟模型数值分析的基础上形成一个方案,随后建立一个带有隔振系统的驾驶室原型样模,实体振动测量提供了非常令人满意的结果。     

Ileoanal anastomosis for ulcerative colitis: results of an evolutionary surgical procedure

BACKGROUND/AIMS: Proctocolectomy with ileoanal anastomosis (IAA) has proved to be the most suitable surgical treatment for ulcerative colitis. The aim of this study was to compare the results of IAA according to the evolution of surgical procedures and particularly to compare the results of stapled versus hand-sewn anastomosis. METHODOLOGY: From 1984 to 1996, 37 men and 31 women were operated on in our centre for ulcerative colitis. The anastomosis between the J pouch and the dentate line was handsewn in 35 patients (group 1) and stapled in 33 patients (group 2). RESULTS: The mean operative time was significantly shorter in group 2 as compared with group 1 (265+/-59 vs. 323+/-53, p<0.01, respectively), whereas morbidity and functional results were comparable in both groups. In 10 patients with stapled IAA, a diverting ileostomy was not performed and the morbidity in this group did not increase. CONCLUSIONS: These results suggest that stapled IAA anastomosis is a safe procedure. The stapling technique of IAA simplifies total excision of the rectum and could mean that a diverting ileostomy is not necessary.     

Characterization of a de novo 48,XX,+r(X),+r(17) by in situ hybridization in a patient with neurofibromatosis (NF1)

The authors analyze the errors in the treatment of detachment of the retina in children. The errors were found not only in the surgical policy, but in the management of the pre- and postoperative period as well. They suggest rational methods for the pre- and postoperative management of patients with detachment of the retina and adequate schemes of surgical treatment.     

The Role of Glp-1 Receptor Agonists in Insulin Resistance with Concomitant Obesity Treatment in Polycystic Ovary Syndrome

Insulin resistance is documented in clamp studies in 75% of women with polycystic ovary syndrome (PCOS). Although it is not included in the diagnostic criteria of PCOS, there is a crucial role of this metabolic impairment, which along with hormonal abnormalities, increase each other in a vicious circle of PCOS pathogenesis. Insulin resistance in this group of patients results from defects at the molecular level, including impaired insulin receptor-related signaling pathways enhanced by obesity and its features: Excess visceral fat, chronic inflammation, and reactive oxygen species. While lifestyle intervention has a first-line role in the prevention and management of excess weight in PCOS, the role of anti-obesity pharmacological agents in achieving and maintaining weight loss is being increasingly recognized. Glucagon-like peptide-1 receptor agonists (GLP1-RAs) not only act by reducing body weight but also can affect the mechanisms involved in insulin resistance, like an increasing expression of glucose transporters in insulin-dependent tissues, decreasing inflammation, reducing oxidative stress, and modulating lipid metabolism. They also tend to improve fertility either by increasing LH surge in hypothalamus-pituitary inhibition due to estrogen excess connected with obesity or decreasing too high LH levels accompanying hyperinsulinemia. GLP1-RAs seem promising for effective treatment of obese PCOS patients, acting on one of the primary causes of PCOS at the molecular level.     

Characterization of a Slurry Process Used to Make a Plastic-Bonded Explosive

The effects of agitation rate, air sweep rate, and reactor temperature in the production of PBX 9501, a plastic-bonded explosive molding powder, were investigated. These variables affected the agglomerate length, the agglomerate shape, and the bulk density of the molding powder, but had very little effect on the properties of pressed pieces made from the molding powder.