Measurement of mechanical properties in a 316L stainless steel welded joint

The aim of this study was to measure the mechanical properties of weld material taken from a single weld bead laid down on a 316L steel plate. Due to the low available volume of weld material, microsamples with a total length of 5.5 mm were used. The Digital Image Correlation method (DIC), which enables measurement of mechanical properties of very small samples, was employed for the strain measurements in a uniaxial tensile test. Samples were cut out from three different zones of the specimen: plate, weld, and the heat affected zone. The material from heat affected zone showed the highest value of the Ultimate Tensile Strength (UTS) (580 ± 7 MPa) and yield strength (339 ± 6 MPa). Plate material had lower UTS (559 ± 5 MPa) and yield strength (304 ± 7 MPa). The lowest values of UTS (526 ± 6 MPa) and yield strength (291 ± 8 MPa) have been revealed for the weld. The values obtained for UTS, yield strength and elongation to failure for the plate material were compared with data obtained using standard test specimens. No significant differences between results obtained for the microsamples and standard samples have been found.     

Structure-activity relationship in the ability of flavonols to inhibit chemiluminescence

Fourteen flavonoids were evaluated for their ability to inhibit chemiluminescence, either of neutrophils that had been briefly exposed to both luminol and phorbol-myristate acetate or to an enzymatic system with H2O2, luminol and horseradish peroxidase. Using chemiluminescence as the quantitative parameter, it can be concluded that the hydroxyl group in position 3 of the flavonols is vital for their inhibitory effect, and that two hydroxyl groups on the phenyl ring are optimal for such an effect. It was also noted that the C2-C3 double bond is essential for the flavonols' anti-oxidative effect. It is suggested that the ability of flavonols to suppress chemiluminescence is reciprocally correlated with their lipophilicity.     

Infectious complications of lung transplantation. Impact of cystic fibrosis

It has been suggested that the presence of airway pathogens prior to lung transplantation (LT) in patients with cystic fibrosis (CF) may place these patients at a higher risk for infectious complications after LT. There is particular concern regarding patients colonized with multiresistant Pseudomonas, including P. cepacia, and fungi, including Aspergillus. We report our experience with LT for patients with CF and compare the results with those of patients with LT for other indications. Between January 1990 and March 1993, we performed LT for 27 patients with CF and 32 without CF. Nearly all (89%) of the patients with CF were colonized with P. aeruginosa; many were cultured with P. cepacia (19%) and Aspergillus (63%). The non-CF group rarely had organisms identified pre-LT. No patients with CF underwent pre-LT sinus drainage or received pre-LT treatment for Aspergillus. All of the patients received perioperative antibiotics and a standard regimen of immunosuppression and prophylactic antibiotics. The incidence of infectious complications was the same in the two groups; however, there was an association between obliterative bronchiolitis and pulmonary infections. One of the patients with CF with P. cepacia died as a result of this organism. None of the patients with CF required treatment for Aspergillus post-transplant. We conclude that patients with CF, despite the presence of airway pathogens, are at no greater risk of infectious complications after LT than are other patients.     

The Discovery of Potent Nonstructural Protein 5A (NS5A) Inhibitors with a Unique Resistance Profile—Part 2

In ongoing studies towards novel hepatitis C virus (HCV) therapeutics, inhibitors of nonstructural protein 5A (NS5A) were evaluated. Specifically, starting from previously reported lead compounds, peripheral substitution patterns of a series of biaryl‐linked pyrrolidine NS5A replication complex inhibitors were probed and structure–activity relationships were elucidated. Using molecular modelling and a supercritical fluid chromatographic (SFC) technique, intramolecular H‐bonding and peripheral functional group topology were evaluated as key determinants of activity and membrane permeability. The novel compounds exhibited retained potency as compared with the lead compounds, and also showed promising results against a panel of resistance viruses. Together, the results of the study take us a step closer towards understanding the potency of daclatasvir, a clinical candidate upon which the compounds were based, and to designing improved analogues as second‐generation antiviral agents targeting NS5A.     

Prediction of the solubility of hydrogen in hydrocarbon solvents through cubic equations of state

Soave—Redlich—Kwong and the Peng—Robinson equations of state have been applied to the calculation of hydrogen solubility in hydrocarbon solvents. The interaction parameter can be obtained from experimental data: vapour liquid equilibria or Henry's constants. It has been shown that the so obtained value can be correlated as a simple function of temperature only, regardless of the solvent nature, and a predictive procedure has been developed which results in a rather good calculation of hydrogen-solvents vapour liquid equilibria.     

A new F-score gradient-based training rule for the linear model

Pattern Analysis and Applications - Delta rule is a standard, well-established approach to train perceptron recognition model. However, mean squared error, on which it is based, is not suitable...     

Pentoxifylline

Pentoxifylline (PTX), methylxanthine derivative and phosphodiesterase inhibitor, has been in use for more than 20 years (with minimal side effects) for the potent hemorrheologic properties and was recently discovered to have influence on function of some immune cells and production of cytokines. Human and animal studies have shown that PTX therapy results in a variety of physiologic changes at the cellular level, which may be important in treating a diverse group of human afflictions. Immune modulation includes increased leukocyte deformability and chemotaxis, decreased endothelial leukocyte adhesion, decreased neutrophil degranulation and release of superoxides, decreased production of TNF-alpha and decreased NK cell activity. Potential medical uses of PTX are reviewed.