Surface currents, scattering, and applications in the Rayleigh region

Extended Maue integral equations for determining the surface magnetic fields and currents are developed and applied for points of discontinuous and continuous surface normal. Methods using the associated integral operators are shown to be useful in obtaining solutions which otherwise might not be tractable. Application is made to evaluate the total surface current on a perfectly conducting sphere for general plane wave incident fields. The dyadic result becomes, at normal incidence, proportional to the incident surface current, which, in all cases of field incidence, has a Rayleigh region limiting value of 3/2. The nature of the dyadic result is examined and the behavior of the limiting current ratio is briefly treated for nonspherical shapes including its deviation from 3/2 for near-spherical shapes.     

The use of Landsat-3 thermal data to help differentiate land covers

Landsat-3 Multispectral Scanner Subsystem (MSS) digital data of the Baltimore, Maryland area taken 24 May 1978 were examined to show the potential usefulness of thermal data (Band 8) to provide better discrimination between agricultural and residential areas, certain types of urban/industrial areas and water, cloud shadows and water, and bare-extractive areas and bright urban cover types. High altitude aircraft imagery taken 3 May 1978, was used for ground truth and training site verification. Two classifications were made per training site; the initial one using Bands 4, 5, and 7 and a second in which the thermal data were included with the visible and near infrared data. This allowed a direct comparison of areas spectrally similar with and without the inclusion of the thermal data. Commission errors determined from selected subsets of the data showed reductions of 95% for the urban/industrial versus water themes, 84% for the residential versus agriculture themes, 64.0% for the bare-extractive versus bright urban themes, and 24% for the cloud shadow versus water themes when the thermal data were included in the signature. The omission errors ranged from less than 10% for the cloud shadow versus water to 47% for the residential versus agriculture themes. This indicates that the thermal data can aid in classifying certain themes providing there is good thermal differentiation.     

The turbulent burning velocity of iso-octane/air mixtures

Turbulent burning velocities of iso-octane air mixtures have been measured for expanding flame kernels within a turbulent combustion bomb. High speed schlieren images were used to derive turbulent burning velocity. Turbulent velocity measurements were made at u′ = 0.5, 1.0, 2.0, 4.0, 6.0 m/s, equivalence ratios of 0.8, 1.0, 1.2, 1.4 and pressures of P = 0.1, 0.5, 1.0 MPa. The turbulent burning velocity was found to increase with time and radius from ignition, this was attributed to turbulent flame development. The turbulent burning velocity increased with increasing rms turbulent velocity, and with pressure; although differences were found in the magnitude of this increase for different turbulent velocities. Generally, raising the equivalence ratio resulted in enhanced turbulent burning velocity, excepting measurements made at the lowest turbulent velocity. The results obtained in this study have been compared with those evaluated for a number turbulent burning velocity correlations and the differences are discussed.     

A Drug Screening Pipeline Using 2D and 3D Patient-Derived In Vitro Models for Pre-Clinical Analysis of Therapy Response in Glioblastoma

Glioblastoma is one of the most common and lethal types of primary brain tumor. Despite aggressive treatment with chemotherapy and radiotherapy, tumor recurrence within 6–9 months is common. To overcome this, more effective therapies targeting cancer cell stemness, invasion, metabolism, cell death resistance and the interactions of tumor cells with their surrounding microenvironment are required. In this study, we performed a systematic review of the molecular mechanisms that drive glioblastoma progression, which led to the identification of 65 drugs/inhibitors that we screened for their efficacy to kill patient-derived glioma stem cells in two dimensional (2D) cultures and patient-derived three dimensional (3D) glioblastoma explant organoids (GBOs). From the screening, we found a group of drugs that presented different selectivity on different patient-derived in vitro models. Moreover, we found that Costunolide, a TERT inhibitor, was effective in reducing the cell viability in vitro of both primary tumor models as well as tumor models pre-treated with chemotherapy and radiotherapy. These results present a novel workflow for screening a relatively large groups of drugs, whose results could lead to the identification of more personalized and effective treatment for recurrent glioblastoma.     

Experimental studies of the role of chemical kinetics in turbulent flames

Flames of di-t-butyl-peroxide (DTBP) decomposition in a 0.376DTBP + 1.0N₂ mixture are studied in laminar and turbulent media. The observed values of unstretched laminar burning velocity are in reasonable agreement with the value obtained from the Zel’dovich-Semenov-Frank-Kamenetsky theory. Turbulent explosions in this particular mixture are characterized by a number of features that are believed to be common for all developing turbulent flames and have relevance to spark-ignition engine combustion of lean mixtures. Flame propagation is unsteady and is characterized by a mass burning rate that increases in time. The rate of the flame acceleration varies from one explosion to another. If the burning rate is related to the average flame radius, however, it exhibits much smaller variations. This phenomenon bears a striking resemblance to cycle-to-cycle variations in a spark-ignition engine. Comparisons of the present results with mixtures of significantly different composition, chemical kinetics, and exothermicity, but with similar laminar flame speed and Lewis number show that the data obtained in closed-volume explosions are in good agreement if the unsteady character of the flame is taken into account. The differences in details of the kinetic mechanisms and thermochemistry appear to be responsible for the flame behaviour only near the limit of extinction by turbulence. __________ Translated from Fizika Goreniya i Vzryva, Vol. 45, No. 4, pp. 43–52, July–August, 2009.     

Effects of morphiceptin in the medial preoptic area on male sexual behavior

Morphiceptin, a selective mu opioid agonist, injected into the medial preoptic area (MPOA), delayed the onset of copulation in male rats, but did not affect genital reflexes, sexual motivation or general motor activity. In a dose-dependent manner, morphiceptin (100 ng and 1000 ng) injected into the MPOA increased mount and intromission latencies. Similar injections of morphiceptin into the ventromedial hypothalamus had no effect on any parameter of copulation. The increase in copulatory latencies following the injection of the highest dose of morphiceptin was blocked by pretreatment with the opioid antagonist naloxone. In the X-maze task, morphiceptin had no effect on sexual motivation, as measured by the percentage of trials on which the male chose the female's chamber, but it increased the number of trials in which the subject did not select a chamber within 60 s and the latency to the female the first time he chose her chamber. Similar to the copulation task, the mount and intromission latencies were also increased in the X-maze, after the male reached the female. Morphiceptin in the MPOA had no effect on ex copula genital reflexes, tested in restrained supine males, or on motor activity, tested in a grid box. These results suggest that morphiceptin disrupts either the specific copulatory somatomotor pattern or a more general motivational component.     

Cryptococcal myositis: a case report and review of the literature

Only rare cases of cryptococcal myositis have been previously reported in the literature. All of these cases have occurred in the setting of human immunodeficiency virus (HIV) infection. We report a case of cryptococcal myositis diagnosed premortem on a needle biopsy in a heart transplant patient undergoing immunosuppressive therapy.     

Influence of multiwall carbon nanotube functionality and loading on mechanical properties of PMMA/MWCNT bone cements

Poly (methyl methacrylate) (PMMA) bone cement—multi walled carbon nanotube (MWCNT) nanocomposites with weight loadings ranging from 0.1 to 1.0 wt% were prepared. The MWCNTs investigated were unfunctionalised, carboxyl and amine functionalised MWCNTs. Mechanical properties of the resultant nanocomposite cements were characterised as per international standards for acrylic resin cements. These mechanical properties were influenced by the type and wt% loading of MWCNT used. The morphology and degree of dispersion of the MWCNTs in the PMMA matrix at different length scales were examined using field emission scanning electron microscopy. Improvements in mechanical properties were attributed to the MWCNTs arresting/retarding crack propagation through the cement by providing a bridging effect and hindering crack propagation. MWCNTs agglomerations were evident within the cement microstructure, the degree of these agglomerations was dependent on the weight fraction and functionality of MWCNTs incorporated into the cement.