Combination treatment for osteosarcoma with baculoviral vector mediated gene therapy (p53) and chemotherapy (adriamycin)

The insect baculovirus Autographa californica multiple nuclear polyhedrosis virus (AcMNPV) has been evaluated as a vector for gene delivery to human tumor cells. A human osteogenic sarcoma cell line, Saos-2, was found to be highly susceptible to infection with a baculoviral vector, with nearly 100% of Saos-2 cells being able to express a lacZ reporter gene after a brief exposure to the virus at a m.o.i. of 30 pfu/cell. The production of beta-galactosidase protein was 18-times greater than that in HepG2 cells which were previously thought to be the mammalian cells most susceptible to the baculovirus. The possibility of developing a baculovirus as a cytotoxic vector for p53-defective cancer was tested by destruction of Saos-2 cells (p53-/-) with a recombinant baculovirus containing the wild type p53 gene (BV-p53) in vitro. The p53 baculovirus induced apoptotic cell death in tumor cells in a dose-dependent manner with approximately 60% killing at an m.o.i. of 160 pfu/cell. Combined treatments of gene therapy (p53) and chemotherapy (adriamycin) resulted in synergistic and potent killing of the osteogenic sarcoma cells. For example, greater than 95% of Saos-2 cells were killed by the combination of BV-p53 (m.o.i. of 100) and adriamycin (35 ng/ml), whereas approximately 50% and approximately 55% cells were killed by BV-p53 and adriamycin alone, respectively. These results indicate that a baculoviral gene delivery vector can be used to efficiently target certain types of mammalian cells and the combination treatment of gene-therapy mediated by a baculovirus and chemotherapy may enhance induction of apoptosis in cancer cells.     

Thermoelastic Determination of Individual Stresses in Vicinity of a Near-Edge Hole Beneath a Concentrated Load

Thermoelastic data are combined with an Airy stress function to determine the individual stresses on and near the boundary of a circular hole which is located below a concentrated edge-load in a plate. Coefficients of the stress function are evaluated from the measured temperatures and the local traction-free conditions are satisfied by imposing s_rr = t_rq = 0 {\sigma_{r{\rm{r}}}} = {\tau_{r\theta }} = 0 analytically on the edge of the hole. The latter has the advantage of reducing the number of coefficients in the stress function series. The method simultaneously smoothes the measured input data, satisfies the local boundary conditions and evaluates individual stresses on, and in the neighbourhood of, the edge of the hole. Attention is paid to how many coefficients to retain in the stress function series. Although the presence of high stress concentration factors, together with a hole-diameter-to-plate-thickness ratio of only two, result in some three-dimensional effects, these are relatively small and the agreement between the thermoelastic values, those from recorded strains and FEM-predicted surface stresses is good.     

Energy-dependent excitation cross section measurements of the diagnostic lines of Fe XVII

By implementing a large-area, gain-stabilized microcalorimeter array on an electron beam ion trap, the electron-impact excitation cross sections for the dominant x-ray lines in the Fe XVII spectrum have been measured as a function of electron energy establishing a benchmark for atomic calculations. The results show that the calculations consistently predict the cross section of the resonance line to be significantly larger than measured. The lower cross section accounts for several problems found when modeling solar and astrophysical Fe XVII spectra.     

Plutonium measurements in Hanford DOE site waste samples

This paper describes development work to prepare a method to measure absolute²³⁹Pu content and Pu-isotopics by ICP-MS in acidified Hanford DOE-site samples which are very high in⁹⁰Sr,⁹⁹Tc, and¹³⁷Cs radioactivity and which are frequently high in organic carbon content. Samples with very large⁹⁰Sr and¹³⁷Cs contents have historically been difficult to analyze for Pu content by each of three alpha-counting techniques in use at SRS, and analysis by ICP-MS in these samples is complicated by the high organics content. We report an ion exchange chemical preparation to obtain fraction of Pu that does not contain any fission product contribution and no interfering organics to allow measure of absolute²³⁹Pu and of²³⁹Pu through²⁴¹Pu isotopics by ICP-MS. The method uses a²⁴²Pu spike to measure Pu recovery and is demonstrated in this paper with three distinct commercially available resins and with over 300 samples. Measured absolute²³⁹Pu contents in sixty-three spiked/unspiked duplicates have agreed within 15% precision. Overall²⁴²Pu recoveries were near 90% with 25% precision. Comparisons of absolute²³⁹Pu contents measured directly on three samples agreed within the quoted 25% uncertainty.     

Using logic to define the Aufbau–Hund–Pauli relation: a guide to teaching orbitals as a single,natural, unfragmented rule-set

The general chemistry curriculum includes a prelude that consumes nearly all of the first semester and occupies the first third of the typical textbook. This necessary prelude to the main event is comparable in scope to precalculus though not broken out as a formal ‘prechemistry’ course. Atomic orbitals account for much of this prelude-to-chemistry. By tradition, orbital theory is conveyed to the student in three disjunct pieces, presented in the following illogical order: the Pauli principle, the Aufbau principle, and Hund’s rule. (Often the n + l rule is tossed into the mix as well, though with no fixed place in the scheme). In the early twentieth century, as various researchers announced new insights into the atom at unpredictable intervals, no one could have been faulted for teaching orbitals in such a manner, catch-as-catch-can. A hundred years on, the vestiges of that (presumed) practice look wrong, and are indefensible. In the approach advocated here, orbitals would be taught as a single hierarchical rule-set, with the parts coherently sequenced as Aufbau–Hund–Pauli (and with Madelung’s n + l rule rehabilitated as part of Aufbau, no longer a free-floating mnemonic aid only). Logic aside, pragmatism offers its own argument for adopting this scheme: A tighter approach to Aufbau can lighten the ‘prechemistry’ burden significantly and bring the student that much sooner to chemistry itself.     

Simultaneous Determination of Key Osmoregulants in Halophytes Using HPLC–ELSD

Osmoregulants are the substances produced by plants that assist in tolerating environmental stresses. Three commonly analysed osomoregulants include mannitol, betaine and proline. A simple, sensitive and rapid HPLC–ELSD method has been developed for the simultaneous analysis of these common osmoregulants in plant extracts. Osmoregulants were extracted using 80 % ethanol and separated on an NH₂ column using 0.1 % formic acid and acetonitrile as the mobile phase. Retention time repeatability was 0.85, 1.50, and 0.93 % for mannitol, betaine and proline, respectively. The limit of detection (μmol) was 1.43 × 10^?4, 7.81 × 10^?5 and 1.08 × 10^?4 for mannitol, betaine and proline, respectively. The developed method was applied to three different plant extracts, Stylosanthes guianensis, Atriplex cinerea and Rhagodia baccata. A second method using a C18 column with 0.1 % heptafluorobutyric acid and acetonitrile as the mobile phase proved to be a useful complementary method for verifying tentative peak identifications.     

Simultaneous quantitative analysis of polyphenolic compounds in human plasma by liquid chromatography tandem mass spectrometry

A diet rich in polyphenolic compounds has recognized health benefits, and as such is routinely monitored as part of dietary intervention studies. A method for the simultaneous determination of 36 phenolic compounds, including phenolic acids and flavonoids, using liquid chromatography and tandem mass spectrometry is described here. The target analytes were quantified based on their specific mass spectral fragments using a selected reaction monitoring approach. A C18 column with embedded aromatic functionality ensured separation of all phenolic compounds studied which included several pairs of isomers. Sample preparation involved the use of β‐glucuronidase to release the phenolic compounds from their conjugated forms. The intra‐day and inter‐day precision and accuracy was less than 7% for all phenolic compounds studied. Recoveries, where plasma was spiked with three different concentrations of the analytes, ranged from 95–115%. The limits of detection and quantification were 0.23–3.89 and 1.15–7.79 nM, respectively. The method was successfully applied to real samples and the range reported for each phenolic compound, with the exception of hydroferulic acid, nordihydroguaiaretic acid, methylgallate, and m‐coumaric acid, was at least an order of magnitude higher than the limit of quantification for the method.     

An accurate and efficient method for the incompressible Navier–Stokes equations using the projection method as a preconditioner

The projection method is a widely used fractional-step algorithm for solving the incompressible Navier–Stokes equations. Despite numerous improvements to the methodology, however, imposing physical boundary conditions with projection-based fluid solvers remains difficult, and obtaining high-order accuracy may not be possible for some choices of boundary conditions. In this work, we present an unsplit, linearly-implicit discretization of the incompressible Navier–Stokes equations on a staggered grid along with an efficient solution method for the resulting system of linear equations. Since our scheme is not a fractional-step algorithm, it is straightforward to specify general physical boundary conditions accurately; however, this capability comes at the price of having to solve the time-dependent incompressible Stokes equations at each timestep. To solve this linear system efficiently, we employ a Krylov subspace method preconditioned by the projection method. In our implementation, the subdomain solvers required by the projection preconditioner employ the conjugate gradient method with geometric multigrid preconditioning. The accuracy of the scheme is demonstrated for several problems, including forced and unforced analytic test cases and lid-driven cavity flows. These tests consider a variety of physical boundary conditions with Reynolds numbers ranging from 1 to 30000. The effectiveness of the projection preconditioner is compared to an alternative preconditioning strategy based on an approximation to the Schur complement for the time-dependent incompressible Stokes operator. The projection method is found to be a more efficient preconditioner in most cases considered in the present work.