A 2-4 keV multilayer mirrored channel for the NIF Dante system.

During inertial confinement fusion experiments at the National Ignition Facility (NIF), a capsule filled with deuterium and tritium (DT) gas, surrounded by a DT ice layer and a high-density carbon ablator, is driven to the temperature and densities required to initiate fusion. In the indirect method, 2 MJ of NIF laser light heats the inside of a gold hohlraum to a radiation temperature of 300 eV; thermal x rays from the hohlraum interior couple to the capsule and create a central hotspot at tens of millions degrees Kelvin and a density of 100-200 g/cm3. During the laser interaction with the gold wall, m-band x rays are produced at ∼2.5 keV; these can penetrate into the capsule and preheat the ablator and DT fuel. Preheat can impact instability growth rates in the ablation front and at the fuel-ablator interface. Monitoring the hohlraum x-ray spectrum throughout the implosion is, therefore, critical; for this purpose, a Multilayer Mirror (MLM) with flat response in the 2-4 keV range has been installed in the NIF 37° Dante calorimeter. Precision engineering and x-ray calibration of components mean the channel will report 2-4 keV spectral power with an uncertainty of ±8.7%.

Prediction of enthalpy and standard Gibbs energy of vaporization of haloaromatics from atomic properties.

Halogenated benzenes form a class of pollutants with a huge number of members - 1504 distinct benzene compounds, where one or more hydrogen atoms are replaced by halogens, may exist theoretically. This study presents a user friendly method for accurate prediction of vapor pressures and enthalpies of vaporization, at 298.15 K, of any mono or poly halobenzene compound. The derived equations for the prediction of those vaporization properties depend just on the number of each constituent halogen atom. This is a consequence of the absence of intramolecular interactions between the halogen atoms, revealed after examining vaporization results of ca. 40 halogenated benzenes. In order to rationalize the estimation equations, the contribution of the halogen atoms for the referred to above properties of vaporization was decomposed into two atomic properties - the volume and electron affinity. Extension of the applicability of the estimation method to substituted benzenes containing other substituent groups beyond halogen atoms as well as to some polycyclic aromatic species was tested with success.

Mach-Zehnder recording systems for pulsed power diagnostics.

Fiber-optic transmission and recording systems, based on Mach-Zehnder modulators, have been developed and installed at the National Ignition Facility (NIF), and are being developed for other pulsed-power facilities such as the Z accelerator at Sandia, with different requirements. We present the design and performance characteristics for the mature analog links, based on the system developed for the Gamma Reaction History diagnostic at the OMEGA laser and at NIF. For a single detector channel, two Mach-Zehnders are used to provide high dynamic range at the full recording bandwidth with no gaps in the coverage. We present laboratory and shot data to estimate upper limits on the radiation effects as they impact recorded data quality. Finally, we will assess the technology readiness level for mature and developing implementations of Mach-Zehnder links for these environments.

Observation of high soft x-ray drive in large-scale hohlraums at the National Ignition Facility.

The first soft x-ray radiation flux measurements from hohlraums using both a 96 and a 192 beam configuration at the National Ignition Facility have shown high x-ray conversion efficiencies of ∼85%-90%. These experiments employed gold vacuum hohlraums, 6.4 mm long and 3.55 mm in diameter, heated with laser energies between 150-635 kJ. The hohlraums reached radiation temperatures of up to 340 eV. These hohlraums for the first time reached coronal plasma conditions sufficient for two-electron processes and coronal heat conduction to be important for determining the radiation drive.

The first measurements of soft x-ray flux from ignition scale Hohlraums at the National Ignition Facility using DANTE (invited).

The first 96 and 192 beam vacuum Hohlraum target experiments have been fielded at the National Ignition Facility demonstrating radiation temperatures up to 340 eV and fluxes of 20 TW/sr as viewed by DANTE representing an ∼20 times flux increase over NOVA/Omega scale Hohlraums. The vacuum Hohlraums were irradiated with 2 ns square laser pulses with energies between 150 and 635 kJ. They produced nearly Planckian spectra with about 30±10% more flux than predicted by the preshot radiation hydrodynamic simulations. To validate these results, careful verification of all component calibrations, cable deconvolution, and software analysis routines has been conducted. In addition, a half Hohlraum experiment was conducted using a single 2 ns long axial quad with an irradiance of ∼2×10(15) W/cm(2) for comparison with NIF Early Light experiments completed in 2004. We have also completed a conversion efficiency test using a 128-beam nearly uniformly illuminated gold sphere with intensities kept low (at 1×10(14) W/cm(2) over 5 ns) to avoid sensitivity to modeling uncertainties for nonlocal heat conduction and nonlinear absorption mechanisms, to compare with similar intensity, 3 ns OMEGA sphere results. The 2004 and 2009 NIF half-Hohlraums agreed to 10% in flux, but more importantly, the 2006 OMEGA Au Sphere, the 2009 NIF Au sphere, and the calculated Au conversion efficiency agree to ±5% in flux, which is estimated to be the absolute calibration accuracy of the DANTEs. Hence we conclude that the 30±10% higher than expected radiation fluxes from the 96 and 192 beam vacuum Hohlraums are attributable to differences in physics of the larger Hohlraums.

A comparative 3-month clinical investigation of the safety and efficacy of a battery-operated and a rechargeable oscillating-rotating power toothbrush.

PURPOSE: To compare the safety and efficacy of two oscillating-rotating power toothbrushes, the rechargeable Braun Oral-B D8 and the battery-powered Colgate Actibrush. MATERIALS AND METHODS: This was a randomized, examiner-blind, parallel-group study, carried out over 3 months of product use, involving a total of 113 healthy subjects with a plaque score of > or = 1.5 and a gingivitis score of > or = 1.1. Subjects were given written and verbal instructions in the use of their respective power brushes and were told to brush twice per day. At baseline, hard and soft tissues were examined, and plaque scores and gingival scores were recorded after 12-18 hrs of no oral hygiene. Subjects returned after 3 months, at which time soft and hard tissues were re-examined and plaque and gingivitis scores were recorded. RESULTS: No evidence was found of soft or hard tissue trauma and both brushes were considered to be safe when used according to the manufacturers' instructions. After 3 months, whole mouth plaque scores had decreased by 7% in the D8 group but had increased by 4.3% in the Actibrush group. The decrease from baseline in the D8 group was statistically significant, but the increase in the Actibrush group was not. The difference between the two groups was statistically significant both for the whole mouth and all individual sites. Whole mouth gingivitis scores were also reduced significantly from baseline in both groups, by 22.5% in the D8 group and by 17.5% in the Actibrush group. For whole mouth scores and all individual sites (interproximal, buccal and lingual), the D8 was significantly more effective than the Actibrush.

A single-use and 3-month clinical investigation of the comparative efficacy of a battery-operated power toothbrush and a manual toothbrush.

PURPOSE: To compare the safety and efficacy of a manual toothbrush and a battery-operated power toothbrush in two separate studies, one utilizing a single-use design and the other a 3-month parallel-group design. MATERIALS AND METHODS: The toothbrushes compared in the two studies were the Oral-B CrossAction manual toothbrush and the Colgate Actibrush battery-operated power toothbrush. The single-use study, which used a single-blind, cross-over design, involved 71 healthy subjects, who were instructed to abstain from oral hygiene for 23-25 hours prior to brushing with each of the two toothbrushes. Plaque was measured using the Proximal Marginal Index (PMI) pre- and post-brushing. The 3-month parallel-group study involved a total of 113 subjects who had plaque (PMI), gingivitis and bleeding (Loe and Silness) scored at baseline and after 1 and 3 months of product use. RESULTS: In both studies, the two toothbrushes were found to be safe. In the single-use study, significantly greater amounts of plaque were removed by the CrossAction manual toothbrush than by the Actibrush for the whole mouth as well as for marginal and approximal sites (P < 0.001). In the 3-month study, significantly greater plaque reduction was achieved with the CrossAction brush, the advantage being significant at 1 month for all sites except lingual sites (P < 0.05). At 3 months, there were consistent numerical advantages in favor of the CrossAction at all sites except lingual sites. Reductions in gingivitis were found to be similar with both toothbrushes.

Some legal, social, and ethical issues related to the genetic testing revolution, as exemplified in the long QT syndrome.

Molecular Biology is revolutionizing medicine. There are a number of conditions, particularly exemplified by the long QT syndrome, where there is no structural abnormality but where a subset of patients is prone to sudden death. The issues of appropriate care are very complex, because there is tremendous overlap between patients with prolongation of the QT who remain asymptomatic and those with prolongation who are very symptomatic. Furthermore, even those who are prone to have one of the abnormal genes, may be asymptomatic. A large literature has developed, from both legal and ethical aspects, related to the fact that in genetic disease per se, not only is the person at risk, but so are many members of his or her family. A large literature has also developed as to which should be prime, the patient's privacy or the responsibility to make sure the entire family is knowledgeable and perhaps tested. At the present moment our care is based upon the fact that the precise identification of the gene is not yet available on a routine basis. This of course, may soon change. But we will still have difficult decisions to make. Obviously, we have a responsibility as physicians to be as precise as our discipline allows, but we have a responsibility to be flexible. Relief of anxiety, as an example, has to be a prime issue. This is certainly the case now when any information related to infants with potential sudden death is still incomplete. We must not approach the care of the patient in such a way that protection of the physician may interfere with appropriate care. The discussion necessarily includes a variety of aspects.

Using 12-lead ECG and synthesized VCG in detection of right ventricular hypertrophy with terminal right conduction delay versus partial right bundle branch block in the pediatric population.

In pediatric electrocardiogram (ECG) analysis, mild right ventricular hypertrophy (RVH) and especially mild RVH with terminal right conduction delay (RVHtcd) are often confused with partial right bundle branch block (PRBBB). This is problematic for computer ECG analysis algorithms and even for most experienced pediatric cardiologists. This study was designed to achieve better classification of mild RVHtcd and PRBBB by combining the 12-lead synthesized vectocardiogram (VCG) transverse plane measurements with scalar ECG measurements. Pediatric ECGs used in the study were recorded with 15 leads and a 500 Hz sampling rate at the Lucile Salter Packard Children's Hospital, Stanford University Medical Center. Out of 4,200 ECGs collected consecutively over a period of 18 months, 447 RVH, 335 RBBB and 589 Normal were interpreted by expert pediatric cardiologists, and were included in the study. Statistical comparison of ECG and VCG measurements were done in stratified ECG sets (412) that have a visually indistinguishable waveform pattern, 117 RVHtcd, 96 PRBBB and 199 normal, showed significant differences in initial and terminal vectors in the transverse plane. The mean angle of the initial vector was anterior (57.2 degrees +/- 41.8) in the normal group, left anterior in the PRBBB group (34.4 degrees +/- 39.5) and in the RVHtcd group (31.9 degrees +/- 41.0) and. The mean angle of the terminal vector was right anterior (158.3 degrees +/- 36.8) in the PRBBB group, rightward (179.7 degrees +/- 29.9) in the RVHtcd group and right posterior (212.6 degrees +/- 37.8) in the normal group. These are clearly applicable features for a classification algorithm. Significantly improved classification results were obtained from a new algorithm using combined ECG and VCG measurements versus an existing algorithm. The limitation of this study stems from the unavailability of a more reliable gold standard. It may be necessary to used body surface potentials obtained with a large number of electrodes to accurately differentiate the study groups.

Chondrocyte culture and assay.

Chondrocytes constitute the sole cell type found within cartilage, and control the formation and composition of cartilage. Cellular, biochemical and pharmacological studies of arthritis and other cartilage disorders have increasingly focused on chondrocyte function. Three methods are presented in this unit for culturing chondrocytes, and two assays are described that characterize proteoglycan synthesis, a key measure of chondrocyte function.Chondrocytes constitute the sole cell type found within cartilage, and control the formation and composition of cartilage.

Antimicrobial and cancer cell growth inhibitory activities of 3beta-acetoxy-17beta-(L-prolyl)amino-5alpha-androstane in vitro.

The in vitro activity of the steroidal amide 3beta-acetoxy-17beta-(L-prolyl)amino-5alpha-androstane against 179 gram-positive clinical isolates was examined. The minimum bactericidal concentration (MBC)/MIC ratios were < or = 2 for 73% of methicillin-resistant Staphyllococcus aureus, 59% of vancomycin-resistant Enterococcus spp. and 88% of penicillin-resistant Streptococcus pneumoniae. The androstane derivative was bactericidal for a variety of other gram-positive genera, including Nocardia, Corynebacterium and Listeria. Variation in MICs is pH 6-8 media was slight. The frequency of occurrence of bacterial spontaneous mutations to resistance ranged from 10(-6) to 10(-9). Kill curve analysis confirmed the bactericidal nature of the steroidal amide, and demonstrated that killing was time dependent but not concentration dependent for all organisms. The ability of 3beta-acetoxy-17beta-(L-prolyl)amino-5alpha-androstane to inhibit human cancer cell growth was also evaluated. The concentration required to inhibit 50% of cell growth (GI50) was < 2.5 mg/l for all cell lines examined. In single-dose murine toxicity evaluations, the androstane derivative was non-toxic at doses up to 400 mg/kg.

The Women and Infants Demonstration Project: an integrated approach to AIDS prevention and research.

The Women and Infants Demonstration Project is a multisite, behavioral intervention research effort funded by the Centers for Disease Control. The project is evaluating a theory-based, integrated intervention model to increase the use of condoms for prevention of both sexually transmitted diseases (STDs) and unintended pregnancy among women and their partners at risk of infection with HIV. The importance of utilizing carefully targeted, credible and persistent risk reduction interventions to effect lasting behavior change has become evident over the last ten years of the AIDS epidemic. The theory-based intervention components being evaluated in this intervention study involve one-on-one stage-tailored outreach; the development and distribution of community-tailored HIV prevention materials, called role-model stories; and the development of organizational and peer networking, all within a community mobilization framework. This article describes each of the intervention components being evaluated during this 5-year study. Such an intervention effort represents an important contribution in the design of community-level AIDS prevention intervention efforts which support individual-level behavioral changes by women at risk for HIV and other sexually transmitted infections.

PIP: The Women and Infants Demonstration Project is a multi-site, behavioral intervention research effort currently being funded by the US Centers for Disease Control. The project is evaluating a theory-based, integrated intervention model to increase condom use for the prevention of sexually transmitted diseases (STD) and unintended pregnancy among women and their partners at risk of infection with HIV. The theory-based intervention components being evaluated in the study involve one-on-one stage-tailored outreach; the development and distribution of community-tailored HIV prevention materials, known as role model stories; and the development of organizational and peer networking, all within a community mobilization framework. Each of the intervention components being evaluated is described.

Characterization of recombinant human cathepsin B expressed at high levels in baculovirus.

The lysosomal cysteine protease cathepsin B has been studied intensely for many years because of its unique characteristics and its potential involvement in disease states. A reproducible, high yield expression system for active recombinant protein is key to biochemical and biophysical studies as well as rational drug design. Although several microbial and mammalian expression systems for recombinant human cathepsin B have been described, these have been limited by low or variable yields. Further, in some of these systems hyper-glycosylation of the enzyme near the active site affects its activity. We describe a baculovirus expression system and purification scheme that solve all of these problems. Yields of active, protected enzyme were reproducibly in excess of 25 mg/L. Since this protein was not hyper-glycosylated, it had greater activity than cathepsin B produced in yeast systems as indicated by a threefold increase in Kcat. In addition, the biophysical properties of the baculovirus-expressed cathepsin B, as measured by dynamic light scattering, were more amenable to crystallographic study since the data indicated proteins of more uniform size. Therefore, this system for the production of recombinant human cathepsin B constitutes a major improvement in both quantity and quality over those previously reported. Further, we demonstrate that the manner of expression and purification of this enzyme has profound effects on its kinetic and physical parameters.

Unification of some literature models of aromaticity: calculational and conceptual study of a set of one-ring species.

Numerous models have been suggested for the important concept of aromaticity. In the current study, a set of recently suggested models of aromaticity/homoaromaticity/anti-aromaticity for one-ring species [e.g. pyridazine, oxazole, tropilidene (cycloheptatriene), 1,4-dithiin, [8]-annulene (cyclooctatetraene)] is shown to have a common mathematical framework from which a new, unifying quantitative equation has been derived. Calculational and conceptual application is made to a well defined set of one-ring carbocycles.

Collagen II promoter and enhancer interact synergistically through Sp1 and distinct nuclear factors.

The collagen II gene is expressed primarily in chondrocytes. Its transcription is activated through the interaction of cell type-specific regulatory elements located in the promoter region and in the first intron. In this study, we found that a short promoter sequence including two GC boxes was required for efficient enhancer-mediated transcription. Gel-shift analysis, site mutations, and footprint analysis showed that one of the GC boxes bound functionally to an Sp1-related factor and that an oligonucleotide containing this GC box did interact with an enhancer-nuclear factor complex. Additionally, an enhancer-derived oligonucleotide was found to complex CIIZFP, a zinc-finger protein that binds to the enhancer within the first intron and Sp1, but only in presence of CIIZFP. Antibodies against Sp1 specifically inhibited the formation of this complex. Western/Southwestern analysis also showed that a protein complex including Sp1 was able to bind the enhancer and the promoter regions in non-denaturing conditions. This complex was dissociated by denaturation. These results suggest that the formation of a nuclear protein-mediated loop structure between the promoter and enhancer may regulate transcription of the collagen II gene transcription.

Altered expression of basement-membrane components and collagenases in ascitic xenografts of OVCAR-3 ovarian cancer cells.

Ascitic ovarian cancer cells, which derive from solid tumors, complicate the treatment of ovarian cancer by spreading throughout the peritoneal cavity. Because basement-membrane components may influence tumor-cell proliferation and dissemination, the present studies examined the production of (a) basement-membrane attachment and migration factors (laminin, fibronectin and type IV collagen); (b) a laminin receptor, the 32/67-kDa laminin-binding protein, the presence of which correlates with malignancy; and (c) metalloproteinases (types I and IV collagenase and stromelysin), by ascitic and cultured OVCAR-3 cells and solid OVCAR-3 tumors. The cultured cells and solid tumors produced high levels of mRNA encoding attachment factors and metalloproteinases, and low levels of mRNA for the 32/67-kDa laminin receptor. In contrast, the ascitic ovarian cells had low or undetectable levels of mRNA encoding laminin, type IV collagen and metalloproteinases, but higher levels of transcripts for the laminin receptor. Our results suggest that the apparent inability of ascitic OVCAR-3 cells to attach to host-tissue surfaces may be a consequence, in part, of low levels of expression of laminin, type IV collagen and/or type IV collagenase.