Diffusion MR Characteristics Following Concurrent Radiochemotherapy Predicts Progression-Free and Overall Survival in Newly Diagnosed Glioblastoma.

The standard of care for newly diagnosed glioblastoma (GBM) is surgery, then radiotherapy (RT) with concurrent temozolomide (TMZ), followed by adjuvant TMZ. We hypothesized patients with low diffusivity measured using apparent diffusion coefficient (ADC) histogram analysis evaluated after RT+TMZ, prior to adjuvant TMZ, would have a significantly shorter progression-free (PFS) and overall survival (OS). To test this hypothesis we evaluated 120 patients with newly diagnosed GBM receiving RT+TMZ followed by adjuvant TMZ. MRI was performed after completion of RT+TMZ, prior to initiation of adjuvant TMZ. A double Gaussian mixed model was used to describe the ADC histograms within the enhancing tumor, where ADCL and ADCH were defined as the mean ADC value of the lower and higher Gaussian distribution, respectively. An ADCL value of 1.0 um2/ms and ADCH value of 1.6 um2/ms were used to stratify patients into high and low risk categories. Results suggest patients with low ADCL had significantly shorter PFS (Cox Hazard Ratio = 0.12, P = 0.0006). OS was significantly shorter with low ADCL tumors, showing a median OS of 407 vs. 644 days (Cox Hazard Ratio = 0.31, P = 0.047). ADCH was not predictive of PFS or OS when accounting for age and ADCL. In summary, newly diagnosed glioblastoma patients with low ADCL after completion of RT+TMZ are likely to progress and die earlier than patients with higher ADCL. Results suggest ADC histogram analysis may be useful for patient risk stratification following completion of RT+TMZ

Disclosures of funding sources and conflicts of interest in published HIV/AIDS research conducted in developing countries

Objectives: Disclosures of funding sources and conflicts of interests (COI) in published peer-reviewed journal articles have recently begun to receive some attention, but many critical questions remain, for example, how often such reporting occurs concerning research conducted in the developing world and what factors may be involved. Design: Of all articles indexed in Medline reporting on human subject HIV research in 2007 conducted in four countries (India, Thailand, Nigeria and Uganda), this study explored how many disclosed a funding source and COI, and what factors are involved. Results: Of 221 articles that met the criteria, 67.9% (150) disclosed the presence or absence of a funding source, but only 20% (44) disclosed COI. Studies from Uganda were more likely, and those from Nigeria were less likely to mention a funding source (p<0.001). Of articles in journals that had adopted International Committee of Medical Journal Editors (ICMJE) guidelines, 56% did not disclose COI. Disclosure of funding was more likely when: ≥50% of the authors and the corresponding author were from the sponsoring country, the sponsor country was the USA, and the articles were published in journals in which more of the editors were from the sponsoring countries. Conclusions: Of the published studies examined, over a third did not disclose funding source (ie, whether or not there was a funding source) and 80% did not disclose whether COI existed. Most articles in ICMJE-affiliated journals did not disclose COI. These data suggest the need to consider alteration of policies to require that published articles include funding and COI information, to allow readers to assess articles as fully as possible

Erfolgsfaktoren für die Kundengewinnung mit digitalem Marketing

Den Absatz zu steigern, ist das übergeordnete Ziel von effizientem Marketing. Die Digitalisierung begründet die Umsetzung vieler Online-Marketingaktivitäten. Ein wichtiger Player im digitalen Marketing ist Google AdWords, ein Tool, welches es Unternehmen ermöglicht, dass deren Produkte und Dienstleistungen von potenziellen Kunden gefunden werden, wenn auf der Suchmaschine von Google danach gesucht wird. Die Identifikation von Erfolgsfaktoren bei der Arbeit mit Google AdWords ist aufgrund der Schnelllebigkeit des Themenfelds sowie des komplexen AdWords-Auktionssystems eine Herausforderung. Eine Fallstudienanalyse, in deren Rahmen erfahrene Unternehmungen beim Marketing mit Google AdWords sowie Fachexperten befragt werden, deckt die Erfolgsfaktoren für Marketingmaßnahmen mit Google AdWords auf. Eine moderne und nutzerfreundliche Webseite mit relevanten Inhalten sowie eine hohe Relevanz zwischen Keyword, Werbeanzeige und Zielseite sind essenzielle Voraussetzungen für erfolgreiche Google-AdWords-Kampagnen

Heterogeneous processes: Laboratory, field, and modeling studies

The efficiencies of chemical families such as ClO(x) and NO(x) for altering the total abundance and distribution of stratospheric ozone are controlled by a partitioning between reactive (active) and nonreactive (reservoir) compounds within each family. Gas phase thermodynamics, photochemistry, and kinetics would dictate, for example, that only about 1 percent of the chlorine resident in the lower stratosphere would be in the form of active Cl or ClO, the remainder existing in the reservoir compounds HCl and ClONO2. The consistency of this picture was recently challenged by the recognition that important chemical transformations take place on polar regions: the Airborne Antarctic Ozone Experiment (AAOE) and the Airborne Arctic Stratospheric Expedition (AASA). Following the discovery of the Antarctic ozone hole, Solomon et al. suggested that the heterogeneous chemical reaction: ClONO2(g)+HCl(s) yields Cl2(g)+HNO3(s) could play a key role in converting chlorine from inactive forms into a species (Cl2) that would rapidly dissociate in sunlight to liberate atomic chlorine and initiate ozone depletion. The symbols (s) and (g) denote solid phase, or adsorbed onto a solid surface, and gas phase, respectively, and represent the approach by which such a reaction is modeled rather than the microscopic details of the reaction. The reaction was expected to be most important at altitudes where PSC's were most prevalent (10 to 25 km), thereby extending the altitude range over which chlorine compounds can efficiently destroy ozone from the 35 to 45 km region (where concentrations of active chlorine are usually highest) to lower altitudes where the ozone concentration is at its peak. This chapter will briefly review the current state of knowledge of heterogeneous processes in the stratosphere, emphasizing those results obtained since the World Meteorological Organization (WMO) conference. Sections are included on laboratory investigations of heterogeneous reactions, the characteristics and climatology of PSC's, stratospheric sulfate aerosols, and evidence of heterogeneous chemical processing

HIV/AIDS Research Conducted in the Developing World and Sponsored by the Developed World: Reporting of Research Ethics Committee Review in Two Countries

We explored how often journal articles reporting HIV research sponsored by a developed country, but conducted in a developing country, mention research ethics committee (REC) approval from both countries, and what factors are involved. Of all such 2007 articles on Medline conducted in one of four developing countries (N = 154), only 52% mentioned such dual approval. Mention of dual vs. single approval was more likely among articles with ≥ 50% sponsor country authors, and the United States as the sponsor country. Also, dual approval was more likely among articles that mentioned informed consent and funding, had ≥ 50% sponsor country authors, were biomedical (vs. psychosocial), and appeared in journals adopting International Committee Medical Journal Editors (ICMJE) guidelines. Dual approval was thus obtained in only half of the articles and was associated with ethical and logistic issues, indicating the need for clearer and more universally accepted guidelines

A constrained Potts antiferromagnet model with an interface representation

We define a four-state Potts model ensemble on the square lattice, with the constraints that neighboring spins must have different values, and that no plaquette may contain all four states. The spin configurations may be mapped into those of a 2-dimensional interface in a 2+5 dimensional space. If this interface is in a Gaussian rough phase (as is the case for most other models with such a mapping), then the spin correlations are critical and their exponents can be related to the stiffness governing the interface fluctuations. Results of our Monte Carlo simulations show height fluctuations with an anomalous dependence on wavevector, intermediate between the behaviors expected in a rough phase and in a smooth phase; we argue that the smooth phase (which would imply long-range spin order) is the best interpretation.Comment: 61 pages, LaTeX. Submitted to J. Phys.

Synthesis, Pore Morphology, and Dielectric Property of Mesoporous Low-k Material PSMSQ using a Reactive High-Temperature Porogen, TEPSS

A high-temperature reactive porogen, triethoxy(polystyrene)silane (TEPSS) (M w =3,500 g/mole), suitable for late-porogen removal integration scheme has been synthesized in p-xylene via atom transfer radical polymerization. TEPSS was then grafted onto poly(methyl-silsesquioxane) (MSQ) matrix (k=2.9) to circumvent possible phase separation between matrix and porogen in the hybrid approach and porogen aggregation. Our results shows porous low-k MSQ films possess uniform pore size, 24 nm for porosity up to 40%, primarily due to low PDI and reactive porogen, and the dielectric constant is decreased to 2.37 at 40% porosity. In addition, less porogen aggregation was observed at porogen loading ~40 v%

Low field hysteresis in disordered ferromagnets

We analyze low field hysteresis close to the demagnetized state in disordered ferromagnets using the zero temperature random-field Ising model. We solve the demagnetization process exactly in one dimension and derive the Rayleigh law of hysteresis. The initial susceptibility a and the hysteretic coefficient b display a peak as a function of the disorder width. This behavior is confirmed by numerical simulations d=2,3 showing that in limit of weak disorder demagnetization is not possible and the Rayleigh law is not defined. These results are in agreement with experimental observations on nanocrystalline magnetic materials.Comment: Extended version, 18 pages, 5 figures, to appear in Phys. Rev.

Brief but Efficient: Acute HIV Infection and the Sexual Transmission of HIV

Background. We examined whether viral dynamics in the genital tract during the natural history of acute human immunodeficiency virus type 1 (HIV-1) infection could explain efficient heterosexual transmission of HIV. Methods. We measured HIV-1 concentration in blood and semen samples from patients with acute and long-term HIV-1 infection. We explored the effect of changes in viral dynamics in semen on the probability of transmission per coital act, using a probabilistic model published elsewhere. Results. Considered over time from infection, semen HIV-1 concentrations, in men with acute infection, increase and decrease in approximate parallel with changes occurring in blood. Modeling suggests that these acute dynamics alone are sufficient to increase probability of heterosexual transmission by 8-10-fold between peak (day 20 after infection, based on the model) and virologic set points (day 54 and later after infection). Depending on the frequency of coitus, men with average semen HIV-1 loads and without sexually transmitted diseases (STDs) would be expected to infect 7%-24% of susceptible female sex partners during the first 2 months of infection. The predicted infection rate would be much higher when either partner has an STD. Conclusions. Empirical biological data strongly support the hypothesis that sexual transmission by acutely infected individuals has a disproportionate effect on the spread of HIV-1 infection. Acute hyperinfectiousness may, in part, explain the current pandemic in heterosexual individual