326 research outputs found
Probing secondary coordination sphere interactions within porphyrin-cored polymer nanoparticles
A suite of zinc porphyrin-cored random coil polymers and polymeric nanoparticles with varying degrees of potential hydrogen bonding character and steric bulk were synthesized and characterized to study secondary coordination sphere interactions. The reaction of cyanide with N,N-dimethylformamide in the presence of porphyrin-cored polymeric nanoparticles was monitored via UV-Vis spectroscopy. It is shown that the zinc porphyrin-cored polymers and nanoparticles catalyzed the reaction of cyanide with N,N-dimethylformamide with the highest reaction rates occurring with polymeric nanoparticles with a greater number of potential hydrogen bond donors and greater steric bulk
Factors Affecting Surgical Decisions in Newly Diagnosed Young Women with Early-Stage Breast Cancer
Given that young women with breast cancer often have concerns and priorities attributable to their life stage, we conducted a series of interviews to better understanding the surgical decision-making experience among women diagnosed at age ≤40. Women spoke of how the potential effect of an extended recovery was affecting their decision and, in some cases, contributing to decisional conflict. Several women described their worry of leaving cancer cells behind; others cited the need for continued surveillance as a consideration. Attention to situational anxiety and concerns about recurrence are warranted to ensure that decisions are made in a supportive and patient-centered setting
Rotational Studies of Late-Type Stars. VII. M34 (NGC 1039) and the Evolution of Angular Momentum and Activity in Young Solar-Type Stars
We analyze Keck Hires observations of rotation in F, G, and K dwarf members
of the open cluster M34 (NGC 1039), which is 250 Myr old, and we compare them
to the Pleiades, Hyades, and NGC 6475. The upper bound to rotation seen in M34
is about a factor of two lower than for the 100 Myr-old Pleiades, but most M34
stars are well below this upper bound, and it is the overall convergence in
rotation rates that is most striking. A few K dwarfs in M34 are still rapid
rotators, suggesting that they have undergone core-envelope decoupling,
followed by replenishment of surface angular momentum from an internal
reservoir. Our comparison of rotation in these clusters indicates that the time
scale for the coupling of the envelope to the core must be close to 100 Myr if
decoupling does, in fact, occur.Comment: 16 pages + 1 table + 5 figure
Keck Spectra of Pleiades Brown Dwarf Candidates and a Precise Determination of the Lithium Depletion Edge in the Pleiades
We have obtained intermediate resolution spectra of eleven candidate brown
dwarf members of the Pleiades open cluster using the Keck II telescope and LRIS
spectrograph. Our primary goal was to determine the location of the "lithium
depletion edge" in the Pleiades and hence to derive a precise age for the
cluster. All but one of our 11 program objects have radial velocities
appropriate for Pleiades members, have moderately strong H alpha emission, and
have spectral types M6 to M8.5, as expected for their (R-I) colors.
We have constructed a color-magnitude diagram for the faint end of the
Pleiades main sequence, including only stars for which high S/N spectra in the
region of the lithium 6708 Angstrom absorption line have been obtained. These
data allow us to accurately determine the Pleiades single-star lithium
depletion edge at I(c0) = 17.80, R-I(c0) = 2.20, spectral type = M6.5. By
reference to theoretical evolutionary models, this converts fairly directly
into an age for the Pleiades of 125 Myr. This is significantly older than the
age that is normally quoted, but does agree with some other recent estimates.Comment: 12 pages, including 3 Figures. Accepted by ApJ Letter
ПОБОЧНЫЕ ЭФФЕКТЫ СОРАФЕНИБА, СУНИТИНИБА И ТЕМСИРОЛИМУСА И ИХ ЛЕЧЕНИЕ У БОЛЬНЫХ МЕТАСТАТИЧЕСКИМ ПОЧЕЧНО-КЛЕТОЧНЫМ РАКОМ
Objective: to provide a systematic review of the adverse reactions of sorafenib, sunitinib, and temsirolimus and to outline actions for their prevention and correction.Materials and methods. To provide a description of the main methods to decrease the toxicity of these drugs, the authors made a systemat- ic review of their adverse reactions, by using the publications available in the PubMed database, monographs on the medicines, and instruc- tions for their medical use. Results. The frequency of their adverse reactions varied from < 1 to 72%. Grades III—IV side effects are noted more rarely; their incidence is < 1 to 13% for sorafenib, < 1 to 16% for sunitinib, and 1 to 20% for temsirolimus. Sinitinib causes most grades III—IV adverse reactions and sofafenib does the least. However, close comparative studies of the safety of these kinase inhibitors are still lacking. Virtually all side effects can be effectively prevented and treated. Conclusion. The prevention, timely recognition, and treatment of the adverse reactions of these agents are of great importance, which allows avoidance of the unneeded dosage reduction that may result in worse therapeutic efficiency. Цель исследования — представить систематический обзор побочных эффектов сорафениба, сунитиниба и темсиролимуса, а также в общих чертах описать меры по их предупреждению и коррекции. Материалы и методы. Для того чтобы представить описание основных методов, направленных на снижение токсичности этих препаратов, нами проведен систематический обзор побочных эффектов на основе публикаций в базе данных PubMed, монографий по лекарственным препаратам и инструкций по их медицинскому применению.Результаты. Частота развития побочных эффектов варьирует от < 1 до 72%. Побочные эффекты III—IV степени отмечаются реже, частота их возникновения от < 1 до 13% для сорафениба, от < 1 до 16% — для сунитиниба и от 1 до 20% — для темсиролимуса. Сунитиниб вызывает наибольшее количество побочных эффектов III—IV степени, а сорафениб — наименьшее. Однако все еще отсутствуют тщательные сравнительные клинические исследования безопасности этих ингибиторов киназ. Практически все побочные эффекты можно эффективно предупреждать и лечить.Заключение. Большое значение имеют профилактика, своевременное распознавание и лечение побочных эффектов этих препаратов, что позволяет избежать ненужного снижения дозы, грозящего ослаблением эффективности лечения.
Targeting deforestation rates in climate change policy: a "Preservation Pathway" approach
We present a new methodological approach to incorporating deforestation within the international climate change negotiating regime. The approach, called "Preservation Pathway" combines the desire for forest preservation with the need to reduce emissions associated with forest loss by focusing on the relative rate of change of forest cover as the criteria by which countries gain access to trading preserved forest carbon stocks. This approach avoids the technically challenging task of quantifying historical or future deforestation emission baselines. Rather, it places emphasis on improving quantification of contemporary stocks and the relative decline in deforestation rates necessary to preserve those stocks. This approach places emphasis on the complete emissions trajectory necessary to attain an agreed-upon preserved forest and as such, meets both forest conservation and climate goals simultaneously
Stranded research? Leading finance journals are silent on climate change
Finance research has shaped the modern financial system, influencing investors and market participants directly through research findings and indirectly through teaching and training programmes. Climate change presents major risks to the global financial system as well as new opportunities for investors. Is climate finance an important topic in finance research? We systematically analyse the content of 20,725 articles published in the leading 21 finance journals between January 1998 and June 2015. We find that only 12 articles (0.06%) are related in some way to climate finance. The three elite finance journals (Journal of Finance, Journal of Financial Economics and Review of Financial Studies) did not publish a single article related to climate finance over the 17.5-year period. We repeat our analysis across a sample of 29 elite business journals spanning accounting, economics, management, marketing and operations research, as well as finance. We find a similar dearth of published climate finance research. We consider four possible explanations for this failure of top finance and business journals to engage with climate finance as a research topic. These include methodological constraints and editorial policies. We conclude by arguing why it is critical for climate-related research to be given greater attention and prominence in finance journals
The Social and Ethical Acceptability of NBICs for Purposes of Human Enhancement: Why Does the Debate Remain Mired in Impasse?
The emergence and development of convergent technologies for the purpose of improving human performance, including nanotechnology, biotechnology, information sciences, and cognitive science (NBICs), open up new horizons in the debates and moral arguments that must be engaged by philosophers who hope to take seriously the question of the ethical and social acceptability of these technologies. This article advances an analysis of the factors that contribute to confusion and discord on the topic, in order to help in understanding why arguments that form a part of the debate between transhumanism and humanism result in a philosophical and ethical impasse: 1. The lack of clarity that emerges from the fact that any given argument deployed (arguments based on nature and human nature, dignity, the good life) can serve as the basis for both the positive and the negative evaluation of NBICs. 2. The impossibility of providing these arguments with foundations that will enable others to deem them acceptable. 3. The difficulty of applying these same arguments to a specific situation. 4. The ineffectiveness of moral argument in a democratic society. The present effort at communication about the difficulties of the argumentation process is intended as a necessary first step towards developing an interdisciplinary response to those difficulties
Keck Spectra of Brown Dwarf Candidates and a Precise Determination of the Lithium Depletion Boundary in the Alpha Persei Open Cluster
We have identified twenty-seven candidate very low mass members of the
relatively young Alpha Persei open cluster from a six square degree CCD imaging
survey. Based on their I magnitudes and the nominal age and distance to the
cluster, these objects should have masses less than 0.1 Msunif they are cluster
members. We have subsequently obtained intermediate resolution spectra of
seventeen of these objects using the Keck II telescope and LRIS spectrograph.
We have also obtained near-IR photometry for many of the stars. Our primary
goal was to determine the location of the "lithium depletion boundary" and
hence to derive a precise age for the cluster. We detect lithium with
equivalent widths greater than or equal to 0.4 \AA in five of the program
objects. We have constructed a color-magnitude diagram for the faint end of the
Alpha Persei main sequence. These data allow us to accurately determine the
Alpha Persei single-star lithium depletion boundary at M(I) = 11.47, M(Bol)
= 11.42, (R-I) = 2.12, spectral type M6.0. By reference to theoretical
evolutionary models, this converts fairly directly into an age for the Alpha
Persei cluster of 90 10 Myr. At this age, the two faintest of our
spectroscopically confirmed members should be sub-stellar (i.e., brown dwarfs)
according to theoretical models.Comment: Accepted Ap
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