The electronic excitation induced by ultrashort laser pulses and the subsequent photodissociation dynamics of molecular fluorine in an argon matrix are studied. The interactions of photofragments and host atoms are modeled using a diatomics-in-molecule Hamiltonian. Two types of methods are compared: (1) quantum-classical simulations where the nuclei are treated classically, with surface-hopping algorithms to describe either radiative or nonradiative transitions between different electronic states, and (2) fully quantum-mechanical simulations, but for a model system of reduced dimensionality, in which the two most essential degrees of freedom are considered. Some of the main results follow: (1) The sequential energy transfer events from the photoexcited Fz into the lattice modes are such that the ``reduced dimensionality'' model is valid for the first 200 fs. This, in turn, allows us to use the quantum results to investigate the details of the excitation process with short laser pulses. Thus, it also serves as a reference for the quantum-classical ``surface hopping'' model of the excitation process. Moreover, it supports the validity of a laser pulse control strategy developed on the basis of the ``reduced dimensionality'' model. (2) In both the quantum and quantum-classical simulations, the separation of the F atoms following photodissociation does not exceed 20 bohr. The cage exit mechanisms appear qualitatively similar in the two sets of simulations, but quantum effects an quantitatively important. (3) Nonlinear effects are important in determining the photoexcitation yield. In summary, this paper demonstrates that quantum-classical simulations combined with reduced dimensionality quantum calculations can be a powerful approach to the analysis and control of the dynamics of complex systems.
We test poly(4-vinylpyridine) as a new matrix polymer in photorefractive polymer composites. It has excellent compatibility with OH-derivatized electro-optical chromophores due to H-bonding. Due to the slightly higher polarity, the molecular figure-of-merit of the chromophores is enhanced, yielding improved steady-state PR performance compared with PVK-based reference materials. However, because of the H-bonding the orientational mobility of the chromophores is hindered, limiting the dynamics of grating formation.
INTRODUCTION
Why Have Clinical Trials of Sepsis Been Unsuccessful?
It is disconcerting that entering the third millennium, severe microbial infections and their sequelae e.g., sep- sis, septic shock, ARDS, “flesh-eating syndromes,” still claim the lives of numerous patients annually. Further- more, it is of great interest that while immunomodu- lating agents have proved beneficial in the treatment of inflammatory conditions such as rheumatoid arthri- tis, a large series of clinical trials which have been con- ducted in the last decade and which have mainly tested only single immunomodulating agents as therapies for septic shock, have been mostly unsuccessful. In 1996, Verhoef et al. (1) have stated that reviewing the liter- ature on sepsis therapies “the area of immunomodula- tion has now become an area of more realism and the results of early trials have forced investigators to go back to the drawing board to re-investigate the whole con- cept of immunotherapy and immunoprophylaxis. In a more recent Point of View in Critical Care Medicine, entitled “Sepsis research: We must change course,” Dr. Nasraway has hit the nail on its head (2). Reviewing the disappointing results of no less than 29 prospec- tive controlled studies of human sepsis performed in the last decade, he has questioned whether “it is rational to attempt to alter the inflammatory responses by admin- istering a single immunomodulating agent while simul- taneously failing to control for the many interventions that also alter cytokine expression?” He has also raised serious doubts about the morality of any future trials of sepsis if conducted in the present manner. Baue (3), Opal and Yu (4), Cross et al. (5), Teplick and Ruben (6) and Abraham (7), have recently assessed the state of the art in sepsis research prevention and treatment, the reasons why the trials of sepsis have invariably failed to prolong the lives of septic patients, the hazards involved in the future use of multidrug strategies in sepsis, and the con- tributions of animal models to the development effec- tive therapeutic regimens in humans. Reading through the extensive literature on sepsis research and treatment, it was surprising to realize that no less than 35 different anti-inflammatory agents and strategies have been rec- ommended, usually singly, to cope with post-infectious sequelae (in 1–13). It is however important to stress that, at the bedside, anti-inflammatory agents are too often administered to patients when the deleterious pathophys- iological cascades leading to septic shock and organ fail- ure have already been irreversibly initiated. Therefore, one cannot avoid assuming that the recommendations to test only one antagonist, at time, to suppress the patho- physiological cascades in sepsis and septic shock, might have been unrealistic to begin with and also erroneous. Presumably, these have been based on the concept that there might exist a single “omnipotent” pro-inflamma- tory agonist generated following microbial invasions of the blood stream, which is efficiently neutralized, on time, might inhibit the multiple pathophysiological cas- cades responsible for the sepsis syndrome. Also, the use of multidrug strategies (4, 5, 8, 13) has been ham- pered by reports warning against the hazards of combi- nation therapies in sepsis (4, 5, 16). Is it possible that, today, sepsis research has reached a dead end because of “flawed concept or faulty implementation?” (5).
Results from animal models have clearly indicated that the inhibition of septic shock induced either by endotoxin (LPS), lipoteichoic acid (LTA), peptidogly- can (PPG) or by viable microbial cells, has been mostly successful only if the anti-inflammatory agent has been administered prior to microbial challenge. This strongly suggests that the main obstacle facing clinicians at the bedside is that once sepsis symptoms have appeared, it might already be too late to effectively prevent the pathophysiological cascades leading to tissue damage and organ failure. Therefore, strategies to prevent sep- tic shock and of additional post-infectious sequelae in humans should inonvolve distinct preventive measures especially in defined groups of high-risk patients (3–13).
Lay summary:
The article investigates why and how certain public sector information technology (IT) projects are successfully implemented whilst others are not. The article discovers that, in public organizations, bureaucrats, technologists, and politicians form coalitions with a shared technical interest. These coalitions develop concrete project agendas and are the driving force behind successful IT projects.
Publication significance:
The failure or success of IT projects in the public sector is a key challenge to the ability of public organizations to operate effectively and utilize technological innovations. Therefore, it is critical to understand what factors drive these projects. The article draws on original research to make a surprising discovery: the successful implementation of IT projects in the public sector depends on the influence of interest-based coalitions of bureaucrats, technologists and politicians.
A monolayer of conducting polymer, polyaniline (PAN), was assembled on hydroxyl-terminated surfaces, such as quartz, glass, indium−tin oxide, and native oxide on Si. The approach for assembling two-dimensional monolayers of PAN is based on a chemical or electrochemical surface polymerization of electrostatically bound anilinium. The latter was bound to the negatively charged sulfonate group of mercaptoethanesulfonate that was previously coupled by an SN2 reaction to an iodopropyl self-assembled monolayer. The consecutive assembling steps were followed by X-ray photoelectron spectroscopy, UV−vis−NIR spectroscopy, variable angle spectroscopic ellipsometry, contact angle, and atomic force microscopy measurements. The characteristic electronic properties of the PAN monolayers were studied by UV−vis−NIR spectroscopy and cyclic voltametry.
A monolayer of conducting polymer, polyaniline (PAN), was assembled on hydroxyl-terminated surfaces, such as quartz, glass, indium-tin oxide, and native oxide on Si. The approach for assembling two-dimensional monolayers of PAN is based on a chem. or electrochem. surface polymn. of electrostatically bound anilinium. The latter was bound to the neg. charged sulfonate group of mercaptoethanesulfonate that was previously coupled by an SN2 reaction to an iodopropyl self-assembled monolayer. The consecutive assembling steps were followed by XPS, UV-vis-NIR spectroscopy, variable angle spectroscopic ellipsometry, contact angle, and at. force microscopy measurements. The characteristic electronic properties of the PAN monolayers were studied by UV-vis-NIR spectroscopy and cyclic voltammetry. [on SciFinder(R)]
The instantaneous response time of parametric optical nonlinearities enable real-time processing of, and interaction between, spatial and temporal optical waveforms. We review the various signal-processing alternatives based on three- and fourwave- mixing arrangements among spatial and temporal information carrying waveforms. The fast response time of the interaction permits information exchange between the time and space domains, providing the ability to correlate and convolve signals from the two domains.We demonstrate the usefulness of real-time signal processing with optical nonlinearities with the following experiments: converting waveforms from the time to space domain as well as from the space to time domain, spectral phase conjugation and spectral inversion of ultrafast waveforms, transmission of the spatial correlation function on an ultrafast waveform, and a suggestion for a single-shot triple autocorrelation measurement.
The prepn. and characterization of octadecylsilane, C18, monolayers on indium-tin oxide (ITO) were studied carefully. A reproducible procedure was developed for the formation of C18/ITO employing octadecyltrimethoxysilane (OTMS) as a monomer. The films were studied by electrochem., wettability, IR and at. force microscopy. All these measurements provide evidence for the formation of a disorganized, 'brush-type' monolayer with a max. surface fractional coverage of 0.90 ± 0.04. The surface coverage can be controlled through the silanization time. The applications and implications of such disorganized monolayers in electroanal. chem. are discussed. [on SciFinder(R)]
KL Wilson, R Benavente, B Burke, R Craigie, R Foisner, K Furukawa, L Gerace, RD Goldman, Y Gruenbaum, C Harris, CJ Hutchison, G Krohne, GE Morris, H Otto, AJ Simon, and HJ Worman. 2001. “Problems with LAP nomenclature..” Nat Cell Biol, 3, 4, Pp. E90.
As globalisation increases, much of the economic growth is found at local and regional levels. This monograph features a collection of papers by an international selection of writers which examine the factors promoting this sub-national economic growth. The collection focuses on the new industries that drive this growth, how policy is implemented to facilitate it, and the new forms of governance emerging as a means of regulating this economic activity. Issues considered include: the role of these new industries; income, employment, job creation and training; relationships between global and local forces; and the importance of sub-national governance
Much of economic theory is concerned with the existence of prices. In particular, economists are interested in whether various outcomes defined by diverse postulates turn out to be actually generated by prices. Whenever this is the case, a theory of endogenous price formation is derived. In the present analysis, a well-known game-theoretic solution concept is considered: value. Nonatomic games are considered that are defined by finitely many nonnegative measures. Nonatomic vector measure games arise, for example, from production models and from finite-type markets. It is shown that the value of such a game need not be a linear combination of the nonatomic nonnegative measures. This is in contrast to all the values known to date. Moreover, this happens even for certain differentiable market games. In the economic models, this means that the value allocations are not necessarily produced by prices. All the examples presented are special cases of a new class of values.
BACKGROUND:
Survey studies suggest that patients with various dermatologic conditions experience concomitant psychologic distress.
OBJECTIVE:
The purpose of this study was to determine which types of psychologic distress may be correlated with dystrophic disease of the nail in nonpsychiatric patients.
METHODS:
Fifty-seven adult subjects presenting for treatment of nail dystrophies completed a survey instrument, which included 5 psychometric measures.
RESULTS:
On average, patients rated the severity of their nail dystrophy and functional deficit higher (7.40/10 and 6.00, respectively) than investigators (6.15 and 3.75, respectively). Compared with age- and sex-matched nonpsychiatric patients, subjects in the study were moderately more anxious and minimally to mildly more depressed. Subjects had moderately depressed total self-concept, but their body image was approximately normal. Overall, subjects exhibited markedly more severe psychologic symptoms (84th percentile) than the normal sample, with the scores on the psychoticism, obsessive-compulsive, and paranoid ideation subscales being the most elevated.
CONCLUSION:
The subjects with nail dystrophy had markedly exacerbated psychologic symptoms compared with age- and sex-matched nonpsychiatric patients.
The relationship between public investment and regional econimic development is of perennial interest. It is particularly topical now as issues of infrastructre and innovation are high on policy agendas in may countries. Public investment is often viewed as possible method for 'jump-starting' lagging regional economics and also as a requirement for the continued development of more prosperous regions. Public investment and Regional Economic Development provides systematic analysis of the complex relationship betweem public investment and regional economic development. The authors offer new insights into the key issues of regional growth, and present a broad variety of perspectives ranging from transport and housing infrastructure through to human capital and innovation.
With contributions from leading regional scientists, and each themed section of the book prefaced with an editorial introduction to ensure coherence, this illumination book is sure to offer policymakers new research insights in key issues of regional growth. Academics and researchers of urban and regional planning, geography and economic development will also find the book of great interest.
A generic wavelength-selective switching method is presented. The method is based on the voltage-controlled photorefractive effect in paraelectric crystals. The switch consists of a crystal at the paraelectric phase in which a space charge grating was stored by a photorefractive process. Diffraction occurs by the application of a uniform electric field that causes the space charge grating to induce an index grating. Results of the diffraction efficiency as a function of the applied field and the time dependence of the diffracted beam are presented. The performance envelop of a switch based on this effect is briefly discussed.
