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Controlling curve‐crossing dynamics of a model diatomic system between two dissociative electronic states through radiative coupling with a third bound state is examined. Starting with an initial wave packet on one of the crossing surfaces, optimal control theory is used to design the radiative field to either enhance or eliminate (at our choice) selectivity of one product channel over another. A new optimization procedure is introduced which filters out dc and low frequency components from the optimal field, but still allows for resonant transitions to a third bound state. This procedure forces the fields to employ interesting physical mechanisms involving the bound state in order to control the electronic branching ratios rather than directly negating or enhancing the diabatic coupling term in the Hamiltonian. A new propagation scheme for a multisurface Hamiltonian using Pauli matrices is also presented.

Antihypertensive treatment is an essential, life-prolonging measure in primary hypertension. It prevents apoplexy, myocardial infarction, and hypertensive kidney failure. Chronic kidney failure is associated with hypertension and an accelerated form of arteriosclerosis. Demise from cardiovascular affliction is a leading cause of death in renal patients (chronic renal failure stages II-IV, renal failure requiring dialysis, renal transplantation). What, then, is the role of antihypertensive treatment in such patients, and, specifically, what is achieved by renin-angiotensin-aldosterone (RAA) system modifying agents? Two meta-analyses have recently investigated these issues. An article in The Lancet evaluated eight studies on dialysis patients (n = 1679). It concluded that antihypertensives are beneficial in reducing cardiovascular morbidity and mortality. However, we criticize these conclusions and show that the data are not convincingly in favor of antihypertensive treatment. A meta-analysis in the American Heart Journal assessed the role of antihypertensive agents and RAA system modifying drugs in 45,758 patients (from 25 studies), who were in stages I-III of renal failure, i.e., not (yet) requiring dialysis. The authors claim that angiotensin- -converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARB) significantly reduced cardiovascular outcomes. However, our analysis of the data is not consistent with their conclusions. It showed that the results were quite mixed, that the authors may have overemphasized the positive results, and that considering all the results, it should be concluded that antihypertensive treatments, including those with ACEI/ARB, may not be superior to placebo (sic!) in renal patients. Rather than doing meta-analyses, larger primary studies are needed to reveal the real role of antihypertensive treatments in renal patients.

Single-molecule manipulation studies have revealed that double-stranded DNA undergoes a structural transition when subjected to tension. At forces that depend on the attachment geometry of the DNA (65 pN or 110 pN), it elongates ≈1.7-fold and its elastic properties change dramatically. The nature of this overstretched DNA has been under debate. In one model, the DNA cooperatively unwinds, while base pairing remains intact. In a competing model, the hydrogen bonds between base pairs break and two single DNA strands are formed, comparable to thermal DNA melting. Here, we resolve the structural basis of DNA overstretching using a combination of fluorescence microscopy, optical tweezers, and microfluidics. In DNA molecules undergoing the transition, we visualize double- and single-stranded segments using specific fluorescent labels. Our data directly demonstrate that overstretching comprises a gradual conversion from double-stranded to single-stranded DNA, irrespective of the attachment geometry. We found that these conversions favorably initiate from nicks or free DNA ends. These discontinuities in the phosphodiester backbone serve as energetically favorable nucleation points for melting. When both DNA strands are intact and no nicks or free ends are present, the overstretching force increases from 65 to 110 pN and melting initiates throughout the molecule, comparable to thermal melting. These results provide unique insights in the thermodynamics of DNA and DNA-protein interactions.

Cyclic voltammetry was employed to determine the formal reduction potential and heterogeneous electrontransfer rate constant of cytochrome c immobilized on three different metal substrates chemically modified with 11- mercaptoundoecanoic acid. The metal substrates include smooth gold and silver electrodes as well as nanoscopically rough silver electrodes obtained via an oxidation-reduction cycle. Electrode roughening followed a protocol typically employed to prepare surface-enhanced Raman active surfaces such that the electrochemical results can be compared with those determined by surface-enhanced resonance Raman spectroscopy of cytochrome c. The roughness of the surfaces was estimated by means of atomic force microscopy. For all systems midpoint potentials were found to be -0.068 V (vs SCE), although for rough silver electrode the midpoint potential slightly shifted in time from -0.051 V to -0.068 V within 24 h. The heterogeneous electron-transfer rate constants differ for the various metal substrates and were found to be smaller by a factor of 2.5 for the rough and smooth Ag substrates compared to Au electrodes. These findings imply that it is primarily the kind of metal rather than its surface morphology that controls the thermodynamics and kinetics of interfacial redox processes of immobilized cytochrome c. The present paper reconciles the partly conflicting results obtained by electrochemical methods, usually done on Au, and surface-enhanced resonance Raman spectroscopic techniques which are usually performed on Ag electrodes. © 2009 American Chemical Society.

The possibility of controlling unimolecular–dissociation processes with multiple laser fields in the collisional regime is examined. Employing the Bloch equations to describe optical excitation and decay processes, optimal control theory is used to design amplitude modulated fields which produce the desired excited‐state products. The selectivity of the product distribution of a simple four‐state photodissociation system is shown to have a square‐root dependence on the relative value of the mean dephasing time T2 to the pulse length τ, i.e, (T2/τ)1/2. The equivalence between T2 decay and phase disruptions occurring in a random‐walk fashion is also examined. In the Appendix it is shown that the essential effect of the system temperature is to introduce a Boltzmann population factor on the product selectivity without affecting the nature of the optimal field.

Ion channels in the apical cell membrane of monolayers of rabbit renal collecting duct principal cells in primary culture were investigated with the patch-clamp technique. Besides three or more types of cation channels published previously, three types of anion channels were observed. Most frequent was an outwardly rectifying Cl– selective channel with the slope conductance of 30.4 ± 4.8 pS (n = 6) in symmetrical isotonic NaCl solutions at 0 mV holding potential. This channel was only observed in excised patches. Its open probability was independent of the calcium concentration at the cytoplasmic surface of the membrane patch. The channel had complex open/close kinetics and was blocked by 5-nitro-2-(3-phenylpropylamino) benzoic acid from the extracellular surface. Inhibition increased at more cytoplasm-positive membrane potentials. Secondly, a high conductance, poorly selective anion channel was observed. It had a linear current voltage (I/V) relation with a conductance of 267 ± 46 pS (n = 4) and exhibited at least four substates. The open probability of this channel decreased sharply with increasing membrane potentials of either polarity. Thirdly, and least frequently, a bursting Cl– selective channel was observed which displayed a peculiar I/V relation in isotonic NaCl solutions. Near 0 mV it had a slope conductance of ≈ 50 pS which increased to 113 ± 11 pS (n = 4) at potentials exceeding ± 50 mV. Since the peritubular cell membrane of principal cells is Cl– permeable, it is conceivable that one or more of these channels contribute to collecting duct Cl– absorption particularly in situations in which the luminal Cl– concentration and the transepithelial potential difference are high.

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections. The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing their Clostridium difficile infection (CDI) prevention efforts. Refer to the Society for Healthcare Epidemiology of America/Infectious Diseases Society of America “Compendium of Strategies to Prevent Healthcare-Associated Infections” Executive Summary and Introduction and accompanying editorial for additional discussion.1. Increasing rates of CDIC. difficile now rivals methicillin-resistant Staphylococcus aureus (MRSA) as the most common organism to cause healthcare-associated infections in the United States.a. In the United States, the proportion of hospital discharges in which the patient received the International Classification of Diseases, Ninth Revision discharge diagnosis code for CDI more than doubled between 2000 and 2003, and CDI rates continued to increase in 2004 and 2005 (L. C. McDonald, MD, personal communication, July 2007). These increases have been seen in pediatric and adult populations, but elderly individuals have been disproportionately affected. CDI incidence has also increased in Canada and Europe.b. There have been numerous reports of an increase in CDI severity.c. Most reports of increases in the incidence and severity of CDI have been associated with the BI/NAP1/027 strain of C. difficile. This strain produces more toxins A and B in vitro than do many other strains of C. difficile, produces a third toxin (binary toxin), and is highly resistant to fluoroquinolones.

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections. The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals to implement and prioritize their surgical site infection (SSI) prevention efforts. Refer to the Society for Healthcare Epidemiology of America/Infectious Diseases Society of America “Compendium of Strategies to Prevent Healthcare-Associated Infections” Executive Summary and Introduction and accompanying editorial for additional discussion.1. Burden of SSIs as complications in acute care facilities.a. SSIs occur in 2%-5% of patients undergoing inpatient surgery in the United States.b. Approximately 500,000 SSIs occur each year.2. Outcomes associated with SSIa. Each SSI is associated with approximately 7-10 additional postoperative hospital days.b. Patients with an SSI have a 2-11 times higher risk of death, compared with operative patients without an SSI.i. Seventy-seven percent of deaths among patients with SSI are direcdy attributable to SSI.c. Attributable costs of SSI vary, depending on the type of operative procedure and the type of infecting pathogen; published estimates range from $3,000 to $29,000.i. SSIs are believed to account for up to $10 billion annually in healthcare expenditures.1. Definitionsa. The Centers for Disease Control and Prevention National Nosocomial Infections Surveillance System and the National Healthcare Safety Network definitions for SSI are widely used.b. SSIs are classified as follows (Figure):i. Superficial incisional (involving only skin or subcutaneous tissue of the incision)ii. Deep incisional (involving fascia and/or muscular layers)iii. Organ/space

Preventable healthcare-associated infections (HAIs) occur in US hospitals. Preventing these infections is a national priority, with initiatives led by healthcare organizations, professional associations, government and accrediting agencies, legislators, regulators, payers, and consumer advocacy groups. To assist acute care hospitals in focusing and prioritizing efforts to implement evidence-based practices for prevention of HAIs, the Society for Healthcare Epidemiology of America and the Infectious Diseases Society of America Standards and Practice Guidelines Committee appointed a task force to create a concise compendium of recommendations for the prevention of common HAIs. This compendium is implementation focused and differs from most previously published guidelines in that it highlights a set of basic HAI prevention strategies plus special approaches for use in locations and/or populations within the hospital when infections are not controlled by use of basic practices, recommends that accountability for implementing infection prevention practices be assigned to specific groups and individuals, and includes proposed performance measures for internal quality improvement efforts.

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections. The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing their central line–associated bloodstream infection (CLABSI) prevention efforts. Refer to the Society for Healthcare Epidemiology of America/Infectious Diseases Society of America “Compendium of Strategies to Prevent Healthcare-Associated Infections” Executive Summary and Introduction and accompanying editorial for additional discussion.1. Patients at risk for CLABSIs in acute care facilitiesa. Intensive care unit (ICU) population: The risk of CLABSI in ICU patients is high. Reasons for this include the frequent insertion of multiple catheters, the use of specific types of catheters that are almost exclusively inserted in ICU patients and associated with substantial risk (eg, arterial catheters), and the fact that catheters are frequently placed in emergency circumstances, repeatedly accessed each day, and often needed for extended periods.b. Non-ICU population: Although the primary focus of attention over the past 2 decades has been the ICU setting, recent data suggest that the greatest numbers of patients with central lines are in hospital units outside the ICU, where there is a substantial risk of CLABSI.2. Outcomes associated with hospital-acquired CLABSIa. Increased length of hospital stayb. Increased cost; the non-inflation-adjusted attributable cost of CLABSIs has been found to vary from $3,700 to $29,000 per episode

Leben ist Reisen und Reisen ist Leben, so oder ahnlich ein Wort von Jean Paul. Ruhelos ist unser Herz, klagt Augustinus in der ersten Autobiographie der Weltgeschichte. Von Kindesbeinen an laufen wir; Laufen lernen ist die erste grosse Herausforderung fur die kleinen Menschlein. Wer laufen gelernt hat, lauft dann taglich, vom Schlaf- ins Badezimmer, vom Wohnraum in die Kuche oder umgekehrt. Bald droht der Schulweg, spater der Weg zur Arbeit. Man beginnt mit Lust auf die Berge oder durch Stadte zu laufen und fruh kommt das Gefahrenwerden, spater — ein triumphaler Schritt — das selber Fahren hinzu. Nicht nur zur Arbeit, sondern in die Ferien, zu Freunden und Bekannten, an Anlassen wie Konzerte oder Einladungen. Zwischen zielorientierte und zweckgerichtete, also entschlossene Ortsveranderungen und Reisen schieben sich im Verlaufe des Erwachsenwerdens zunehmend ungerichtete, unsystematische und unmethodische Bewegungen: Herumbummeln in der Wohnung, Herumtreiben in den Stadten, Flanieren in Supermarkten, Stobern in Buchhandlungen und, wie Elfriede Jelinek es einmal genannt hat: Herumtigern in sich selbst.

One-phonon ionization of donors in germanium via intervalley scattering by slow TA phonons at the X point of the Brillouin zone is demonstrated by the stress dependence of phonoconductivity. Superconducting aluminum junctions are used as tunable quasimonochromatic phonon sources up to these extreme frequencies. The ionization probability is found to be increased when donor levels associated with stress-shifted higher valleys of the conduction band cross the lowest valley(s).

The apical cell membrane of cultured monolayers of collecting duct principal cells was investigated with the patch-clamp technique to study single ion channels. A broad spectrum of channel events was observed which complicated the analysis. Although principal cells absorb mainly Na+ ions and although most patches must have contained an Na+ conductance as evidenced by asymmetric clamp currents in the presence of amiloride, single Na+ channel events could not be identified with certainty, possibly because single-channel conductance was too low (≤5pS). Instead, non-selective cation channels of 21.2 ± 4.0 pS were frequently observed. They were impermeable to choline and anions but did not discriminate between Na+ and K+. These channels, however, do not appear to participate in active Na+ absorption. Different types of K+ channels were observed: a high-conductance Ca2+-activated K+ channel and a bursting low-conductance K+ channel. Since the former channel has been denied a role in K+ secretion/ absorption in native collecting ducts, the latter might be involved. In addition three types of CΓ channels have been observed which will be described separately. At least one of those, a 30-pS outwardly rectifying Cl- channel appears to allow small amounts of Cl- ions to be absorbed across principal cells.

Our objective was to determine the role of the Rho-associated kinase (ROK) for the regulation of FBF (FBF) and to unmask a potential role of ROK for the regulation of endothelium-derived nitric oxide (NO). Moreover, the effect of fasudil on the constrictor response to endothelin-1 was recorded. Regarding background, phosphorylation of the myosin light chain (MLC) determines the calcium sensitivity of the contractile apparatus. MLC phosphorylation depends on the activity of the MLC kinase and the MLC phosphatase. The latter enzyme is inhibited through phosphorylation by ROK. ROK has been suggested to inhibit NO generation, possibly via the inhibition of the Akt pathway. In this study, the effect of intra-arterial infusion of the ROK inhibitor fasudil on FBF in 12 healthy volunteers was examined by venous occlusion plethysmography. To unmask the role of NO, fasudil was infused during NO clamp. As a result, fasudil markedly increased FBF in a dose-dependent manner from 2.34 ± 0.21 to 6.96 ± 0.93 ml/100 ml forearm volume at 80 μg/min ( P < 0.001). At 1,600 μg/min, fasudil reduced systolic, diastolic, and mean arterial pressure while increasing heart rate. Fasudil abolished the vasoconstrictor effect of endothelin-1. The vascular response to fasudil (80 μmol/min) was blunted during NO clamp (104 ± 18% vs. 244 ± 48% for NO clamp + fasudil vs. fasudil alone; data as ratio between infused and noninfused arm with baseline = 0%, P < 0.05). In conclusion, 1) basal peripheral and systemic vascular tone depends on ROK; 2) a significant portion of fasudil-induced vasodilation is mediated by NO, suggesting that vascular bioavailable NO is negatively regulated by ROK; and 3) the constrictor response to endothelin involves the activation of ROK.

We present an approach to measure the angular dependence of the diffusely scattered intensity of a multiple scattering sample in backscattering geometry. Increasing scattering strength give rise to an increased width of the coherent backscattering and sets higher demands on the angular detection range. This is of particular interest in the search for the transition to Anderson localization of light. To cover a range of -60° to +85° from direct back-reflection, we introduced a new parallel intensity recording technique. This allows one-shot measurements, with fast alignment and short measuring time, which prevents the influence of illumination variations. Configurational average is achieved by rotating the sample and singly scattered light is suppressed with the use of circularly polarized light up to 97%. This implies that backscattering enhancements of almost two can be achieved. In combination with a standard setup for measuring small angles up to plusmn;3°, a full characterization of the coherent backscattering cone can be achieved. With this setup we are able to accurately determine transport mean free paths as low as 235 nm. © 2007 American Institute of Physics.

The GATT/WTO Settlement System by Ernst-Ulrich Petersmann. Published by Kluwer Law International, Dordrecht (1997, xvii + 344 pp ). Softback. Price £60. ISBN 90-411-0933-1. Readers of this publication will require little persuasion as to the importance of international arbitration to the conduct of world trade. It may be taken almost as axiomatic that arbitration between private parties facilitates international trade by making available neutral tribunals in which the parties are prepared to place their confidence. Accordingly, disputes, as and when they arise, can be resolved predictably and the arbitrators' awards will be enforceable internationally through the framework of the New York Convention. The use to which arbitration can be put has even been extended in the investment area Covered by the Energy Charter Treaty, so as to permit private investors to compel arbitration against host states (an exciting development, as discussed in (1996) 12 Arbitration International 429). All these dispute resolution techniques assume access to the market in question in the first place. The value of the book now under review is that it offers an introduction to the dispute settlement system of the World Trade Organization (WTO), which addresses these questions of market access. As this may well be an area not over-familiar even to relatively experienced arbitration practitioners, the book has the potential to make a significant contribution to the development of a rounded knowledge of dispute resolution in international trade. The author, Ernst-Ulrich Petersmann, writes with obvious knowledge of his subject-matter and the authority of his position as Legal Adviser to the WTO (and previously to GATT). The agreement establishing the WTO came into force on 1 January 1995, following the completion of the marathon Uruguay Round of multilateral trade negotiations (1986–1994). The WTO …

Background Hyponatremia (serum sodium concentration

High-density server facilities have quickly become a widespread reality. Not only are they adding nearly 1 GW to the US economy load, but many of these major data centers are using this increase in power in a way that exceeds all market expectations. Past predictions for high-density servers racks in the year 2006 showed loads in the neighborhood of 8KW, but today's reality shows it is in the magnitude of 300% higher ? and in some case even more, racks of 35KW are installed and commissioned. Why are we so far ahead of the forecast for needed energy? Power-hungry processors and super-charged servers.

Hyponatremia is a frequent and symptomatic electrolyte disorder for which specific treatments have been lacking. Hyponatremia is attributable to nonosmotic vasopressin stimulation and continued increased fluid intake. In the past, peptidic derivatives of arginine vasopressin proved that blockade of vasopressin V-2 receptors served to improve hyponatremia, however, these antagonists had intrinsic agonistic activity, too. In the past decade, random screening of molecules uncovered nonpeptide, orally available vasopressin antagonists without agonistic properties. The agents show competitive binding to the vasopressin V-2 receptor at an affinity comparable with that of arginine vasopressin. Four antagonists have undergone extensive study. Three of these agents--lixivaptan or VPA 985; SR 121 463 B; tolvaptan or OPC 41,061--are specific V-2 antagonists whereas conivaptan or YM 087 is a V-1/V-2 mixed antagonist. In animal and clinical studies all of the agents were able to correct water retention and hyponatremia in a dose-dependent manner. There was no tachyphylaxis, even when the agents were given over many weeks. It is expected that the clinical use of the agents will lead to a major improvement in the treatment of hyponatremia.

Diffusive transport is among the most common phenomena in nature [1]. However, as predicted by Anderson [2], diffusion may break down due to interference. This transition from diffusive transport to localization of waves should occur for any type of classical or quantum wave in any media as long as the wavelength becomes comparable to the transport mean free path $\ell^*$ [3]. The signatures of localization and those of absorption, or bound states, can however be similar, such that an unequivocal proof of the existence of wave localization in disordered bulk materials is still lacking. Here we present measurements of time resolved non-classical diffusion of visible light in strongly scattering samples, which cannot be explained by absorption, sample geometry or reduction in transport velocity. Deviations from classical diffusion increase strongly with decreasing $\ell^*$ as expected for a phase transition. This constitutes an experimental realization of the critical regime in the approach to Anderson localization., Comment: 5 pages, 4 figures