bluuebunny/crossref_metadata_2025 huggingface dataset:
Adverse Drug Events and Associated Factors in Heart Failure Therapy Among the Very Elderly
Authors: Sztramko Richard , Chau Vicky , Wong Roger
Published: January 2012

IntroductionHeart failure (HF) is common in older adults and standard therapy involves the use of multiple medications. We assessed the nature, frequency, and factors associated with adverse drug events (ADEs) associated with standard HF therapy among older adults greater than 75 years of age. The efficacy and predictors of ADEs were assessed in this patient population, as well.MethodsSystematic review using standardized databases including MEDLINE, Ageline, and CINAHL from January 1st 1988 to January 1st, 2010 and references from published literature. Randomized trials and studies with observational, cohort, and cross-sectional design were included. Two investigators independently selected the studies and extracted the data (kappa = 0.86).ResultsTwenty-five studies were identified. ADEs were reported in 13/23 (57%) studies. Syncope, bradycardia, and hypotension as a result of beta blockers occurred in greater frequency compared to younger populations. Spironolactone therapy resulted in increased rates of hyperkalemia, acute renal failure, and medication discontinuation. Factors associated with ADEs included advanced age, poor left ventricular function, and increasing New York Heart Association Class. Efficacy of beta blockers and ACE inhibitors appears to extend to the elderly population, but the magnitude of effect size is unclear. Very few studies reported associations between ADE and patients’ comorbidities (4/13 studies, 31%) or functional status (3/13 studies, 23%).ConclusionADEs in CHF therapy among the very elderly occurred at a greater frequency, but were generally poorly characterized in the literature despite a relatively common occurrence. Further studies are warranted.
Capture of Fluorescence Decay Times by Flow Cytometry
Authors: Houston Jessica P. , Naivar Mark A. , Jenkins Patrick , Freyer James P.
Published: January 2012

In flow cytometry, the fluorescence decay time of an excitable species has been largely underutilized and is not likely found as a standard parameter on any imaging cytometer, sorting, or analyzing system. Most cytometers lack fluorescence lifetime hardware mainly owing to two central issues. Foremost, research and development with lifetime techniques has lacked proper exploitation of modern laser systems, data acquisition boards, and signal processing techniques. Secondly, a lack of enthusiasm for fluorescence lifetime applications in cells and with bead‐based assays has persisted among the greater cytometry community. In this unit, new approaches that address these issues and demonstrate the simplicity of digitally acquiring fluorescence relaxation rates in flow cytometry are described. This unit provides protocols and a Commentary section describing a most comprehensive discourse on acquiring the fluorescence lifetime with frequency‐domain methods. This unit covers (1) standard fluorescence lifetime acquisition (protocol‐based) with frequency‐modulated laser excitation, (2) digital frequency‐domain cytometry analyses, and (3) interfacing fluorescence lifetime measurements onto sorting systems. This unit also discusses how digital methods are used for aliasing to harness higher frequency ranges. Also, a final discussion is provided on heterodyning and processing of waveforms for multi‐exponential decay extraction. Curr. Protoc. Cytom. 59:1.25.1‐1.25.21. © 2012 by John Wiley & Sons, Inc.
Practical Methods for Molecular In Vivo Optical Imaging
Authors: Chen Hannah , Thorne Stephen H.
Published: January 2012

Traditional approaches for translating observations of molecular events into the context of a living organism have suffered from the requirements for either sacrificing animals at multiple time points prior to labor‐intensive analyses of multiple tissues, or have relied on subjective observations or measurements of the animals over time. Recently, a plethora of dedicated animal‐imaging modalities and the release of modified clinical imaging devices dedicated for animal imaging have allowed for the design of quantitative real‐time experiments incorporating fewer animals and providing whole‐animal analyses. Of these modalities, optical imaging (bioluminescence and fluorescence) has emerged as a powerful research tool, allowing investigators with limited whole‐animal imaging expertise to rapidly and inexpensively translate models produced in cellular assays into the context of a living animal. Here we will outline the steps necessary for translation of models established in culture systems into rodents. Curr. Protoc. Cytom. 59:12.24.1‐12.24.11. © 2012 by John Wiley & Sons, Inc.
Wnt‐Notch signalling: An integrated mechanism regulating transitions between cell states
Authors: Muñoz‐Descalzo Silvia , de Navascues Joaquin , Arias Alfonso Martinez
Published: January 2012

The activity of Wnt and Notch signalling is central to many cell fate decisions during development and to the maintenance and differentiation of stem cell populations in homeostasis. While classical views refer to these pathways as independent signal transduction devices that co‐operate in different systems, recent work has revealed intricate connections between their components. These observations suggest that rather than operating as two separate pathways, elements of Wnt and Notch signalling configure an integrated molecular device whose main function is to regulate transitions between cell states in development and homeostasis. Here, we propose a general framework for the structure and function of the interactions between these signalling systems that is focused on the notion of ‘transition states’, i.e. intermediates that arise during cell fate decision processes. These intermediates act as checkpoints in cell fate decision processes and are characterised by the mixed molecular identities of the states involved in these processes.

Editor's suggested further reading in BioEssays: Notch: Implications of endogenous inhibitors for therapy Abstract
Cytoskeletal Dynamics and Lung Fluid Balance
Authors: Vogel Stephen M. , Malik Asrar B.
Published: January 2012

This article examines the role of the endothelial cytoskeleton in the lung's ability to restrict fluid and protein to vascular space at normal vascular pressures and thereby to protect lung alveoli from lethal flooding. The barrier properties of microvascular endothelium are dependent on endothelial cell contact with other vessel‐wall lining cells and with the underlying extracellular matrix (ECM). Focal adhesion complexes are essential for attachment of endothelium to ECM. In quiescent endothelial cells, the thick cortical actin rim helps determine cell shape and stabilize endothelial adherens junctions and focal adhesions through protein bridges to actin cytoskeleton. Permeability‐increasing agonists signal activation of “small GTPases” of the Rho family to reorganize the actin cytoskeleton, leading to endothelial cell shape change, disassembly of cortical actin rim, and redistribution of actin into cytoplasmic stress fibers. In association with calcium‐ andSrc‐regulated myosin light chain kinase (MLCK), stress fibers become actinomyosin‐mediated contractile units. Permeability‐increasing agonists stimulate calcium entry and induce tyrosine phosphorylation of VE‐cadherin (vascular endothelial cadherin) and β‐catenins to weaken or pull apart endothelial adherens junctions. Some permeability agonists cause latent activation of the small GTPases, Cdc42 and Rac1, which facilitate endothelial barrier recovery and eliminate interendothelial gaps. Under the influence of Cdc42 and Rac1, filopodia and lamellipodia are generated by rearrangements of actin cytoskeleton. These motile evaginations extend endothelial cell borders across interendothelial gaps, and may initiate reannealing of endothelial junctions. Endogenous barrier protective substances, such as sphingosine‐1‐phosphate, play an important role in maintaining a restrictive endothelial barrier and counteracting the effects of permeability‐increasing agonists. © 2012 American Physiological Society.Compr Physiol2:449‐478, 2012.
Peripheral Chemoreceptors: Function and Plasticity of the Carotid Body
Authors: Kumar Prem , Prabhakar Nanduri R.
Published: January 2012

The discovery of thesensorynature of the carotid body dates back to the beginning of the 20th century. Following these seminal discoveries, research into carotid body mechanisms moved forward progressively through the 20th century, with many descriptions of the ultrastructure of the organ and stimulus‐response measurements at the level of the whole organ. The later part of 20th century witnessed the first descriptions of the cellular responses and electrophysiology of isolated and cultured type I and type II cells, and there now exist a number of testable hypotheses of chemotransduction. The goal of this article is to provide a comprehensive review of current concepts on sensory transduction and transmission of the hypoxic stimulus at the carotid body with an emphasis on integrating cellular mechanisms with the whole organ responses and highlighting the gaps or discrepancies in our knowledge. It is increasingly evident that in addition to hypoxia, the carotid body responds to a wide variety of blood‐borne stimuli, including reduced glucose and immune‐related cytokines and we therefore also consider the evidence for a polymodal function of the carotid body and its implications. It is clear that the sensory function of the carotid body exhibits considerable plasticity in response to the chronic perturbations in environmental O2that is associated with many physiological and pathological conditions. The mechanisms and consequences of carotid body plasticity in health and disease are discussed in the final sections of this article. © 2012 American Physiological Society.Compr Physiol2:141‐219, 2012.
Mechanics and Function of the Pulmonary Vasculature: Implications for Pulmonary Vascular Disease and Right Ventricular Function
Authors: Lammers Steven , Scott Devon , Hunter Kendall , Tan Wei , Shandas Robin , Stenmark Kurt R.
Published: January 2012

The relationship between cardiac function and the afterload against which the heart muscle must work to circulate blood throughout the pulmonary circulation is defined by a complex interaction between many coupled system parameters. These parameters range broadly and incorporate system effects originating primarily from three distinct locations: input power from the heart, hydraulic impedance from the large conduit pulmonary arteries, and hydraulic resistance from the more distal microcirculation. These organ systems are not independent, but rather, form a coupled system in which a change to any individual parameter affects all other system parameters. The result is a highly nonlinear system which requires not only detailed study of each specific component and the effect of disease on their specific function, but also requires study of the interconnected relationship between the microcirculation, the conduit arteries, and the heart in response to age and disease. Here, we investigate systems‐level changes associated with pulmonary hypertensive disease progression in an effort to better understand this coupled relationship. © 2012 American Physiological Society.Compr Physiol2:295‐319, 2012.
Phylogenetic Analyses: Comparing Species to Infer Adaptations and Physiological Mechanisms
Authors: Rezende Enrico L. , Diniz‐Filho José Alexandre F.
Published: January 2012

Comparisons among species have been a standard tool in animal physiology to understand how organisms function and adapt to their surrounding environment. During the last two decades, conceptual and methodological advances from different fields, including evolutionary biology and systematics, have revolutionized the way comparative analyses are performed, resulting in the advent of modern phylogenetic statistical methods. This development stems from the realization that conventional analytical methods assume that observations are statistically independent, which is not the case for comparative data because species often resemble each other due to shared ancestry. By taking evolutionary history explicitly into consideration, phylogenetic statistical methods can account for the confounding effects of shared ancestry in interspecific comparisons, improving the reliability of standard approaches such as regressions or correlations in comparative analyses. Importantly, these methods have also enabled researchers to address entirely new evolutionary questions, such as the historical sequence of events that resulted in current patterns of form and function, which can only be studied with a phylogenetic perspective. Here, we provide an overview of phylogenetic approaches and their importance for studying the evolution of physiological processes and mechanisms. We discuss the conceptual framework underlying these methods, and explain when and how phylogenetic information should be employed. We then outline the difficulties and limitations inherent to comparative approaches and discuss potential problems researchers may encounter when designing a comparative study. These issues are illustrated with examples from the literature in which the incorporation of phylogenetic information has been useful, or even crucial, for inferences on how species evolve and adapt to their surrounding environment. © 2012 American Physiological Society.Compr Physiol2:639‐674, 2012.
Pulmonary Circulation at Exercise
Authors: Naeije Robert , Chesler N.
Published: January 2012

The pulmonary circulation is a high‐flow and low‐pressure circuit, with an average resistance of 1 mmHg/min/L in young adults, increasing to 2.5 mmHg/min/L over four to six decades of life. Pulmonary vascular mechanics at exercise are best described by distensible models. Exercise does not appear to affect the time constant of the pulmonary circulation or the longitudinal distribution of resistances. Very high flows are associated with high capillary pressures, up to a 20 to 25 mmHg threshold associated with interstitial lung edema and altered ventilation/perfusion relationships. Pulmonary artery pressures of 40 to 50 mmHg, which can be achieved at maximal exercise, may correspond to the extreme of tolerable right ventricular afterload. Distension of capillaries that decrease resistance may be of adaptative value during exercise, but this is limited by hypoxemia from altered diffusion/perfusion relationships. Exercise in hypoxia is associated with higher pulmonary vascular pressures and lower maximal cardiac output, with increased likelihood of right ventricular function limitation and altered gas exchange by interstitial lung edema. Pharmacological interventions aimed at the reduction of pulmonary vascular tone have little effect on pulmonary vascular pressure‐flow relationships in normoxia, but may decrease resistance in hypoxia, unloading the right ventricle and thereby improving exercise capacity. Exercise in patients with pulmonary hypertension is associated with sharp increases in pulmonary artery pressure and a right ventricular limitation of aerobic capacity. Exercise stress testing to determine multipoint pulmonary vascular pressures‐flow relationships may uncover early stage pulmonary vascular disease. © 2012 American Physiological Society.Compr Physiol2:711‐741, 2012.
Regulation of Ion Channels by Membrane Lipids
Authors: Rosenhouse‐Dantsker Avia , Mehta Dolly , Levitan Irena
Published: January 2012

The major membrane lipid regulators of ion channel function includecholesterol, one of the main lipid components of the plasma membranes,phosphoinositides, a group of regulatory phospholipids that constitute a minor component of the membrane lipids but are known to play key roles in regulation of multiple proteins andsphingolipids, particularlysphingosine‐1‐phosphate, a signaling biolipid that is generated from ceramide and is known to regulate multiple cellular functions. Furthermore, specific effects of all the lipid modulators are highly heterogeneous varying significantly between different types of ion channels, as well as between different cell types. In terms of the mechanisms, three general mechanisms have been shown to underlie lipid regulation of ion channels: specific lipid‐protein interactions, changes in the physical properties of the membrane, and facilitating the association of the channel proteins with other regulatory proteins within multiproteins signaling complexes termed membrane rafts. In this article, we present comprehensive analysis of the roles of several lipid modulators, including cholesterol, bile acids, phosphoinositides, and sphingolipids on ion channel function. © 2012 American Physiological Society.Compr Physiol2:31‐68, 2012.
Bioenergetics of Exercising Humans
Authors: Brooks George A.
Published: January 2012

Human muscles, limbs and supporting ventilatory, cardiovascular, and metabolic systems are well adapted for walking, and there is reasonable transfer of efficiency of movement to bicycling. Our efficiency and economy of movement of bipedal walking (≈30%) are far superior to those of apes. This overall body efficiency during walking and bicycling represents the multiplicative interaction of a phosphorylative coupling efficiency of ≈60%, and a mechanical coupling efficiency of ≈50%. These coupling efficiencies compare well with those of other species adapted for locomotion. We are capable runners, but our speed and power are inferior to carnivorous and omnivorous terrestrial mammalian quadrupeds because of biomechanical and physiological constraints. But, because of our metabolic plasticity (i.e., the ability to switch among carbohydrate (CHO)‐ and lipid‐derived energy sources) our endurance capacity is very good by comparison to most mammals, but inferior to highly adapted species such as wolves and migratory birds. Our ancestral ability for hunting and gathering depends on strategy and capabilities in the areas of thermoregulation, and metabolic plasticity. Clearly, our competitive advantage of survival in the biosphere depends in intelligence and behavior. Today, those abilities that served early hunter‐gatherers make for interesting athletic competitions due to wide variations in human phenotypes. In contemporary society, the stresses of regular physical exercise serve to minimize morbidities and mortality associated with physical inactivity, overnutrition, and aging. © 2012 American Physiological Society.Compr Physiol2:537‐562, 2012.
Motility, Survival, and Proliferation
Authors: Gerthoffer William T. , Schaafsma Dedmer , Sharma Pawan , Ghavami Saeid , Halayko Andrew J.
Published: January 2012

Airway smooth muscle has classically been of interest for its contractile response linked to bronchoconstriction. However, terminally differentiated smooth muscle cells are phenotypically plastic and have multifunctional capacity for proliferation, cellular hypertrophy, migration, and the synthesis of extracellular matrix and inflammatory mediators. These latter properties of airway smooth muscle are important in airway remodeling which is a structural alteration that compounds the impact of contractile responses on limiting airway conductance. In this overview, we describe the important signaling components and the functional evidence supporting a view of smooth muscle cells at the core of fibroproliferative remodeling of hollow organs. Signal transduction components and events are summarized that control the basic cellular processes of proliferation, cell survival, apoptosis, and cellular migration. We delineate known intracellular control mechanisms and suggest future areas of interest to pursue to more fully understand factors that regulate normal myocyte function and airway remodeling in obstructive lung diseases. © 2012 American Physiological Society.Compr Physiol2:255‐281, 2012.
Neural Control of the Upper Airway: Integrative Physiological Mechanisms and Relevance for Sleep Disordered Breathing
Authors: Horner Richard L.
Published: January 2012

The various neural mechanisms affecting the control of the upper airway muscles are discussed in this review, with particular emphasis on structure‐function relationships and integrative physiological motor‐control processes. Particular foci of attention include the respiratory function of the upper airway muscles, and the various reflex mechanisms underlying their control, specifically the reflex responses to changes in airway pressure, reflexes from pulmonary receptors, chemoreceptor and baroreceptor reflexes, and postural effects on upper airway motor control. This article also addresses the determinants of upper airway collapsibility and the influence of neural drive to the upper airway muscles, and the influence of common drugs such as ethanol, sedative hypnotics, and opioids on upper airway motor control. In addition to an examination of these basic physiological mechanisms, consideration is given throughout this review as to how these mechanisms relate to integrative function in the intact normal upper airway in wakefulness and sleep, and how they may be involved in the pathogenesis of clinical problems such obstructive sleep apnea hypopnea. © 2012 American Physiological Society.Compr Physiol2:479‐535, 2012.
TRPChannels
Authors: Gees Maarten , Owsianik Grzegorz , Nilius Bernd , Voets Thomas
Published: January 2012

TRP channels constitute a large superfamily of cation channel forming proteins, all related to the gene product of the transient receptor potential (trp) locus inDrosophila. In mammals, 28 different TRP channel genes have been identified, which exhibit a large variety of functional properties and play diverse cellular and physiological roles. In this article, we provide a brief and systematic summary of expression, function, and (patho)physiological role of the mammalian TRP channels. © 2012 American Physiological Society.Compr Physiol2:563‐608, 2012.
Cryo‐EM in the Study of Membrane Transport Proteins
Authors: Kim Laura Yaunhee , Johnson Matthew C. , Schmidt‐Krey Ingeborg
Published: January 2012

Electron cryomicroscopy (cryo‐EM) has evolved as a widely used approach to understand a range of structure‐function questions, particularly of membrane proteins. Studies by both electron crystallography and single particle analysis have provided a wealth of information on membrane transport proteins. Cryo‐EM methods with an emphasis on electron crystallography, which has yielded the most membrane transport protein structural information of any of the cryo‐EM techniques, are described here. Two‐dimensional crystallization approaches are outlined, as well as advances in cryo‐EM specimen preparation, data collection, and image processing. Examples of membrane transport protein structure described serve to illustrate some of the advances in both structural understanding and methods. Further examples outline impressive results that were obtained by a combination of electron crystallography and X‐ray crystallography as well as additional complementary methods. © 2012 American Physiological Society.Compr Physiol2:283‐293, 2012.
Micropuncture of the Kidney: A Primer on Techniques
Authors: Lorenz John N.
Published: January 2012

Techniques to evaluate renal function at the single nephron level have been instrumental and indispensible in furthering our understanding of the mammalian kidney. Techniques that were first introduce in the 1920s, and later refined in the 1950s and 1960s, permit sophisticated interrogation of glomerular filtration and hemodynamics, and tubular epithelial transport activity. Much of what we know about the physiology and pathophysiology of the kidney has been produced or, to some degree, confirmed by renal micropuncture. While micropuncture is perhaps not as widely employed as before, it remains an essential tool for comprehensive evaluation of kidney function, particularly in this age of genetically pliable experimental models. This review aims to provide a introduction to common methodologies and approaches used to conduct micropuncture experiments. Topics covered include instrumentation and equipment, pipet fabrication techniques, animal preparation, and experimental procedures for evaluating single nephron hemodynamics and tubular function. © 2012 American Physiological Society.Compr Physiol2:621‐637, 2012.
Weight loss/maintenance as an effective tool for controlling type 2 diabetes: novel methodology to sustain weight reduction
Authors: Gage Dennis
Published: January 2012

The type 2 diabetes epidemic closely parallels the obesity epidemic. Although weight loss is frequently initiated successfully, most patients regain substantial amounts of weight within the first year after completing a weight loss programme. Several studies have shown success over time with weight loss and type 2 diabetes prevention and/or remission. These include the Diabetes Prevention Program and the Look AHEAD study. Novel approaches to weight management have recently found their way onto the internet.

With advances in medicine, there has been more patient success in the weight maintenance field. We review the Weight Management System that permits daily counselling to patients who have been losing or maintaining weight. The Weight Management System is a method that combines four fundamental elements: (1) remote daily weight monitoring by the system and the health professional; (2) daily feedback from the system and, when necessary, the health professional; (3) customized information for the needs and desires of the particular patient; and (4) a proprietary algorithm to detect early signs of weight regain. Recent beta testing of this system has confirmed Dr Rena Wing's statistics and has opened up a novel approach to long‐term weight management and diabetes prevention. Copyright © 2012 John Wiley & Sons, Ltd.
Utilizing soil indicators to explain historical vegetation changes of a peatland subjected to flood inundation
Authors: Blyth James M. , Campbell David I. , Schipper Louis A.
Published: January 2012

Flooding and land use changes can be a significant source of nutrients to wetlands and contribute to ecosystem changes at a community level. We studied changes in vegetation composition and peat properties in a New Zealand wetland incorporated into a flood control scheme. Lack of hydrological records pre‐development of the flood control scheme allowed the opportunity to use nutrient and physical indicators developed for restiad vegetation groups, to identify if increased flooding was the primary cause for ecological succession. Vegetation changes along a 2.3‐km transect were related to hydrological processes, peat characteristics and atmospheric ammonia inputs. Measurements for peat and vegetation composition were taken from 27 sites, whereas hydrological analysis incorporated seven automated water level sites and a historical investigation of 46 years of river flood records. Ammonia deposition was higher on the farmland/wetland fringe (4.0 kg N ha−1 year−1) but decreased to background levels (2–2.5 kg N ha−1 year−1) 500 m into the wetland. Classification and ordination of vegetation data with environmental variables identified six main groups along a gradient from low nutrients and stable water tables (farthest from the river) to high nutrients and a dynamic water table near the river. Invasion over 50 years of the native scrub tree Leptospermum scoparium into restiad bog was linked to enhanced nutrient inputs and physical degradation from flooding, portrayed through levels higher than restiad indicator target ranges. This study shows that target ranges for vegetation indicators can be used as a tool to identify ecological succession and invasion. Copyright © 2012 John Wiley & Sons, Ltd.
In Situ X‐ray Absorption Spectroscopy/Energy‐Dispersive X‐ray Diffraction Studies on the Hydrothermal Formation of Bi2W1–xMoxO6 Nanomaterials
Authors: Zhou Ying , Antonova Elena , Lin Yuanhua , Grunwaldt Jan‐Dierk , Bensch Wolfgang , Patzke Greta R.
Published: January 2012

Bi2WO6 has attracted considerable interest as a visible‐light‐driven photocatalyst with a layered Aurivillius structure. The catalytic performance of bismuth tungstate is notably enhanced through the partial substitution of tungsten with molybdenum. Whereas hydrothermally obtained Bi2W1–xMoxO6 solid solutions maintain the Bi2WO6 structure, their morphologies vary with the molybdenum content. Lower Mo contents (x < 0.5) favor the formation of hierarchically nanostructured microspheres that consist of sheet‐like building blocks. Their disintegration is observed for greater extents of W/Mo substitution, hand in hand with a decrease in the surface area. Raman spectra furthermore indicate changes in the local structure of the octahedral W/Mo moieties upon variation of the Mo content. As little is known about the growth kinetics and hydrothermal formation processes of nanostructured Bi2W1–xMoxO6 catalysts, in situ XAS investigations were performed to determine the onset of their hydrothermal formation from Bi(NO3)3·5H2O, K2WO4 andNa2MoO4. In situ energy‐dispersive X‐ray diffraction (EDXRD) experiments revealed a correlation between particle shape, Mo content and formation pathway of the Bi2W1–xMoxO6 nanomaterials. The results are compared to related in situ studies on hierarchically structured W/Mo oxides.
The bed morphology of upland single‐thread channels in semi‐arid environments: evidence of repeating bedforms and their wider implications for gravel‐bed rivers
Authors: Powell D Mark , Laronne Jonathan B , Reid Ian , Barzilai Ronel
Published: January 2012

Single‐thread, gravel‐bed streams of moderate slope in the northern Negev are characterized by three channel units: bars exhibit steeper than average slopes and poorly sorted mixtures of small–medium cobbles and coarse–very coarse pebbles; flats are associated with more gentle slopes and well‐sorted medium–fine pebbles and granules; and transitional units have intermediate slopes and grain size. In general, all three units are planar, span the full channel width and have well‐defined boundaries. Bars and flats are more common than the transitional units and alternate downstream for distances of several hundred metres, forming sequences that are reminiscent of the riffle–pool structure commonly observed in humid‐temperate gravel‐bed rivers. A notable contrast is the absence of significant bed relief: bars lack crests and flats lack depressions. The relative lack of bed relief in bar–flat sequences is attributed to the high rate of sediment supply from the sparsely vegetated hillslopes which promotes the infilling of depressions and to the erosion of crests under conditions of intense transport. This reduction of bed relief lowers channel roughness, which in turn increases flow velocity and, therefore, the ability of the channel to transmit the large sediment loads it receives. Although our analyses pertain to a semi‐arid river system, the results have wider implications for understanding the adjustment of channel bedform to high sediment loads in other fluvial environments. Copyright © 2012 John Wiley & Sons, Ltd.
Bed evolution measurement with flowing water in morphodynamics experiments
Authors: Visconti Francesco , Stefanon Luana , Camporeale Carlo , Susin Francesca , Ridolfi Luca , Lanzoni Stefano
Published: January 2012

A new approach for the profiling of movable sediment beds in laboratory experiments is presented. It couples a triangulation laser sensor and an ultrasonic level transmitter, and allows a non‐intrusive, fast and accurate measurement of bed topography without stopping the experimental runs. The distortion of the laser beam due to the refraction at the water surface is corrected by contemporaneously measuring the elevation of the water surface through the ultrasonic level transmitter and taking advantage of geometrical relations involving the water depth, distance of the sensors from the water surface, and the angles that the emitted laser beam forms with the vertical before and after refraction. Several tests, under either still‐ or flowing‐water conditions, as well as increasing/decreasing water surface elevation, were carried out to evaluate the accuracy of the measurements. These tests indicate that good‐quality measurements are obtained for flow depths in the range 0 < D < 60 mm, typical of morphodynamic laboratory experiments. Finally, two relevant applications to movable bed experiments carried out under either lagoonal or fluvial conditions are presented that show the effectiveness of the proposed profiling technique. Copyright © 2012 John Wiley & Sons, Ltd.
Tissue imprint for molecular mapping of deep surgical margins in patients with head and neck squamous cell carcinoma
Authors: Roh Jong–Lyel , Westra William H. , Califano Joseph A. , Sidransky David , Koch Wayne M.
Published: January 2012

Background

Tissue imprinting can generate molecular marker maps of tumor cells at deep surgical margins. The purpose of this study was to evaluate the feasibility of this method for detection of residual head and neck squamous cell carcinoma (HNSCC).

Methods

Paired fresh tissue and nitrocellulose membrane imprints of tumor and deep margins were collected from 17 HNSCC resections. DNA was amplified using quantitative methylation‐specific polymerase chain reaction (qMSP) for p16, DCC, KIF1A, and EDNRB. Levels of methylation in tumors and deep margins were compared.

Results

DNA from imprints was adequate for qMSP. Hypermethylation of target genes was present in 12 of 17 tumors and in 8 deep margins. Methylation level was better from margin imprints than tissue. During follow‐up (median, 13 months), local or regional recurrences occurred in 6 cases of which 5 had molecularly positive margins.

Conclusion

Tissue imprinting is feasible for molecular detection of residual tumor at deep surgical margins and may correlate with locoregional recurrence. © 2012 Wiley Periodicals, Inc. Head Neck, 2012
Safety assessment of transgenic Bacillus thuringiensis rice T1c‐19 in Sprague–Dawley rats from metabonomics and bacterial profile perspectives
Authors: Cao Sishuo , He Xiaoyun , Xu Wentao , Luo YunBo , Yuan Yanfang , Liu Pengfei , Cao Bo , Shi Hui , Huang Kunlun
Published: January 2012

Bacillus thuringiensis rice is facing commercialization as the main food source in the near future. The unintended effects of genetically modified (GM) organisms are the most important barriers to their promotion. We aimed to establish a new in vivo evaluation model for genetically modified foods by using metabonomics and bacterial profile approaches. T1c‐19 rice flour or its transgenic parent MH63 was used at 70% wt/wt to produce diets that were fed to rats for ∼ 90 days. Urine metabolite changes were detected using 1H NMR. Denaturing gradient gel electrophoresis and real‐time polymerase chain reaction (RT‐PCR) were used to detect the bacterial profiles between the two groups. The metabonomics was analyzed for metabolite changes in rat urine, when compared with the non‐GM rice group, where rats were fed a GM rice diet. Several metabolites correlated with rat age and sex but not with GM rice diet. Significant biological differences were not identified between the GM rice diet and the non‐GM rice diet. The bacteria related to rat urine metabolites were also discussed. The results from metabonomics and bacterial profile analyses were comparable with the results attained using the traditional method. Because metabonomics and bacterial profiling offer noninvasive, dynamic approaches for monitoring food safety, they provide a novel process for assessing the safety of GM foods. © 2012 IUBMB IUBMB Life, 2012.
Effects of activating transcription factor 4 deficiency on carbohydrate and lipid metabolism in mammals
Authors: Wang Chunxia , Guo Feifan
Published: January 2012

It has been shown that the mammalian activating transcription factor 4 (ATF4) is involved in many different physiological events, such as eye development, stress response, learning, and memory. However, several recent studies have demonstrated that ATF4 also plays an important role in the regulation of lipid and glucose metabolism, energy homeostasis, insulin secretion, and sensitivity, suggesting that ATF4 is a master regulator of metabolism. This review summarizes the most recent progress in the understanding of the novel roles of ATF4 in the regulation of metabolism. © 2012 IUBMB IUBMB Life, 2012.
Effects of vegetation type on mercury concentrations and pools in two adjacent coniferous and deciduous forests
Authors: Obrist Daniel , Johnson Dale W. , Edmonds Robert L.
Published: January 2012

Vegetation type and ecosystem structure affect major aspects of the mercury (Hg) cycle in terrestrial ecosystems which serve as important storage pools for a long‐term legacy of natural and anthropogenic Hg release to the environment. The goal of this study was to evaluate the integrated effects of 80 y of different vegetative type on Hg accumulation and partitioning in terrestrial ecosystems by comparing Hg concentrations and pools of two adjacent forests: a coniferous Douglas fir (Pseudotsuga menziesii) and a deciduous red alder (Alnus rubra) stand. These stands grew for > 80 y in close proximity (200 m) with identical site histories, soil parent materials, and atmospheric exposure. Results showed that the Douglas fir stand was characterized by significantly higher Hg concentrations and Hg : C ratios in aboveground biomass compared to the deciduous red alder forest. For foliage, higher Hg concentrations (plus 43 μg kg–1) were expected due to foliage age, but Hg concentrations also were higher in woody tissues (by 2 to 18 μg kg–1) indicating increased uptake of atmospheric Hg by coniferous tissues. These differences were reflected—and further increased—in litter horizons where Hg‐concentration differences increased in highly decomposed litter to > 200 μg kg–1. In soils, no difference in concentrations of Hg was observed, but Hg : C ratios were consistently higher in the coniferous Douglas fir. Estimation of pool sizes of C and Hg in soils and at the whole ecosystem level showed that considerably smaller C pools in the coniferous stand as a result of faster C turnover and lower productivity did not lead to corresponding declines in Hg‐pool sizes. The partitioning of Hg among ecosystem components—including distribution between aboveground and belowground components and distribution through the soil profile—was largely unaffected by forest type. Methyl‐Hg concentrations observed in litter layers were also significantly higher in litter of Douglas fir, along with a higher proportion of methylated Hg of total Hg. In soils, methyl‐Hg concentrations were similar in both stands. Comparison of these adjacent forest stands highlights that vegetation type affects concentrations of total Hg in otherwise equivalent sites and that differences also exist in respect to methylated Hg.
Alleviation of drought stress in winter wheat by late foliar application of zinc, boron, and manganese
Authors: Karim Md. Rezaul , Zhang Yue‐Qiang , Zhao Rong‐Rong , Chen Xin‐Ping , Zhang Fu‐Suo , Zou Chun‐Qin
Published: January 2012

In many regions, drought during flowering and grain‐filling inhibits micronutrient acquisition by roots resulting in yield losses and low micronutrient concentrations in cereal grains. A field and a greenhouse experiment were conducted to study the effect of foliar applications of zinc (Zn), boron (B), and manganese (Mn) at late growth stages of winter wheat (Triticum aestivum L.) grown with or without drought stress from booting to maturity. Foliar applications of Zn, B, and Mn did not affect grain yield in the absence of drought. However, under drought, foliar application of Zn and B in the field increased grain yield (15% and 19%, respectively) as well as raising grain Zn and B concentration, while Zn and Mn sprays in the greenhouse increased grain yield (13% and 10%, respectively), and also increased grain Zn and Mn concentrations. Furthermore, under drought stress both in the field and greenhouse experiment the rate of photosynthesis, pollen viability, number of fertile spikes, number of grains per spike, and particularly water‐use efficiency (WUE) were increased by late foliar application of micronutrients. These results indicate that by increasing WUE foliar application of Zn, B, and Mn at booting to anthesis can reduce the harmful effects of drought stress that often occur during the late stages of winter wheat production. These findings therefore are of high relevance for farmers' practice, the extension service, and fertilizer industry.
Updates on the multimodality management of desmoplastic small round cell tumor
Authors: Kallianpur Ashwin A. , Shukla Nootan K. , Deo Suryanarayan V.S. , Yadav Praveen , Mudaly Dillip , Yadav Rajni , Palaniappan Ramanathan M.
Published: January 2012

Desmoplastic Small Round Cell Tumor (DSRCT) is a rare and an aggressive malignancy with poor outcome. This tumor can co‐express epithelial, neural, and mesenchymal markers. The molecular hallmark of DSRCT is the EWS–WT1 fusion protein. Despite the diversities in treatment modality, the best results have been seen with radical surgery and adjuvant or neoadjuvant chemotherapy. J. Surg. Oncol. 2012; 105:617–621. © 2011 Wiley Periodicals, Inc.
Properties of Reversible Diels–Alder Furan/Maleimide Polymer Networks as Function of Crosslink Density
Authors: Toncelli Claudio , De Reus Dennis C. , Picchioni Francesco , Broekhuis Antonius A.
Published: January 2012

Thermally reversible thermosets are synthesized based on furan functionalized polyketones crosslinked with (methylene‐di‐p‐phenylene)bis‐maleimide. The number of furan groups present along the backbone and the crosslinker/furan molar ratio are varied. According to DSC measurements the de‐crosslinking temperature does not change significantly as function of furan intake and its molar ratio with the crosslinker. All samples show an almost complete recovery of storage and loss modulus. The crosslinked samples are recycled up to seven times without significant quality loss. This suggests that a change in conformation does not result in different visco‐elastic behavior. The most crosslinked sample is able to fully repair itself within 1 hour. A number of low crosslink density materials additionally show a shape memory effect.
Synthesis and Fluorescent Properties of Carbazole‐Substituted Hydroxyethylcelluloses
Authors: Zhang Lingzhi , Zhou Jinping , Zhang Lina
Published: January 2012

Carbazole‐substituted hydroxyethylcelluloses (Cz‐HECs) are homogeneously synthesized by reacting hydroxyethylcellulose (HEC) with N‐3′‐bromopropyl carbazole (Br‐Cz). The structure of Cz‐HECs is characterized with elemental analysis and NMR, and the DS of the carbazole is in the range 0.11–0.43, determined from nitrogen content. The fluorescent properties of Cz‐HECs are measured using a spectrofluorimeter. The results show that the fluorescence lifetime increases as the DS increases, and the fluorescent intensity of Cz‐HECs is stronger than that of Br‐Cz. All samples exhibit concentration self‐quenching properties. The addition of acrylonitrile, as an electron acceptor, quenches the emission spectra of Cz‐HECs, and the fluorescence quenching is found to be a dynamic quenching by analyzing with the Stern–Volmer equation.
Plasmagestützte Immobilisierung von Enzymen
Authors: Vorhaben Torge , Häckel Marko , Bornscheuer Uwe T. , Menyes Ulf
Published: January 2012

Physikalische Plasmen modifizieren Oberflächen gezielt und umweltfreundlich. Mit funktionellen Gruppen entstehen so in wenigen Schritten Oberflächen mit maßgeschneiderten Eigenschaften, beispielsweise um Enzyme darauf zu fixieren.
Azalogie‐Prinzip: hin und zurück
Authors: Offermanns Heribert
Published: January 2012

Eine C‐H‐Gruppe in einem Benzolring durch die isoelektronische =N‐Einheit zu ersetzen, hat der Pharmaforschung wichtige Medikamente geliefert. Aber man kann den Spieß auch umdrehen.
Zertrümmern und fördern
Authors: Osterath Brigitte
Published: January 2012

Fracking hilft, unkonventionelle Erdgasvorkommen zu erschließen. Weil dabei große Mengen Chemikalien ins Erdreich gelangen, ist die Technik umstritten.
Cyberkriminalität: Eine Gefahr für die chemische Industrie?
Authors: Zirkenbach Sven
Published: January 2012

Schadprogramme für chemische Anlagen zu schreiben, erfordert wahrscheinlich zu viel Aufwand, um sich finanziell zu lohnen. Dennoch sollten Steuersysteme für Industrieanlagen vor unbefugtem Zugriff aus dem Internet geschützt sein.
Wertschöpfungsschritt Produktion
Authors: Ziemer Henning
Published: January 2012

Ob es günstiger ist, Vorprodukte im eigenen Unternehmen herzustellen oder möglichst viel der Produktion auszulagern, zeigen Kennzahlen auch für mittelständische Unternehmen der Spezialchemie.
Mischungen und Polymere reachkonform eingeführt
Authors: Döller Regina
Published: January 2012

Um die korrekte Registrierung von Importen aus Ländern außerhalb der europäischen Gemeinschaft sicherzustellen, müssen Importeure den Lieferanten den vertraulichen Umgang mit ihren Daten garantieren können. Wie das gelingt, zeigt das Beispiel Japan.
Geld für den Chemiemittelstand
Authors: Bengs Holger
Published: January 2012

Das Bundeswirtschaftsministerium fördert weitere fünf Jahre lang mittelständische Unternehmen mit Innovationsgutscheinen.
Mit atomaren Sensoren Moleküle erkennen
Authors: Kichin Georgy , Temirov Ruslan , Wagner Christian , Tautz F. Stefan
Published: January 2012

Atome oder kleine Moleküle zwischen Spitze und Oberfläche verbessern die Auflösung eines Rastertunnelmikroskops und machen so die chemisch‐geometrische Struktur einzelner Moleküle sichtbar. Damit lassen sich auch Wechselwirkungen zwischen Molekülen abbilden, etwa Wasserstoffbrückenbindungen.
Highly stacked InGaAs quantum dot laser diodes fabricated by ultrahigh‐rate molecular beam epitaxial growth technique
Authors: Tanoue Fumihiko , Sugawara Hiroharu , Akahane Kouichi , Yamamoto Naokatsu
Published: January 2012

Up to 19 stacks of high‐density (∼5 × 1010 cm‐2) self‐assembled InGaAs quantum dots (QDs) on a GaAs (001) substrate were fabricated by ultrahigh‐rate (1.0 ML/s) solid‐source molecular beam epitaxial (MBE) deposition. Using these QDs, stripe laser diodes were designed and fabricated for use in 1.0‐μm waveband applications, and their operation at room‐temperature was investigated. Laser diodes having a larger number of QDs in the active region exhibited lower threshold current densities. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transport and magnetotransport effects in indium antimonide doped with manganese within quasimetal‐insulator transition
Authors: Obukhov S. A.
Published: January 2012

InSb crystals doped with manganese within the critical concentration of metal‐insulator transition (Ncr = 2×1017 cm‐3) demonstrate colossal negative magnetoresitance and Hall constant sign inversion at low temperatures in magnetic field – unusual for nonmagnetic materials. Studies of the magnetotransport and conductivity dependency on temperature and manganese concentration revealed that both holes and electrons influence the effects. An excitonic insulator phase conception is proposed as a new approach for the explanation of conductivity and magnetotransport anomalies in p‐InSb(Mn). (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)