bluuebunny/crossref_metadata_2025 huggingface dataset:
Dengue infections in non-immune travellers to Thailand
Authors: MASSAD E. , ROCKLOV J. , WILDER-SMITH A.
Published: April 2012

Dengue is the most frequent arboviral disease and is expanding geographically. Dengue is also increasingly being reported in travellers, in particular in travellers to Thailand. However, data to quantify the risk of travellers acquiring dengue when travelling to Thailand are lacking. Using mathematical modelling, we set out to estimate the risk of non-immune persons acquiring dengue when travelling to Thailand. The model is deterministic with stochastic parameters and assumes a Poisson distribution for the mosquitoes' biting rate and a Gamma distribution for the probability of acquiring dengue from an infected mosquito. From the force of infection we calculated the risk of dengue acquisition for travellers to Thailand arriving in a typical year (averaged over a 17-year period) in the high season of transmission. A traveller arriving in the high season of transmission and remaining for 7 days has a risk of acquiring dengue of 0·2% (95% CI 0·16–0·23), whereas the risk for travel of 15 and 30 days' duration is 0·46% (95% CI 0·41–0·50) and 0·81% (95% CI 0·76–0·87), respectively. Our data highlight that the risk of non-immune travellers acquiring dengue in Thailand is substantial. The incidence of 0·81% after a 1-month stay is similar to that reported in prospective seroconversion studies in Israeli travellers to Thailand, highlighting that our models are consistent with actual data. Risk estimates based on mathematical modelling offer more detailed information depending on various travel scenarios, and will help the travel medicine provider give better evidence-based advice for travellers to dengue-endemic countries.
Paul Broca and the Evolutionary Genetics of Cerebral Asymmetry
Authors: Crow Tim J.
Published: April 2012

In 1873, within two years of the publication ofThe Descent of Man, Friedrich Max Mueller wrote:

There is one difficulty which Mr Darwin has not sufficiently appreciated … There is between the whole animal kingdom on the one side, and man, even in his lowest state, on the other, a barrier which no animal has ever crossed, and that barrier is – Language … If anything has a right to the name of specific difference, it is language, as we find it in man, and in man only … If we removed the name of specific difference from our philosophic dictionaries, I should still hold that nothing deserves the name of man except what is able to speak … a speaking elephant or an elephantine speaker could never be called an elephant.' and (quoting Schleicher) ‘If a pig were ever to say to me, “I am a pig” it would ipso facto cease to be a pig’.
The Sad and Sorry History of Consciousness: being, among other things, a Challenge to the ‘Consciousness-studies Community’
Authors: Hacker P.M.S.
Published: April 2012

The term ‘consciousness’ is a latecomer upon the stage of Western philosophy. The ancients had no such term. Sunoida, like its Latin equivalent conscio, meant the same as ‘I know together with’ or ‘I am privy, with another, to the knowledge that’. If the prefixes sun and cum functioned merely as intensifiers, then the verbs meant simply ‘I know well’ or ‘I am well aware that’. Although the ancients did indeed raise questions about the nature of our knowledge of our own perceptions and thought, and introduced the idea of an inner sense, they did not characterize the mind as the domain of consciousness. Aristotelians conceived of the mind as the array of powers that distinguish humanity from the rest of animate nature. The powers of self-movement, of perception and sensation, and of appetite, are shared with other animals. What is distinctive of humanity, and what characterizes the mind, are the powers of the intellect – of reason, and of the rational will. Knowledge of these powers is not obtained by consciousness or introspection, but by observation of their exercise in our engagement with the world around us. The mediaevals followed suit. They likewise lacked any term for consciousness, although they too indulged in reflections upon ‘inner senses’ – in the wake of Avicenna's distinguishing, arguably to excess, five such senses.
Advanced characterization of a W-band phase shifter based on liquid crystals and MEMS technology
Authors: Fritzsch Carsten , Giacomozzi Flavio , Karabey Onur Hamza , Bildik Saygin , Colpo Sabrina , Jakoby Rolf
Published: April 2012

In this paper, we present a continuously tunable phase shifter realized in MEMS technology. Varactors with liquid crystal as a tunable dielectric layer underneath gold bridges are used to build a loaded line phase shifter. Measurements show that the phase shifter has a differential phase shift of 92°, a figure of merit (FoM) of 42°/dB and an input matching of −19 dB at 76 GHz.The tuning speed of the phase shifter is measured at different temperatures between 10 and 50°C. The realized phase shifter can be used in combination with MEMS switches in order to build a 360° tunable reflection phase shifter.
Membrane protein expression triggers chromosomal locus repositioning in bacteria
Authors: Libby Elizabeth A. , Roggiani Manuela , Goulian Mark
Published: April 2012

It has long been hypothesized that subcellular positioning of chromosomal loci in bacteria may be influenced by gene function and expression state. Here we provide direct evidence that membrane protein expression affects the position of chromosomal loci in
Escherichia coli
. For two different membrane proteins, we observed a dramatic shift of their genetic loci toward the membrane upon induction. In related systems in which a cytoplasmic protein was produced, or translation was eliminated by mutating the start codon, a shift was not observed. Antibiotics that block transcription and translation similarly prevented locus repositioning toward the membrane. We also found that repositioning is relatively rapid and can be detected at positions that are a considerable distance on the chromosome from the gene encoding the membrane protein (>90 kb). Given that membrane protein-encoding genes are distributed throughout the chromosome, their expression may be an important mechanism for maintaining the bacterial chromosome in an expanded and dynamic state.
Laurdan generalized polarization fluctuations measures membrane packing micro-heterogeneity in vivo
Authors: Sanchez Susana A. , Tricerri Maria A. , Gratton Enrico
Published: April 2012

Cellular membranes are heterogeneous in composition, and the prevailing theory holds that the structures responsible for this heterogeneity in vivo are small structures (10–200 nm), sterol- and sphingolipid-enriched, of different sizes, highly dynamic denominated rafts. Rafts are postulated to be platforms, which by sequestering different membrane components can compartmentalize cellular processes and regulate signaling pathways. Despite an enormous effort in this area, the existence of these domains is still under debate due to the characteristics of the structures itself: small in size and highly mobile, which from the technical point of view implies using techniques with high spatial and temporal resolution. In this report we measured rapid fluctuations of the normalized ratio of the emission intensity at two wavelengths of Laurdan, a membrane fluorescent dye sensitive to local membrane packing. We observed generalized polarization fluctuations in the plasma membrane of intact rabbit erythrocytes and Chinese hamster ovary cells that can be explained by the existence of tightly packed micro-domains moving in a more fluid background phase. These structures, which display different lipid packing, have different sizes; they are found in the same cell and in the entire cell population. The small size and characteristic high lipid packing indicate that these micro-domains have properties that have been proposed for lipid rafts.
Crystal structure of a
Trypanosoma brucei
metacaspase
Authors: McLuskey Karen , Rudolf Jana , Proto William R. , Isaacs Neil W. , Coombs Graham H. , Moss Catherine X. , Mottram Jeremy C.
Published: April 2012

Metacaspases are distantly related caspase-family cysteine peptidases implicated in programmed cell death in plants and lower eukaryotes. They differ significantly from caspases because they are calcium-activated, arginine-specific peptidases that do not require processing or dimerization for activity. To elucidate the basis of these differences and to determine the impact they might have on the control of cell death pathways in lower eukaryotes, the previously undescribed crystal structure of a metacaspase, an inactive mutant of metacaspase 2 (MCA2) from
Trypanosoma brucei
, has been determined to a resolution of 1.4 Å. The structure comprises a core caspase fold, but with an unusual eight-stranded β-sheet that stabilizes the protein as a monomer. Essential aspartic acid residues, in the predicted S1 binding pocket, delineate the arginine-specific substrate specificity. In addition, MCA2 possesses an unusual N terminus, which encircles the protein and traverses the catalytic dyad, with Y31 acting as a gatekeeper residue. The calcium-binding site is defined by samarium coordinated by four aspartic acid residues, whereas calcium binding itself induces an allosteric conformational change that could stabilize the active site in a fashion analogous to subunit processing in caspases. Collectively, these data give insights into the mechanistic basis of substrate specificity and mode of activation of MCA2 and provide a detailed framework for understanding the role of metacaspases in cell death pathways of lower eukaryotes.
Env-less endogenous retroviruses are genomic superspreaders
Authors: Magiorkinis Gkikas , Gifford Robert J. , Katzourakis Aris , De Ranter Joris , Belshaw Robert
Published: April 2012

Endogenous retroviruses (ERVs) differ from typical retroviruses in being inherited through the host germline and therefore are a unique combination of pathogen and selfish genetic element. Some ERV lineages proliferate by infecting germline cells, as do typical retroviruses, whereas others lack theenvgene required for virions to enter cells and thus behave like retrotransposons. We wished to know what factors determined the relative abundance of different ERV lineages, so we analyzed ERV loci recovered from 38 mammal genomes byin silicoscreening. By modeling the relationship between proliferation and replication mechanism in detail within one group, the intracisternal A-type particles (IAPs), and performing simple correlations across all ERV lineages, we show that when ERVs lose theenvgene their proliferation within that genome is boosted by a factor of ∼30. We also show that ERV abundance follows the Pareto principle or 20/80 rule, with ∼20% of lineages containing 80% of the loci. This rule is observed in many biological systems, including infectious disease epidemics, where commonly ∼20% of the infected individuals are responsible for 80% of onward infection. We thus borrow simple epidemiological and ecological models and show that retrotransposition and loss ofenvis the trait that leads endogenous retroviruses to becoming genomic superspreaders that take over a significant proportion of their host's genome.
Mechanistic stoichiometry of proton translocation by cytochrome

cbb
3
Authors: Rauhamäki Virve , Bloch Dmitry A. , Wikström Mårten
Published: April 2012

Cytochrome

cbb
3

belongs to the superfamily of respiratory heme-copper oxidases that couple the reduction of molecular oxygen to proton translocation across the bacterial or mitochondrial membrane. The

cbb
3

-type enzymes are found only in bacteria, and are both structurally and functionally the most distant from their mitochondrial counterparts. The mechanistic H
+
/e
−
stoichiometry of proton translocation in these

cbb
3

-type cytochrome
c
oxidases has remained controversial. A stoichiometric efficiency of only one-half that of the mitochondrial

aa
3

-type enzyme was recently proposed to be related to adaptation of the organism to microaerobic environments. Here, proton translocation by the
Rhodobacter sphaeroides
enzyme was studied using purified cytochrome

cbb
3

reconstituted into liposomes. An H
+
/e
−
stoichiometry of proton translocation close to unity was observed using the oxygen pulse method, but solely in conditions in which the vast majority of the enzyme was fully reduced in the anaerobic state before the O
2
pulse. These data were compared with results using whole cells or spheroplasts, and the discrepancies in the literature data were discussed. Our results suggest that a proton-pumping efficiency of 1 H
+
/e
−
may be achieved using the single-proton uptake pathway identified in the structure of cytochrome

cbb
3

. The mechanism of proton pumping thus differs from that of the

aa
3

-type oxidases of mitochondria and bacteria.
Action controls dopaminergic enhancement of reward representations
Authors: Guitart-Masip Marc , Chowdhury Rumana , Sharot Tali , Dayan Peter , Duzel Emrah , Dolan Raymond J.
Published: April 2012

Dopamine is widely observed to signal anticipation of future rewards and thus thought to be a key contributor to affectively charged decision making. However, the experiments supporting this view have not dissociated rewards from the actions that lead to, or are occasioned by, them. Here, we manipulated dopamine pharmacologically and examined the effect on a task that explicitly dissociates action and reward value. We show that dopamine enhanced the neural representation of rewarding actions, without significantly affecting the representation of reward value as such. Thus, increasing dopamine levels with levodopa selectively boosted striatal and substantia nigra/ventral tegmental representations associated with actions leading to reward, but not with actions leading to the avoidance of punishment. These findings highlight a key role for dopamine in the generation of appetitively motivated actions.
Gas-liquid transfer data used to analyze hydrophobic hydration and find the nature of the Kauzmann-Tanford hydrophobic factor
Authors: Baldwin Robert L.
Published: April 2012

Hydrophobic free energy for protein folding is currently measured by liquid-liquid transfer, based on an analogy between the folding process and the transfer of a nonpolar solute from water into a reference solvent. The second part of the analogy (transfer into a nonaqueous solvent) is dubious and has been justified by arguing that transfer out of water probably contributes the major part of the free energy change. This assumption is wrong: transfer out of water contributes no more than half the total, often less. Liquid-liquid transfer of the solute from water to liquid alkane is written here as the sum of 2 gas-liquid transfers: (
i
) out of water into vapor, and (
ii
) from vapor into liquid alkane. Both gas-liquid transfers have known free energy values for several alkane solutes. The comparable values of the two different transfer reactions are explained by the values, determined in 1991 for three alkane solutes, of the cavity work and the solute-solvent interaction energy. The transfer free energy is the difference between the positive cavity work and the negative solute-solvent interaction energy. The interaction energy has similar values in water and liquid alkane that are intermediate in magnitude between the cavity work in water and in liquid alkane. These properties explain why the transfer free energy has comparable values (with opposite signs) in the two transfers. The current hydrophobic free energy is puzzling and poorly defined and needs a new definition and method of measurement.
Photothermic regulation of gene expression triggered by laser-induced carbon nanohorns
Authors: Miyako Eijiro , Deguchi Tomonori , Nakajima Yoshihiro , Yudasaka Masako , Hagihara Yoshihisa , Horie Masanori , Shichiri Mototada , Higuchi Yuriko , Yamashita Fumiyoshi , Hashida Mitsuru , Shigeri Yasushi , Yoshida Yasukazu , Iijima Sumio
Published: April 2012

The development of optical methods to control cellular functions is important for various biological applications. In particular, heat shock promoter-mediated gene expression systems by laser light are attractive targets for controlling cellular functions. However, previous approaches have considerable technical limitations related to their use of UV, short-wavelength visible (vis), and infrared (IR) laser light, which have poor penetration into biological tissue. Biological tissue is relatively transparent to light inside the diagnostic window at wavelengths of 650–1,100 nm. Here we present a unique optical biotechnological method using carbon nanohorn (CNH) that transforms energy from diagnostic window laser light to heat to control the expression of various genes. We report that with this method, laser irradiation within the diagnostic window resulted in effective heat generation and thus caused heat shock promoter-mediated gene expression. This study provides an important step forward in the development of light-manipulated gene expression technologies.
Building a ‘counter-community of emotions’: feminist encounters and socio-cultural difference in 1970s Turin1
Authors: Bracke Maud Anne
Published: April 2012

The article analyses cross-class encounters within 1970s feminist campaigning from the perspective of the history of emotions. It is based on a case study of a feminist women's sexual health clinic (consultorio autogestito) in a working-class district near Turin, the Falchera, in the mid-1970s. The article investigates the role played by emotions in the creation of a sense of community among women from different socio-economic and educational backgrounds. The encounters between feminist activists from Turin and working-class women living at the Falchera are understood as framed by these emotional exchanges, which led the women involved to question in new ways their own life-stories, aspirations and understanding of libertà. It is argued that these exchanges led to a reshaping of feminist politics at the grass-roots, specifically in the articulation of strongly situated notions of liberation. The analysis is based on original interviews and interviews published at the time.
Trichoplein and Aurora A block aberrant primary cilia assembly in proliferating cells
Authors: Inoko Akihito , Matsuyama Makoto , Goto Hidemasa , Ohmuro-Matsuyama Yuki , Hayashi Yuko , Enomoto Masato , Ibi Miho , Urano Takeshi , Yonemura Shigenobu , Kiyono Tohru , Izawa Ichiro , Inagaki Masaki
Published: April 2012

The primary cilium is an antenna-like organelle that modulates differentiation, sensory functions, and signal transduction. After cilia are disassembled at the G0/G1 transition, formation of cilia is strictly inhibited in proliferating cells. However, the mechanisms of this inhibition are unknown. In this paper, we show that trichoplein disappeared from the basal body in quiescent cells, whereas it localized to mother and daughter centrioles in proliferating cells. Exogenous expression of trichoplein inhibited primary cilia assembly in serum-starved cells, whereas ribonucleic acid interference–mediated depletion induced primary cilia assembly upon cultivation with serum. Trichoplein controlled Aurora A (AurA) activation at the centrioles predominantly in G1 phase. In vitro analyses confirmed that trichoplein bound and activated AurA directly. Using trichoplein mutants, we demonstrate that the suppression of primary cilia assembly by trichoplein required its ability not only to localize to centrioles but also to bind and activate AurA. Trichoplein or AurA knockdown also induced G0/G1 arrest, but this phenotype was reversed when cilia formation was prevented by simultaneous knockdown of IFT-20. These data suggest that the trichoplein–AurA pathway is required for G1 progression through a key role in the continuous suppression of primary cilia assembly.
A VHF driven coaxial atmospheric air plasma: electrical and optical characterization
Authors: Byrns Brandon , Wooten Daniel , Lindsay Alexander , Shannon Steven
Published: April 2012

A coaxially driven VHF plasma source for atmospheric air plasmas has been built and characterized. Electrical and optical characterization of this source present a unique operating regime when compared to state of the art atmospheric systems such as dielectric barrier discharge, pulsed dc, microwave, or ac blown arc discharges. The discharge does not appear to produce streamers or arcs, but instead remains as a steady-state glow located at the end of the inner coaxial power feed. Plasma impedance was determined by comparing the loaded and unloaded impedance of the coaxial source RF input; this termination impedance was combined with a simple high-frequency global model to estimate an electron density of approximately 1011 cm−3 at 400 W delivered power in air. Optical emission characterization of the source shows a monotonic increase in emission with respect with power; the relative intensity of the peaks from excited species, however, remains constant over a power range from 300 to 600 W. This unique source geometry presents a possible pathway for high gas throughput, large area, high power density processes such as surface modification, air purification, media removal and chemical surface treatment.
A new model of the L–H transition in tokamaks*
Authors: Fundamenski W. , Militello F. , Moulton D. , McDonald D.C.
Published: April 2012

A new model of the L–H transition in tokamaks is proposed, based on the criterion that the transition occurs when plasma turbulence and shear Alfvén waves compete in the vicinity of the last-closed flux surface. The model is used to predict the scaling of the H-mode access power, P
L–H, with magnetic and plasma variables. The predictions are in good agreement with the experimental scaling of P
L–H with plasma size, density, magnetic field and edge safety factor (plasma current). They are also qualitatively consistent with the dependence of P
L–H on ion mass and charge, limiter versus divertor plasmas, single versus double null configurations, the divertor leg length and H–L versus L–H hysteresis. Most notably, the model explains the appearance of the minimum in P
L–H with plasma density (in terms of the transition between sheath limited and conduction limited scrape-off layer (SOL) transport) and correctly predicts the scaling of the density minimum with magnetic field and Greenwald number. Finally, the effect of toroidal field reversal is included by making the normalized correlation length of the eddy and maximum safety factor in the edge-SOL layer functions of
B
 × ∇B direction.
Characterization of the pedestal in Alcator C-Mod ELMing H-modes and comparison with the EPED model
Authors: Walk J.R. , Snyder P.B. , Hughes J.W. , Terry J.L. , Hubbard A.E. , Phillips P.E.
Published: April 2012

A dedicated series of ELMing H-mode discharges on Alcator C-Mod spanning a broad range of plasma parameters, including plasma current (400–1000 kA), magnetic field (3.5–8 T), and plasma shaping, are presented with experimental scalings of the plasma pedestal with bulk plasma and engineering parameters. The H-modes presented achieve pedestals with densities spanning 5 × 1019–2.5 × 1020 m−3 and temperatures of 150–1000 eV (corresponding to 5–40 kPa in the pressure pedestal), over a width of 3–5% of poloidal flux. The observed pedestal structure is compared with the most recent iteration of the EPED class of models, which uniquely predict the pedestal width and height for a set of scalar input parameters via a combination of stability calculations for peeling–ballooning MHD modes and kinetic-ballooning modes.
The general principles of echocardiography
Authors: Garbi Madalina
Published: April 2012

Knowledge of basic ultrasound principles and current echocardiography technology features is essential for image interpretation and for optimal use of equipment during image acquisition and post-processing.

Echocardiography uses ultrasound waves to generate images of cardiovascular structures and to display information regarding the blood flow through these structures.

The present chapter starts by presenting the physics of ultrasound and the construction and function of instruments. Image formation, optimization, display, presentation, storage, and communication are explained. Advantages and disadvantages of available imaging modes (M-mode, 2D, 3D) are detailed and imaging artefacts are illustrated. The biological effects of ultrasound and the need for quality assurance are discussed.
Transoesophageal and intracardiac echocardiography
Authors: Rost Christian , Flachskampf Frank A.
Published: April 2012

Transoesophageal echocardiography (TOE), a minimal-risk, semi-invasive imaging procedure is nowadays an indispensable part of routine echocardiography. It is mainly necessary and indicated: ◆ To analyse some structures insufficiently seen transthoracically, such as the left atrial appendage or the thoracic aorta. ◆ In situations that prohibit the use of conventional transthoracic windows, such as the patient undergoing cardiac surgery.

As in transthoracic echocardiography (TTE), the TOE examination consists of a sequence of views defined by internal landmarks; unlike TTE, depending on the patient’s tolerance and the clinical question, not all of these have to be obtained in every examination. Important typical indications for TOE are the search for signs of endocarditis, the search for cardiogenic emboli, diagnosis of left atrial (appendage) thrombi before cardioversion, diagnosis of aortic dissection, characterization of mitral and aortic valve pathology especially in the context of surgical repair, intraoperative monitoring of left ventricular function, and monitoring of interventional cardiac procedures monitored.

For some indications, intracardiac echocardiography has been found useful. This procedure involves insertion of a transducer-tipped catheter into the caval vein and advancement to the right heart, or intra-aortic placement. Applications are electrophysiological procedures, interventional closure of atrial septal defect, aortic stent placement, and others.
Quantification of left ventricular function and synchrony using tissue Doppler, strain imaging, and speckle tracking
Authors: Voigt Jens-Uwe
Published: April 2012

Modern echocardiographic systems allow the quantitative and qualitative assessment of regional myocardial function by measuring velocity, motion, deformation, and other parameters of myocardial function.

Both colour Doppler (CD) and spectral Doppler modes provide one-dimensional estimates of velocity. From CD data only, further parameters can be derived. Tracking techniques have recently been introduced which provide all parameters two-dimensionally, but at the cost of lower temporal resolution.

Several clinical applications have been proposed, including regional and global systolic function assessment, evaluation of diastolic cardiac properties, and assessment of ventricular dyssynchrony.

This chapter provides an introduction to the method of Doppler- and tracking-based function assessment and provides a basis for understanding its different clinical applications.
Assessment of diastolic function
Authors: Galderisi Maurizio , Mondillo Sergio
Published: April 2012

Modern assessment of left ventricular (LV) diastolic function should be based on the estimation of degree of LV filling pressure (LVFP), which is the true determinant of symptoms/signs and prognosis in heart failure.

In order to achieve this goal, standard Doppler assessment of mitral inflow pattern (E/A ratio, deceleration time, isovolumic relaxation time) should be combined with additional manoeuvres and/or ultrasound tools such as: ◆ Valsalva manoeuvre applied to mitral inflow pattern. ◆ Pulmonary venous flow pattern. ◆ Velocity flow propagation by colour M-mode. ◆ Pulsed wave tissue Doppler of mitral annuls (average of septal and lateral E′ velocity).

In intermediate doubtful situations, the two-dimensional determination of left atrial (LA) volume can be diagnostic, since LA enlargement is associated with a chronic increase of LVFP in the absence of mitral valve disease and atrial fibrillation.

Some new echocardiographic technologies, such as the speckle tracking-derived LV longitudinal strain and LV torsion, LA strain, and even the three-dimensional determination of LA volumes can be potentially useful to add further information. In particular, the reduction of LV longitudinal strain in patients with LV diastolic dysfunction and normal ejection fraction demonstrates that a subclinical impairment of LV systolic function already exists under these circumstances.
Replacement heart valves
Authors: Chambers John B. , Vanoverschelde Jean-Louis
Published: April 2012

Echocardiography is the gold-standard investigation for assessing replacement valve function and detecting pathology. Transthoracic echocardiography (TTE) is sufficient for assessing patients routinely with no evidence of pathology. However, in patients with suspected dysfunction, the addition of transoesophageal echocardiography is usually necessary. Stress echocardiography may also be necessary in patients with exertional symptoms unexplained by the resting TTE.

There are comprehensive International Guidelines for the echocardiographic assessment of prosthetic valves1 and the management of clinical problems.2,3 Stented valves placed using transcatheter techniques are rapidly becoming established.4 The aim of this chapter is to summarize the normal appearance of replacement valves by position and also to describe the diagnosis of pathology.
Infective endocarditis
Authors: Habib Gilbert , Thuny Franck
Published: April 2012

Echocardiography plays a key role in the assessment of infective endocarditis. It is useful for the diagnosis of endocarditis, the assessment of severity of the disease, the prediction of short-term and long-term prognosis, the prediction of embolic risk, the management of the complications of endocarditis, and the follow-up of patients under specific antibiotic therapy.

The ‘Guidelines on the prevention, diagnosis, and treatment of infective endocarditis’ of the European Society of Cardiology and the ‘Recommendations for the practice of echocardiography in infective endocarditis’ of the European Association for Echocardiography recently underlined the value and limitations of echocardiography in infective endocarditis, and gave clear recommendations for the optimal use of both transthoracic echocardiography and transoesophageal echocardiography in infective endocarditis.
Tumours and masses
Authors: Andrade M.J.
Published: April 2012

Transthoracic and transoesophageal echocardiography is the first-line diagnostic tool for imaging space-occupying lesions of the heart. Cardiac masses can be classified as tumours, thrombi, vegetations, iatrogenic material, or normal variants. Occasionally, extracardiac masses may compress the heart and create a mass effect. Cardiac masses may be suspected from the clinical presentation. This is the case in patients with an embolic event presumed of cardiac origin or in patients with infective endocarditis. Otherwise, a cardiac mass can be identified during the routine investigation of common, non-specific cardiac manifestations or as an incidental finding.

In general, an integrated approach which correlates the patient’s clinical picture with the echocardiographic findings may reasonably predict the specific nature of encountered cardiac masses and, in the case of tumours, discriminate between primary versus secondary, and benign versus malignant. Furthermore, echocardiography alone or with complementary imaging modalities, can provide information to help decide on the resectability of cardiac tumours, enhance effective diagnosis and management of infective endocarditis, and assist in planning therapy and follow-up. Because several normal structures and variants may mimic pathological lesions, a thorough knowledge of potential sources of misinterpretation is crucial for a correct diagnosis. After surgical resection, histological investigation is mandatory to confirm the diagnosis.
Echocardiography in the emergency room
Authors: Nešković Aleksandar N. , Hagendorff Andreas
Published: April 2012

Echocardiography can provide rapid and accurate assessment of cardiac morphology and haemodynamics under stressful conditions in the emergency room (ER). Using this information, critical decisions regarding management of cardiovascular emergencies and the critically ill are made. To avoid potentially catastrophic errors with medicolegal consequences, adequate education and experience in echocardiography and cardiology are required and teamwork is encouraged. In addition, emergency cases must be well documented and this documentation stored and retrievable. Transthoracic echocardiography is the main source of the information in the emergency setting, while transoesophageal, contrast, and stress echocardiography are used when needed and in special circumstances.

In this chapter, the principles, practice, and specific considerations related to echocardiography in the ER are discussed and a brief overview of echocardiographic assessment in cardiac emergencies is provided. Detailed information regarding echocardiographic features of particular cardiovascular diseases and conditions that may be presented to the emergency physician in the ER can be found elsewhere in this book in the related chapters.
Vascular imaging
Authors: Pedro Mónica M. , Cardim N.
Published: April 2012

The use of vascular ultrasonography (alone or combined with newer techniques like angio-magnetic resonance or angio-computed tomography) is an essential tool for the diagnosis and the assessment of vascular diseases. It is also useful for the follow-up after surgical or endovascular interventions (avoiding the need to use angiography in any therapeutic decision in most cases). The integration of two-dimensional echocardiography, colour flow imaging and spectral Doppler makes the morphological and functional assessment of vascular disease possible in almost every territory.

For a long time, vascular ultrasonography was exclusively performed by non-cardiologists. Nowadays, in modern echo laboratories, vascular echography is frequently performed by cardiologists, often in cooperation with vascular surgeons and radiologists.

In this chapter, we review the essential concepts of the use of vascular ultrasound imaging in the study of the territories that are most commonly evaluated: ◆ Cerebrovascular circulation. ◆ Abdominal circulation. ◆ Lower limb circulation (arterial and venous disease).

In each of these sections, we describe the technical details of the ultrasonic examination, the normal recordings, the abnormal findings of specific diseases/syndromes affecting each territory, and the postoperative/post-interventional evaluation and follow-up.
Transfusion of Stored Autologous Blood Does Not Alter Reactive Hyperemia Index in Healthy Volunteers
Authors: Berra Lorenzo , Coppadoro Andrea , Yu Binglan , Lei Chong , Spagnolli Ester , Steinbicker Andrea U. , Bloch Kenneth D. , Lin Tian , Sammy Fatima Y. , Warren H. Shaw , Fernandez Bernadette O. , Feelisch Martin , Dzik Walter H. , Stowell Christopher P. , Zapol Warren M.
Published: April 2012

Background

Transfusion of human blood stored for more than 2 weeks is associated with increased mortality and morbidity. During storage, packed erythrocytes progressively release hemoglobin, which avidly binds nitric oxide. We hypothesized that the nitric oxide mediated hyperemic response after ischemia would be reduced after transfusion of packed erythrocytes stored for 40 days.

Methods and Results

We conducted a crossover randomized interventional study, enrolling 10 healthy adults. Nine volunteers completed the study. Each volunteer received one unit of 40-day and one of 3-day stored autologous leukoreduced packed erythrocytes, on different study days according to a randomization scheme. Blood withdrawal and reactive hyperemia index measurements were performed before and 10 min, 1 h, 2 h, and 4 h after transfusion. The reactive hyperemia index during the first 4 h after transfusion of 40-day compared with 3-day stored packed erythrocytes was unchanged. Plasma hemoglobin and bilirubin concentrations were higher after transfusion of 40-day than after 3-day stored packed erythrocytes (P = 0.02, [95% CI difference 10-114 mg/l] and 0.001, [95% CI difference 0.6-1.5 mg/dl], respectively). Plasma concentrations of potassium, lactate dehydrogenase, haptoglobin, and cytokines, as well as blood pressure, did not differ between the two transfusions and remained within the normal range. Plasma nitrite concentrations increased after transfusion of 40-day stored packed erythrocytes, but not after transfusion of 3-day stored packed erythrocytes (P = 0.01, [95% CI difference 0.446-0.66 μM]).

Conclusions

Transfusion of autologous packed erythrocytes stored for 40 days is associated with increased hemolysis, an unchanged reactive hyperemia index, and increased concentrations of plasma nitrite.
AZD-3043
Authors: Egan Talmage D. , Obara Shinju , Jenkins Thomas E. , Jaw-Tsai Sarah S. , Amagasu Shanti , Cook Daniel R. , Steffensen Scott C. , Beattie David T.
Published: April 2012

Background

Propofol can be associated with delayed awakening after prolonged infusion. The aim of this study was to characterize the preclinical pharmacology of AZD-3043, a positive allosteric modulator of the γ-aminobutyric acid type A (GABA(A)) receptor containing a metabolically labile ester moiety. The authors postulated that its metabolic pathway would result in a short-acting clinical profile.

Methods

The effects of AZD-3043, propofol, and propanidid were studied on GABA(A) receptor-mediated chloride currents in embryonic rat cortical neurons. Radioligand binding studies were also performed. The in vitro stability of AZD-3043 in whole blood and liver microsomes was evaluated. The duration of the loss of righting reflex and effects on the electroencephalograph evoked by bolus or infusion intravenous administration were assessed in rats. A mixed-effects kinetic-dynamic model using minipigs permitted exploration of the clinical pharmacology of AZD-3043.

Results

AZD-3043 potentiated GABA(A) receptor-mediated chloride currents and inhibited [(35)S]tert-butylbicyclophosphorothionate binding to GABA(A) receptors. AZD-3043 was rapidly hydrolyzed in liver microsomes from humans and animals. AZD-3043 produced hypnosis and electroencephalograph depression in rats. Compared with propofol, AZD-3043 was shorter acting in rats and pigs. Computer simulation using the porcine kinetic-dynamic model demonstrated that AZD-3043 has very short 50 and 80% decrement times independent of infusion duration.

Conclusions

AZD-3043 is a positive allosteric modulator of the GABA(A) receptor in vitro and a sedative-hypnotic agent in vivo. The esterase dependent metabolic pathway results in rapid clearance and short duration of action even for long infusions. AZD-3043 may have clinical potential as a sedative-hypnotic agent with rapid and predictable recovery.
Spontaneous Breathing during General Anesthesia Prevents the Ventral Redistribution of Ventilation as Detected by Electrical Impedance Tomography
Authors: Radke Oliver C. , Schneider Thomas , Heller Axel R. , Koch Thea
Published: April 2012

Background

Positive-pressure ventilation causes a ventral redistribution of ventilation. Spontaneous breathing during general anesthesia with a laryngeal mask airway could prevent this redistribution of ventilation. We hypothesize that, compared with pressure-controlled ventilation, spontaneous breathing and pressure support ventilation reduce the extent of the redistribution of ventilation as detected by electrical impedance tomography.

Methods

The study was a randomized, three-armed, observational, clinical trial without blinding. With approval from the local ethics committee, we enrolled 30 nonobese patients without severe cardiac or pulmonary comorbidities who were scheduled for elective orthopedic surgery. All of the procedures were performed under general anesthesia with a laryngeal mask airway and a standardized anesthetic regimen. The center of ventilation (primary outcome) was calculated before the induction of anesthesia (AWAKE), after the placement of the laryngeal mask airway (BEGIN), before the end of anesthesia (END), and after arrival in the postanesthesia care unit (PACU).

Results

The center of ventilation during anesthesia (BEGIN) was higher than baseline (AWAKE) in both the pressure-controlled and pressure support ventilation groups (pressure control: 55.0 vs. 48.3, pressure support: 54.7 vs. 48.8, respectively; multivariate analysis of covariance, P < 0.01), whereas the values in the spontaneous breathing group remained at baseline levels (47.9 vs. 48.5). In the postanesthesia care unit, the center of ventilation had returned to the baseline values in all groups. No adverse events were recorded.

Conclusions

Both pressure-controlled ventilation and pressure support ventilation induce a redistribution of ventilation toward the ventral region, as detected by electrical impedance tomography. Spontaneous breathing prevents this redistribution.
Temporal Downscaling of Crop Coefficient and Crop Water Requirement from Growing Stage to Substage Scales
Authors: Shang Songhao
Published: April 2012

Crop water requirement is essential for agricultural water management, which is usually available for crop growing stages. However, crop water requirement values of monthly or weekly scales are more useful for water management. A method was proposed to downscale crop coefficient and water requirement from growing stage to substage scales, which is based on the interpolation of accumulated crop and reference evapotranspiration calculated from their values in growing stages. The proposed method was compared with two straightforward methods, that is, direct interpolation of crop evapotranspiration and crop coefficient by assuming that stage average values occurred in the middle of the stage. These methods were tested with a simulated daily crop evapotranspiration series. Results indicate that the proposed method is more reliable, showing that the downscaled crop evapotranspiration series is very close to the simulated ones.
Hydrogen Generation from Al-NiCl2/NaBH4Mixture Affected by Lanthanum Metal
Authors: Qiang Sun Wen , Fan Mei-Qiang , Fei Yong , Pan Hua , Wang Liang Liang , Yao Jun
Published: April 2012

The effect of La on Al/NaBH4hydrolysis was elaborated in the present paper. Hydrogen generation amount increases but hydrogen generation rate decreases with La content increasing. There is an optimized composition that Al-15 wt% La-5 wt% NiCl2/NaBH4mixture (Al-15 wt% La-5 wt% NiCl2/NaBH4weight ratio, 1 : 3) has 126 mL g−1 min−1maximum hydrogen generation rate and 1764 mL g−1hydrogen generation amount within 60 min. The efficiency is 88%. Combined with NiCl2, La has great effect on NaBH4hydrolysis but has little effect on Al hydrolysis. Increasing La content is helpful to decrease the particle size of Al-La-NiCl2in the milling process, which induces that the hydrolysis byproduct Ni2B is highly distributed into Al(OH)3and the catalytic reactivity of Ni2B/Al(OH)3is increased therefore. But hydrolysis byproduct La(OH)3deposits on Al surface and leads to some side effect. The Al-La-NiCl2/NaBH4mixture has good stability in low temperature and its hydrolytic performance can be improved with increasing global temperature. Therefore, the mixture has good safety and can be applied as on board hydrogen generation material.
In VitroSynergistic Effect ofPsidium guineense(Swartz) in Combination with Antimicrobial Agents against Methicillin-ResistantStaphylococcus aureusStrains
Authors: Fernandes Tiago Gomes , de Mesquita Amanda Rafaela Carneiro , Randau Karina Perrelli , Franchitti Adelisa Alves , Ximenes Eulália Azevedo
Published: April 2012

The aim of this study was to evaluate the antimicrobial activity of aqueous extract ofPsidium guineenseSwartz (Araçá-do-campo) and five antimicrobials (ampicillin, amoxicillin/clavulanic acid, cefoxitin, ciprofloxacin, and meropenem) against twelve strains ofStaphylococcus aureuswith a resistant phenotype previously determined by the disk diffusion method. FourS. aureusstrains showed resistance to all antimicrobial agents tested and were selected for the study of the interaction between aqueous extract ofP. guineenseand antimicrobial agents, by the checkerboard method. The criteria used to evaluate the synergistic activity were defined by the fractional inhibitory concentration index (FICI). AllS. aureusstrains were susceptible toP. guineenseas determined by the microdilution method. The combination of theP. guineenseextract with the antimicrobial agents resulted in an eight-fold reduction in the MIC of these agents, which showed a FICI ranging from 0.125 to 0.5, suggesting a synergistic interaction against methicillin-resistantStaphylococcus aureus(MRSA) strains. The combination of the aqueous extract ofP. guineensewith cefoxitin showed the lowest FICI values. This study demonstrated that the aqueous extract ofP. guineensecombined with beta lactamics antimicrobials, fluoroquinolones, and carbapenems, acts synergistically by inhibiting MRSA strains.
Cytotoxic, Virucidal, and Antiviral Activity of South American Plant and Algae Extracts
Authors: Faral-Tello Paula , Mirazo Santiago , Dutra Carmelo , Pérez Andrés , Geis-Asteggiante Lucía , Frabasile Sandra , Koncke Elina , Davyt Danilo , Cavallaro Lucía , Heinzen Horacio , Arbiza Juan
Published: April 2012

Herpes simplex virus type 1 (HSV-1) infection has a prevalence of 70% in the human population. Treatment is based on acyclovir, valacyclovir, and foscarnet, three drugs that share the same mechanism of action and of which resistant strains have been isolated from patients. In this aspect, innovative drug therapies are required. Natural products offer unlimited opportunities for the discovery of antiviral compounds. In this study, 28 extracts corresponding to 24 plant species and 4 alga species were assayedin vitroto detect antiviral activity against HSV-1. Six of the methanolic extracts inactivated viral particles by direct interaction and 14 presented antiviral activity when incubated with cells already infected. Most interesting antiviral activity values obtained are those ofLimonium brasiliense, Psidium guajava,andPhyllanthus niruri, which inhibit HSV-1 replicationin vitrowith 50% effective concentration (EC50) values of 185, 118, and 60 μg/mL, respectively. For these extracts toxicity values were calculated and therefore selectivity indexes (SI) obtained. Further characterization of the bioactive components of antiviral plants will pave the way for the discovery of new compounds against HSV-1.
Insomnia in Pregnancy and Factors Related to Insomnia
Authors: Kızılırmak Aynur , Timur Sermin , Kartal Bahtışen
Published: April 2012

This study aims to investigate insomnia experienced by pregnant women and factors associated with it. This study was designed as hospital-based, descriptive, and cross-sectional research. The participants were 486 people chosen with nonprobability random sampling method. The data were collected through Women’s Health Initiative Insomnia Rating Scale, Beck Depression Inventory, and Interview Form. Insomnia prevalence in women participating in this study was found 52.2%. The results of logistic regression analysis showed that the risk of insomnia was 2.03 times higher for those in the third trimester than those in the first and second trimesters, 2.19 times higher for those 20 years old and over than younger ones, and 2.63 times higher for those who had depression syndrome than those who did not. Insomnia in pregnant women who participated in this study was found to be at high rates.