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Purpose: This report explores the overlooked potential of bioprinting to automate biomanufacturing of simple tissue structures, such as the uniform deposition of (mono)layers of progenitor cells on sheetlike decellularized extracellular matrices (dECM). In this scenario, dECM serves as a biodegradable celldelivery matrix to provide enhanced regenerative microenvironments for tissue repair. The Tissue-Engineered Muscle Repair (TEMR) technology—where muscle progenitor cells are seeded onto a porcine bladder acellular matrix (BAM), serves as a representative testbed for bioprinting applications. Previous work demonstrated that TEMR implantation improved functional outcomes following VML injury in biologically relevant rodent models.Materials and Methods: In the described bioprinting system, a cell-laden hydrogel bioink is used to deposit high cell densities (1.4 × 105-3.5 × 105 cells/cm2), onto both sides of the bladder acellular matrix as proof-of-concept.Results: These bioprinting methods achieve a reproducible and homogeneous distribution of cells, on both sides of the BAM scaffold, after just 24hrs, with cell viability as high as 98%. These preliminary results suggest bioprinting allows for improved dual-sided cell coverage compared to manual-seeding.Conclusions: Bioprinting can enable automated fabrication of TEMR constructs with high fidelity and scalability, while reducing biomanufacturing costs and timelines. Such bioprinting applications are underappreciated, yet critical, to expand the overall biomanufacturing paradigm for tissue engineered medical products. In addition, biofabrication of sheet-like implantable constructs, with cells deposited on both sides, is a process that is both scaffold and cell-type agnostic, and furthermore, is amenable to many geometries, and thus, additional tissue engineering applications beyond skeletal muscle. [ABSTRACT FROM AUTHOR]

Ultraviolet laser-induced desorption of neutral atoms and molecules from nominally transparent, ionic materials can yield particle velocities consistent with surface temperatures of a few thousand kelvin even in the absence of visible surface damage. The origin of the laser absorption required for this surface heating has been often overlooked. In this work, we report simultaneous neutral emission and laser transmission measurements on single-crystal NaCl exposed to 248-nm excimer laser radiation. As much as 20% of the incident radiation at 248 nm must be absorbed in the near-surface region to account for the observed particle velocities. We show that the laser absorption grows from low values over several pulses and saturates at values sufficient to account for the surface temperatures required to explain the observed particle velocity distributions. The growth of absorption in these early pulses is accompanied by a corresponding increase in the emission intensities. The diffuse reflectance spectra acquired after exposure suggest that near-surface V-type centers are responsible for most of the absorption at 248 nm in single-crystal NaCl. [ABSTRACT FROM AUTHOR]

We show that low partial pressures of water vapor (10-5 Pa) dramatically increase the intensity of neutral Na and Cl emissions from cleaved, single-crystal NaCl during pulsed laser irradiation at 248 nm (KrF excimer). The time-of-flight distributions of these emissions are consistent with thermal desorption from laser-heated surfaces. Significantly, introducing water vapor lowers the particle velocities and thus the effective surface temperature during emission. Transmission measurements confirm that laser absorption is reduced in the presence of water vapor. The Arrhenius analysis of the emission intensities and effective temperatures show reduced activation energies in the presence of water vapor, which more than compensate for the vapor-induced reduction in laser absorption and surface temperature. Atomic force and scanning electron microscopy of the irradiated surfaces show evidence for accelerated monolayer-scale erosion in the presence of water vapor. A mechanism for the effect of water on these emission and erosion processes is proposed and discussed. [ABSTRACT FROM AUTHOR]

Both photons and electrons may be used to excite surface plasmon polaritons, the collective charge density fluctuations at the surface of metal nanostructures. By virtue of their nanoscopic and dissipative nature, a detailed characterization of surface plasmon (SP) eigenmodes in real space-time ultimately requires joint nanometer spatial and femtosecond temporal resolution. The latter realization has driven significant developments in the past few years, aimed at interrogating both localized and propagating SP modes. In this mini-review, we briefly highlight different techniques employed by our own groups to visualize the enhanced electric fields associated with SPs. Specifically, we discuss recent hyperspectral optical microscopy, tip-enhanced Raman nano-spectroscopy, nonlinear photoemission electron microscopy, as well as correlated scanning transmission electron microscopy-electron energy loss spectroscopy measurements targeting prototypical plasmonic nanostructures and constructs. Through selected practical examples from our own laboratories, we examine the information content in multidimensional images recorded by taking advantage of each of the aforementioned techniques. In effect, we illustrate how SPs can be visualized at the ultimate limits of space and time. [ABSTRACT FROM AUTHOR]

Thin films of CsBr deposited on Cu(100) have been proposed as next-generation photocathode materials for applications in particle accelerators and free-electron lasers. However, the mechanisms underlying an improved photocathode performance as well as their long-term stability remain poorly understood. We present Density Functional Theory (DFT) calculations of the work function reduction following the application of CsBr thin film coatings to Cu photocathodes. The effects of both flat and rough interface and van der Waals forces are examined. Calculations suggest that CsBr films can reduce the Cu(100) work function by about 1.5 eV, which would explain the observed increase in quantum efficiency (QE) of coated vs. uncoated photocathodes. A model explaining the experimentally observed laser activation of photocathodes is provided whereby the photo-induced creation of Br vacancies and Cs–Br di-vacancies and their subsequent diffusion to the Cu/CsBr interface lead to a further increase in QE after a period of laser irradiation. [ABSTRACT FROM AUTHOR]

N2 fixation fuels ~ 50 % of new primary production in the oligotrophic South Pacific Ocean. The VAHINE experiment has been designed to track the fate of diazotroph derived nitrogen (DDN) and carbon within a coastal lagoon ecosystem in a comprehensive way. For this, large-volume (~ 50 m³) mesocosms were deployed in the New Caledonia lagoon and were intentionally fertilized with dissolved inorganic phosphorus (DIP) to stimulate N2 fixation. This study examined the temporal dynamics of the prokaryotic community together with the evolution of biogeochemical parameters for 23 consecutive days in one of these mesocosms (M1) and in the Nouméa lagoon using MiSeq 16S rRNA gene sequencing. We observed clear successions within M1, some of which were not mirrored in the lagoon. The dominating classes in M1 were alpha- and gammaproteobacteria, cyanobacteria (mainly Synechococcus), eukaryotic microalgae, on days 10 and 14 Marine Group II euryarchaea, on days 12-23 also Flavobacteriia. Enclosure led to significant changes in the M1 microbial community, probably initiated by the early decay of Synechococcus and diatoms. However, we did not detect a pronounced bottle effect with a copiotroph-dominated community. The fertilization with ~ 0.8 μM DIP on day 4 did not have directly observable effects on the overall community within M1, as the data samples obtained from before and four days after fertilization clustered together, but likely influenced the development of individual populations later on, like Defluviicoccus-related bacteria and UCYN-C type diazotrophic cyanobacteria. Growth of UCYN-C led to among the highest N2 fixation rates ever measured in this region and enhanced growth of nearly all abundant heterotrophic groups in M1. We further show that different Rhodobacteraceae were the most efficient heterotrophs in the investigated system and we observed niche partitioning within the SAR86 clade. Whereas the location in- or outside the mesocosm had a significant effect on community composition, the temporal effect was significantly stronger and similar in both locations, suggesting that overarching abiotic factors were more influential than the enclosure. While temporal community changes were evident, prokaryotic diversity (Shannon Index) only declined slightly from ~ 6.5 to 5.7 or 6.05 in the lagoon and M1, respectively, throughout the experiment, highlighting the importance of multiple and varying sources of organic matter maintaining competition. [ABSTRACT FROM AUTHOR]

N2 fixation fuels ~ 50% of new primary production in the oligotrophic South Pacific Ocean. The VAHINE mesocosm experiment designed to track the fate of diazotroph derived nitrogen (DDN) in the New Caledonia lagoon. Here, we examined the temporal dynamics of heterotrophic bacterial production during this experiment. Three replicate large-volume (~ 50 m³) mesocosms were deployed and were intentionally fertilized with dissolved inorganic phosphorus (DIP) to stimulate N2 fixation. We specifically examined relationships between N2 fixation rates and primary production, determined bacterial growth efficiency and established carbon budgets of the system from the DIP fertilization to the end of the experiment (days 5-23). Heterotrophic bacterioplankton production (BP) and alkaline phosphatase activity (APA) were statistically higher during the second phase of the experiment (P2: days 15-23), when chlorophyll biomass started to increase compared to the first phase (P1: days 5-14). Among autotrophs, Synechococcus abundances increased during P2, possibly related to its capacity to assimilate leucine and to produce alkaline phosphatase. Bacterial growth efficiency based on the carbon budget was notably higher than generally cited for oligotrophic environments (27-43%), possibly due to a high representation of proteorhodopsin-containing organisms within the picoplanctonic community. The carbon budget showed that the main fate of gross primary production (particulate + dissolved) was respiration (67%), and export through sedimentation (17%). BP was highly correlated with particulate primary production and chlorophyll biomass during both phases of the experiment but slightly correlated, and only during P2 phase, with N2 fixation rates. Our results suggest that most of the DDN reached the heterotrophic bacterial community through indirect processes, like mortality, lysis and grazing. [ABSTRACT FROM AUTHOR]

Metal nanoparticles exhibit a localized surface plasmon resonance (LSPR) which is very sensitive to the size and shape of the nanoparticle and the surrounding dielectric medium. The coupling between the electromagnetic radiation and the localized surface plasmon in metallic nanoparticles results in a sizable enhancement of the incident fields, making them possible candidates for plasmonic applications. In particular, partially exposed metallic nanoparticles distributed in a dielectric matrix can provide prime locations for LSPR spectroscopy and sensing. We report the synthesis and characterization of a plasmonic substrate consisting of Ag nanoparticles partially buried in MgO. Ag nanoparticles of different shapes and size distributions were synthesized below the surface of MgO by implanting 200 keV Ag+ ions followed by annealing at 1000 °C for 10 and 30 h. A detailed optical and structural characterization was carried out to understand the evolution of the Ag nanoparticle and size distribution inside the MgO matrix. Micro x-ray diffraction (Micro-XRD) was employed to investigate the structural properties and estimate the crystallite size. The nanoparticles evolved from a spherical to a faceted morphology with annealing time, assuming an octahedral shape truncated at the (001) planes, as visualized from aberration-corrected transmission electron microscopy (TEM) images. The nanoparticles embedded in MgO were shown to be pure metallic Ag using atom probe tomography (APT). The nanoparticles were partially exposed to the surface by employing plasma etch techniques to remove the overlaying MgO. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to study the surface morphology and obtain a height distribution for the partially exposed nanoparticles. [ABSTRACT FROM AUTHOR]

Photoelectron emission microscopy (PEEM) is a versatile technique that can image a variety of materials including metals, semiconductors and even insulators. Under favorable conditions the most advanced aberration corrected instruments have a spatial resolution approaching 2 nm. Although PEEM cannot compete with transmission or scanning electron microscopies for ultimate resolution, the technique is much gentler and has the unique advantage of imaging structure as well as electronic and magnetic states on the nanoscale. Since the image contrast is derived from spatial variations in electron photoemission intensity, PEEM is ideal for interrogating both static and dynamic electronic properties of complex nanostructured materials. Here, we review the key principles and contrast mechanisms of PEEM and briefly summarize materials applications of PEEM. [ABSTRACT FROM AUTHOR]

•Based on computational prediction of RNA secondary structures, a long antisense RNA (asRNA) was found in chloroplasts of Arabidopsis, Nicotiana tabacum and poplar, which occurs in two to three major transcripts. •Mapping of primary 5′ ends, northern hybridizations and quantitative real-time reverse transcription polymerase chain reaction (qPCR) experiments demonstrated that these transcripts originate from a promoter that is typical for the plastid-encoded RNA polymerase and are over their full length in antisense orientation to the gene ndhB and therefore were designated asRNA_ndhB. •The asRNA_ndhB transcripts predominantly accumulate in young leaves and at physiological growth temperatures. Two nucleotide positions in the mRNA that are subject to C-to-U RNA editing and which were previously found to be sensitive to elevated temperatures are covered by asRNA_ndhB. Nevertheless, the correlation between the accumulation of asRNA_ndhB and RNA editing appeared weak in a temperature shift experiment. •With asRNA_ndhB, we describe the first asRNA of plant chloroplasts that covers RNA editing sites, as well as a group II intron splice acceptor site, and that is under developmental control, raising the possibility that long asRNAs could be involved in RNA maturation or the control of RNA stability. [ABSTRACT FROM AUTHOR]

Microbial biodiversity provides an increasingly important source of medically and industrially useful compounds. We have isolated 14 actinomycete species from a collection of approximately 300 plant stem samples from the upper Amazonian rainforest in Peru. All of the cultured isolates produce substances with inhibitory activity directed at a range of potential fungal and bacterial pathogens. For some organisms, this activity is very broad in spectrum while other organisms show specific activity against a limited number of organisms. Two of these organisms preferentially inhibit bacterial test organisms over eukaryotic organisms. rDNA sequence analysis indicates that these organisms are not equivalent to any other cultured deposits in GenBank. Our results provide evidence of the untapped biodiversity in the form of biologically active microbes present within the tissues of higher plants. [ABSTRACT FROM AUTHOR]

Three novel endophytic streptomycetes have been isolated and characterized from plants with ethnobotanical uses on the Malay Peninsula including: Thottea grandiflora (family – Aristolochiaceae), Polyalthia spp. (family – Annonaceae), and Mapania sp. (family – Cyperaceae). Each isolate, as studied by scanning electron microscopy, has small hyphae, and produces typical barrel-shaped spores arising by hyphal fragmentation. Interestingly, although none has any detectable antibacterial killing properties, each has demonstrable killing activity against one or more pathogenic fungi including organisms such as Phytophthora erythroseptica, Pythium ultimum, Sclerotinia sclerotiorum, Mycosphaerella fijiensis and Rhizoctonia solani. Molecular biological studies on the rRNA gene sequence of each isolate revealed that it is distinct from all other genetic accessions of streptomyectes in GenBank, and each bears some genetic similarity to other streptomycetes. The bioactivity of each microbe was extractable in various organic solvents. [ABSTRACT FROM AUTHOR]

Copyright of HNO is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Endophytic streptomycetes have been isolated and characterized from several species of Nothofagus and other plants growing in the southern reaches of Patagonia. No endophytic streptomycete was obtained from any plant species studied in Northern Patagonia. However, from Southern Patagonia, biologically active Streptomyces spp. from several plant species were isolated. Each isolate, as studied by scanning electron microscopy (SEM), has small hyphae, some produce typical barrel-shaped spores in culture and each has some unique hyphal surface structures. Interestingly, although none has any detectable antibacterial killing properties, each has demonstrable killing activity against one or more pathogenic fungi including representative plant pathogenic organisms such as Phytophthora erythroseptica, Pythium ultimum, Sclerotinia sclerotiorum, Mycosphaerella fijiensis, and Rhizoctonia solani. The 16S rDNA sequences of the isolates were distinct from all other genetic accessions of Streptomyces in GenBank. However, isolate C-2 from Chiliotrichum diffusum (Compositae) is identical, in all respects, to isolate C-4 obtained from Misodendrum punctulatum (Loranthaceae). These results confirm that endophytic streptomycetes represent a novel source of biologically active microorganisms. [ABSTRACT FROM AUTHOR]

This article describes the overall design of the motional Stark effect diagnostic on Tore Supra (not water cooled in its first version) and the results obtained. The diagnostic is composed of nine viewing lines measuring the plasma every 8 cm with a spatial resolution varying from 3 to 6 cm. A tube placed inside the port adjacent to the neutral beam contains a stainless-steel mirror and SFL6 optic lenses that carry the image of the neutral beam towards the optical fibers. On Tore Supra the diagnostics having components inside the machine have to face thermal load difficulties linked with the long shots, and this will be the case for ITER diagnostics. This is why for safety reasons the insulating window is placed at the rear side of the tube, and consequently the optics is under the machine vacuum. For motional Stark effect, before reaching the thermal limits on the components, a first limitation comes from the polarization modifications induced by the temperature gradients on the lenses (birefringence effect). This limitation is estimated in terms of plasma duration. The associated diagnostic neutral beam (60 keV, 400 kW, 5 s) works in hydrogen for a higher velocity and a better plasma penetration. As a consequence the beam spectrum exhibits a large Doppler shift and a clear separation of the Stark components. The detection uses the classical elements of the polarimetry method, wide aperture photoelastic modulators, linear polarizer, narrow interference filters, and photomultipliers. The signal is processed digitally (250 kHz) for the extraction of the Fourier components that allow the calculation of the magnetic field pitch angles. The first measurements obtained during Ohmic shots for various plasma currents are in good agreement with the current diffusion calculations done with the CRONOS code. [ABSTRACT FROM AUTHOR]

This study evaluates the feasibility of a new class of partially restrained connections using shape memory alloys. In the martensitic form, shape memory alloys (SMAs) have the ability to recover large residual deformations by heating the alloy above its transformation temperature. The proposed connection consists of four large diameter NiTi SMA bars connecting the beam flange to the column flange and serve as the primary moment transfer mechanism. Two full-scale connections were tested using the SAC loading protocol. The connections exhibited a high level of energy dissipation, large ductility capacity, and no strength degradation after being subjected to cycles up to 4% drift. Following the initial testing series, the tendons were heated to recover the residual beam tip displacement. After initiating the shape memory effect within the tendons, the connections were retested, displaying repeatable and stable hysteretic behavior. An additional test was performed under dynamic loading to examine the strain rate effects on the performance of the connection. The dynamic tests showed similar behavior, except for a decrease in energy dissipation capacity when compared to the quasi-static tests. [ABSTRACT FROM AUTHOR]

A simple interference filter spectrometer, together with a modulated neutral diagnostic beam is used on the Tore Supra tokamak for the measurement of carbon impurity profiles by charge exchange spectroscopy. A temporal resolution of 8 ms with a good signal to noise ratio is obtained with a neutral hydrogen beam of about 1 A equivalent neutral current at the plasma edge at 45 kV. Experimental results with ion cyclotron heating show that fast changes of the heating power are followed by transient modifications of the carbon impurity profile. The evolution of the C[sup 6+] profile from peaked to hollow and back to normal can be followed step by step and a typical diffusion time of about 30 ms is measured. [ABSTRACT FROM AUTHOR]

The active particle diagnostic technique is used to study the ion temperature at five spatial points along the path of a hydrogen diagnostic beam. The temperature of the main ion plasma component (deuterium ions) measured by this diagnostic technique along the beam path is compared with the temperature of carbon ions (C[sup +5]). A study is made of the following characteristic features of the behavior of the ion temperature profiles T[sub i] in various TORE SUPRA operating modes: the formation of flat and even hollow T[sub i] profiles in ohmic discharges with q∼3 at the plasma edge, the change in T[sub i] profiles in ergodic divertor discharges, and the difference between the temperature of the bulk ions measured by the active particle diagnostic technique and the temperature of C[sup +5] ions in the plasma region r/a > 0.5. The features revealed are explained at a qualitative level. © 2002 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

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Pregnancy causes substantial changes in the cardiovascular system: cardiac output (40%-50%) and blood volume (40%) increase whereas systemic peripheral resistance and arterial pressure decrease. The rise in progesterone and estrogen levels accompanying pregnancy stimulates the renin-angiotensin-aldosterone system. Increased prostaglandin production follows renin activation; simultaneously, the arterial vessels show diminished angiotensin sensitivity. The result is pronounced vasodilatation. Cardiovascular diseases remain the most important nonobstetric cause of maternal death. The physiological changes in the cardiovascular system during pregnancy influence cardiac diseases in different ways. Pregnancy, labor, and delivery appear to be well tolerated in gravidae with an atrial septal defect, ventricular septal defect, and patent ductus arteriosus. Sometimes congestive heart failure occurs and appropriate medical therapy is necessary. Pregnant women with uncorrected cyanotic congenital heart disease (Eisenmenger's syndrome, tetralogy of Fallot) constitute a high-risk group because of right ventricular insufficiency and hypoxic attacks. The consequences for anaesthesia in parturients with congenital heart disease are discussed. The symptoms of acquired mitral or aortic stenosis are aggravated by the physiological changes in the cardiovascular system during pregnancy; the clinical symptoms of valve insufficiency are ameliorated by vasodilatation. Peripartum cardiomyopathy clinically shows similar features to idiopathic dilated cardiomyopathy. The basis of treatment is the same as that of congestive heart failure, with the therapeutic spectrum ranging from diet to heart transplantation. Women with hypertrophic cardiomyopathy tolerate pregnancy, labor, and delivery surprisingly well. Vaginal delivery is possible, but epidural anaesthesia is contraindicated. Hypertensive disorders associated with pregnancy are classified into three groups: chronic, transient, and pre-eclamptic hypertension. Whereas chronic and transient hypertension do not affect the outcome of pregnancy appreciably, pre-eclampsia presents a potential danger to mother and fetus. Pre-eclamptic hypertension is accompanied by low cardiac output and plasma volume. An upregulation of angiotensin receptors enhances vascular reactivity, with the consequence of high peripheral resistance. For antihypertensive therapy hydralazine, alpha-methyldopa, and magnesium sulfate are the drugs of choice. A generalised recommendation of anaesthesia for the pre-eclamptic gravida cannot be made because both general and epidural anaesthesia have risks of severe side effects. [ABSTRACT FROM AUTHOR]

Monitoring of ventilation in infants is difficult and often not very reliable. In this study, transcutaneous measurement of blood gas tensions was used to investigate the influence of four different modes of ventilation on oxygenation and ventilation in anaesthetized infants. METHODS. In a randomised study, transcutaneously measured PO2 (tc-PO2) and PCO2 (tcPCO2) tensions were continuously registered in 42 ASA class I and II infants between 3 and 24 weeks of age undergoing minor surgical procedures (inguinal hernia repair). Two breathing systems combined with different modes of ventilation were evaluated: manual ventilation with Kuhn's T-piece system and face mask (group A; n = 11) or endotracheal tube (group B; n = 10); manual ventilation with paediatric circuit system and face mask (group C; n = 11); and mechanical ventilation with paediatric circle system, endotracheal tube, and positive end-expiratory pressure (PEEP) 3 cm H2O (group D; n = 10). Transcutaneous values were measured by a combined tcPO2/PCO2 electrode (E 5277, Radiometer). Anaesthesia was maintained by controlled ventilation with N2O/O2 (67%/33%) and halothane 0.5-1.5 vol.%. Surgical and anaesthetic techniques were standardized and the anaesthetist was blinded to the measured values. RESULTS. Preoperative mean tcPO2 values while spontaneously breathing air ranged between 69 and 75 mmHg in all patients. During anaesthesia and controlled ventilation (FiO2 = 0.33), there was a significant increase in tcPO2 (P < 0.01) in 3 groups: in groups A and D mean tcPO2 increased to 90-100 mmHg and in group C to 110-120 mmHg. In contrast, tcPO2 in group B reached only 75-80 mmHg, which was not considered significant. Postoperatively, tcPO2 immediately reached baseline values in all patients (Fig. 2). Compared to preoperative values, the alveolar-tcPO2 difference (AtcDO2) significantly increased during anaesthesia in all groups (Fig. 3). The tcPCO2 measurements revealed marked alveolar dysventilation, with hyperventilation supervening in groups A, B, and D; in group C, however, most (7 of 11) infants were normoventilated (Fig. 4). CONCLUSIONS. Adverse effects of anaesthesia on pulmonary function in infants are caused by loss of the PEEP effect induced by the physiological subglottic stenosis. Endotracheal intubation and the increase in chest wall compliance during anaesthesia lead to a decrease in functional residual capacity (FRC) associated with premature airway closure and ventilation/perfusion mismatch. These pathophysiological disturbances result in a marked increase in AaDO2 and low arterial PO2 values despite high FiO2, as could be observed when intubated infants had been ventilated with a high-flow T-piece system (group B). Mechanical ventilation with a paediatric circuit system and endotracheal tube allows the use of low PEEP levels (group D), which may replace the lost subglottic function and partially restore the FRC. Ventilation by mask does not disturb the functional subglottic stenosis, and the impairment of pulmonary function will depend solely on the decrease in FRC caused by increased chest wall compliance (group A). If mask ventilation is combined with a paediatric circuit system (group C), the pressure relief valve produces a low PEEP of 2 to 3 cm H2O, which may partially counteract the decrease in FRC. With regard to oxygenation, the paediatric circle system proved to be superior to the high-flow T-piece system independent of whether children were ventilated via a face mask or an endotracheal tube. The group-specific differences in degree of dysventilation with manual ventilation show that the type of breathing system is important with regard to the size of the tidal volume delivered. Thus, tidal volumes will be unintentionally increased by the high fresh gas flow needed when a T-piece system is used. The lower flow and preadjusted pressure limit may prevent the delivery of excessive tidal volumes with the paediatric circuit system... [ABSTRACT FROM AUTHOR]

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The initial decay time of the spectrum and the integrated intensity of depolarized light scattered from a system of interacting spherical and optically isotropic colloidal particles as a function of scattering angle is calculated in the double scattering approximation. These quantities can be reduced in the short-time regime to the static structure factor of single scattering, as observed in polarized scattering for systems of intermediate concentrations of colloidal particles. The results are applied to charged polysterene spheres in solutions and it is shown by numerical calculations that the presence of interactions can modify the angular dependence of initial decay time and integrated intensity considerably. [ABSTRACT FROM AUTHOR]

In order to study DNA replication control elements in cyanobacteria we cloned and sequenced the dnaA gene from the marine cyanobacterium Prochlorococcus marinus. The dnaA gene is ubiquitous among bacteria and encodes the DNA replication initiation factor DnaA. The deduced amino acid sequence of the P. marinus DnaA protein shows highest similarity to the DnaA protein from the freshwater cyanobacterium Synechocystis sp. PCC6803. Using a solid-phase DNA binding assay we demonstrated that both cyanobacterial DnaA proteins specifically recognize chromosomal origins, oriC, of Escherichia coli and Bacillus subtilis in vitro. The genetic environment of dnaA is not conserved between the two cyanobacteria. Upstream of the P. marinusdnaA gene we identified a gene encoding a putative ATP-binding cassette (ABC) transport protein. The gor gene encoding glutathione reductase lies downstream of dnaA. Comparison of the genetic structure of dnaA regions from 15 representative bacteria shows that the pattern of genes flanking dnaA is not universally conserved among them. [ABSTRACT FROM AUTHOR]

Salicornia pacifica stem tissues were treated with ATP, Ca(NO3)2 and Pb(N3)2 to localize ATPase. ATPase activity was present along the plasma membranes and in the cytoplasm of the cortical palisade, inner cortex and vascular cells of young shoots. ATPase was also present in the plasma membranes of tracheids which are present in the palisade region. Ouabain did not inhibit ATPase, but NaF- crown ethers, and N,N'-dicyclohexyl carbodiimide (DCCD) did so in vitro. Only DCCD significantly inhibited (82%) ATPase in tissues processed for electron microscopy. Energy dispersive microanalysis was used to verify that the precipitates were Pb phosphate. [ABSTRACT FROM AUTHOR]

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Copyright of Computing is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Computing is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Computing is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A generalized hydrodynamic theory is developed for systems of interacting Brownian particles on the basis of a Fokker-Planck equation General results are derived for correlation functions, frequency- and wave-vector dependent transport coefficients Explicit expressions for moments, cumulants and the hydrodynamic limits of the transport coefficients are given For the special cases of overdamped systems with and without hydrodynamic interaction the general results are simplified As an example for the application of this approach the system of charged spherical polystyrene spheres in aqueous solution is treated in detail The generalized transport functions are evaluated in mode coupling approximation and detailed numerical results are presented for various collective and single-particle properties Finally, the relationship to a corresponding Smoluchowski approach is discussed. [ABSTRACT FROM AUTHOR]

The influences of glyceryl trinitrate, isosorbide dinitrate and sodium nitroprusside intravenously on haemodynamics, coronary circulation and myocardial oxygen consumption were investigated in closed chest dogs (n = 8). In an attempt to simulate heart failure the dogs received blood transfusion (15 ml/kg) in the presence of halothane-induced myocardial depression. All three nitrates reduced the loads for the left ventricle. With isosorbide dinitrate and sodium nitroprusside the preload and pulmonary pressure decreased to a greater extent than with glyceryl trinitrate. The haemodynamic results suggest that sodium nitroprusside is the favourable nitrate in left ventricular failure because it produces a balanced reduction in the ratio of pre- and afterload. Four micrograms/kg X min sodium nitroprusside induced marked coronary dilatation; glyceryl trinitrate had only a slight coronary vasodilating effect. With isosorbide dinitrate the myocardial blood flow remained well adapted to oxygen demand, the coronary vascular resistance did not change. Sodium nitroprusside produced a significant change of the transmural myocardial blood distribution-expressed as the epi/endocardial blood flow ratio. The ratio was increased by sodium nitroprusside, much more than by glyceryl trinitrate or isosorbide dinitrate. [ABSTRACT FROM AUTHOR]

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