Series Of Different Conditions Research Articles

Mechanism of self-reaction evolution of Fe@ Al2O3 catalyst for growing carbon nanotube array

In this work, for the synthesis of CNT arrays, a one-step heat-treated aluminum foil substrate-supported Fe(NO3)3 solution “self-reactive process” was developed to prepare Fe@Al2O3 nanoparticles with a diameter of about 20 nm and a catalyst layer thickness of about 2–3 mm. The results show that the key to maintain the small nanoparticle state is the interfacial interaction between the metal and the metal oxide, which enables the Fe nanoparticles to anchor on the Al2O3 surface and effectively prevents the aggregation or segregation of the Fe nanoparticles. Furthermore, by comparing the characterization parameters of the catalyst nanoparticles prepared under a series of different conditions, it was found that the aluminum foil substrate was oxidized to Al2O3 by the Fe(NO3)3 precursor in a one-step heat treatment, which could be explained by the oxidation of nitrate ions. Meanwhile, the core-shell structure formed by some of the Al2O3 particles with the catalyst prevented the agglomeration of the catalyst during the reduction process by co-deposition of metal oxides with Fe catalyst. This method saves a lot of time compared with other catalyst preparation methods for growing CNT.

Efficiency stability of HPGe detectors under distinct count rates

In this work the reproducibility of the efficiency of different HPGe detectors was analyzed under a series of different conditions. The detectors studied were plugged either to a regular analogical amplifier or to a digital signal processing (DSP) device, in order to evaluate the possible differences between either setup. Detectors were inspected by performing a long series of sequential measurements with standard calibration sources, and comparing the standard deviation of the number of counts per second in each series to the uncertainty of the individual measurements. Detectors were also subjected to distinct count rates, in order to verify the possible experimental issues associated with this parameter. The results allow a discussion on the stability of the detectors’ efficiencies over a few days, the possible dependence with the count rate, and the estimation of the uncertainty related to the efficiency variation.

Serial co-expression analysis of host factors from SARS-CoV viruses highly converges with former high-throughput screenings and proposes key regulators.

The current genomics era is bringing an unprecedented growth in the amount of gene expression data, only comparable to the exponential growth of sequences in databases during the last decades. This data allow the design of secondary analyses that take advantage of this information to create new knowledge. One of these feasible analyses is the evaluation of the expression level for a gene through a series of different conditions or cell types. Based on this idea, we have developed Automatic and Serial Analysis of CO-expression, which performs expression profiles for a given gene along hundreds of heterogeneous and normalized transcriptomics experiments and discover other genes that show either a similar or an inverse behavior. It might help to discover co-regulated genes, and common transcriptional regulators in any biological model. The present severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is an opportunity to test this novel approach due to the wealth of data that are being generated, which could be used for validating results. Thus, we have identified 35 host factors in the literature putatively involved in the infectious cycle of SARS-CoV viruses and searched for genes tightly co-expressed with them. We have found 1899 co-expressed genes whose assigned functions are strongly related to viral cycles. Moreover, this set of genes heavily overlaps with those identified by former laboratory high-throughput screenings (with P-value near 0). Our results reveal a series of common regulators, involved in immune and inflammatory responses that might be key virus targets to induce the coordinated expression of SARS-CoV-2 host factors.

Pelvic floor dysfunctions: how to image patients?

Pelvic floor dysfunctions embrace a large series of different conditions in which functional abnormalities of the pelvic floor lead to impairment in urinary and sexual functions and in rectal voiding. A multidisciplinary approach is needed in the evaluation of these patients, as well as the adoption of imaging studies adequate to explore the complex anatomy of the region and its dynamic functionality. Available imaging studies include: endoanal and transperineal ultrasound, X-ray defecography and MR defecography. The purpose of this review article is to illustrate the technique, indications, the current role, and diagnostic value of each one of these. The recent availability of new imaging techniques and related advantages will also be discussed.

Removal of formaldehyde from the air with a suspended growth bioreactor

In the present study, the root zone of Canna flaccida Salisb. was selected as the biological component. We found that the adsorption rate of formaldehyde (FA) by C. flaccida was initially low, before increasing substantially. 13CNMR analysis indicated that C. flaccida can metabolize H13CHO and the major metabolic products were organic acid and amino acids. On this basis, we had designed a suspended growth bioreactor (SGB) to remove FA. An SGB was tested under a series of different conditions and the results showed that FA removal efficiency was strongly influenced by water volume, root zone weight, and gas flow rate. More than 52% of the FA was removed in 1 h and the maximum elimination capacity reached 35.112 mg m−3 h−1. After 24 h, no FA remained in the SGB. Running for 15 days, the concentration of FA in the lab space decreased from 1.12 to 0.82 mg m−3, and the concentration of FA in the SGB reached a low level. These results confirmed that SGB is an effective way to remove FA.

Emergency Response Community Effectiveness: A simulation modeler for comparing Emergency Medical Services with smartphone-based Samaritan response

Mobile emergency response applications involving location-based alerts and physical response of networked members increasingly appear on smartphones to address a variety of emergencies. EMS (Emergency Medical Services) administrators, policy makers, and other decision makers need to determine when such systems present an effective addition to traditional Emergency Medical Services. We developed a software tool, the Emergency Response Community Effectiveness Modeler (ERCEM) that accepts parameters and compares the potential smartphone-initiated Samaritan/member response to traditional EMS response for a specific medical condition in a given geographic area. This study uses EMS data from the National EMS Information System (NEMSIS) and analyses geographies based on Rural-Urban Commuting Area (RUCA) and Economic Research Service (ERS) urbanicity codes. To demonstrate ERCEM's capabilities, we input a full year of NEMSIS data documenting EMS response incidents across the USA. We conducted three experiments to explore anaphylaxis, hypoglycemia and opioid overdose events across different population density characteristics, with further permutations to consider a series of potential app adoption levels, Samaritan response behaviors, notification radii, etc. Our model emphasizes how medical condition, prescription adherence levels, community network membership, and population density are key factors in determining the effectiveness of Samaritan-based Emergency Response Communities (ERC). We show how the efficacy of deploying mHealth apps for emergency response by volunteers can be modelled and studied in comparison to EMS. A decision maker can utilize ERCEM to generate a detailed simulation of different emergency response scenarios to assess the efficacy of smartphone-based Samaritan response applications in varying geographic regions for a series of different conditions and treatments.

A radiative transfer model for atmospheric transmission from target to satellite with geodetic coordinates

A radiative transfer model named TSG (atmospheric transmission from Target to Satellite with Geodetic coordinates) was proposed. Compared with MODTRAN, TSG modifies satellite altitude to 300–36,000km, geodetic coordinates of target and satellite can be input together in each calculation, zenith and azimuth angle are automatically calculated according to geodetic coordinates of target and satellite and Greenwich Time. Atmospheric transmissions from target to satellite were calculated and analyzed by TSG. And a series of different conditions were used in TSG validation, validation results show that relative differences of average transmittance and integrated radiance between TSG and MODTRAN are less than 1% and 5% in 2000–3000cm−1, and are less than 8% and 7% in 3000–4000cm−1, respectively. TSG has good computation accuracy, and it is much more convenient than MODTRAN in calculating atmospheric transmission from target to satellite with geodetic coordinates. The results have important significance in target detecting, tracking and recognition.

Preparation and properties of plasma sprayed strontium-doped calcium polyphosphate coating for bone tissue engineering

The purpose of this study was to scale-up the usage of strontium-doped calcium polyphosphate (SCPP) to major load-bearing applications in bone substitute application. SCPP powders were used to prepare biological coatings on titanium (Ti) substrates by plasma-spraying under a series of different conditions. Microstructure and bonding strength (with titanium substrates) of the SCPP coatings were investigated by an inductively coupled plasma-mass spectrometer, X-ray diffraction analysis, a scanning electron microscope and a strength test machine. The results showed the main crystal type of coating remained β-crystal SCPP. The surface and cross-sectional morphologies of coatings showed that the SCPP coatings were fairly dense. The bonding strength between the SCPP and Ti was higher than normal plasma spraying coatings. Furthermore, the research on the interactions between ROS17/2.5 cells and various SCPP coatings-Ti substrates indicated that the coating-implants possessed good cytocompatibility with osteoblasts. Therefore, SCPP is considered to be a biological coating material with good prospect in clinical application.

Synthesis, characterization and kinetics of bentonite supported nZVI for the removal of Cr(VI) from aqueous solution

Bentonite supported nanoscale zero-valent iron (B-nZVI) was synthesized by the sodium borohydride reduction method, characterized with SEM, and used for aqueous Cr(VI) removal. Bentonite decreased nano-Fe0 aggregation and thus increase Cr(VI) removal efficiency. At 35°C and 250rmin−1, 99% Cr(VI) removal was achieved from aqueous solution containing 50mgL−1 of Cr(VI) by B-nZVI, while only 66% removal was achieved with unsupported nZVI after an experimental duration of 3h when the Fe0 loadings were 1.5gL−1. XRD indicated the existence of iron oxide and iron-chromium hydroxide coprecipitation on the surface of B-nZVI after exposure to an aqueous solution of Cr(VI). Kinetics studies under a series of different conditions showed that reduction of Cr(VI) to Cr(III) could be expressed by pseudo first-order reaction kinetics, with initial Cr(VI) and B-nZVI concentrations, pH and temperature as variables. The apparent activation energy of Cr(VI) remediation by B-nZVI was 21kJmol−1, which was characteristic of a chemically controlled reaction. These results demonstrated that B-nZVI could potentially be used as a new material for use in situ remediation.

Impulsive control of nonlinear systems with time-varying delays

A whole impulsive control scheme of nonlinear systems with time-varying delays, which is an extension for impulsive control of nonlinear systems without time delay, is presented in this paper. Utilizing the Lyapunov functions and the impulsive-type comparison principles, we establish a series of different conditions under which impulsively controlled nonlinear systems with time-varying delays are asymptotically stable. Then we estimate upper bounds of impulse interval and time-varying delays for asymptotically stable control. Finally a numerical example is given to illustrate the effectiveness of the method.

Uso clínico de autoanticuerpos en neurología

Auto-antibody determinations are very important in current clinical practice, not only in immunology or rheumatology but also in the neurosciences. These antibodies have both diagnostic and prognostic implications which, unfortunately, are often overused or are granted undue importance when it comes to interpreting them. On requesting their determination it is therefore necessary to know their indications, utility and application.To present a series of auto-antibodies that are relatively commonly used in neurology and which have primary and secondary effects on both the central and the peripheral nervous system, including the neuromuscular junction and muscle tissue.In this review we cover a series of different conditions, including diseases such as vasculitis, cerebrovascular disease, neurological paraneoplastic syndromes, dysimmune polyneuropathies and inflammatory myopathies. Special attention is given, when relevant, to the indications and, particularly, to the value and weight that should be granted to both positive and negative results.Appropriate interpretation and knowledge of the scope and limitations of auto-antibodies are essential, because otherwise they will lead to mistaken diagnoses and, consequently, erroneous treatment.

Cell-cell adhesion by homophilic interaction of the neuronal recognition molecule axonin-1.

The axonal surface glycoprotein axonin-1, which occurs both as a glycosyl-phosphatidylinositol-anchored membrane-bound form and a secreted form, promotes neurite outgrowth and is thought to be involved in axon-guidance mechanisms in the developing nervous system. Recently, we have demonstrated that the neurite-outgrowth-promoting activity of axonin-1, presented as a substratum for cultured neurons, is mediated by a heterophilic interaction with the axonal glycoprotein neuronglia cell-adhesion molecule (Ng-CAM). Here we present evidence for homophilic (like-like) binding among axonin-1 molecules. Axonin-1 was heterologously expressed in myeloma cells. Clonal cell lines, with exposed membrane-bound axonin-1 at their surface, formed large multicellular aggregates. Incubations of transfected and parental myeloma cells, under a series of different conditions, revealed homophilic axonin-1/axonin-1 interactions across the intermembrane space as the molecular mechanism promoting stable cell-cell contacts. Using structural and functional characterisation, recombinant axonin-1 was very similar to native axonin-1, suggesting that homophilic axonin-1 interactions are also established in neurons. The capability of axonin-1 to interact with both Ng-CAM and other axonin-1 molecules might contribute to the formation of macromolecular networks at contact sites of growth cones and axons, comprising molecules of both membranes, and thus represent a mechanism for regulating neurite outgrowth and pathfinding.

An index to quantify the apparent regulation of orthophosphate concentration in mammalian cells

We have shown previously that the concentration of orthophosphate (P,) in human erythrocytes and skeletal muscle is regulated in response to changes in the extracellular Pi concentration (Bevington et al., 1986). This is in marked contrast to earlier reports that P, simply distributes passively between mammalian cells and extracellular fluid (Deuticke, 1967; Tenenhouse & Scriver, 1975). To compare the extent of regulation of the cellular PI concentration between cell types or in a given cell type under a series of different conditions, some convenient method is needed to quantify the regulation. Wc therefore propose the following phosphate regulation index, p . If the relationship between the extracellular P, concentration (C, in mmol/l) and the cellular P, concentration (C,) is approximately linear, so that Cz = a + bC,, p is taken to be the ratio of the steady-state cellular P, concentration when C , = 0 to the cellular Pi concentration when C , = 1 mM, so that p = a / ( a + 6 ) . The value of 1 mM is chosen for the second extracellular P, concentration as this is approximately the concentration in normal human extracellular fluid. This index has some useful properties. In a cell which can regulate its P, concentration perfectly so that C', is constant as C, varies, p = 1; whereas in a cell in which P, is passively distributed so that C, is directly proportional to C,, p = 0. A furthcr advantage is that p is the ratio of two cellular P, concentrations, so that it is independent of the units in which the concentrations are expressed (e.g. mmol/l of cell water, or pmol/mg of protein). In Table 1 we summarize 10 published studies of the relationship betwecn C, and C, from which values of p can be derived. In seven of the 10 studies the relationship deviates markedly from that expected if P, distributes passively (because p 0.4). In -human erythrocytes, p seems to depend on the precise conditions under which it is measured.

The adsorption of gold sols on asbestos surface charge sites

The adsorption of gold sols on the surface of amosite and chrysotile asbestos has been investigated under a series of different conditions. The gold sols had diameters near 300 Å and their negative charge was measured by an electrophoresis technique. Asbestos fibres were added to sol solutions with pH from 5.0 to 6.8 and the location and density of the deposited sols were determined by electron microscopy. Per cent surface area coverage by sols ranged from 11 to 4% for amosite and 27 to 3% for chrysotile. The surface coverages were interpreted to give the amount and location of the surface charges for the asbestos fibres as a function of solution pH. The results were also correlated with the surface ion impurities as measured for the asbestos samples (reported here) and the zeta potentials for similar asbestos (as reported elsewhere). In general, it is concluded that for chrysotile, which has a positive zeta potential, the negative sols are attracted to Mg 2+ or impurity cation sites on the brucite surface layer. On the other hand, since amosite and the sols both have negative zeta potentials, a specific adsorption mechanism possibly involving Fe 3+ ions on the amosite surface is required. These results were compared with predictions of a current calculation of charged surface interactions in an electrolytic solution [1].

The fading of radio waves of medium and high frequencies

The fading of radio waves of medium and high frequencies returned from the ionosphere is analysed. The experimental data on high frequencies were recorded by the author at normal incidence using a pulse transmitter, and, when necessary, a circularly polarized receiving aerial. The medium-frequency records were made by the B.B.C. using continuous-wave transmissions from broadcasting stations at different distances up to 1 500 kilometres.A review is given of some theories suggested to explain the production of fading in terms of an ionosphere with varying irregularities in the horizontal plane. The theoretical nature of the fading curve, both with regard to the distribution of amplitude and the variation with time, is indicated, and is compared with experimental results.It is shown that all fading curves can be explained in terms of a wave which is the sum of a steady, specularly reflected component, and a random component with a Rayleigh distribution of amplitude. The relative magnitudes of these two components have been determined for a series of different conditions, and the results are summarized. It is also shown that the rate of variation of the amplitude of the received signal is approximately, but not exactly, in accord with the theories, and from this rate of change it is possible to calculate the “effective velocity” of the irregularities in the ionosphere. If the fading is caused by irregular “turbulent” motions of the irregularities, the “effective velocity” is the r.m.s. velocity of these motions; if it is due to a steady drift of the irregular ionosphere as a whole with a velocity vw, then the “effective velocity” is approximately equal to vw/14. The “effective velocities” deduced from 122 records made at vertical incidence, and 55 made at oblique incidence, lie between 0.3 and 8.0 m/sec and have an average value of 1.9 m/sec.