Sequential Capture Research Articles

Fine particle sorting and classification in the cyclonic centrifugal field

Abstract Fine particle sorting and classification are not only important processes during the powder preparation, but also vital to the sequential separation of discrete fine particles with different sizes. The moving fine particles with different sizes have different trajectories in the cyclonic centrifugal field under the actions of radial and axial forces, which inspire us to develop a novel cyclonic multi-product sorting classifier. Both particle size and mass distribution gradually increase axially from the inlet side to the outlet side and radially from the inside to the outside at the rectangular outlet of the sorting classifier. When the mean particle size of the inlet is 15.7 μm and the coefficient of variance is 90.1%, 12 different particle sizes (the minimum and maximum particle sizes are 8.41 and 26.16 μm, respectively) with better monodispersion are obtained, all products achieve a particle coefficient of variance below 40%. An effective calculation method was used to represent the overall sorting and classification performance of sorting classifiers with different height. The results show that the best height is 5 times as high as the rectangular inlet, and the optimum gas flow is 30–60 m 3 /h with the pressure drop not exceed of 80 Pa. The present study could also serve as a useful guide in the industrial sequential separation and capture of fine particles of different sizes. Notably, it may exhibit a high potential for the control of PM 2.5 throughout studies in future.

Production of 6He and 9Be by radiative capture and four-body recombination

In this work we estimate the production rates for the three-body radiative capture processes α + n + n → 6He + γ and α + α + n → 9Be + γ, as well as the four-body recombination reactions α + α + n + n → 6He + α, α + n + n + n → 6He + n, α + α + n + n → 9Be + n and α + α + α + n → BeBe + α. These processes compete as a source of 6He and 9Be. The hyperspherical adiabatic expansion method is used. With this method no assumption is made about the capture mechanism. Both sequential and direct capture are included. The production rates for the radiative and the four-body recombination processes are found to be comparable for a mass density of about 107g/cm3 ( ∼ 1030 neutrons/cm3) and temperatures of a few GK.

Two-dimensional electron-momentum distributions for transfer ionization in fast proton-helium collisions

The momentum distribution of the electron in the reaction $p$ $+$ He $\ensuremath{\rightarrow}$ H $+$ He${}^{2+}$ $+$ $e$ is measured for projectile energies ${E}_{p}=300$ and 630 keV/u at very small scattering angles of the hydrogen. We present two-dimensional distributions parallel $({k}_{\ensuremath{\parallel}})$ and perpendicular $({k}_{\ensuremath{\perp}})$ to the projectile beam as well as distributions ${k}_{\ensuremath{\parallel}}$ for fixed ${k}_{\ensuremath{\perp}}$. Theoretical calculations were carried out within the plane wave first Born approximation, which includes both mechanisms of the electron emission, namely, the shake-off and the sequential capture and ionization. It is shown that electron correlations in the initial ground-state wave function of the target play the most important role in the explanation of the experimentally observed enhanced backward electron emission.

Impact of Active Patient follow-up on Worst-case Implant Survival Analysis

Patients lost to follow-up pose problems when performing implant survival analysis. We are unaware of any report detailing how implant survival is affected by the sequential capture of patients. To assess the logistics of long-term follow-up of patients undergoing Birmingham Hip Resurfacing (BHR), and to determine what impact this had on implant survival with time. Between 1997 and 2006 data was prospectively collected on consecutive BHR's implanted by a single surgeon in patients under 50 years of age. Survival analysis was performed at monthly intervals during this study with all patients lost to follow-up at any point in time considered to have failed. There were 447 BHR's implanted in 393 patients. At study commencement cumulative 10-year survival was 42% (95% CI 36% to 48%) calculated on the confirmed knowledge of the outcome at that time of 275 BHR's, with the remaining 172 lost to follow-up and considered to have been revised. As patients were actively followed-up there was gradual improvement in survival and narrowing of confidence intervals with a final 10-year BHR survival of 96.3% (95% CI 93.7% to 98.3%) with no loss to follow-up. The findings demonstrate improvement in long-term implant survival with the sequential capture of young and active patients undergoing BHR who were initially considered lost to follow-up. The results reiterate the recommendation that every effort should be made to follow all patients up after joint replacement. This will improve the accuracy of survival reporting and assist comparison between different prostheses.

The entitlements of unallied hunters after a sequential capture

As the famous fox case of Pierson v Post illustrates, rival hunters who have separately contributed to the capture of a wild animal may have different notions about which of them owns the prey. During the Stone Age, hunter-gatherers likely developed sophisticated norms to resolve these sorts of controversies. Each of the contributors to this symposium focuses on common law property rights in prey that North American judges articulated during the nineteenth century. Their articles analyse the rules of the game that applied in the Newfoundland sealery, North Pacific whaling grounds, and rural Long Island. In each setting, both hunters and judges tailored the applicable rules of capture to the characteristics of the hunted animal. When hunters’ customs were opaque, as they commonly were, judges sought to crystallize definitive legal rules. The articles in the symposium strikingly illustrate the gulf between ‘humanistic’ and ‘scientific’ styles of legal analysis.

Magnesium Augments Platelet Activation and Coagulation in Citrated Blood Product

AbstractAbstract 3438Massive transfusion is defined as infusion of 10 units of red blood cells in 24 hours during treatment of uncontrolled bleeding. Mortality rates are 28.3% higher for patients that undergo massive transfusion. Administered blood products are collected from donors using citrate inhibition for anti-coagulation. Citrate chelates calcium, thus preventing its interactions with clotting enzymes and eliminating coagulation activity. Severe trauma patients suffer compromised liver function slowing citrate clearance and further reducing calcium availability. Under this scenario, calcium is empirically replaced due to concerns regarding hemostasis, however magnesium, which is also chelated by citrate, is not empirically replaced. Our goal was to describe both platelet aggregation and coagulation under conditions of increasing magnesium concentration following citrate chelation to ascertain the true spectrum of magnesium influence upon hemostasis.To analyze platelet activation/aggregation, de-identified whole blood (WB) was anti-coagulated with citrate (10.9mM) and corn trypsin inhibitor (CTI) (0.1mg/mL), or citrate and 50μL pPACK (final). Platelet-rich plasma (PRP) was prepared through centrifugation at 200g for 10 minutes. Subsequent spin at 2000g for 10 minutes yielded platelet-poor plasma (PPP). Remaining packed red blood cells were combined with PRP (platelets calcein-tagged to 10μM final) to simulate 40% hematocrit. Shear rate of 920/sec was induced for arterial flow conditions for 10 minutes at 37°C through a microchannel (350μm W × 70μm H × 5000μm L) pre-coated with a solution of 100μg/mL type-I collagen blocked with 0.5% BSA/1X PBS. Fluorescent signal intensity of calcein-tagged platelets was quantified through sequential image capture every 30 seconds using Fluxion BioFlux 1000. For coagulation analyses, citrate/CTI inhibited WB, PRP, and PPP was analyzed via thromboelastograph (TEG) following large volume pre-mixing with tissue factor (1:5000). TEG cups were preloaded with varying concentrations of calcium chloride (0M, 5.5mM, 10.9mM, 15mM), or calcium chloride (15mM) with magnesium sulfate (0M, 3mM, 3.5mM, 4.5mM) before blood or component addition. TEG data were collected for 90 minutes. Statistical analyses were performed with GraphPad Prism 5 software. Comparisons were drawn using linear analysis and area under the curve.Data indicate that re-attainment of physiological magnesium concentration in citrated blood: (1) facilitates platelet activation/aggregation, and (2) augments coagulation parameters through accelerated clot time and increased clot strength. Rate of platelet aggregation was significantly increased at final magnesium concentrations of 1.5mM (p<0.01), and 3mM (p<0.005) when added to re-calcified WB. Further, addition of magnesium to PPP reduced time to initiation of clot formation (4.5mM), increased clot strength (1mM, 3mM), and increased rate of clot formation (1mM, 3mM). These data suggest supplemental magnesium improves hemostatic properties in citrated WB and PPP with or without re-calcification. The incidence and severity of hypocalcemia and hypomagnesimia in massive transfusion, and effects on hemostatic function remain to be established. Replacement of magnesium during massive transfusion may represent a therapeutic opportunity. Disclosures:No relevant conflicts of interest to declare.

Nanosilica-supported polyethoxyamines as low-cost, reversible carbon dioxide sorbents

Novel hybrid quasi-solid-state sorbents pairing inexpensive CO2-reactive polyethoxyamine (Jeffamine®) fluids with an abundantly available silica support have been investigated for carbon capture. The highest performance sorbent was capable of reversibly capturing close to 70mg of CO2 per gram of sorbent at 45°C, could be almost fully (∼90%) regenerated by simple vacuum swing, and was stable over many sequential capture–release cycles. The new supports can be handled as solventless, free-flowing powders even post-CO2 capture, obviating the mass flow problems arising from viscous liquid (or solid, gel, or wax) formation frequently attending carbamate formation. Our results have important ramifications for reducing the high costs of thermal regeneration in conventional carbon capture schemes, particularly in comparison with the aqueous monoethanolamine-based system currently favoured industrially. The strategy of uniformly dispersing a functional fluid onto a solid nanosupport in a manner that allows intimate contact with and diffusion of external gaseous species is additionally projected to find value in a range of gas separation and sensing endeavours.

Direct hole and delayed electron capture on a picosecond timescale by Eu2+ centers in CaGa2S4 monitored by synchroscan with horizontal blanking

A Eu2+ concentration and temperature dependent energy transfer study from the host lattice to Eu2+ luminescence centers in Ca(1–x)EuxGa2S4 (x = 0.001 to 0.05) was performed with a special streak camera that combines the high timing resolution of a conventional synchroscan operation (&amp;lt;2 ps) with the ability to study long lived states (10 ns − 1 ms) typical for rare earth and transition metal ions. Two transfer mechanisms from the CaGa2S4 host lattice to the Eu2+ ions were identified. A fast transfer process (&amp;lt;4 ps) is interpreted as sequential hole-electron capture by the Eu2+ ions, and slower process (&amp;gt;1 ns) is interpreted as the sequential capture of a hole and an electron by Eu2+ but with the electron first entering an intermediate state trapped near Eu3+. Energy transfer via a self-trapped excitonic (STE) state is unlikely because of the absence of an anti-correlation between the STE decay-time and the Eu2+ rise-time as well as between the STE emission intensity and the Eu2+ intensity. All rise-time spectra were successfully fitted with a model representing the above transfer mechanisms.

Study on the Luminescence and Energy Level of Lanthanide Ions in Lu0.8Sc0.2BO3 Host

Emission and excitation spectra of undoped and Ln(3+) (Ln = Ce, Pr, Nd, Yb)-doped Lu(0.8)Sc(0.2)BO(3) were studied by vacuum ultraviolet spectroscopy, and the X-ray excited luminescence spectra were measured as well at room temperature. The undoped specimen presented two different emissions upon excitation at energies in the vicinity of the band gap or with X-ray. The emission at the highest energy side, located at 4.77 eV, was ascribed to self-trapped exciton, which is anchored by electron capture around the Sc site. We also observed three broad emission bands at 4.43, 3.02, and 2.10 eV, which might be attributed to the trapped exciton, defect -related emissions, or both. Energy transfer processes to the doped lanthanide ions in Lu(0.8)Sc(0.2)BO(3) via exciton state or sequential electron-hole capture are discussed. Finally, the energy level diagram for divalent and trivalent lanthanides in Lu(0.8)Sc(0.2)BO(3) was constructed using the obtained spectroscopic parameters and the three parameters method (Dorenbos, P. J. Phys.: Condens. Matter 2003, 15, 8417).

Generation of monospecific antibodies based on affinity capture of polyclonal antibodies

A method is described to generate and validate antibodies based on mapping the linear epitopes of a polyclonal antibody followed by sequential epitope-specific capture using synthetic peptides. Polyclonal antibodies directed towards four proteins RBM3, SATB2, ANLN, and CNDP1, potentially involved in human cancers, were selected and antibodies to several non-overlapping epitopes were generated and subsequently validated by Western blot, immunohistochemistry, and immunofluorescence. For all four proteins, a dramatic difference in functionality could be observed for these monospecific antibodies directed to the different epitopes. In each case, at least one antibody was obtained with full functionality across all applications, while other epitope-specific fractions showed no or little functionality. These results present a path forward to use the mapped binding sites of polyclonal antibodies to generate epitope-specific antibodies, providing an attractive approach for large-scale efforts to characterize the human proteome by antibodies.

Direct and sequential radiative three-body reaction rates at low temperatures

We investigate the low-temperature reaction rates for radiative capture processes of three particles. We compare direct and sequential capture mechanisms and rates using realistic phenomenological parametrizations of the corresponding photodissociation cross sections.Energy conservation prohibits sequential capture for energies smaller than that of the intermediate two-body structure. A finite width or a finite temperature allows this capture mechanism. We study generic effects of positions and widths of two- and three-body resonances for very low temperatures. We focus on nuclear reactions relevant for astrophysics, and we illustrate with realistic estimates for the $\alpha$-$\alpha$-$\alpha$ and $\alpha$-$\alpha$-$n$ radiative capture processes. The direct capture mechanism leads to reaction rates which for temperatures smaller than 0.1 GK can be several orders of magnitude larger than those of the NACRE compilation.

Homologous Mukaiyama Reactions via Trapping of the Nazarov Intermediate with Silyloxyalkenes

Treatment of 1,4-pentadien-3-ones and silyloxyalkenes with BF(3)·OEt(2) at room temperature or lower initiates a domino process consisting of sequential 4π electrocyclization and capture of the resulting cyclopentenyl cation by the electron-rich trap. The overall process furnishes 1,4-dicarbonyl products containing highly substituted cyclopentanones in good yields and with the establishment of up to five new stereocenters.

Enhanced Sequential Carrier Capture into Individual Quantum Dots and Quantum Posts Controlled by Surface Acoustic Waves

Individual self-assembled quantum dots and quantum posts are studied under the influence of a surface acoustic wave. In optical experiments we observe an acoustically induced switching of the occupancy of the nanostructures along with an overall increase of the emission intensity. For quantum posts, switching occurs continuously from predominantly charged excitons (dissimilar number of electrons and holes) to neutral excitons (same number of electrons and holes) and is independent of whether the surface acoustic wave amplitude is increased or decreased. For quantum dots, switching is nonmonotonic and shows a pronounced hysteresis on the amplitude sweep direction. Moreover, emission of positively charged and neutral excitons is observed at high surface acoustic wave amplitudes. These findings are explained by carrier trapping and localization in the thin and disordered two-dimensional wetting layer on top of which quantum dots nucleate. This limitation can be overcome for quantum posts where acoustically induced charge transport is highly efficient in a wide lateral matrix-quantum well.

Bicaudal-D binds clathrin heavy chain to promote its transport and augments synaptic vesicle recycling

Cargo transport by microtubule-based motors is essential for cell organisation and function. The Bicaudal-D (BicD) protein participates in the transport of a subset of cargoes by the minus-end-directed motor dynein, although the full extent of its functions is unclear. In this study, we report that in Drosophila zygotic BicD function is only obligatory in the nervous system. Clathrin heavy chain (Chc), a major constituent of coated pits and vesicles, is the most abundant protein co-precipitated with BicD from head extracts. BicD binds Chc directly and interacts genetically with components of the pathway for clathrin-mediated membrane trafficking. Directed transport and subcellular localisation of Chc is strongly perturbed in BicD mutant presynaptic boutons. Functional assays show that BicD and dynein are essential for the maintenance of normal levels of neurotransmission specifically during high-frequency electrical stimulation and that this is associated with a reduced rate of recycling of internalised synaptic membrane. Our results implicate BicD as a new player in clathrin-associated trafficking processes and show a novel requirement for microtubule-based motor transport in the synaptic vesicle cycle.

Abstract A28: Improving detection through SELF (selective excitation light fluorescence) imaging

Abstract The use of fluorescence imaging and spectroscopy for the detection of early neoplastic epithelial lesions has been well established, with clinically adopted devices in for use in the lung (Onco-LIFE, SAFE-1000, etc), the oral cavity (VELScope and Identaf 3000) and others in development for the cervix and dermatology. Primarily these imaging technologies make use of fluorescence excitation illumination of a single wavelength (predominately in the near UV to blue wavelength ranges) and differentiate between normal and not normal tissue based upon intensity changes and spectral shifts in the emitted tissue autofluorescence (not normal -darker with less green or blue relative the red fluorescence). SELF imaging makes use of a multitude of illumination wavelengths to specifically couple to the action spectra of the fluorophores within the tissue to enhance the differentiation between tissue states, fluorophores and their immediate environment. This methodology makes use of the different absorption spectra (action spectra) of different fluorophores or similar flourophores in different environments. Conventionally this can be done through the sequential illumination with many different excitation wavelengths and sequential image capture, to collect a hyperspectral excitation image data cube followed by some form of spectra unmixing to resolve the individual targets (components) contributing to the image. Each target is identified by a unique weighted sum of pixel intensities across the excitation wavelengths in the data cube. Through the use of a programmable light source such as the OneLight (OneLight Corp.) in which not only the wavelengths of the illumination light, but their individual intensities (alone or in combination) can be selected under computer control it is possible to not only rapidly illuminate with separate excitation wavelengths but to illuminate with a collection of weighted (each wavelength has a different selected intensity) spectra to specifically couple to selected fluorescence targets (specific fluorophores or fluorophores in specific local environments). Thus instead of needing to illuminate with a series of 10 separate excitation wavelengths and collect separate 10 images on can illuminate with a few (2–3) weighted profiles of excitation wavelengths and collect a few (2–3) images, the number of spectra used (images collected) determines the number of targets differentiated. In this fashion it is possible to detect in an image many more specific flourophore types than with conventional fluorescence imaging. SELF imaging in microscopy, wide field macroscopic imaging and ex vivo and in vivo imaging has been demonstrated and will be presented. Citation Information: Cancer Prev Res 2010;3(1 Suppl):A28.

Sex-Related Mortality of White Ibis(Eudocimus albus)Nestlings During a Starvation Event

Abstract During a time of food stress, we observed sex-biased mortality during the nestling stage in a sexually size dimorphic species of wading bird, the White Ibis (Eudocimus albus). Over four days spread out over a week, we captured a total of 180 25–32 d old White Ibis nestlings from a colony of several thousand breeding pairs. On sequential capture dates we caught significantly fewer females than males. Through this time period male nestlings had higher body condition indices (mass/tarsus) than females, though the rates at which male and female body condition increased over the week were not significantly different. Several sources of evidence suggest that our sampling was not sex-biased and was reflective of actual changes in abundance of males and females. These data indicate that despite the greater caloric requirements of males, their larger size may have conferred a competitive advantage over female siblings in obtaining food from parents during a time of food shortage.

Trypanosoma brucei RNA Binding Proteins p34 and p37 Mediate NOPP44/46 Cellular Localization via the Exportin 1 Nuclear Export Pathway

We have previously identified and characterized two novel nuclear RNA binding proteins, p34 and p37, which have been shown to interact with a family of nucleolar phosphoproteins, NOPP44/46, in Trypanosoma brucei. These proteins are nearly identical, the major difference being an 18-amino-acid insert in the N terminus of p37. In order to characterize the interaction between p34 and p37 and NOPP44/46, we have utilized an RNA interference (RNAi) cell line that specifically targets p34 and p37. Within these RNAi cells, we detected a disruption of a higher-molecular-weight complex containing NOPP44/46, as well as a dramatic increase in nuclear NOPP44/46 protein levels. We demonstrated that no change occurred in NOPP44/46 mRNA steady-state levels or stability, nor was there a change in cellular protein levels. These results led us to investigate whether p34 and p37 regulate NOPP44/46 cellular localization. Examination of the p34 and p37 amino acid sequences revealed a leucine-rich nuclear export signal, which interacts with the nuclear export factor exportin 1. Immune capture experiments demonstrated that p34, p37, and NOPP44/46 associate with exportin 1. When these experiments were performed with p34/p37 RNAi cells, NOPP44/46 no longer associated with exportin 1. Sequential immune capture experiments demonstrated that p34, p37, NOPP44/46, and exportin 1 exist in a common complex. Inhibiting exportin 1-mediated nuclear export led to an increase in nuclear NOPP44/46 proteins, indicating that they are exported from the nucleus via this pathway. Together, our results demonstrate that p34 and p37 regulate NOPP44/46 cellular localization by facilitating their association with exportin 1.

Sequential Capture of CO2 and SO2 in a Pressurized TGA Simulating FBC Conditions

Four FBC-based processes were investigated as possible means of sequentially capturing SO2 and CO2. Sorbent performance is the key to their technical feasibility. Two sorbents (a limestone and a dolomite) were tested in a pressurized thermogravimetric analyzer (PTGA). The sorbent behaviors were explained based on complex interaction between carbonation, sulfation, and direct sulfation. The best option involved using limestone or dolomite as a SO2-sorbent in a FBC combustor following cyclic CO2 capture. Highly sintered limestone is a good sorbent for SO2 because of the generation of macropores during calcination/carbonation cycling.

Two-neutron capture reactions and therprocess

Rates for the 4He(2n, γ )6He and 6He(α, n)9Be reactions have been calculated, including both resonant and nonresonant contributions. The sequential two-neutron capture process on 4He has also been reevaluated on the basis of new experimental results. It is shown that a one-step dineutron capture reaction may enhance the sequential two-neutron reaction rate by several orders of magnitude. This opens the possibility that reaction flow through 4He(2n, γ )6He(α, n)9Be may occur in competition with the bottle-neck three-body reactions 4He(2α, γ )12C and the 4He(αn, γ )9Be that initiate the α process and provide seed nuclei for the r process. Here we explore the effect of such dineutron capture on r-process nucleosynthesis. We show that such reactions have little effect on the final abundance and would change only r-process abundances in an extremely neutron-rich low-temperature r process.

A New Camera for High-Resolution Infrared Imaging of Works of Art

A new camera - SIRIS (scanning infrared imaging system) - developed at the National Gallery in London, UK allows highresolution images to be made in the near infrared region (900-1700 nm). The camera is based on a commercially available 320 × 256 pixel indium gallium arsenide area array sensor. This relatively small sensor is moved across the focal plane of the camera using two orthogonal translation stages to give images of c. 5000 × 5000 pixels. The main advantages of the SIRIS camera over scanning infrared devices or sequential image capture and mosaic assembly are its comparative portability and rapid image acquisition - making a 5000 × 5000 pixel image takes less than 20 minutes. The SIRIS camera can operate at a range of resolutions, from around 2.5 pixels per millimetre over an area of up to 2 × 2 m to 10 pixels per millimetre when examining an area measuring 0.5 × 0.5 m. The development of the mechanical, optical and electronic components of the camera, including the design of a new lens, is described. The software used to control image capture and to assemble the individual frames into a seamless mosaic image is mentioned. The camera was designed primarily to examine underdrawings in paintings; preliminary results from test targets and paintings imaged in situ are presented and the quality of the images compared with those from other cameras currently used for this application.