Development of an open-tubular trypsin reactor for on-line digestion of proteins

A study was initiated to construct a micro-reactor for protein digestion based on trypsin-coated fused-silica capillaries. Initially, surface plasmon resonance was used both for optimization of the surface chemistry applied in the preparation and for monitoring the amount of enzyme that was immobilized. The highest amount of trypsin was immobilized on dextran-coated SPR surfaces which allowed the covalent coupling of 11 ng mm−2 trypsin. Fused-silica capillaries were modified in a similar manner and the resulting open-tubular trypsin-reactors having a pH optimum of pH 8.5, display a high activity when operated at 37 °C and are stable for at least two weeks when used continuously. Trypsin auto-digestion fragments, sample carry-over, and loss of signal due to adsorption of the protein were not observed. On-line digestion without prior protein denaturation, followed by micro-LC separation and photodiode array detection, was tested with horse-heart cytochrome C and horse skeletal-muscle myoglobin. The complete digestion of 20 pmol μL−1 horse cytochrome C was observed when the average residence time of the protein sample in a 140 cm ×50 μm capillary immobilized enzyme reactor (IMER) was 165 s. Mass spectrometric identification of the injected protein on the basis of the tryptic peptides proved possible. Protein digestion was favorable with respect to reaction time and fragments formed when compared with other on-line and off-line procedures. These results and the easy preparation of this micro-reactor provide possibilities for miniaturized enzyme-reactors for on-line peptide mapping and inhibitor screening

Формирование и продвижение кредитных продуктов и услуг

Кредитная услуга - одна из составляющих кредитной политики банка. Стремление к максимальному получению прибыли от ее предоставления и увеличению потока клиентов приводит к созданию комплекса (совокупности) услуг, а именно - кредитному продукту. Изучив интересы хозяйствующих субъектов, их потребности, банк может более точно разрабатывать приоритеты кредитной политики во взаимоотношениях с реальным сектором экономики. Обратная зависимость этого фактора - создание конкретного кредитного продукта и построение системы продвижения кредитных услуг, которая призвана осуществлять анализ, диагностику текущей ситуации, обеспечение взаимодействия между банками, нацелить взаимоотношения банка и заемщика на долгосрочную перспективу

Cascade Boltzmann - Langevin approach to higher-order current correlations in diffusive metal contacts

The Boltzmann - Langevin approach is extended to calculations of third and fourth cumulants of current in diffusive-metal contacts. These cumulants result from indirect correlations between current fluctuations, which may be considered as "noise of noise". The calculated third cumulant coincides exactly with its quantum-mechanical value. The fourth cumulant tends to its quantum-mechanical value $-e^3I/105$ at high voltages and to a positive value $2e^2T/3R$ at V=0 changing its sign at $eV \sim 20T$.Comment: 6 pages, 2 eps figures, typo corrected, minor change

The Baryonic Tully-Fisher Relation

We explore the Tully-Fisher relation over five decades in stellar mass in galaxies with circular velocities ranging over 30 < Vc < 300 km/s. We find a clear break in the optical Tully-Fisher relation: field galaxies with Vc < 90 km/s fall below the relation defined by brighter galaxies. These faint galaxies are however very gas rich; adding in the gas mass and plotting baryonic disk mass Md = M* + Mg in place of luminosity restores a single linear relation. The Tully-Fisher relation thus appears fundamentally to be a relation between rotation velocity and total baryonic mass of the form Md = A Vc^4.Comment: 10 pages including 1 color figure. Accepted for publication in ApJ Letter

Physical Conditions and Star Formation Activity in the Intragroup Medium of Stephan's Quintet

New multi-band observations of the famous compact group of galaxies Stephan's Quintet (SQ) are presented and analyzed. These include far infrared (FIR) images at 60$\mu m$ and 100$\mu m$ (ISOPHOT C-100 camera), radio continuum images at 1.4 GHz (VLA B-array) and 4.86 GHz (VLA C-array), and long-slit optical spectrographs (Palomar $200"$ telescope). With these new data, we aim to learn more about the X-ray/radio ridge in the middle of the intragroup medium (IGM) and the IGM starburst SQ-A, both are likely to be caused by the high speed collision ($\sim 900$ km s$^{-1}$) between the intruder galaxy NGC 7318b ($v = 5700$ km s$^{-1}$) and the IGM ($v = 6600$ km s$^{-1}$).Comment: 31 pages text, 17 figures. Accepted by ApJ. A PS file including all figures can be found in http://spider.ipac.caltech.edu/staff/cxu/preprints/sq/apj_sq.ps.g

The Disk and Dark Halo Mass of the Barred Galaxy NGC 4123. I. Observations

The non-circular streaming motions in barred galaxies are sensitive to the mass of the bar and can be used to lift the degeneracy between disk and dark matter halo encountered when fitting axisymmetric rotation curves of disk galaxies. In this paper, we present photometric and kinematic observations of NGC 4123, a barred galaxy of modest size (V_rot = 130 km/sec, L = 0.7 L_*), which reveal strong non-circular motions. The bar has straight dust lanes and an inner Lindblad resonance. The disk of NGC 4123 has no sign of truncation out to 10 scale lengths, and star-forming regions are found well outside R_25. A Fabry-Perot H-alpha velocity field shows velocity jumps of >100 km/sec at the location of the dust lanes within the bar, indicating shocks in the gas flow. VLA observations yield the velocity field of the H I disk. Axisymmetric mass models yield good fits to the rotation curve outside the bar regionfor disk I-band M/L of 2.25 or less, and dark halos with either isothermal or power-law profiles can fit the data well. In a companion paper, we model the full 2-D velocity field, including non-circular motions, to determine the stellar M/L and the mass of the dark halo.Comment: accepted by ApJ, 16 pages, 9 figures (1 color), uses emulateapj.sty, onecolfloat.st

POLY(TRIMETHYLENE CARBONATE)AND POLY(D,L-LACTIC ACID) MODIFY HUMAN DENDRITIC CELL RESPONSES TO STAPHYLOCOCCI BUT DO NOT AFFECT Th1 AND Th2 CELL DEVELOPMENT

Biomaterial-associated infections (BAIs) are frequent complications in the use of medical devices (biomaterials) correlated with considerable patient discomfort and high treatment costs. The presence of a biomaterial in the host causes derangement of local immune responses increasing susceptibility to infection. Dendritic cells (DCs) have an important role in directing the nature of immune responses by activating and controlling CD4+ T helper (Th) cell responses. To assess the immunomodulatory effect of the combined presence of biomaterials and Staphylococcus aureus (S. aureus) or Staphylococcus epidermidis (S. epidermidis), DC-mediated T cell proliferation and Th1/Th2 cell development were measured using an in vitro human cell system. Poly(trimethylene carbonate) (PTMC) and poly(D,L-lactic acid) (PDLLA) modified the production of the DC pro-inflammatory cytokines TNF-α, IL-6 and IL-23 in response to S. aureus and S. epidermidis. However, this modified cytokine production did not cause differences in Th1/Th2 cell polarisation, showing a Th1 cell predominance. In the absence of staphylococci, neither of the biomaterials induced DC-mediated T cell proliferation or Th1/Th2 cell polarisation. Moreover, either in the absence or presence of the biomaterials, S. aureus was a more potent inducer of DC cytokine secretion, T cell proliferation and Th1 cell development than S. epidermidis. In conclusion, although PTMC and PDLLA modulated DC cytokine responses to staphylococci, this did not alter the resulting Th cell development. This result suggested that, in this human cell model, Th1/Th2 cell responses were mainly determined by the species of bacteria and that PTMC or PDLLA did not detectably influence these responses

Andreev Reflection In Ferromagnet-Superconductor Junctions

The transport properties of a ferromagnet-superconductor (FS) junction are studied in a scattering formulation. Andreev reflection at the FS interface is strongly affected by the exchange interaction in the ferromagnet. The conductance G_FS of a ballistic point contact between F and S can be both larger or smaller than the value G_FN with the superconductor in the normal state, depending on the ratio of the exchange and Fermi energies. If the ferromagnet contains a tunnel barrier (I), the conductance G_FIFS exhibits resonances which do not vanish in linear response -- in contrast to the Tomasch oscillations for non-ferromagnetic materials.Comment: 8 pages, RevTeX v3.0, including 3 encapsulated postscript figures; [2017: figures included in text

Stellar science from a blue wavelength range - A possible design for the blue arm of 4MOST

From stellar spectra, a variety of physical properties of stars can be derived. In particular, the chemical composition of stellar atmospheres can be inferred from absorption line analyses. These provide key information on large scales, such as the formation of our Galaxy, down to the small-scale nucleosynthesis processes that take place in stars and supernovae. By extending the observed wavelength range toward bluer wavelengths, we optimize such studies to also include critical absorption lines in metal-poor stars, and allow for studies of heavy elements (Z>38) whose formation processes remain poorly constrained. In this context, spectrographs optimized for observing blue wavelength ranges are essential, since many absorption lines at redder wavelengths are too weak to be detected in metal-poor stars. This means that some elements cannot be studied in the visual-redder regions, and important scientific tracers and science cases are lost. The present era of large public surveys will target millions of stars. Here we describe the requirements driving the design of the forthcoming survey instrument 4MOST, a multi-object spectrograph commissioned for the ESO VISTA 4m-telescope. We focus here on high-density, wide-area survey of stars and the science that can be achieved with high-resolution stellar spectroscopy. Scientific and technical requirements that governed the design are described along with a thorough line blending analysis. For the high-resolution spectrograph, we find that a sampling of >2.5 (pixels per resolving element), spectral resolution of 18000 or higher, and a wavelength range covering 393-436 nm, is the most well-balanced solution for the instrument. A spectrograph with these characteristics will enable accurate abundance analysis (+/-0.1 dex) in the blue and allow us to confront the outlined scientific questions. (abridged)Comment: 14 pages, 8 figures, accepted for publication in A

Shot noise in ferromagnet--normal metal systems

A semiclassical theory of the low frequency shot noise in ferromagnet - normal metal systems is formulated. Non-collinear magnetization directions of the ferromagnetic leads, arbitrary junctions and the elastic and inelastic scattering regimes are considered. The shot noise is governed by a set of mesoscopic parameters that are expressed in terms of the microscopic details of the junctions in the circuit. Explicit results in the case of ballistic, tunnel, and diffusive junctions are evaluated. The shot noise, the current and the Fano factor are calculated for a double barrier ferromagnet - normal metal - ferromagnet system. It is demonstrated that the shot noise can have a non-monotonic behavior as a function of the relative angle between the magnetizations of the ferromagnetic reservoirs.Comment: 17 pages, 7 figure