Water contamination of urban areas by pharmaceuticals

The occurrence and fate data of pharmaceuticals in the environment were described in the article. The main list of pharmaceuticals groups identified in surface and sewage waters was shown according to studies of laboratories in the U.S. and Europe. The main approaches for reduction of pharmaceuticals releasing into environment and monitoring of surface water were considered

CD21-/low B cells: a snapshot of a unique B cell subset in health and disease

B cells represent one of the cellular components of the immune system thatprotects the individual from invading pathogens. In response to the invader,these cells differentiate into plasma cells and produce large amounts of antibodiesthat bind to and eliminate the pathogen. A hallmark of autoimmune diseases isthe production of autoantibodies i.e. antibodies that recognize self. Those that areconsidered pathogenic can damage tissues and organs, either by direct binding orwhen deposited as immune complexes. For decades, B cells have been consideredto play a major role in autoimmune diseases by antibody production. However, aspathogenic autoantibodies appear to derive mainly from T cell dependentresponses, T cells have been the focus for many years. The successful treatment ofpatients with autoimmune diseases with either B cell depletion therapy(rituximab) or inhibition of B cell survival (belimumab), suggested that notonly the autoantibodies but also other B cell features are important. This hascaused a surg e of interest in B cells and their biology resulting in theidentification of various subsets e.g. regulatory B cells, several memory B cellsubsets etc. Also, in other conditions such as chronic viral infect ions and primaryimmunodeficiency, several B cell subsets with unique characteristics have beenidentified. In this review, we will discuss one of these subsets, a subset that isexpanded in conditions characterized by chronic immune stimulation. This B cellsubset lacks, or expresses low, surface levels of the complement receptor 2(CD21) and has therefore been termed CD21-/lowB cell

Resonant Auger spectroscopy at the L2,3 shake-up thresholds as a probe of electron correlation effects in nickel

The excitation energy dependence of the three-hole satellites in the L3-M4,5M4,5 and L2-M4,5M4,5 Auger spectra of nickel metal has been measured using synchrotron radiation. The satellite behavior in the non-radiative emission spectra at the L3 and L2 thresholds is compared and the influence of the Coster-Kronig channel explored. The three-hole satellite intensity at the L3 Auger emission line reveals a peak structure at 5 eV above the L3 threshold attributed to resonant processes at the 2p53d9 shake-up threshold. This is discussed in connection with the 6-eV feature in the x-ray absorption spectrum.Comment: 8 pages, 4 figures; http://prb.aps.org/abstract/PRB/v58/i7/p3677_

Position controlled self-catalyzed growth of GaAs nanowires by molecular beam epitaxy

GaAs nanowires are grown by molecular beam epitaxy using a self-catalyzed, Ga-assisted growth technique. Position control is achieved by nano-patterning a SiO2 layer with arrays of holes with a hole diameter of 85 nm and a hole pitch varying between 200 nm and 2 \mum. Gallium droplets form preferentially at the etched holes acting as catalyst for the nanowire growth. The nanowires have hexagonal cross-sections with {110} side facets and crystallize predominantly in zincblende. The interdistance dependence of the nanowire growth rate indicates a change of the III/V ratio towards As-rich conditions for large hole distances inhibiting NW growth.Comment: 9 pages, 4 figure

Prevalence of resistance associated polymorphisms in Plasmodium falciparum field isolates from southern Pakistan

<p>Abstract</p> <p>Background</p> <p>Scarce data are available on <it>Plasmodium falciparum </it>anti-malarial drug resistance in Pakistan. The aim of this study was, therefore, to determine the prevalence of <it>P. falciparum </it>resistance associated polymorphisms in field isolates from southern Pakistan.</p> <p>Methods</p> <p>Blood samples from 244 patients with blood-slide confirmed <it>P. falciparum </it>mono-infections were collected between 2005-2007. Single nucleotide polymorphisms in the <it>P. falciparum </it>chloroquine resistance transporter (<it>pfcrt </it>K76T), multi drug resistance (<it>pfmdr1 </it>N86Y), dihydrofolate reductase (<it>pfdhfr </it>A16V, N51I, C59R, S108N, I164L) and dihydropteroate synthetase (<it>pfdhps </it>A436S, G437A and E540K) genes and <it>pfmdr1 </it>gene copy numbers were determined using PCR based methods.</p> <p>Results</p> <p>The prevalence of <it>pfcrt </it>76T and <it>pfmdr1 </it>86Y was 93% and 57%, respectively. The prevalence of <it>pfdhfr </it>double mutations 59R + 108N/51R + 108N was 92%. The <it>pfdhfr </it>triple mutation (51I, 59R, 108N) occurred in 3% of samples. The <it>pfdhfr </it>(51I, 59R, 108N) and <it>pfdhps </it>(437G, 540E) quintuple mutation was found in one isolate. <it>Pfdhps </it>437G was observed in 51% and 540E in 1% of the isolates. One isolate had two <it>pfmdr1 </it>copies and carried the <it>pfmdr1 </it>86Y and <it>pfcrt </it>76T alleles.</p> <p>Conclusions</p> <p>The results indicate high prevalence of <it>in vivo </it>resistance to chloroquine, whereas high grade resistance to sulphadoxine-pyrimethamine does not appear to be widespread among <it>P. falciparum </it>in southern Pakistan.</p

Intramolecular vibronic dynamics in molecular solids: C60

Vibronic coupling in solid C60 has been investigated with a combination of resonant photoemission spectroscopy (RPES) and resonant inelastic x-ray scattering (RIXS). Excitation as a function of energy within the lowest unoccupied molecular orbital resonance yielded strong oscillations in intensity and dispersion in RPES, and a strong inelastic component in RIXS. Reconciling these two observations establishes that vibronic coupling in this core hole excitation leads to predominantly inelastic scattering and localization of the excited vibrations on the molecule on a femtosecond time scale. The coupling extends throughout the widths of the frontier valence bands.

Isotope shift in the electron affinity of chlorine

The specific mass shift in the electron affinity between ^{35}Cl and ^{37}Cl has been determined by tunable laser photodetachment spectroscopy to be -0.51(14) GHz. The isotope shift was observed as a difference in the onset of the photodetachment process for the two isotopes. In addition, the electron affinity of Cl was found to be 29138.59(22) cm^{-1}, giving a factor of 2 improvement in the accuracy over earlier measurements. Many-body calculations including lowest-order correlation effects demonstrates the sensitivity of the specific mass shift and show that the inclusion of higher-order correlation effects would be necessary for a quantitative description.Comment: 16 pages, 6 figures, LaTeX2e, amsmat

Many-body-QED perturbation theory: Connection to the Bethe-Salpeter equation

The connection between many-body theory (MBPT)--in perturbative and non-perturbative form--and quantum-electrodynamics (QED) is reviewed for systems of two fermions in an external field. The treatment is mainly based upon the recently developed covariant-evolution-operator method for QED calculations [Lindgren et al. Phys. Rep. 389, 161 (2004)], which has a structure quite akin to that of many-body perturbation theory. At the same time this procedure is closely connected to the S-matrix and the Green's-function formalisms and can therefore serve as a bridge between various approaches. It is demonstrated that the MBPT-QED scheme, when carried to all orders, leads to a Schroedinger-like equation, equivalent to the Bethe-Salpeter (BS) equation. A Bloch equation in commutator form that can be used for an "extended" or quasi-degenerate model space is derived. It has the same relation to the BS equation as has the standard Bloch equation to the ordinary Schroedinger equation and can be used to generate a perturbation expansion compatible with the BS equation also for a quasi-degenerate model space.Comment: Submitted to Canadian J of Physic

Decreased Prevalence of Plasmodium Falciparum Resistance Markers to Amodiaquine Despite its wide Scale use as ACT Partner Drug in Zanzibar.

Zanzibar has recently undergone a rapid decline in Plasmodium falciparum transmission following combined malaria control interventions with artemisinin-based combination therapy (ACT) and integrated vector control. Artesunate-amodiaquine (ASAQ) was implemented as first-line treatment for uncomplicated P. falciparum malaria in Zanzibar in 2003. Resistance to amodiaquine has been associated with the single nucleotide polymorphism (SNP) alleles pfcrt 76T, pfmdr1 86Y, 184Y and 1246Y. An accumulation of these SNP alleles in the parasite population over time might threaten ASAQ efficacy.The aim of this study was to assess whether prolonged use of ASAQ as first-line anti-malarial treatment selects for P. falciparum SNPs associated with resistance to the ACT partner drug amodiaquine. The individual as well as the combined SNP allele prevalence were compared in pre-treatment blood samples from patients with uncomplicated P. falciparum malaria enrolled in clinical trials conducted just prior to the introduction of ASAQ in 2002-2003 (n = 208) and seven years after wide scale use of ASAQ in 2010 (n = 122). There was a statistically significant decrease of pfcrt 76T (96-63%), pfmdr1 86Y (75-52%), 184Y (83-72%), 1246Y (28-16%) and the most common haplotypes pfcrt/pfmdr1 TYYD (46-26%) and TYYY (17-8%), while an increase of pfcrt/pfmdr1 KNFD (0.4-14%) and KNYD (1-12%). This is the first observation of a decreased prevalence of pfcrt 76T, pfmdr1 86Y, 184Y and 1246Y in an African setting after several years of extensive ASAQ use as first-line treatment for uncomplicated malaria. This may support sustained efficacy of ASAQ on Zanzibar, although it was unexpected considering that all these SNPs have previously been associated with amodiaquine resistance. The underlying factors of these results are unclear. Genetic dilution by imported P. falciparum parasites from mainland Tanzania, a de-selection by artesunate per se and/or an associated fitness cost might represent contributing factors. More detailed studies on temporal trends of molecular markers associated with amodiaquine resistance are required to improve the understanding of this observation

High accuracy calculation of 6s -> 7s parity nonconserving amplitude in Cs

We calculated the parity nonconserving (PNC) 6s -> 7s amplitude in Cs. In the Dirac-Coulomb approximation our result is in a good agreement with other calculations. Breit corrections to the PNC amplitude and to the Stark-induced amplitude $\beta$ are found to be -0.4% and -1% respectively. The weak charge of $^{133}$Cs is $Q_W=-72.5 \pm 0.7$ in agreement with the standard model.Comment: 4 pages, LaTeX2e, uses revtex4.cls, submitted to PR