213 research outputs found
Detection of Balamuthia mandrillaris DNA by real-time PCR targeting the RNase P gene
<p>Abstract</p> <p>Background</p> <p>The free-living amoeba <it>Balamuthia mandrillaris </it>may cause fatal encephalitis both in immunocompromised and in – apparently – immunocompetent humans and other mammalian species. Rapid, specific, sensitive, and reliable detection requiring little pathogen-specific expertise is an absolute prerequisite for a successful therapy and a welcome tool for both experimental and epidemiological research.</p> <p>Results</p> <p>A real-time polymerase chain reaction assay using TaqMan<sup>® </sup>probes (real-time PCR) was established specifically targeting the RNase P gene of <it>B. mandrillaris </it>amoebae. The assay detected at least 2 (down to 0.5) genomes of <it>B. mandrillaris </it>grown in axenic culture. It did not react with DNA from closely related <it>Acanthamoeba </it>(3 species), nor with DNA from <it>Toxoplasma gondii</it>, <it>Leishmania major</it>, <it>Pneumocystis murina</it>, <it>Mycobacterium bovis </it>(BCG), human brain, various mouse organs, or from human and murine cell lines. The assay efficiently detected <it>B. mandrillaris </it>DNA in spiked cell cultures, spiked murine organ homogenates, <it>B. mandrillaris</it>-infected mice, and CNS tissue-DNA preparations from 2 patients with proven cerebral balamuthiasis. This novel primer set was successfully combined with a published set that targets the <it>B. mandrillaris </it>18S rRNA gene in a duplex real-time PCR assay to ensure maximum specificity and as a precaution against false negative results.</p> <p>Conclusion</p> <p>A real-time PCR assay for <it>B. mandrillaris </it>amoebae is presented, that is highly specific, sensitive, and reliable and thus suited both for diagnosis and for research.</p
Single-photon emission from Ni-related color centers in CVD diamond
Color centers in diamond are very promising candidates among the possible
realizations for practical single-photon sources because of their long-time
stable emission at room temperature. The popular nitrogen-vacancy center shows
single-photon emission, but within a large, phonon-broadened spectrum (~100nm),
which strongly limits its applicability for quantum communication. By contrast,
Ni-related centers exhibit narrow emission lines at room temperature. We
present investigations on single color centers consisting of Ni and Si created
by ion implantation into single crystalline IIa diamond. We use systematic
variations of ion doses between 10^8/cm^2 and 10^14/cm^2 and energies between
30keV and 1.8MeV. The Ni-related centers show emission in the near infrared
spectral range (~770nm to 787nm) with a small line-width (~3nm FWHM). A
measurement of the intensity correlation function proves single-photon
emission. Saturation measurements yield a rather high saturation count rate of
77.9 kcounts/s. Polarization dependent measurements indicate the presence of
two orthogonal dipoles.Comment: 8 pages, published in conference proceedings of SPIE Photonics Europe
201
Erhebungen von Beliefs im Lehramtsstudium Physik
Im Rahmen des längsschnittlichen Forschungsprojektes „Studienerfolg im Fach
Physik“ wurden relevante Aspekte und Risikofaktoren für einen erfolgreichen
Studieneinstieg bei Physik- und Lehramtsstudierenden an verschiedenen
Hochschulstandorten erhoben. Beispielsweise zeigen die empirischen Befunde,
dass mit der Aufnahme des Studiums verschiedene Eingangsvoraussetzun-gen und
zeitlich stabile disparate motivationale Ausprägungen bei den Studierenden im
Fach Phy-sik und im Lehramt Physik vorliegen (vgl. [1]-[4]). Aufbauend auf
diesen Befunden werden seit dem Wintersemester 2010/2011 modifizierte Stu-
dienmodule in der Experimentalphysik für die Lehramtsstudierenden im Rahmen
des Projekts „MINT-Lehrerbildung neu denken“ zur Gestaltung der
Studieneingangsphase angeboten. Dabei werden sowohl methodische als auch
inhaltlich-didaktische Interventionen umgesetzt. Erste Be-funde hinsichtlich
der Evaluation dieser Neugestaltung werden im Folgenden vorgestellt
Atrial Natriuretic Peptide, a Regulator of Nuclear Factor-κB Activation in Vivo
Natriuretic peptides (NPs) comprise a family of vasoactive hormones that play important roles in the regulation of cardiovascular and renal homeostasis. Along this line, atrial NP (ANP) (international non-proprietary name: carperitide, HANP) is an approved drug for the treatment of acute heart failure. In recent years, evidence has been given that the NP system possesses a far broader biological spectrum than the regulation of blood pressure and volume homeostasis. In fact, a substantial amount of in vitro work indicates that ANP affects important inflammatory processes and signaling pathways. Quite surprisingly, however, no information exists on the in vivo antiinflammatory potential and signaling of ANP. We show here that pretreatment of lipopolysaccharide (Salmonella abortus equi, 2.5 mg/kg)-challenged mice with ANP (5μg/kg iv, 15 min) rapidly inhibits nuclear factor-κB activation via inhibition of phosphorylation and degradation of the IκB-α protein. ANP also reduces Akt activation upon lipopolysaccharide injection. In ANP-pretreated mice, the increase of TNF-α serum concentration is markedly prevented; most importantly, the survival of these animals improved. These findings demonstrate both in vitro and in vivo an antiinflammatory profile of ANP that deserves to be further investigated in a therapeutic perspective
MicroRNA-100 Reduced Fetal Bovine Muscle Satellite Cell Myogenesis and Augmented Intramuscular Lipid Deposition by Modulating IGF1R
Previously, microRNA-100 (miR-100) and its putative mRNA target, insulin-like growth factor receptor-1 (IGF1R) were identified as differentially and inversely expressed in bovine longissimus dorsi (LD) muscles with divergent intramuscular fat (IMF) content by our group. While IGF1R signaling is implicated in myogenesis and muscle lipid metabolism, the underlying regulatory mechanisms are poorly understood. In the present study, we aimed to investigate the regulation of IGF1R by miR-100 during bovine muscle satellite cell (BMSC) myogenesis and lipid deposition. MiR-100 was confirmed to target the IGF1R 3 '-untranslated region (3 '-UTR) by luciferase reporter assay. Furthermore, expression of miR-100 and IGF1R was reciprocal during BMSC differentiation, suggesting a crosstalk between the two. Correspondingly, miR-100 mimic (agomiR) suppressed the levels of IGF1R, PI3K/AKT pathway signaling, myogenic gene MYOG, muscle structural components MYH7 and MYH8, whereas the inhibitor (antagomiR) had no clear stimulating effects. The IGF1R inhibitor (BMS-754807) curtailed receptor levels and triggered atrophy in muscle myotubes but did not influence miR-100 expression. AgomiR increased oleic acid-induced lipid deposition in BMSC myotubes supporting its involvement in intramuscular fat deposition, while antagomiR had no effect. Moreover, mitochondrial beta-oxidation and long-chain fatty acid synthesis-related genes were modulated by agomiR addition. Our results demonstrate modulatory roles of miR-100 in BMSC development, lipid deposition, and metabolism and suggest a role of miR-100 in marbling characteristics of meat animals and fat oxidation in muscle.Peer reviewe
Transformation, Politics and Implementation
Working in environments characterised by a high degree of uncertainty, uncontrollability and unpredictability, development agents try to organise complex realities into manageable units. What principles influence the decision on adequate approaches and necessary steps
Electronic transitions of single silicon vacancy centers in the near-infrared spectral region
Photoluminescence (PL) spectra of single silicon vacancy (SiV) centers
frequently feature very narrow room temperature PL lines in the near-infrared
(NIR) spectral region, mostly between 820 nm and 840 nm, in addition to the
well known zero-phonon-line (ZPL) at approx. 738 nm [E. Neu et al., Phys. Rev.
B 84, 205211 (2011)]. We here exemplarily prove for a single SiV center that
this NIR PL is due to an additional purely electronic transition (ZPL). For the
NIR line at 822.7 nm, we find a room temperature linewidth of 1.4 nm (2.6 meV).
The line saturates at similar excitation power as the ZPL. ZPL and NIR line
exhibit identical polarization properties. Cross-correlation measurements
between the ZPL and the NIR line reveal anti-correlated emission and prove that
the lines originate from a single SiV center, furthermore indicating a fast
switching between the transitions (0.7 ns). g(2) auto-correlation measurements
exclude that the NIR line is a vibronic sideband or that it arises due to a
transition from/to a meta-stable (shelving) state.Comment: 9 pages, 7 figures, v2 accepted for publication in Phys. Rev.
Hepatitis E virus: Efficacy of pasteurization of plasma‐derived VWF/FVIII concentrate determined by pig bioassay
Background Hepatitis E virus (HEV) is the leading cause of acute hepatitis throughout the world. Increasing blood component transfusion-associated HEV infections highlight the need for reliable virus inactivation procedures for plasma derivatives from pooled plasma donations.
Study Design and Methods An animal infection study was conducted to evaluate the efficiency of HEV inactivation by pasteurization during the manufacturing process of the von Willebrand Factor/Factor VIII (VWF/FVIII) concentrate Haemate P/Humate-P (CSL Behring, Marburg, Germany). For this purpose, groups of pigs were inoculated with stabilized VWF/FVIII intermediate spiked with HEV-positive liver homogenate and exposed to increasing incubation times of 0, 3, 6, and 10 h at 60 degrees C. Animals were evaluated for virus replication over 27 days and in a subsequent trial over 92 days.
Results Virus replication was detected in animals up to the 6-h pasteurization group. In contrast, pasteurization for 10 h did not reveal virus detection when the observation period was 27 days. In an additional experiment using the 10-h pasteurized material, two individuals started virus excretion and seroconverted when the observation period was extended to 92 days. Based on the total infection rate (2 of 12) of the animals inoculated with the sample pasteurized for 10 h, a virus reduction factor of at least 4.7 log(10) is calculated.
Conclusion This study demonstrates that pasteurization at 60 degrees C for 10 h of an HEV-positive plasma derivative leads to the effective reduction of infectivity, resulting in a VWF/FVIII product with an appropriate margin of safety for HEV
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