Photodynamic treatment with fractionated light decreases production of reactive oxygen species and cytotoxicity in vitro via regeneration of glutathione

Photodynamic therapy removes unwanted or harmful cells by overproduction of reactive oxygen species (ROS). Fractionated light delivery in photodynamic therapy may enhance the photodynamic effect in tumor areas with insufficient blood supply by enabling the reoxygenation of the treated area. This study addresses the outcome of fractionated irradiation in an in vitro photodynamic treatment (PDT) system, where deoxygenation can be neglected. Our results show that fractionated irradiation with light/dark intervals of 45/60 s decreases ROS production and cytotoxicity of PDT. This effect can be reversed by addition of 1,3-bis-(2-chlorethyl)-1-nitrosurea (BCNU), an inhibitor of the glutathione reductase. We suggest that the dark intervals during irradiation allow the glutathione reductase to regenerate reduced glutathione (GSH), thereby rendering cells less susceptible to ROS produced by PDT compared with continuous irradiation. Our results could be of particular clinical importance for photodynamic therapy applied to well-oxygenated tumors.     

Enzymatic Conversion of Flavonoids using Bacterial Chalcone Isomerase and Enoate Reductase

Flavonoids are a large group of plant secondary metabolites with a variety of biological properties and are therefore of interest to many scientists, as they can lead to industrially interesting intermediates. The anaerobic gut bacterium Eubacterium ramulus can catabolize flavonoids, but until now, the pathway has not been experimentally confirmed. In the present work, a chalcone isomerase (CHI) and an enoate reductase (ERED) could be identified through whole genome sequencing and gene motif search. These two enzymes were successfully cloned and expressed in Escherichia coli in their active form, even under aerobic conditions. The catabolic pathway of E. ramulus was confirmed by biotransformations of flavanones into dihydrochalcones. The engineered E. coli strain that expresses both enzymes was used for the conversion of several flavanones, underlining the applicability of this biocatalytic cascade reaction.     

Plasma membrane properties involved in the photodynamic efficacy of merocyanine 540 and tetrasulfonated aluminum phthalocyanine

Merocyanine 540 (MC540)-mediated photodynamic damage to erythrocytes was strongly reduced when illumination was performed at pH 8.5 as compared to pH 7.4. This could be explained by high pH-mediated hyperpolarization of the erythrocyte membrane, resulting in decreased MC540 binding at pH 8.5. In accordance, the MC540-mediated photooxidation of open ghosts was not inhibited at pH 8.5. Photoinactivation of vesicular stomatitis virus (VSV) was not inhibited at pH 8.5. This suggests that illumination at increased pH could be an approach to protect red blood cells selectively against MC540-mediated virucidal phototreatment. With tetrasulfonated aluminum phthalocyanine (AIPcS4) as photosensitizer, damage to erythrocytes, open ghosts and VSV was decreased when illuminated at pH 8.5. A decreased singlet oxygen yield at high pH could be excluded. The AIPcS4-mediated photooxidation of fixed erythrocytes was strongly dependent on the cation concentration in the buffer, indicating that the surface potential may affect the efficacy of this photosensitizer. This study showed that altering the environment of the target could increase both the efficacy and the specificity of a photodynamic treatment.     

Two-gluon jets from υ'(10.0)

We propose to search for two-gluon jets with $\text{E}{}_{\mathrm{<mtext>jet</mtext>}}\text{? 5 GeV}\text{in e}{}^{\mathrm{+}}\text{e}{}^{\mathrm{?}}\text{→ υ' → γ +}{}^3\text{P}{}_2\text{→ γ + 2}\text{g}\text{→ γ + 2}\text{jets}$. The gluonic origin of the jets can be tested by measuring the angular correlation. The rate and the energy of the monochromatic photon of this and of the competing processes are estimated.     

Measurement Error Correction for Distributed Properties – Filter Cake Thickness Measurements

The measurement of a distributed property is frequently encountered in engineering applications. The impact of a possible measurement error on the measured distribution is described and two methods to account for such an error are detailed: A Fourier transform based deconvolution procedure and a moment based deconvolution approach via kernel estimators are presented. The deconvolution methods can be used in many particle characterization and process applications where particle features or properties are commonly presented in a distributed form. In the current instance, these methods are carefully explored by using artificially generated data and applied to experimental data obtained from filter cake thickness measurements.     

Measurement of the B(+) production cross section in pp collisions at sqrt[s]=7 TeV

Measurements of the total and differential cross sections dσ/dp(T)(B) and dσ/dy(B) for B(+) mesons produced in pp collisions at sqrt[s]=7 TeV are presented. The data correspond to an integrated luminosity of 5.8 pb(-1) collected by the CMS experiment operating at the LHC. The exclusive decay B(+)→J/ψK(+), with J/ψ→μ(+)μ(-), is used to detect B(+) mesons and to measure the production cross section as a function of p(T)(B) and y(B). The total cross section for p(T)(B)>5 GeV and |y(B)|<2.4 is measured to be 28.1±2.4±2.0±3.1 μb, where the first uncertainty is statistical, the second is systematic, and the last is from the luminosity measurement.     

Emergence of information transmission in a prebiotic RNA reactor

A poorly understood step in the transition from a chemical to a biological world is the emergence of self-replicating molecular systems. We study how a precursor for such a replicator might arise in a hydrothermal RNA reactor, which accumulates longer sequences from unbiased monomer influx and random ligation. In the reactor, intra- and intermolecular base pairing locally protects from random cleavage. By analyzing stochastic simulations, we find temporal sequence correlations that constitute a signature of information transmission, weaker but of the same form as in a true replicator.     

Measurement of the t-channel single top quark production cross section in pp collisions at √s=7 TeV

Electroweak production of the top quark is measured for the first time in pp collisions at √=7 TeV, using a data set collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb?1. With an event selection optimized for t-channel production, two complementary analyses are performed. The first one exploits the special angular properties of the signal, together with background estimates from the data. The second approach uses a multivariate analysis technique to probe the compatibility with signal topology expected from electroweak top-quark production. The combined measurement of the cross section is 83.6±29.8(stat+syst)±3.3(lumi) pb, consistent with the standard model expectation.     

Search for stopped Gluinos in pp collisions at square root s=7 TeV

The results of the first search for long-lived gluinos produced in 7 TeV pp collisions at the CERN Large Hadron Collider are presented. The search looks for evidence of long-lived particles that stop in the CMS detector and decay in the quiescent periods between beam crossings. In a dataset with a peak instantaneous luminosity of 1×10(32) cm-2 s-1, an integrated luminosity of 10 pb-1, and a search interval corresponding to 62 hours of LHC operation, no significant excess above background was observed. Limits at the 95% confidence level on gluino pair production over 13 orders of magnitude of gluino lifetime are set. For a mass difference mg - mχ1(0) >100 GeV/c2, and assuming BR(g→gχ1(0))=100%, mg < 370 GeV/c2 are excluded for lifetimes from 10 μs to 1000 s.     

Study of Z Boson Production in PbPb Collisions at √S(NN)=2.76 TeV

A search for Z bosons in the μ(+)μ(-) decay channel has been performed in PbPb collisions at √S(NN)=2.76 TeV with the CMS detector at the LHC, in a 7.2 μb(-1) data sample. The number of opposite-sign muon pairs observed in the 60-120 GeV/c(2) invariant mass range is 39, corresponding to a yield per unit of rapidity (y) and per minimum bias event of [33.8±5.5(stat)±4.4(syst)]×10(-8), in the |y|<2.0 range. Rapidity, transverse momentum, and centrality dependencies are also measured. The results agree with next-to-leading order QCD calculations, scaled by the number of incoherent nucleon-nucleon collisions.