Reversible and Irreversible Interactions of Poly(3-hexylthiophene) with Oxygen Studied by Spin-Sensitive Methods

Understanding of degradation mechanisms in polymer:fullerene bulk-heterojunctions on the microscopic level aimed at improving their intrinsic stability is crucial for the breakthrough of organic photovoltaics. These materials are vulnerable to exposure to light and/or oxygen, hence they involve electronic excitations. To unambiguously probe the excited states of various multiplicities and their reactions with oxygen, we applied combined magneto-optical methods based on multifrequency (9 and 275 GHz) electron paramagnetic resonance (EPR), photoluminescence (PL), and PL-detected magnetic resonance (PLDMR) to the conjugated polymer poly(3-hexylthiophene) (P3HT) and polymer:fullerene bulk heterojunctions (P3HT:PCBM; PCBM = [6,6]-phenyl-C61-butyric acid methyl ester). We identified two distinct photochemical reaction routes, one being fully reversible and related to the formation of polymer:oxygen charge transfer complexes, the other one, irreversible, being related to the formation of singlet oxygen under participation of bound triplet excitons on the polymer chain. With respect to the blends, we discuss the protective effect of the methanofullerenes on the conjugated polymer bypassing the triplet exciton generation

Discharge protocol in acute pancreatitis: an international survey and cohort analysis

There are several overlapping clinical practice guidelines in acute pancreatitis (AP), however, none of them contains suggestions on patient discharge. The Hungarian Pancreatic Study Group (HPSG) has recently developed a laboratory data and symptom-based discharge protocol which needs to be validated. (1) A survey was conducted involving all members of the International Association of Pancreatology (IAP) to understand the characteristics of international discharge protocols. (2) We investigated the safety and effectiveness of the HPSG-discharge protocol. According to our international survey, 87.5% (49/56) of the centres had no discharge protocol. Patients discharged based on protocols have a significantly shorter median length of hospitalization (LOH) (7 (5;10) days vs. 8 (5;12) days) p < 0.001), and a lower rate of readmission due to recurrent AP episodes (p = 0.005). There was no difference in median discharge CRP level among the international cohorts (p = 0.586). HPSG-protocol resulted in the shortest LOH (6 (5;9) days) and highest median CRP (35.40 (13.78; 68.40) mg/l). Safety was confirmed by the low rate of readmittance (n = 35; 5%). Discharge protocol is necessary in AP. The discharge protocol used in this study is the first clinically proven protocol. Developing and testifying further protocols are needed to better standardize patients' care

LHCb: Measurement of the relative yields of the decay modes Bd,s→D(s)±π∓B_{d,s} \to D^{\pm}_{(s)}\pi^{\mp} and Bd,s→D(s)±K±B_{d,s} \to D^{\pm}_{(s)} K^{\pm} and determination of fd/fsf_d /f_s for 7 TeV pppp collisions

A fit to the invariant mass distributions is used to determine the relative abundances of the four decay modes $B_{d,s} \to D^{\pm}_{(s)}\pi^{\mp}$ and $B_{d,s} \to D^{\pm}_{(s)} K^{\mp}$ for $B_{d,s}$ mesons produced in 7 TeV $pp$ collisions at the LHC. From these, the relative branching fractions of the kaon modes with respect to the pion modes, and the value of $f_d /f_s$, are determined

Antibiotic therapy in acute pancreatitis: From global overuse to evidence based recommendations

Background & objectives: Unwarranted administration of antibiotics in acute pancreatitis presents a global challenge. The clinical reasoning behind the misuse is poorly understood. Our aim was to investigate current clinical practices and develop recommendations that guide clinicians in prescribing antibiotic treatment in acute pancreatitis. Methods Four methods were used. 1) Systematic data collection was performed to summarize current evidence; 2) a retrospective questionnaire was developed to understand the current global clinical practice; 3) five years of prospectively collected data were analysed to identify the clinical parameters used by medical teams in the decision making process, and finally; 4) the UpToDate Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system was applied to provide evidence based recommendations for healthcare professionals. Results The systematic literature search revealed no consensus on the start of AB therapy in patients with no bacterial culture test. Retrospective data collection on 9728 patients from 22 countries indicated a wide range (31–82%) of antibiotic use frequency in AP. Analysis of 56 variables from 962 patients showed that clinicians initiate antibiotic therapy based on increased WBC and/or elevated CRP, lipase and amylase levels. The above mentioned four laboratory parameters showed no association with infection in the early phase of acute pancreatitis. Instead, procalcitonin levels proved to be a better biomarker of early infection. Patients with suspected infection because of fever had no benefit from antibiotic therapy. Conclusions The authors formulated four consensus statements to urge reduction of unjustified antibiotic treatment in acute pancreatitis and to use procalcitonin rather than WBC or CRP as biomarkers to guide decision-making

Discharge protocol in acute pancreatitis: an international survey and cohort analysis.

There are several overlapping clinical practice guidelines in acute pancreatitis (AP), however, none of them contains suggestions on patient discharge. The Hungarian Pancreatic Study Group (HPSG) has recently developed a laboratory data and symptom-based discharge protocol which needs to be validated. (1) A survey was conducted involving all members of the International Association of Pancreatology (IAP) to understand the characteristics of international discharge protocols. (2) We investigated the safety and effectiveness of the HPSG-discharge protocol. According to our international survey, 87.5% (49/56) of the centres had no discharge protocol. Patients discharged based on protocols have a significantly shorter median length of hospitalization (LOH) (7 (5;10) days vs. 8 (5;12) days) p < 0.001), and a lower rate of readmission due to recurrent AP episodes (p = 0.005). There was no difference in median discharge CRP level among the international cohorts (p = 0.586). HPSG-protocol resulted in the shortest LOH (6 (5;9) days) and highest median CRP (35.40 (13.78; 68.40) mg/l). Safety was confirmed by the low rate of readmittance (n = 35; 5%). Discharge protocol is necessary in AP. The discharge protocol used in this study is the first clinically proven protocol. Developing and testifying further protocols are needed to better standardize patients' care

Measurement of CP asymmetries in D(s)+→ηπ+ {D}_{(s)}^{+}\to \eta {\pi}^{+} and D(s)+→η′π+ {D}_{(s)}^{+}\to {\eta}^{\prime }{\pi}^{+} decays

Searches for CP violation in the decays ${D}_{(s)}^{+}\to \eta {\pi}^{+}$ and ${D}_{(s)}^{+}\to {\eta}^{\prime }{\pi}^{+}$ are performed using pp collision data corresponding to 6 fb$^{−1}$ of integrated luminosity collected by the LHCb experiment. The calibration channels ${D}_{(s)}^{+}\to \phi {\pi}^{+}$ are used to remove production and detection asymmetries. The resulting CP-violating asymmetries are${\displaystyle \begin{array}{l}{\mathcal{A}}^{CP}=\left({D}^{+}\to \eta {\pi}^{+}\right)=\left(0.34\pm 0.66\pm 0.16\pm 0.05\right)\%,\\ {}{\mathcal{A}}^{CP}=\left({D}_s^{+}\to \eta {\pi}^{+}\right)=\left(0.32\pm 0.51\pm 0.12\right)\%,\\ {}\begin{array}{l}{\mathcal{A}}^{CP}=\left({D}^{+}\to {\eta}^{\prime }{\pi}^{+}\right)=\left(0.49\pm 0.18\pm 0.06\pm 0.05\right)\%,\\ {}{\mathcal{A}}^{CP}=\left({D}_s^{+}\to {\eta}^{\prime }{\pi}^{+}\right)=\left(0.01\pm 0.12\pm 0.08\right)\%,\end{array}\end{array}}$where the first uncertainty is statistical, the second is systematic and the third, relevant for the D$^{+}$ channels, is due to the uncertainty on ${\mathcal{A}}^{CP}=\left({D}^{+}\to \phi {\pi}^{+}\right)$. These measurements, currently the most precise for three of the four channels considered, are consistent with the absence of CP violation. A combination of these results with previous LHCb measurements is presented.[graphic not available: see fulltext]Searches for $CP$ violation in the decays $D^+_{(s)}\rightarrow \eta \pi^+$ and $D^+_{(s)}\rightarrow \eta^{\prime} \pi^+$ are performed using $pp$ collision data corresponding to 6 fb$^{-1}$ of integrated luminosity collected by the LHCb experiment. The calibration channels $D^+_{(s)}\rightarrow \phi \pi^+$ are used to remove production and detection asymmetries. The resulting $CP$-violating asymmetries are $A^{CP}(D^+ \rightarrow \eta \pi^+) = (0.34 \pm 0.66 \pm 0.16 \pm 0.05)\%$, $A^{CP}(D^+_s \rightarrow \eta \pi^+) = (0.32 \pm 0.51 \pm 0.12)\%$, $A^{CP}(D^+ \rightarrow \eta^{\prime} \pi^+) = (0.49 \pm 0.18 \pm 0.06 \pm 0.05)\%$, $A^{CP}(D^+_s \rightarrow \eta^{\prime} \pi^+) = (0.01 \pm 0.12 \pm 0.08)\%$, where the first uncertainty is statistical, the second is systematic and the third, relevant for the $D^+$ channels, is due to the uncertainty on $A^{CP}(D^+ \to \phi \pi^+)$. These measurements, currently the most precise for three of the four channels considered, are consistent with the absence of $CP$ violation. A combination of these results with previous LHCb measurements is presented

Search for D∗(2007)0→μ+μ−D^{*}(2007)^0\to\mu^+\mu^- in B−→π−μ+μ−B^-\to\pi^-\mu^+\mu^- decays

International audienceThe very rare $D^{*}(2007)^0\to\mu^+\mu^-$ decay is searched for by analysing $B^-\to\pi^-\mu^+\mu^-$ decays. The analysis uses a sample of beauty mesons produced in proton-proton collisions collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 9 fb$^{-1}$. The signal signature corresponds to simultaneous peaks in the $\mu^+\mu^-$ and $\pi^-\mu^+\mu^-$ invariant masses. No evidence for an excess of events over background is observed and an upper limit is set on the branching fraction of the decay at ${\cal B}(D^{*}(2007)^0\to\mu^+\mu^-) < 2.6\times 10^{-8}$ at $90\%$ confidence level. This is the first limit on the branching fraction of $D^{*}(2007)^0\to\mu^+\mu^-$ decays and the most stringent limit on $D^{*}(2007)^0$ decays to leptonic final states. The analysis is the first search for a rare charm-meson decay exploiting production via beauty decays

Evidence of a J/ψΛJ/\psi\Lambda structure and observation of excited Ξ−\Xi^- states in the Ξb−→J/ψΛK−\Xi^-_b \to J/\psi\Lambda K^- decay

First evidence of a structure in the $J/\psi{\Lambda}$ invariant mass distribution is obtained from an amplitude analysis of $\Xi_b^-{\rightarrow}J/\psi{\Lambda}K^-$ decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of $3.1\sigma$ including systematic uncertainties and look-elsewhere effect. Its mass and width are determined to be $4458.8\pm2.9^{+4.7}_{-1.1}$ MeV and $17.3\pm6.5^{+8.0}_{-5.7}$ MeV, respectively, where the quoted uncertainties are statistical and systematic. The structure is also consistent with being due to two resonances. In addition, the narrow excited $\Xi^-$ states, $\Xi(1690)^-$ and $\Xi(1820)^-$, are seen for the first time in a $\Xi^-_b$ decay, and their masses and widths are measured with improved precision. The analysis is performed using $pp$ collision data corresponding to a total integrated luminosity of 9 fb$^{-1}$, collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV