Adipose retinol saturase is regulated by β-adrenergic signaling and its deletion impairs lipolysis in adipocytes and acute cold tolerance in mice

OBJECTIVE

Retinol saturase (RetSat) is an endoplasmic reticulum-localized oxidoreductase highly expressed in organs involved in lipid metabolism such as white (WAT) and brown adipose tissue (BAT). Cold exposure was shown to increase RETSAT protein in BAT but its relevance for non-shivering thermogenesis, a process with beneficial effects on metabolic health, is unknown.

METHODS

We analyzed the regulation of RetSat expression in white and brown adipocytes and different murine adipose tissue depots upon β-adrenergic stimulation and cold exposure. RetSat function during the differentiation and β-adrenergic stimulation of brown adipocytes was dissected by loss-of-function experiments. Mice with BAT-specific deletion of RetSat were generated and exposed to cold. Gene expression in human WAT was analyzed and the effect of RetSat depletion on adipocyte lipolysis investigated.

RESULTS

We show that cold exposure induces RetSat expression in both WAT and BAT of mice via β-adrenergic signaling. In brown adipocytes, RetSat has minor effects on differentiation but is required for maximal thermogenic gene and protein expression upon β-adrenergic stimulation and mitochondrial respiration. In mice, BAT-specific deletion of RetSat impaired acute but not long-term adaptation to cold exposure. RetSat expression in subcutaneous WAT of humans correlates with the expression of genes related to mitochondrial function. Mechanistically, we found that RetSat depletion impaired β-agonist-induced lipolysis, a major regulator of thermogenic gene expression in adipocytes.

CONCLUSIONS

Thus, RetSat expression is under β-adrenergic control and determines thermogenic capacity of brown adipocytes and acute cold tolerance in mice. Modulating RetSat activity may allow for therapeutic interventions towards pathologies with inadequate metabolic activity.

Search for Evidence of Baryogenesis and Dark Matter in B^{+}→ψ_{D}+p Decays at BABAR

A new dark sector antibaryon, denoted ψ_{D}, could be produced in decays of B mesons. This Letter presents a search for B^{+}→ψ_{D}+p (and the charge conjugate) decays in e^{+}e^{-} annihilations at 10.58 GeV, using data collected in the BABAR experiment. Data corresponding to an integrated luminosity of 398  fb^{-1} are analyzed. No evidence for a signal is observed. Branching fraction upper limits in the range from 10^{-7}-10^{-5} are obtained at 90% confidence level for masses of 1.0 Collapse

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[Improved quality of stored packed red blood cells by mechanical rinsing]

BACKGROUND

The transfusion of packed red blood cells (PRBC) is associated with various side effects, including storage damage to PRBCs. The cells change their structure, releasing potassium as well as lactate. Mechanical rinsing, available in many hospitals, is able to remove toxic substances and possibly minimizes the negative side effects of transfusion.

OBJECTIVE

The primary aim of our study was to improve the quality of PRBCs before transfusion. The effects of different washing solutions on PRBC quality were analyzed.

MATERIAL AND METHODS

This in vitro study compares 30 mechanically washed PRBCs. They were either processed with standard normal saline 0.9% (n = 15, N group) or a hemofiltration solution containing 4 mmol/l potassium (n = 15, HF group) by a mechanical rinsing device (Xtra, LivaNova, Munich, Germany). A subgroup analysis was performed based on the storage duration of the processed PRBCs (7, 14, 37 days). Samples were taken before washing (EKprä), immediately after washing (EKpost) and 10 h later (EKpost10h), after storage in the "wash medium" at room temperature. Concentrations of ATP (probability of survival in transfused erythrocytes), lactate, citrate and electrolytes (potassium, sodium, chloride, calcium) were tested.

RESULTS AND CONCLUSION

Mechanical rinsing improves pretransfusion quality of PRBC. Washing with a hemofiltration solution results in a more physiological electrolyte composition. Even 10 h after mechanical rinsing with a hemofiltration solution, the quality of 37-day-old PRBC is comparable to young PRBC that have been stored for 7 days and have not been washed. Washing stored PRBC increases the ATP content, which subsequently leads to an increased probability of survival of red cells after transfusion.

Juvenile Larynxpapillomatose

Hintergrund

Trotz multipler Therapieoptionen ist heutzutage eine Heilung der juvenilen rezidivierenden respiratorischen Larynxpapillomatose (JORRP, „juvenile onset recurrent respiratory laryngeal papillomatosis“) nicht möglich. Außerdem weisen viele Medikamente nicht zu unterschätzende Nebenwirkungen auf.

Fragestellung

Darstellung aktueller und früherer Therapieoptionen der JORRP mit Diskussion von Wirkstoff, Darreichungsart und Dosierungen.

Materialien und Methoden

Literaturrecherche und -zusammenfassung. Analyse der Therapieoptionen anhand von Wirkstoff, Darreichungsart, Dosierungen und Nebenwirkungen.

Ergebnisse

Die chirurgische Therapie bleibt weiterhin Grundlage der Therapie. Multiple Therapieoptionen werden beschrieben, jedoch keine mit der Aussicht auf eine vollständige Remission. Der Funktionserhalt der Stimme sowie die Verlängerung des Zeitintervalls zwischen den Eingriffen bzw. die Verminderung der Papillommasse im Rezidivfall bleiben oberstes Gebot. Neue immunmodulatorische Therapieoptionen werden aktuell näher untersucht.

Schlussfolgerungen

Einige der mannigfaltigen Therapieoptionen scheinen zwar vielversprechend zu sein und ein sicheres Nebenwirkungsprofil aufzuweisen, jedoch reicht die aktuelle Datenlage, die überwiegend auf Fallserien basiert, nicht für eine generelle Therapieempfehlung aus. Weitere prospektive Studien mit einer größeren Patientenzahl sind nötig.

Modern technologies for radiofrequency pulmonary vein isolation. Comparison of radiofrequency balloon catheter with high power-short duration ablation in patients with paroxysmal atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Pulmonary vein isolation (PVI) is an established therapy for symptomatic atrial fibrillation (AF). Traditional point by point ablation can be time consuming requiring advanced training. Novel radiofrequency (RF) ablation techniques sought to facilitate PVI. Point by point ablation using high power short duration (HPSD) settings has already shown to be safe and effective whereas there is paucity of data using a novel multi-electrode balloon catheter (Heliostar™, Biosense Webster, CA, USA).

Purpose

We aimed to assess procedure characteristics, efficacy, and safety of the Heliostar™ RF-balloon catheter in direct comparison with the latest RF ablation technique.

Methods

All patients undergoing PVI using the Heliostar™ between September and November 2021 were included in this ongoing single center registry. Procedural data and outcome were assessed and compared with data from patients undergoing initial PVI for paroxysmal AF with the HPSD approach from our specifically designed database. A power setting of 70W/7s (70W/5s at posterior wall) was considered as HPSD.

Results

A total of 51 consecutive patients (61±16 years, 49% male) were included. Of those 13 patients undergoing RF-balloon and 38 patients HPSD ablation. Baseline parameters did not differ between groups. Acute PVI was achieved in all patients. For every RF-application with the RF-balloon all necessary criteria were met: Inflation index was between 0.9 and 1.0 and a minimum of 9/10 electrodes were within impedance range. A mean of 2.8±1.4 applications per vein (LSPV 3.2±2.9, LIPV 2.6±2.5, RSPV 2.8±2.0 and RIPV 1.8±0.8) were necessary to achieve durable isolation. The mean maximum esophageal temperature was 40.2±0.8°C. When comparing procedural parameters with HPSD no statistically significant difference was seen regarding procedure duration (Heliostar™ 111±28min and HPSD 100±25min; p=0.3) and left atrial dwell time (Heliostar™ 90±23min and HPSD 80±26min; p=0.08). Fluoroscopy time (Heliostar™ 17±4min and HPSD 13±5min; p=0.005) and dose (Heliostar™ 3961±1325mGy*cm2 vs. HPSD 3153±1833mGy*cm2; p=0.04) were higher in the Heliostar™ group. No major complication occurred in both groups. A three month follow up was available for 10 patients in the Heliostar™ and for 38 patients in the HPSD group. All 10 Heliostar™ patients and 79% of the HPSD patients were free from atrial arrhythmias at follow up.

Conclusion

The novel multi-electrode RF-balloon has shown to be safe and effective in the first clinical routine AF ablation procedures. The tendency towards longer LA dwell times, procedure durations and the significantly higher fluoroscopy exposition in comparison with the HPSD PVI can be attributed to the learning curve applying a new ablation system. More experience is needed in the future to determine the benefits of the novel RF-balloon.

Procedural and outcome impact of obesity in cryoballoon versus radiofrequency pulmonary vein isolation in atrial fibrillation patients

Funding Acknowledgements

Type of funding sources: None.

Background

Cryoballoon-(CB)- and radiofrequency-(RF)-ablation are the most common techniques for pulmonary vein isolation (PVI) in patients (pts) with symptomatic atrial fibrillation (AF). An increasing number of pts undergoing PVI are obese.

Objective

To address the paucity of procedural differences and outcome data of CB- vs. RF-based PVI in relation to body mass index (BMI) of AF patients.

Methods

All pts undergoing de novo PVI between 01/2018-08/2019 at our university hospital were included in this retrospective analysis. Pts of each group (CB-PVI vs. RF-PVI) were subdivided based on their BMI: normal weight BMI <25kg/m², pre-obesity 25-30kg/m², obesity stage I 30-35kg/m² and severe obesity stage II ≥35kg/m². Hereafter, procedural characteristics and AF recurrence rate during follow-up were compared with regard the different BMI groups.

Results

A total of 526 pts (62% male, 65.3±11.2 years) underwent successful de novo PVI (320 CB and 206 RF). Especially in obese patients, differences in procedural characteristics were noted: A significantly increased contrast medium volume in CB group (all: CB 50 [40-80] vs. RF 20 [20-30], p<0.001; BMI≥35: CB 70 [54.5-102.5] ml vs. RF 20 [15-30] ml, p<0.001). In line with previous studies, the overall procedure time was significantly shorter with CB-PVI (CB 75 [60-100] vs. RF 120 [110-180], p<0.001). Also, as expected, lower fluoroscopy dose was detected in RF group (all: CB 392.4 [197.9-995.9] vs. RF 282.5 [139.8-507.2], p<0.001). The complication rate was equal throughout all BMI groups.

A 12-month follow up was available in 480 of 526 (91%) pts. Freedom from any arrhythmia was comparable between CB-PVI and RF-PVI (CB 77% vs. RF 75%, p=0.63). However, for obese pts a trend towards higher AF recurrence rate after RF- compared to CB-PVI was observed (BMI≥35: CB 24% vs. RF 50%, p=0.099).

Conclusion

For obese pts CB-PVI is similarly safe and effective as RF-PVI. The significantly shorter procedure time for CB-PVI may minimize potential obesity-related complications. However, the lower contrast medium quantity and fluoroscopy dose in RF-PVI must be considered. AF recurrence rates were comparable between CB-PVI und RF-PVI. Randomised trials are needed to evaluate the long-term freedom of AF recurrence in pts with higher BMI comparing CB- vs. RF-based PVI and possible obesity related complication.

Validation of seven risk scores in a prospective and independent cohort: the challenge of predicting recurrence after atrial fibrillation ablation

Funding Acknowledgements

Type of funding sources: None.

Background

Several predictive scores for atrial fibrillation (AF) recurrence after ablation have been developed, only some of these are validated in prospective cohorts. The predictive value of such scores has thus far been limited, and many have not been compared with one another.

Aims

We sought to compare the predictive value of seven previously described risk scores ((CHA2DS2 and CHA2DS2-VASC, HATCH, APPLE, CAAP-AF, BASE-AF2, MB-LATER) for prediction of AF recurrence risk at 12 months after AF ablation. Further, we aimed to identify additional variables to predict recurrences after AF ablation.

Methods

We analyzed data from of our prospective digital AF ablation registry to compare the previously published scores in an independent and prospective cohort (n=883, 50.8% with paroxysmal AF). Patients were undergoing de-novo ablation of AF received a pulmonary vein isolation (PVI) using radiofrequency (RF) ablation or cryoablation. Ablation procedures for recurrences of AF after initial PVI included re-isolation of the pulmonary veins by RF ablation, with additional substrate modification at the operators’ discretion.

Early recurrence and recurrence after ablation were defined as any AF or atrial tachycardia episode lasting ≥ 30 s in the first 3 months after ablation and from the end of the 3-month period to 12 months after ablation. Follow-up of patients was scheduled at regular intervals 3 and 12 months after ablation, and included Holter-ECG, 12-lead ECG and history. Outcome-relevant data from implanted cardiac devices (CIED), such as 2-chamber ICD and pacemakers, or implantable loop recorders were analyzed when available.

A predefined subgroup analysis was performed in the following subgroups: first procedure vs. redo procedure, paroxysmal vs. persistent AF, and RF ablation vs. cryoablation.

Results

The BASE-AF2 (AUC 0.630, p<0.001), MB-LATER (AUC 0.612, p<0.001) CAAP-AF (AUC 0.591, p<0.001), APPLE (AUC 0.591, p<0.001) and CHA2DS2-VASC (AUC 0.547, p=0.018) scores had a significant but modest predictive value for 12-month AF-recurrence. None of these scores was significantly superior. Other previously published scores had no predictive value. There was no difference in the predictive value for 12-month recurrence of AF between first procedure vs. redo procedure and RF ablation vs. cryoablation. Unlike other scores, MB-LATER showed better predictive value for paroxysmal vs. persistent AF (AUC 0.632 vs. 0.551, p=0.038). In the multivariate logistic regression, only age (p=0.006), number of prior electrical cardioversions (p<0.001) and early AF recurrence (p<0.001) were independent predictors of 12-month AF recurrence.

Conclusion

Despite numerous available scores, predicting recurrences after AF ablation remains challenging. New simple and robust predictors are needed, potentially based on diagnostic interventions, as well as novel genetic, functional and anatomic parameters.

Impact of pacing output and cycle length on qrs morphology in ablation of premature ventricular contractions (PACE-MAP-Trial)

Funding Acknowledgements

Type of funding sources: None.

Background

Pace mapping is an established technique to localize the origin of premature ventricular contractions (PVC). The QRS morphology induced by endocardial pacing is compared with a previously recorded template of the target arrhythmia. Based upon historic in-vitro models pacing at the arrhythmia’s coupling interval (CI) and stimulation threshold has become the gold standard in pace mapping.

Purpose

There is a paucity of data supporting pacing at the CI and stimulation threshold as the gold standard for pace mapping. In this prospective study, we sought to assess systematically the impact of variations of pacing output and cycle length on the resulting QRS morphology during pace mapping in the context of PVC ablation (NCT05061498).

Methods

All patients undergoing ablation of idiopathic PVC were prospectively enrolled in this study. Pace mapping was performed using four different parameter settings: (1) A predefined fixed burst at maximum output (10V/2ms), (2) fixed burst at stimulation threshold, (3) coupling interval at maximum output and (4) coupling interval at stimulation threshold. Pacing cycle length (PCL) of the fixed burst was defined as follows: for a CI ≤450ms = PCL of CI+100ms and for a CI ≥450 = PCL of CI-100ms. Using an automated waveform comparison algorithm, the resulting QRS complexes were matched with the clinical PVC, and with the gold standard. For every parameter setting the mean of the matching percentage of three QRS complexes entered the analysis.

Results

We report data of the first 22 consecutive patients (53±15 years, 64% female) enrolled in this ongoing study between May and November 2021. The pacing protocols were performed at 39 different sites: 5/39 epicardially via great cardiac vein, 15/39 in the RVOT 12/39 and 7/22 in the left ventricular cavity. When comparing the QRS morphologies resulting from the four different pace mapping settings with the clinical PVC, the univariate analysis revealed no difference between groups (p=0.9). Furthermore, there was no difference comparing the paced QRS morphologies at different output and cycle length to the gold standard of threshold pacing at coupling interval (p=0.9).

Conclusion

Variations of pacing output and stimulation cycle length during pace mapping does not affect QRS morphology during PVC ablation. Applying a modern automated waveform comparison tool, no advantage was observed when comparing with the gold standard. It is therefore reasonable to assume, that pace mapping can be performed using an easily applicable setting of a fixed burst at maximum pacing output.

Search for an Axionlike Particle in B Meson Decays

Axionlike particles (ALPs) are predicted in many extensions of the standard model, and their masses can naturally be well below the electroweak scale. In the presence of couplings to electroweak bosons, these particles could be emitted in flavor-changing B meson decays. We report herein a search for an ALP, a, in the reaction B^{±}→K^{±}a, a→γγ using data collected by the BABAR experiment at SLAC. No significant signal is observed, and 90% confidence level upper limits on the ALP coupling to electroweak bosons are derived as a function of ALP mass, improving current constraints by several orders of magnitude in the range 0.175  GeV<m_{a}<4.78  GeV.

Search for Lepton Flavor Violation in ϒ(3S)→e^{±}μ^{∓}

We report on the first search for electron-muon lepton flavor violation (LFV) in the decay of a b quark and b antiquark bound state. We look for the LFV decay ϒ(3S)→e^{±}μ^{∓} in a sample of 118 million ϒ(3S) mesons from 27  fb^{-1} of data collected with the BABAR detector at the SLAC PEP-II e^{+}e^{-} collider operating with a 10.36 GeV center-of-mass energy. No evidence for a signal is found, and we set a limit on the branching fraction B[ϒ(3S)→e^{±}μ^{∓}]<3.6×10^{-7} at 90% C. L. This result can be interpreted as a limit Λ_{NP}/g_{NP}^{2}>80  TeV on the energy scale Λ_{NP} divided by the coupling-squared g_{NP}^{2} of relevant new physics (NP).

Search for Darkonium in e^{+}e^{-} Collisions

Collider searches for dark sectors, new particles interacting only feebly with ordinary matter, have largely focused on identifying signatures of new mediators, leaving much of dark sector structures unexplored. In particular, the existence of dark matter bound states (darkonia) remains to be investigated. This possibility could arise in a simple model in which a dark photon (A^{'}) is light enough to generate an attractive force between dark fermions. We report herein a search for a J^{PC}=1^{--} darkonium state, the ϒ_{D}, produced in the reaction e^{+}e^{-}→γϒ_{D}, ϒ_{D}→A^{'}A^{'}A^{'}, where the dark photons subsequently decay into pairs of leptons or pions, using 514  fb^{-1} of data collected with the BABAR detector. No significant signal is observed, and we set bounds on the γ-A^{'} kinetic mixing as a function of the dark sector coupling constant for 0.001<m_{A^{'}}<3.16  GeV and 0.05<m_{ϒ_{D}}<9.5  GeV.

Clinical characterization of respiratory large droplet production during common airway procedures using high-speed imaging

During the COVID-19 pandemic, a significant number of healthcare workers have been infected with SARS-CoV-2. However, there remains little knowledge regarding large droplet dissemination during airway management procedures in real life settings. 12 different airway management procedures were investigated during routine clinical care. A high-speed video camera (1000 frames/second) was for imaging. Quantitative droplet characteristics as size, distance traveled, and velocity were computed. Droplets were detected in 8/12 procedures. The droplet trajectories could be divided into two distinctive patterns (type 1/2). Type 1 represented a ballistic trajectory with higher speed large droplets whereas type 2 represented a random trajectory of slower particles that persisted longer in air. The use of tracheal cannula filters reduced the amount of droplets. Respiratory droplet patterns generated during airway management procedures follow two distinctive trajectories based on the influence of aerodynamic forces. Speaking and coughing produce more droplets than non-invasive ventilation therapy confirming these behaviors as exposure risks. Even large droplets may exhibit patterns resembling the fluid dynamics smaller airborne aerosols that follow the airflow convectively and may place the healthcare provider at risk.

German Registry for Cardiac Operations and Interventions in Patients with Congenital Heart Disease: Report 2020-Comprehensive Data from 6 Years of Experience

Background  Based on a quality assurance initiative of the German Society for Thoracic and Cardiovascular Surgery (DGTHG) and the German Society for Pediatric Cardiology and Congenital Heart Defects (DGPK), a voluntary registry was founded for assessment of treatment and outcomes of patients with congenital heart disease in Germany. This evaluation by the German Registry for cardiac operations and interventions in patients with congenital heart disease reports the data and the outcome over a 6-year period in patients undergoing invasive treatment.

Methods  This real-world database collects clinical characteristics, in-hospital complications, and medium-term outcome of patients who underwent cardiac surgical and interventional procedures within the prospective, all-comers registry. Patients were followed-up for up to 90 days.

Results  In the period from 2013 to 2018, a total of 35,730 patients, 39,875 cases, respectively 46,700 procedures were included at up to 31 German institutions. The cases could be subcategorized according to the treatment intention into 21,027 (52.7%) isolated operations, 17,259 (43.3%) isolated interventions, and 1,589 (4.0%) with multiple procedures. Of these, 4,708 (11.8%) were performed in neonates, 10,047 (25.2%) in infants, 19,351 (48.5%) in children of 1 to 18 years, and 5,769 (14.5%) in adults. Also, 15,845 (33.9%) cases could be allocated to so-called index procedures which underwent a more detailed evaluation to enable meaningful comparability. The mean unadjusted in-hospital mortality of all cases in our registry ranged from 0.3% in patients with isolated interventions and 2.0% in patients with surgical procedures up to 9.1% in patients undergoing multiple procedures.

Conclusion  This annually updated registry of both scientific societies represents voluntary public reporting by accumulating actual information for surgical and interventional procedures in patients with congenital heart disease (CHD) in Germany. It describes advancements in cardiac medicine and is a basis for internal and external quality assurance for all participating institutions. In addition, the registry demonstrates that in Germany, both interventional and surgical procedures for treatment of CHD are offered with high medical quality.

Precision Measurement of the Ratio B(ϒ(3S)→τ^{+}τ^{-})/B(ϒ(3S)→μ^{+}μ^{-})

We report on a precision measurement of the ratio R_{τμ}^{ϒ(3S)}=B(ϒ(3S)→τ^{+}τ^{-})/B(ϒ(3S)→μ^{+}μ^{-}) using data collected with the BABAR detector at the SLAC PEP-II e^{+}e^{-} collider. The measurement is based on a 28  fb^{-1} data sample collected at a center-of-mass energy of 10.355 GeV corresponding to a sample of 122 million ϒ(3S) mesons. The ratio is measured to be R_{τμ}^{ϒ(3S)}=0.966±0.008_{stat}±0.014_{syst} and is in agreement with the standard model prediction of 0.9948 within 2 standard deviations. The uncertainty in R_{τμ}^{ϒ(3S)} is almost an order of magnitude smaller than the only previous measurement.

Search for a Dark Leptophilic Scalar in e^{+}e^{-} Collisions

Many scenarios of physics beyond the standard model predict the existence of new gauge singlets, which might be substantially lighter than the weak scale. The experimental constraints on additional scalars with masses in the MeV to GeV range could be significantly weakened if they interact predominantly with leptons rather than quarks. At an e^{+}e^{-} collider, such a leptophilic scalar (ϕ_{L}) would be produced predominantly through radiation from a τ lepton. We report herein a search for e^{+}e^{-}→τ^{+}τ^{-}ϕ_{L}, ϕ_{L}→ℓ^{+}ℓ^{-} (ℓ=e, μ) using data collected by the BABAR experiment at SLAC. No significant signal is observed, and we set limits on the ϕ_{L} coupling to leptons in the range 0.04<m_{ϕ_{L}}<7.0  GeV. These bounds significantly improve upon the current constraints, excluding almost entirely the parameter space favored by the observed discrepancy in the muon anomalous magnetic moment below 4 GeV at 90% confidence level.

Increasing the Size-Selectivity in Laser-Based g/h Liquid Flow Synthesis of Pt and PtPd Nanoparticles for CO and NO Oxidation in Industrial Automotive Exhaust Gas Treatment Benchmarking

PtPd catalysts are state-of-the-art for automotive diesel exhaust gas treatment. Although wet-chemical preparation of PtPd nanoparticles below 3 nm and kg-scale synthesis of supported PtPd/Al₂O₃ are already established, the partial segregation of the bimetallic nanoparticles remains an issue that adversely affects catalytic performance. As a promising alternative, laser-based catalyst preparation allows the continuous synthesis of surfactant-free, solid-solution alloy nanoparticles at the g/h-scale. However, the required productivity of the catalytically relevant size fraction <10 nm has yet to be met. In this work, by optimization of ablation and fragmentation conditions, the continuous flow synthesis of nanoparticles with a productivity of the catalytically relevant size fraction <10 nm of >1 g/h is presented via an in-process size tuning strategy. After the laser-based preparation of hectoliters of colloid and more than 2 kg of PtPd/Al₂O₃ wash coat, the laser-generated catalysts were benchmarked against an industry-relevant reference catalyst. The conversion of CO by laser-generated catalysts was found to be equivalent to the reference, while improved activity during NO oxidation was achieved. Finally, the present study validates that laser-generated catalysts meet the size and productivity requirements for industrial standard operating procedures. Hence, laser-based catalyst synthesis appears to be a promising alternative to chemical-based preparation of alloy nanoparticles for developing industrial catalysts, such as those needed in the treatment of exhaust gases.

Measurements of the Absolute Branching Fractions of B^{±}→K^{±}X_{cc[over ¯]}

A study of the two-body decays B^{±}→X_{cc[over ¯]}K^{±}, where X_{cc[over ¯]} refers to one charmonium state, is reported by the BABAR Collaboration using a data sample of 424  fb^{-1}. The absolute determination of branching fractions for these decays are significantly improved compared to previous BABAR measurements. Evidence is found for the decay B^{+}→X(3872)K^{+} at the 3σ level. The absolute branching fraction B[B^{+}→X(3872)K^{+}]=[2.1±0.6(stat)±0.3(syst)]×10^{-4} is measured for the first time. It follows that B[X(3872)→J/ψπ^{+}π^{-}]=(4.1±1.3)%, supporting the hypothesis of a molecular component for this resonance.

Search for Rare or Forbidden Decays of the D^{0} Meson

We present a search for nine lepton-number-violating and three lepton-flavor-violating neutral charm decays of the type D^{0}→h^{'-}h^{-}ℓ^{'+}ℓ^{+} and D^{0}→h^{'-}h^{+}ℓ^{'±}ℓ^{∓}, where h and h^{'} represent a K or π meson and ℓ and ℓ^{'} an electron or muon. The analysis is based on 468  fb^{-1} of e^{+}e^{-} annihilation data collected at or close to the ϒ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. No significant signal is observed for any of the twelve modes, and we establish 90% confidence level upper limits on the branching fractions in the range (1.0-30.6)×10^{-7}. The limits are between 1 and 3 orders of magnitude more stringent than previous measurements.

The temporal dynamics of humoral immunity to Rickettsia typhi infection in murine typhus patients

OBJECTIVES

This study examined individuals with Rickettsia typhi infection in the Lao People's Democratic Republic (Lao PDR) to (a) investigate humoral immune dynamics; (b) determine the differences in reference diagnostic results and recommend appropriate cut-offs; (c) determine differences in immune response after different antibiotic treatments; and (d) determine appropriate diagnostic cut-off parameters for indirect immunofluorescence assay (IFA).

METHODS

Sequential serum samples from 90 non-pregnant, adults were collected at seven time-points (days 0, 7, 14, 28, 90, 180 and 365) as part of a clinical antibiotic treatment trial. Samples were tested using IFA to determine IgM and IgG antibody reciprocal end-point titres against R. typhi and PCR.

RESULTS

For all 90 individuals, reciprocal R. typhi IgM and IgG antibody titres ranged from <400 to ≥3200. The median half-life of R. typhi IgM was 126 days (interquartile range 36-204 days) and IgG was 177 days (interquartile range 134-355 days). Overall median patient titres for R. typhi IgM and IgG were significantly different (p < 0.0001) and at each temporal sample collection point (range p < 0.0001 to p 0.0411). Using Bayesian latent class model analysis, the optimal diagnostic cut-off reciprocal IFA titer on patient admission for IgM was 800 (78.6%, 95% CI 71.6%-85.2% sensitivity; 89.9%, 95% CI 62.5%-100% specificity), and for IFA IgG 1600 (77.3%; 95% CI 68.2%-87.6% sensitivity; 99%, 95% CI 95%-100% specificity).

CONCLUSIONS

This study suggests suitable diagnostic cut-offs for local diagnostic laboratories and other endemic settings and highlights antibody persistence following acute infection. Further studies are required to validate and define cut-offs in other geographically diverse locations.

[Medical care of adults with congenital heart diseases : Present and future]

Congenital heart diseases (CHD) are the most common types of congenital organ defects. Thanks to medical progress in congenital cardiology and heart surgery, most children with CHD reach adulthood. Despite primarily successful treatment residual and subsequent conditions as well as (non)cardiac comorbidities can influence the chronic course of the disease and lead to a higher morbidity and mortality. Adults with congenital heart disease (ACHD) in Germany are not tied to the healthcare structure despite the great need for aftercare. According to the results of the medical care of ACHD (MC-ACHD) study, ACHD centers and specialists in Germany are insufficiently perceived despite increased complication rates and the great need for specialist guidance. General practitioners and patients are not adequately informed about existing ACHD facilities. A better awareness of the ACHD problem should be created at the level of primary medical supply in order to optimize care and to reduce morbidity and mortality. Improved future-oriented patient care includes lifelong regular follow-up and the possibility of interdisciplinary, integrated medical care of CHD.

Extraction of form Factors from a Four-Dimensional Angular Analysis of B[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ}

An angular analysis of the decay B[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ}, ℓ∈{e,μ}, is reported using the full e^{+}e^{-} collision data set collected by the BABAR experiment at the ϒ(4S) resonance. One B meson from the ϒ(4S)→BB[over ¯] decay is fully reconstructed in a hadronic decay mode, which constrains the kinematics and provides a determination of the neutrino momentum vector. The kinematics of the semileptonic decay is described by the dilepton mass squared, q^{2}, and three angles. The first unbinned fit to the full four-dimensional decay rate in the standard model is performed in the so-called Boyd-Grinstein-Lebed approach, which employs a generic q^{2} parametrization of the underlying form factors based on crossing symmetry, analyticity, and QCD dispersion relations for the amplitudes. A fit using the more model-dependent Caprini-Lellouch-Neubert (CLN) approach is performed as well. Our form factor shapes show deviations from previous fits based on the CLN parametrization. The latest form factors also provide an updated prediction for the branching fraction ratio R(D^{*})≡B(B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ})=0.253±0.005. Finally, using the well-measured branching fraction for the B[over ¯]→D^{*}ℓ^{-}ν[over ¯]_{ℓ} decay, a value of |V_{cb}|=(38.36±0.90)×10^{-3} is obtained that is consistent with the current world average for exclusive B[over ¯]→D^{(*)}ℓ^{-}ν[over ¯]_{ℓ} decays and remains in tension with the determination from inclusive semileptonic B decays to final states with charm.

Observation of the Decay D^{0}→K^{-}π^{+}e^{+}e^{-}

We report the observation of the rare charm decay D^{0}→K^{-}π^{+}e^{+}e^{-}, based on 468  fb^{-1} of e^{+}e^{-} annihilation data collected at or close to the center-of-mass energy of the ϒ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory. We find the branching fraction in the invariant mass range 0.675<m(e^{+}e^{-})<0.875  GeV/c^{2} of the electron-positron pair to be B(D^{0}→K^{-}π^{+}e^{+}e^{-})=(4.0±0.5±0.2±0.1)×10^{-6}, where the first uncertainty is statistical, the second systematic, and the third due to the uncertainty in the branching fraction of the decay D^{0}→K^{-}π^{+}π^{+}π^{-} used as a normalization mode. The significance of the observation corresponds to 9.7 standard deviations including systematic uncertainties. This result is consistent with the recently reported D^{0}→K^{-}π^{+}μ^{+}μ^{-} branching fraction, measured in the same invariant mass range, and with the value expected in the standard model. In a set of regions of m(e^{+}e^{-}), where long-distance effects are potentially small, we determine a 90% confidence level upper limit on the branching fraction B(D^{0}→K^{-}π^{+}e^{+}e^{-})<3.1×10^{-6}.

Search for a Stable Six-Quark State at BABAR

Recent investigations have suggested that the six-quark combination uuddss could be a deeply bound state (S) that has eluded detection so far, and a potential dark matter candidate. We report the first search for a stable, doubly strange six-quark state in ϒ→SΛ[over ¯]Λ[over ¯] decays based on a sample of 90×10^{6}ϒ(2S) and 110×10^{6}ϒ(3S) decays collected by the BABAR experiment. No signal is observed, and 90% confidence level limits on the combined ϒ(2S,3S)→SΛ[over ¯]Λ[over ¯] branching fraction in the range (1.2-1.4)×10^{-7} are derived for m_{S}<2.05  GeV. These bounds set stringent limits on the existence of such exotic particles.

First Evidence for cos2β>0 and Resolution of the Cabibbo-Kobayashi-Maskawa Quark-Mixing Unitarity Triangle Ambiguity

We present first evidence that the cosine of the CP-violating weak phase 2β is positive, and hence exclude trigonometric multifold solutions of the Cabibbo-Kobayashi-Maskawa (CKM) Unitarity Triangle using a time-dependent Dalitz plot analysis of B^{0}→D^{(*)}h^{0} with D→K_{S}^{0}π^{+}π^{-} decays, where h^{0}∈{π^{0},η,ω} denotes a light unflavored and neutral hadron. The measurement is performed combining the final data sets of the BABAR and Belle experiments collected at the ϒ(4S) resonance at the asymmetric-energy B factories PEP-II at SLAC and KEKB at KEK, respectively. The data samples contain (471±3)×10^{6}BB[over ¯] pairs recorded by the BABAR detector and (772±11)×10^{6}BB[over ¯] pairs recorded by the Belle detector. The results of the measurement are sin2β=0.80±0.14(stat)±0.06(syst)±0.03(model) and cos2β=0.91±0.22(stat)±0.09(syst)±0.07(model). The result for the direct measurement of the angle β of the CKM Unitarity Triangle is β=[22.5±4.4(stat)±1.2(syst)±0.6(model)]°. The measurement assumes no direct CP violation in B^{0}→D^{(*)}h^{0} decays. The quoted model uncertainties are due to the composition of the D^{0}→K_{S}^{0}π^{+}π^{-} decay amplitude model, which is newly established by performing a Dalitz plot amplitude analysis using a high-statistics e^{+}e^{-}→cc[over ¯] data sample. CP violation is observed in B^{0}→D^{(*)}h^{0} decays at the level of 5.1 standard deviations. The significance for cos2β>0 is 3.7 standard deviations. The trigonometric multifold solution π/2-β=(68.1±0.7)° is excluded at the level of 7.3 standard deviations. The measurement resolves an ambiguity in the determination of the apex of the CKM Unitarity Triangle.

Measurement of the D^{*}(2010)^{+}-D^{+} Mass Difference

We measure the mass difference, Δm_{+}, between the D^{*}(2010)^{+} and the D^{+} using the decay chain D^{*}(2010)^{+}→D^{+}π^{0} with D^{+}→K^{-}π^{+}π^{+}. The data were recorded with the BABAR detector at center-of-mass energies at and near the ϒ(4S) resonance, and correspond to an integrated luminosity of approximately 468  fb^{-1}. We measure Δm_{+}=(140 601.0±6.8[stat]±12.9[syst])  keV. We combine this result with a previous BABAR measurement of Δm_{0}≡m(D^{*}(2010)^{+})-m(D^{0}) to obtain Δm_{D}=m(D^{+})-m(D^{0})=(4824.9±6.8[stat]±12.9[syst])  keV. These results are compatible with and approximately five times more precise than the Particle Data Group averages.

A comparison of two molecular methods for diagnosing leptospirosis from three different sample types in patients presenting with fever in Laos

OBJECTIVES

To compare two molecular assays (rrs quantitative PCR (qPCR) versus a combined 16SrRNA and LipL32 qPCR) on different sample types for diagnosing leptospirosis in febrile patients presenting to Mahosot Hospital, Vientiane, Laos.

METHODS

Serum, buffy coat and urine samples were collected on admission, and follow-up serum ∼10 days later. Leptospira spp. culture and microscopic agglutination tests (MAT) were performed as reference standards. Bayesian latent class modelling was performed to estimate sensitivity and specificity of each diagnostic test.

RESULTS

In all, 787 patients were included in the analysis: 4/787 (0.5%) were Leptospira culture positive, 30/787 (3.8%) were MAT positive, 76/787 (9.7%) were rrs qPCR positive and 20/787 (2.5%) were 16SrRNA/LipL32 qPCR positive for pathogenic Leptospira spp. in at least one sample. Estimated sensitivity and specificity (with 95% CI) of 16SrRNA/LipL32 qPCR on serum (53.9% (33.3%-81.8%); 99.6% (99.2%-100%)), buffy coat (58.8% (34.4%-90.9%); 99.9% (99.6%-100%)) and urine samples (45.0% (27.0%-66.7%); 99.6% (99.3%-100%)) were comparable with those of rrs qPCR, except specificity of 16SrRNA/LipL32 qPCR on urine samples was significantly higher (99.6% (99.3%-100%) vs. 92.5% (92.3%-92.8%), p <0.001). Sensitivities of MAT (16% (95% CI 6.3%-29.4%)) and culture (25% (95% CI 13.3%-44.4%)) were low. Mean positive Cq values showed that buffy coat samples were more frequently inhibitory to qPCR than either serum or urine (p <0.001).

CONCLUSIONS

Serum and urine are better samples for qPCR than buffy coat, and 16SrRNA/LipL32 qPCR performs better than rrs qPCR on urine. Quantitative PCR on admission is a reliable rapid diagnostic tool, performing better than MAT or culture, with significant implications for clinical and epidemiological investigations of this global neglected disease.