High BL Research Articles

Systematic Search for and Study of Short-timescale Flare Structures in BL Lac Object Gamma-Ray Emission

We present here the first systematic search of short-timescale γ-ray flares from 29 high Galactic latitude BL Lac objects over 14 yr of Fermi Large Area Telescope data. Using a combined Bayesian Blocks and HOP algorithm, we identified seven high-quality orbital timescale flare segments from three sources and quantified 24 short-timescale flare structures. We then performed a comprehensive analysis of flare symmetry, power spectral density (PSD) of variability, and flux–photon index relation. The main results are as follows. (1) The flare symmetry parameter A shows a “U-shaped” distribution. Short-timescale flares are symmetric while long-timescale flares are asymmetric. The number of fast-rise, slow-decay and slow-rise, fast-decay type flares are equal. No correlation is found between A and peak/integral flux. No parameter evolution is seen between consecutive flares, either. The observations support a scenario where longer-timescale flares originate from the superposition of short, symmetric subhour flares. (2) PSD from yearly to hourly timescales is modeled using the CARMA process. At lower frequencies, the PSD follows the typical broken power-law form. The high-frequency region of the PSD exhibits a continuous power-law shape, indicating that γ-ray variability originates from a single physical process across all probed timescales. (3) The flux–photon index distribution shows a pattern of “harder-when-brighter” or “softer-when-brighter,” but becomes flat above a certain critical flux, with Γ ≈ 2. This behavior cannot be simply explained by a two-component or blazar sequence model, and we speculate it may be related to complex interplay between electron acceleration and cooling.

Revisiting the TeV flare of PKS 2155-304 in 2006

ABSTRACT Blazars, a subclass of active galactic nuclei (AGN), are known to be bright γ-ray sources, frequently exhibiting active (flaring) periods. Blazar PKS 2155-304 is a high synchrotron-peaked BL Lac object located at redshift z = 0.116. On 2006 July 28, an extremely remarkable outburst of VHE γ-ray emission from this blazar was reported by the H.E.S.S. experiment, with an average flux more than 10 times the low-state level. The variability time-scale of this extraordinary flare was as short as approximately 200 s. In order to guarantee the transparency of the emission region for TeV photons, the fast variability demands an extremely high Doppler factor δD > 50 of the jet within the classical one-zone model, leading to the so-called ‘Doppler factor crisis’. Here, we demonstrate that the stochastic dissipation model, which is a multiblob scenario for blazars, can self-consistently explain the giant TeV flares of PKS 2155-304 and the low-state emission before and after the flares, in terms of both multiwavelength spectral and variability characteristics. The required Doppler factor in this model can be as low as 20, which is a reasonable and typical value for blazar jets. The obtained model parameters may shed some light on the physical properties of the relativistic jet.

Effect of travel speed and number of layers on surface waviness of ER70S6 deposits fabricated through non-transferred wire arc additive manufacturing

The present experimental study introduced NTA-WAAM system for fabricating thin-layered structures using ER70S-6 wire. The study is directed towards determining the Sw in the manufactured parts, considering varying level of TS (0.17, 0.19, and 0.24 m/min) and BL (2, 3, 7 layers). The Sw is computed through image processing using canny edge detection method. Increasing the BL from 2 to 7 and reducing TS from 0.24 to 0.17 m/min, the resulting Sw is increased from 1.05 to 2.69 mm. So with high BL, TS should be more to suitably control the Sw because of high heat dissipation and low fluidity of molten pool. In addition to the morphological attributes, microstructural evolution, XRD, Rietveld refinement, tensile, and wear testing are incorporated to present the feasibility and stability of part fabricated through NTA-WAAM. Crystallite size, dislocation density, and residual stress are computed through XRD. It is observed that when approaching the top section from bottom zone of deposition, crystallite size is reduced from 23.43 to 21.85 nm, whereas dislocation density (2.83 × 1012 to 6.52 × 1012m−2) and residual stress (−263.72 to −300.12 MPa) are increased. It indicates the adverse effect of crystallite size towards dislocation density and residual stress, which is primarily attributed to varying level of heat transfer during deposition. The deposit exhibits an ideally refined crystal structure than initial filler wire as χ2≈1 (from Rietveld analysis). Compressive residual stress development further improves the fabricated part’s tensile characteristics. Formation of equiaxed dimples, characterises the ductile failure phenomena, whereas the enhancement in their dimensions reflects the improvement in ductility.

Abstract P5-02-27: Serum thymidine kinase activity as a prognostic marker in women with metastatic breast cancer treated with two different schedules of palbociclib plus second-line endocrine therapy within the CCTG MA38 trial

Abstract Background: Thymidine kinase-1 is a cell proliferation marker downstream of the CDK4/6 pathway, whose activity can be measured in serum to reflect tumor proliferation. The CDK4/6 inhibitor palbociclib (P) is approved for the treatment of patients (pts) with hormone receptor positive metastatic breast cancer (MBC) in first or second line endocrine-based treatment settings. Approximately 10-15% of pts exhibit de novo resistance to P, with circulating levels of thymidine kinase activity (TKa) previously shown as a potential marker of early treatment resistance. Therapeutic strategies to address primary resistance to P are currently lacking. Little is known of the clinical efficacy of alternative dosing schedules of P, and its effect on TKa. Here we report serum TKa measured at different timepoints from samples collected within the MA38 (NCT02630693) study. Methods: MA38 is an open label randomised Phase 2 trial comparing two different schedules of P plus second-line ET in pts with ER-positive, HER2-negative MBC. Pts were assigned to receive physician’s choice ET plus either standard P dosing (125mg daily for 21 days on a 28-day cycle), or 100mg daily continuously. Serum samples were collected at baseline (BL; n=135), at 12 weeks (W12; n=122) and 24 weeks (W24; n=95). TKa was measured with DiviTum®, a refined ELISA-based assay (lower limit of detection [LLOD] = 100 DuA). Kaplan-Meier method estimated BL, W12 and W24 (95% CI) median PFS (mPFS; from randomization until progression by RECIST criteria or death) and overall survival (OS; from randomization until death from any cause) in groups of patients defined by dichotomizing TKa as “high” or “low” at the median. Results: MA38 enrolled 180 pts from December 2015 and February 2017 across Canada. Median follow up was 19 months. Overall, the median age was 60, and 90% of pts were post-menopausal. All pts had estrogen receptor-positive disease, and 64% had visceral metastases. On study, 56% received fulvestrant with P, 34% aromatase inhibitor and 10% tamoxifen. TKa was successfully measured in 100% of samples. Median TKa (mTKa) at BL was 234 DuA (IQR 138.5 - 438). BL TKa was not associated with clinical or pathological characteristics. TKa was prognostic at BL with mPFS of 5.5 months (mo) in pts with high TKa vs 16.3 mo with low TKa (HR=2.43; 95% CI, 1.6-3.7; p< 0.001). Similar results were obtained employing other previously reported cut off values. At multivariate analysis, BL TKa was independent from other prognostic factors including age, ECOG status and presence of visceral metastases (adjusted HR= 2.34; 95%CI 1.5- 3.6; p < 0.001). In terms of OS, BL TKa was an independent prognostic factor (adjusted HR=2.0; 95% CI, 1.1-3.7; p=0.02). At 12 mo, OS rate was 68% in pts with high BL TKa vs 92% in low TKa. Both for PFS and OS, no interaction between BL TKa and study arm was observed. At W12 mTKa was 129.5 DuA (IQR 100 - 219.8) and below LLOD (IQR 100 - 180) at W24. At these timepoints, landmark analyses showed no significant difference in PFS according to TKa. However, at W12 high TKa was significantly associated with worse OS (HR 2.0; 95%CI 1.0- 4.0; p=0.03), with a similar trend at W24 (HR 2.5; 95%CI 0.9-6.4; p=0.06). Conclusions: Baseline TKa is a reliable prognostic marker of both PFS and OS in pts treated with P and ET, further substantiating previous data. Monitoring TKa during treatment may provide important clinical information. A significant relationship between TKa and assigned treatment arm was not observed, suggesting TKa is not influenced by P treatment dose or intensity. These data confirm the role of baseline TKa as a new marker for patient stratification, and supports further investigation for the assessment of the clinical utility of TKa as a monitoring biomarker in the advanced setting. Citation Format: Amelia McCartney, Chiara Biagioni, Bingshu Chen, Lois Shepherd, Karen Gelmon, Anil A. Joy, Wendy Parulekar, Mattias Bergqvist, Ilenia Migliaccio, Angela Leo, Matteo Benelli, Emanuela Risi, Erica Moretti, Luca Livraghi, Laura Biganzoli, Luca Malorni. Serum thymidine kinase activity as a prognostic marker in women with metastatic breast cancer treated with two different schedules of palbociclib plus second-line endocrine therapy within the CCTG MA38 trial [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-02-27.

The Spectral Energy Distributions for 4FGL Blazars

In this paper, the multiwavelength data from radio to X-ray bands for 2709 blazars in the 4FGL-DR3 catalog are compiled to calculate their spectral energy distributions using a parabolic equation . Some important parameters including spectral curvature (P 1), synchrotron peak frequency (P 2, ), and peak luminosity () are obtained. Based on those parameters, we discussed the classification of blazars using the “Bayesian classification” and investigated some mutual correlations. We came to the following results. (1) Based on the Bayesian classification of synchrotron peak frequencies, the 2709 blazars can be classified into three subclasses, i.e., for low synchrotron peak blazars (LSPs), for intermediate synchrotron peak blazars (ISPs), and for high synchrotron peak blazars (HSPs), and there are 820 HSPs, 750 ISPs, and 1139 LSPs. (2) The γ-ray emission has the closest relationship with radio emission, followed by optical emission, while the weakest relationship is that with X-ray emission. The γ-ray luminosity is also correlated with the synchrotron peak luminosity. (3) There are strong positive correlations between the curvature (1/∣P 1∣) and the peak frequency () for all subclasses (FSRQs, (high, intermediate, and low) BL Lacertae objects). For different subclasses, the correlation slopes are different, which implies that there are different acceleration mechanisms and emission processes for different subclasses of blazars.

Refining neutropenia risk assessment in patients treated with first-line endocrine therapy (ET) and cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) for metastatic breast cancer (MBC) through a cell-free DNA workflow (cfDNA).

1027 Background: The combination of ET and CDK4/6i is the current standard of care for hormone receptor (HR)-positive/HER2-negative MBC (luminal MBC), with neutropenia being the main dose limiting toxicity. We previously observed the potential association between leucocyte count (WBC) and different fractions of cell free circulating DNA (cfDNA) (Bortot et al 2020). The present study aimed to evaluate the feasibility of a cfDNA-based workflow as a new tool to assess the risk of treatment induced neutropenia. Methods: The study analyzed a prospective cohort 83 luminal MBC patients (pts) treated with first line ET and CDK4/6i in the CRO-2018-56 multicenter study from 2018 to 2021. cfDNA was characterized through droplet digital PCR (ddPCR) based on different ACTB DNA fragments lengths: short (s), medium (m) and long (l). Blood samples were collected before treatment start (BL) and at the first clinical evaluation after 3 months (E1). Associations between clinical characteristics, neutropenia and cfDNA were explored through Kruskal Wallis, time to G3 neutropenia (NG3) (TTN) was analyzed through log-rank and Cox regression. Results: Neutropenia was G3 in 44 out of 83 pts (53%) and G4 in 2 pts (2%). Median TTN was 1.8 months, 60% of NG3 occurred within 3.7 months. Overall, 74 pts (89%) resolved toxicity within 7 days, 10 pts (12%) reduced CDK4/6i dose after NG3. BL neutrophils count (Neu) and WBC were significantly lower in pts that developed NG3 (P = 0.0013 and P = 0.0020 respectively). De novo metastatic pts had numerically higher Neu (median 4825 vs 3895), but only a numerically lower risk of NG3 was observed (HR 0.53 P = 0.064). Although bone involvement was not associated with risk of developing NG3, the total number of metastatic lesions was associated with higher NG3 (P = 0.0016). In particular, > 5 metastatic lesions were associated with higher NG3 risk (p = 0.013). E1 ACTB_m was significantly lower with respect to BL in pts that experienced NG3 (median 100% vs 16%, P = 0.0136 in NG3 no vs yes) with a consistent impact on the risk of NG3 (HR: 2.81, P = 0.025). No associations were observed for the other ACTB fragment length fractions. BL Neu and ACTB_m dichotomized at the median were then combined to describe 4 distinct TTN risk groups (P = 0.0006). Interestingly, pts with low BL Neu and low E1 ACTB_m had a median TTN of 0.9 months, while pts with high BL Neu and high E1 ACTB_m have not experienced NG3 after a median follow-up of 16.1 months. Conclusions: The present study proofed the concept of using cfDNA to provide clinically meaningful data not only about tumor biology, but also for a comprehensive patient assessment. Based on these results, a prospective study focused on a multiparametric neutropenia risk assessment will be started.

Radio core-dominance of Fermi-blazars: implication for blazar unification

...The distribution of radio core-dominance is consistent with average projection angles of 13.5, 14.8, 16.8, 20.4, and 28.2 for ISPs, LSPs, FSRQs, HSPs, and radio galaxies, respectively. Linear regression analyses of our data yield significant anti-correlation r greater than 0.60 between core-dominance parameter and extended luminosity in each individual subsample, the correlation is significant only when individual subsamples are considered. There is a systematic sequence of the distribution of the different subclasses on the Core-dominance parameter-extended luminosity plane. Nevertheless, little or no correlation between Core-dominance parameter and core luminosity or between Core dominance parameter and gamma-ray luminosity r, less than 0.50 was observed. There is a clear dichotomy between high synchrotron-peaking BL Lacs and other BL Lac subclasses. The results are consistent with a unified view for blazars and can be understood in terms of relativistic beaming persisting at the largest scales.

OUP accepted manuscript

OJ 287 is a well-studied binary black hole system, that occasionally exhibits bright X-ray and optical flares. Here we present a detailed spectral study of its second brightest X-ray flare observed during 2019-2020 using archival Swift and NuSTAR observations along with ToO observations from AstroSat. The entire flaring period is divided into three states, defined as low, intermediate, and high states. The variation of hardness ratio (HR) with 0.3-10.0 keV integrated flux suggests a \enquote{softer-when-brighter} behavior, as also previously reported based on flux-index variations. Simultaneous high state X-ray spectra obtained using Swift, NuSTAR and AstroSat are very steep with a power-law index $>$2. A significant spectral change is observed in AstroSat-SXT and LAXPC spectrum which is consistent with Swift-XRT and NuSTAR spectrum. Together, optical-UV and X-ray spectrum during the high flux state, suggesting the emergence of a new high BL Lacertae (HBL) component. We have modeled the synchrotron peak with publicly available code named GAMERA for low, intermediate, and high flux state. Our modeling suggests the need of high magnetic field to explain the high state under the leptonic scenarios. Increase in the magnetic field value inside the jet could be linked to the increase in accretion rate as expected in the BH-disk impact scenario. The color-magnitude diagram reveals a \enquote{bluer-when-brighter} spectral energy distribution chromatism during the flaring period. Different chromatism or no chromatism at various occasions suggests a complex origin of optical emission, which is believed to be produced by disc impact or through synchrotron emission in the jet.

A comparative study on the characterisation and combustion behaviour of high ash coals from two different geographical origins

The ultimate use of coal is primarily dependent on the composition, distribution, modes of occurrences of the minerals and their association with the organics. Therefore, an adequate knowledge of the minerals, macerals and their ignition behaviour is inevitable for the subsequent utilisation of coal in various aspects. Here, we present a comparative characterisation and combustion study of two high ash non-coking coals (AH and BL) with ash yield of 42.42 and 45 wt% on dry basis and gross calorific value of 3620 and 3363 kcal/kg respectively. Both coals are rich in vitrinite with moderate liptinite and the volume percentage of inertinite is comparatively lower than the vitrinite. Both coals are rich in alumino-silicate minerals and Fe and Ti oxide are present in moderate concentrations. They have crystalline forms with discrete grain boundaries which make them susceptible for beneficiation. The fractionation characteristics like low slagging and fouling potential, high silica ratio and low base to acid ratio suggest that the two coals are feasible for their successive utilisation in thermal power plants. Concerning the macerals’s reactivity; BL coal has a comparatively lower TG peak temperature and burnout temperature than the AH. Also BL sample has relatively more volatile matter. Both coals have high ash fusion temperatures but BL coal ash consists of high proportion of refractory minerals e.g. SiO2, Al2O3 and TiO2. Hence, BL coal has better amenability for easy ignition and its combustion characteristics are expected to be improved than the AH.

The Correlations between Radio and [formula omitted]-ray Emissions in Multibands for Fermi Blazars

A sample including 935 blazars with 415 Flat Spectrum Radio Quasars (FSRQs) and 520 BL Lac objects (BL Lacs) (233 HBLs (High synchrotron peak frequency BL Lacs), 144 IBLs (Intermediate synchrotron peak frequency BL Lacs), and 143 LBLs (Low synchrotron peak frequency BL Lacs)) is selected in Fermi 3FGL catalogue. The correlations between two flux densities of the radio 1.4GHz and γ-ray at 0.1, 0.3, 1, 3, and 10GeV are investigated for the samples of all blazars, FSRQs, BL Lacs, and subclasses of HBLs and LBLs, respectively. Results show that there are strong positive correlations between the two flux densities, with the correlation coefficients r = 0.48∼0.81, and the chance probabilities p all less than 10−4. The correlation coefficient has different trends with the change of γ-ray emission frequency for different blazar samples, and the average correlation coefficients for all the samples at five respective bands decrease with the increase of γ-ray frequency. Therefore, with the increase of γ-ray frequency, the dominant mechanism of γ-ray radiation of blazar is changing, and at the same frequency the dominant mechanism is different for different samples. The γ-ray emission of HBLs may be mainly dominated by the synchrotron self-Compton, while the other mechanisms are responsible for the γ-ray emissions of LBLs. The origin of γ-ray in FSRQs is more complex than that of BL Lacs.

On the Origin and Evolution of Curvature of the Spectral Energy Distribution of Fermi Bright Blazars

Abstract The origin and evolution of spectral curvature in blazar spectral energy distribution (SED) is still unclear. Since the observed SED curvature is related to an intrinsic curvature in emitting electron energy distribution (EED), we study this question by employing a log-parabolic EED with a curvature parameter and peak energy to model the quasi-simultaneous broadband SEDs of selected blazars in the Fermi-LAT Bright AGN Sample using synchrotron and inverse Compton (IC) processes. We find that the log-parabolic IC model can successfully explain the emission in all blazars in our sample. On average, FSRQs have higher magnetic field, Doppler factor, and curvature than BL Lac objects. The BL Lac objects show an anticorrelation between the curvature parameter of the EED and its peak energy, which is a signature of stochastic acceleration. FSRQs do not manifest such correlation and rather show a mild positive relationship between these parameters. This suggests that the evolution of spectral curvature in the BL Lac objects is dominated by a strong stochastic acceleration component, whereas the curvature in FSRQs evolves in a cooling dominated regime due to an additional external Compton component. The strong cooling in FSRQs not only restricts the electron peak energy but also adds extra curvature to the high energy tail of emitting EED. Since the curvature decreases from FSRQs toward high peak BL Lac objects (HBLs), opposite to peak energy, the curvature parameter can be considered a third parameter of the blazar sequence in addition to peak frequency and luminosity.

The Relations of Multi-waveband Effective Spectral Indices for Fermi Blazars

In this paper, the flux densities at the radio (R) 1.4GHz, optical (O) 4.68 × 1014Hz, X-ray (X) 1keV, and γ-ray (γ) 1GeV are obtained from the available literature for a Fermi blazar sample. The 6 effective spectral indices (αRO, αRX, αRγ, αOX, αOγ, and αXγ) between any two of above bands are calculated. The correlations between any two spectral indices are investigated for the whole blazar sample and the subclass samples of FSRQs (Flat Spectral Radio Quasars) and BL Lacs including High synchrotron peak frequency BL Lacs (HBLs) and Low synchrotron peak frequency BL Lacs (LBLs). Results show that: (1) There are close correlations between any two spectral indices for all samples, except for the sample of HBLs and the correlation between αOX and αRγ. This kind of correlations can be explained by the structures of energy spectral distributions at four bands. (2) In the scatter plots of effective spectral index correlations, FSRQs and LBLs are distributed in the same area, but HBLs and FSRQs (LBLs) are distributed in the different areas. (3) The separation degree (discrimination) between the distributions of FSRQs (LBLs) and HBLs differs with the scatter plot of effective spectral index correlations, and the discrimination is related to the frequencies to determine two effective spectral indices.

Transesterification by air/moisture-tolerant bifunctional organocatalyst to produce ‘nonstrained’ γ-butyrolactone-based aliphatic copolyesters: Turning a bane into a boon

It has been a challenge in effective ring-opening copolymerization (ROC) of “nonstrained” γ-butyrolactone (BL) with high-strained cyclic esters or lactones, due to their large difference in reactivity. Transesterification (TEster) would be a promising alternative strategy to ROC for the synthesis of BL-based copolyesters if advanced catalysts could be rationally designed by enabling air/moisture tolerance and preference toward BL ring-opening over chain breakage. Here we report the development of air/moisture-tolerant bifunctional oganocatalyst based on 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)/thiourea(urea) system for efficient TEster reaction of poly(δ-valerolactone) (PVL)/BL or poly(ε-caprolactone) (PCL)/BL, successfully affording BL-based copolyesters, especially poly(BL-co-VL)s, with relatively high BL incorporation (up to 38.3%) and high molecular weight (Mn up to 40.6 kg/mol). Mechanistic study reveals that the enhancement of BL incorporation in TBD/TU(U)-mediated TEster reaction is presumably originated from the preferential activation of BL monomer over the polymer chain, rather than the enhanced bifunctional activation. Thanks to more homosequences present in the copolyesters produced by TEster, the resulting poly(BL-co-VL)s exhibit higher melting temperature (Tm) over those obtained by ROC at similar level of BL incorporation.

P5450Evening levels and circadian changes of salivary cortisol predict adverse events in heart failure patients with comorbid depression - a MOOD-HF substudy

Abstract Background Depression is frequent in heart failure (HF) and associated with adverse clinical outcomes. The randomized MOOD-HF trial showed that in depressed patients with systolic heart failure (HF) the selective serotonin reuptake inhibitor escitalopram (E) improved neither survival nor depression compared to placebo (P). The hypothalamic-pituitary-adrenocortical axis is known to be altered in depression or HF. This MOOD-HF substudy aimed to clarify whether circadian salivary cortisol levels (SCL) were predictive of adverse events in depressed MOOD-HF participants and whether outcomes differed according to treatment with E. Methods MOOD-HF participants (all suffering from symptomatic systolic HF with left ventricular ejection fraction (LVEF) <45% and current major depression) were eligible for the present analysis if providing samples for SCL determination (luminescence immunoassay) at baseline visit (BL) and if not on oral glucocorticosteroid therapy. Depression severity was determined with the Montgomery–Åsberg Depression Rating Scale (MADRS) and LVEF measured by echocardiography. Results In the total study cohort (146 patients on E, 147 on P) median morning SCL at BL was 0.210 μg/dL (IQR 0.141–0.338 μg/dL) and median evening (pm) SCL 0.067 μg/dL (0.036–0.128 μg/dL, p<0.001). Median circadian change was 0.124 μg/dL (0.044–0.239 μg/dL). In patients with BL pm-SCL above the median MADRS-score was 21.7±9.1 and LVEF 33.7±8.4% respectively, in patients with pm-SCL below the median these values were 19.6±9.1 and 36.5±7.8% (p=0.048; p=0.004). During 12 months follow-up the composite endpoint (all-cause death or rehospitalization) occurred least in E-treated patients with low pm-SCL and most often in E-treated patients with high pm-SCL (HR 2.02, 95% CI 1.12–3.65, p=0.010); patients on P had comparable event rates irrespective of BL pm-SCL (Figure A). Thus, numerically patients on E with low BL pm-SCL had lower event rates compared with corresponding P-treated patients (HR 0.76 (0.41–1.40, p=0.796)), while patients with high BL pm-SCL had higher event rates (HR 1.29 (0.74–2.24, p=0.799)) than corresponding P-treated patients. Patients with circadian SCL changes above the median receiving P experienced the composite primary endpoint least, while both subgroups with circadian SCL changes below the median and also patients with circadian SCL changes above the median on E had higher event rates (HR 0.66 (0.45–0.97, p=0.039), Figure B). Conclusion In depressed patients with systolic HF high pm-SCL are associated with more severe disease (depression and cardiac dysfunction). Extending primary MOOD-HF results indicating unfavourable outcomes related to E, the current findings suggest a SCL x treatment interaction with higher event rates in (sicker) patients with high pm-SCL and lower event rates in (less sick) patients with low pm-SCL when treated with the antidepressant. Low circadian changes of SCL were always associated with higher event rates. Acknowledgement/Funding BMBF (Grant 01 KG0702) and Lundbeck A/S Denmark

Without Chords You Flood the Accordian: An Atypical Cause of Sudden Dyspnea in a Healthy Adult

SESSION TITLE: Cardiothoracic Surgery SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Acute mitral valve regurgitation (AMR) occurs when there is structural compromise in components of the mitral valve. Clinical presentations may be confounded by more common cardiopulmonary processes1. This may delay diagnosis and management, thus increasing patient morbidity and mortality2. CASE PRESENTATION: An 84 YOF presents with a 6 day history of myalgias, palpitations, cough + SOB. PMH includes HTN, esophageal spasm, and DVT. Admission exam reveals tachycardia, irregularly irregular rhythm, and grade IV holosystolic murmur along the left sternal border. Bilateral (bl) rales heard in her lower lung fields. ECG confirms A-fib with RVR.WBC is 17,700, lactic acid 1.4 mmol/L, BNP 8,838 pg/mL, procalcitonin 0.46 ng/mL.Urine Streptococcal pneumoniae Ag is positive.Blood, sputum cultures + rapid influenza testing are negative. CXR shows mild cardiomegaly with bl pulmonary edema (Fig 1).Non-contrast chest CT shows bl upper lobe (UL) groundglass densities, moderate bl pleural effusions, bibasilar atelectasis, and focal areas of bl UL nodularity(Fig 2).Despite rate control + broad spectrum antibiotics, her hypoxia worsened.TTE showed EF 70%, normal ventricular sizes, PASP 50 mmHg, moderately dilated LA, myxomatous mitral thickening with a flail posterior leaflet, ruptured chordae tendinae, severe mitral regurgitation and an eccentric anterior jet penetrating the pulmonary veins.Pt is mechanically ventilated due to acute hypoxic respiratory failure + undergoes mitral valve repair.One week post-op, she is in no respiratory distress and saturating well on room air, suggesting complete reversal of her acute cardiopulmonary disease (Fig 3). DISCUSSION: Chord rupture is the most common etiology of AMR, typically affecting the thinner posterior mitral leaflets3. It is most often seen as a spontaneous event in elderly pts with no known heart disease presenting with sudden SOB and hypotension3. LA pressure rapidly increases causing pulmonary congestion + edema3. CXR findings of RUL pulmonary edema has high specificity but bl edema and effusions are more common1-3. Bl pulmonary edema is often interpreted as a manifestation of CHF or underlying infection and can delay tx of the valvular defect.CT findings in AMR include intralobar septal thickening, parabronchial cuffing and diffuse groundglass opacities1,3. CONCLUSIONS: SOB is commonly encountered in medicine.Despite evidence of infection or another common cardiopulmonary process, clinical correlation of sudden dyspnea and new murmur should prompt suspicion of AMR.CXR, CT and echo should all be utilized to evaluate AMR severity and initiate urgent surgical intervention.This case demonstrates the potential to reverse clinical symptoms and drastically improve pt outcomes. Reference #1: Brander L et al. Right-sided pulmonary oedema.Lancet 1999;354:1440. Reference #2: Morris P et al. Focal pulmonary oedema: an unusual presentation of acute mitral regurgitation.Thorax 2013;68:498. Reference #3: Lucenti M et al. Acute shortness of breath. J Emerg Med 2003;24(3):319. DISCLOSURE: The following authors have nothing to disclose: Patrick Twohig, Jaclyn Rivington, Rex Yung No Product/Research Disclosure Information

Enhanced conversion of furfuryl alcohol to alkyl levulinates catalyzed by synergy of CrCl3 and H3PO4

To enhance the yield of alkyl levulinates, a mixed-acid catalyst system consisting of CrCl3 and H3PO4 was investigated for the transformation of furfuryl alcohol (FA). The CrCl3−H3PO4 system exhibited a positive synergistic catalytic activity for the synthesis of alkyl levulinates, which was especially obvious for n-butyl levulinate (BL) synthesis. The strongest synergic effect of mixed-acid system for BL production was achieved at the CrCl3 molar ratio of 0.3 (based on total moles of CrCl3 and H3PO4). Furthermore, the mixed-acid systems consisting of Cr-salts combined with H3PO4 and its salts in catalyzing FA conversion to BL were evaluated, and the evolution process of FA to produce BL was explored in the presence of CrCl3−H3PO4, sole CrCl3, and sole H3PO4. A possible synergistic catalytic pathway of CrCl3 combined with H3PO4 was proposed. Finally, the key process variables were examined. Under optimal conditions, a high BL yield of 95% was achieved from 99% FA conversion catalyzed by the synergy of CrCl3 and H3PO4.

THE SPECTRAL ENERGY DISTRIBUTIONS OF FERMI BLAZARS

ABSTRACT In this paper, multiwavelength data are compiled for a sample of 1425 Fermi blazars to calculate their spectral energy distributions (SEDs). A parabolic function, is used for SED fitting. Synchrotron peak frequency ( ), spectral curvature (P1), peak flux ( ), and integrated flux ( ) are successfully obtained for 1392 blazars (461 flat-spectrum radio quasars [FSRQs], 620 BL Lacs [BLs], and 311 blazars of uncertain type [BCUs]; 999 sources have known redshifts). Monochromatic luminosity at radio 1.4 GHz, optical R band, X-ray at 1 keV and γ-ray at 1 GeV, peak luminosity, integrated luminosity, and effective spectral indices of radio to optical ( ) and optical to X-ray ( ) are calculated. The “Bayesian classification” is employed to log in the rest frame for 999 blazars with available redshift, and the results show that three components are enough to fit the log distribution; there is no ultra-high peaked subclass. Based on the three components, the subclasses of blazars using the acronyms of Abdo et al. are classified, and some mutual correlations are also studied. Conclusions are finally drawn as follows: (1) SEDs are successfully obtained for 1392 blazars. The fitted peak frequencies are compared with common sources from available samples. (2) Blazars are classified as low synchrotron peak sources if log , intermediate synchrotron peak sources if , and high synchrotron peak sources if . (3) Gamma-ray emissions are strongly correlated with radio emissions. Gamma-ray luminosity is also correlated with synchrotron peak luminosity and integrated luminosity. (4) There is an anticorrelation between peak frequency and peak luminosity within the whole blazar sample. However, there is a marginally positive correlation for high synchrotron peak BL Lacs (HBLs), and no correlations for FSRQs or low synchrotron peak BL Lacs (LBLs). (5) There are anticorrelations between the monochromatic luminosities (γ-ray and radio bands) and the peak frequency within the whole sample and BL Lacs. (6) The optical to X-ray ( ) and radio to optical ( ) spectral indices are strongly anticorrelated with peak frequency (log ) within the whole sample, but the correlations for subclasses of FSRQs, LBLs, and HBLs are different.

The Blazar Sequence 2.0

This paper discusses the spectral energy distribution (SED) of all blazars with redshift detected by the Fermi satellite and listed in the 3LAC catalog. The so called “blazar sequence” from the phenomenological point of view will be updated, with no theory or modelling. It will be shown that: (i) pure data show that jet and accretion power are related; (ii) the updated blazar sequence maintains the properties of the old version, albeit with a less pronounced dominance of the γ-ray emission; (iii) at low bolometric luminosities, two different types of objects have the same high energy power: low black hole mass flat spectrum radio quasars and high mass BL Lacs. Therefore, at low luminosities, there is a very large dispersion of SED shapes; (iv) in low power BL Lacs, the contribution of the host galaxy is important. Remarkably, the luminosity distribution of the host galaxies of BL Lacs are spread in a very narrow range; (v) a simple sum of two smoothly joining power laws can describe the blazar SEDs very well.

On the origin of the soft photons of the high-synchrotron-peaked blazar PKS 1424+240

PKS 1424+240 is a distant very high energy gamma-ray BL Lac object with redshift $z=0.601$. It was found that pure synchrotron self-Compton (SSC) process normally need extreme input parameters (e.g., very low magnetic field intensity and extraordinarily large Doppler factor) to explain its multi-wavelength spectral energy distributions (SEDs). To avoid the extreme model parameters, different models have been proposed (e.g., two-zone SSC model or lepto-hadronic model). In this work, we employ the traditional one-zone leptonic model after including a weak external Compton component to re-explore the simultaneous multi-wavelength SEDs of PKS 1424+240 in both high (2009) and low (2013) states. We find that the input parameters of magnetic field and Doppler factor are roughly consistent with those of other BL Lacs if a weak external photon field from either broad line region (BLR) or the dust torus. However, the required energy density of seed photons from BLR or torus is about 3 orders of magnitude less than that constrained in luminous quasars (e.g., flat-spectrum radio quasars, FSRQs). This result suggests that the BLR/torus in BL Lacs is much weaker than that of luminous FSRQs (but not fully disappear), and the inverse-Compton of external photons from BLR/torus may still play a role even in high synchrotron peaked blazars.

Multi-Wavelength Observations of the Blazar 1ES 1011+496 in Spring 2008

The BL Lac object 1ES 1011+496 was discovered at Very High Energy gamma-rays by MAGIC in spring 2007. Before that the source was little studied in different wavelengths. Therefore a multi-wavelength (MWL) campaign was organized in spring 2008. Along MAGIC, the MWL campaign included the Metsahovi radio observatory, Bell and KVA optical telescopes and the Swift and AGILE satellites. MAGIC observations span from March to May, 2008 for a total of 27.9 hours, of which 19.4 hours remained after quality cuts. The light curve showed no significant variability. The differential VHE spectrum could be described with a power-law function. Both results were similar to those obtained during the discovery. Swift XRT observations revealed an X-ray flare, characterized by a harder when brighter trend, as is typical for high synchrotron peak BL Lac objects (HBL). Strong optical variability was found during the campaign, but no conclusion on the connection between the optical and VHE gamma-ray bands could be drawn. The contemporaneous SED shows a synchrotron dominated source, unlike concluded in previous work based on nonsimultaneous data, and is well described by a standard one zone synchrotron self Compton model. We also performed a study on the source classification. While the optical and X-ray data taken during our campaign show typical characteristics of an HBL, we suggest, based on archival data, that 1ES 1011+496 is actually a borderline case between intermediate and high synchrotron peak frequency BL Lac objects.