Effects of Rotation on the Minimum Mass of Primordial Progenitors of Pair Instability Supernovae

The issue of which stars may reach the conditions of electron/positron pair formation instability is of importance to understand the final evolution both of the first stars and of contemporary stars. The criterion to enter the pair instability regime in density and temperature is basically controlled by the mass of the oxygen core. The main sequence masses that produce a given oxygen core mass are, in turn, dependent on metallicity, mass loss, and convective and rotationally-induced mixing. We examine the evolution of massive stars to determine the minimum main sequence mass that can encounter pair-instability effects, either a pulsational pair instability (PPISN) or a full-fledged pair-instability supernova (PISN). We concentrate on zero-metallicity stars with no mass loss subject to the Schwarzschild criterion for convective instability, but also explore solar metallicity and mass loss and the Ledoux criterion. As expected, for sufficiently strong rotationally-induced mixing, the minimum main sequence mass is encountered for conditions that induce effectively homogeneous evolution such that the original mass is converted almost entirely to helium and then to oxygen. For this case, we find that the minimum main sequence mass is ~40 Msun to encounter PPISN and ~65 Msun to encounter a PISN. When mass-loss is taken into account those mass limits become ~50 Msun for PPISN and ~80 Msun for PISN progenitors. The implications of these results for the first stars and for contemporary supernovae is discussed.Comment: 23 pages, 8 figure

Dynamical stabilization and time in open quantum systems

The meaning of time in an open quantum system is considered under the assumption that both, system and environment, are quantum mechanical objects. The Hamilton operator of the system is non-Hermitian. Its imaginary part is the time operator. As a rule, time and energy vary continuously when controlled by a parameter. At high level density, where many states avoid crossing, a dynamical phase transition takes place in the system under the influence of the environment. It causes a dynamical stabilization of the system what can be seen in many different experimental data. Due to this effect, time is bounded from below: the decay widths (inverse proportional to the lifetimes of the states) do not increase limitless. The dynamical stabilization is an irreversible process.Comment: Contribution to the Special Issue "Quantum Physics with Non-Hermitian Operators: Theory and Experiment", Fortschritte der Physik - Progress of Physic

An Open-Label, Multicenter, Phase I, Dose Escalation Study with Phase II Expansion Cohort to Determine the Safety, Pharmacokinetics, and Preliminary Antitumor Activity of Intravenous TKM-080301 in Subjects with Advanced Hepatocellular Carcinoma.

Lessons learnedTKM-080301 showed a favorable toxicity profile at the studied dose.TKM-080301 targeting PLK1 through small interfering RNA mechanism did not demonstrate improved overall survival in patients with advanced hepatocellular carcinoma compared with historical control. Preliminary antitumor activity as shown in this early-phase study does not support further evaluation as a single agent.BackgroundPolo-like kinase 1 (PLK1) is overexpressed in hepatocellular carcinoma (HCC). Knockdown of PLK1 expression by PLK1 small interfering RNA (siRNA) in an HCC cell line showed reduced expression in RNA-induced silencing complex and a reduction in cell proliferation.MethodsA 3 + 3 dose escalation plus expansion cohort at the maximum tolerated dose (MTD) was implemented. Patients with HCC, Eastern Cooperative Oncology Group (ECOG) performance status ≤2, and Child-Pugh score A received TKM-080301 as an intravenous infusion once every week for 3 consecutive weeks, repeated every 28 days.ResultsThe study enrolled 43 patients. The starting dose of TKM-080301 was 0.3 mg/kg, and MTD was declared at 0.75 mg/kg. Following the development of grade 4 thrombocytopenia in two subjects on the expansion cohort, the MTD was redefined at 0.6 mg/kg. Four patients did not have any evaluable postbaseline scan. Of the other 39 subjects who had received at least 0.3 mg/kg, 18 subjects (46.2%) had stable disease (SD) by independent RECIST 1.1 criteria. By Choi criteria, eight subjects (23.1%) had a partial response (PR). For 37 assessable subjects, with 2 subjects censored, median progression-free survival (PFS) was 2.04 months. Median survival for the whole study population was 7.5 months.ConclusionTKM-080301 was generally well tolerated. In this early-phase study, antitumor effect for TKM 080301 was limited. Further evaluation as a single agent in large randomized trials is not warranted

Antegrade Flexible Ureteroscopy for Bilateral Ureteral Stones in a Patient with Severe Hip Joint Ankylosis

In the past several decades there has been a remarkable development of small-caliber, flexible ureteroscopes and various ancillary instruments for stone manipulation and retrieval. Percutaneous antegrade ureteroscopy can be substituted in select cases for retrograde ureteroscopy. We report a case of a 60-year-old man with severe ankylosis in both hip joints who was diagnosed with bilateral ureteral stones. The patient underwent antegrade flexible ureteroscopy and laser lithotripsy. This case illustrates the role of antegrade flexible ureteroscopy combined with the holmium:YAG laser as a minimally invasive, safe, and effective technique for the management of stones in a patient who cannot undergo a retrograde approach

Frontal Sinus Lymphoma Presenting As Progressive Multiple Cranial Nerve Palsy

Primary frontal sinus lymphoma is a very uncommon disease. In all the previously reported cases, the presenting symptoms have been due to the tumor mass effect. We present an unusual case report of an immunocompetent patient who presented with facial palsy, and then progressively developed other cranial nerve palsies over several months. He was later diagnosed with diffuse large B cell lymphoma originating from the frontal sinus. The patient underwent chemotherapy, but eventually had to receive autologous peripheral blood stem cell transplantation. He is currently disease-free. The clinical course, diagnostic workup, and therapeutic outcome are described

Draft genome sequences of three terrestrial isoprene-degrading Rhodococcus strains

Isoprene is produced in abundance by plants and constitutes a carbon source for microbes. The genomes of three isoprene degraders isolated from tree leaves or soil from the campus of the University of East Anglia were sequenced. These high-GC-content isolates are actinobacteria belonging to the genus Rhodococcus

CT Findings of Completely Regressed Hepatocellular Carcinoma with Main Portal Vein Tumor Thrombosis after Transcatheter Arterial Chemoembolization

Objective: The objective of this study was to determine the sequential CT findings of controlled hepatocellular carcinoma (HCC) with main portal vein (MPV) thrombosis with the use of transcatheter arterial chemoembolization and additional intra-arterial cisplatin infusion. Materials and Methods: From January 2004 to September 2006, 138 patients with HCC invading MPV were referred to the angiography unit of our institution for chemoembolization and additional intra-arterial cisplatin infusion. Until August 2008, seven (5%) of 138 patients were followed-up and found not to have tumor recurrence. CT scans were retrospectively reviewed by two radiologists, focusing on the following parameters: the extent of portal vein thrombosis, the diameter of the affected portal vein, and enhancement of portal vein thrombosis. Results: The extent of portal vein thrombosis at the initial presentation was variable: left portal vein (LPV) and MPV (n = 1), right portal vein (RPV) and MPV (n = 3), as well as RPV, LPV and MPV (n = 3). The extent and diameter of the affected portal vein decreased during follow-up examinations. In addition, the degree of enhancement for tumor thrombi and serum alpha-feto-protein levels decreased after the transcatheter arterial chemoembolization. Portal vein thrombosis was found to be completely resolved in one patient, whereas residual thrombus without viability was persistent in six patients. Conclusion: If chemoembolization is effective in patients with HCC that invades the portal vein, the extent and enhancement of portal vein thrombosis is reduced, but residual thrombosis frequently persists for months or years, without evidence of a viable tumor.Shin SW, 2009, KOREAN J RADIOL, V10, P425, DOI 10.3348/kjr.2009.10.5.425El-Serag HB, 2008, GASTROENTEROLOGY, V134, P1752, DOI 10.1053/j.gastro.2008.02.090Shah ZK, 2007, AM J ROENTGENOL, V188, P1320, DOI 10.2214/AJR.06.0134JEON UB, 2007, RAD SOC N AM 93 SCIObi S, 2006, CANCER, V106, P1990, DOI 10.1002/cncr.21832MYUNG SJ, 2006, KOREAN J HEPATOL, V12, P107Georgiades CS, 2005, J VASC INTERV RADIOL, V16, P1653, DOI 10.1097/01.RVI.0000182185.47500.7AKim DY, 2005, CANCER, V103, P2419, DOI 10.1002/cncr.21043Llovet JM, 2003, HEPATOLOGY, V37, P429, DOI 10.1053/jhep.2003.50047Bruix J, 2001, J HEPATOL, V35, P421Lee HS, 1997, CANCER, V79, P2087Tublin ME, 1997, AM J ROENTGENOL, V168, P719CHUNG JW, 1995, AM J ROENTGENOL, V165, P315MATHIEU D, 1984, RADIOLOGY, V152, P127YAMADA R, 1983, RADIOLOGY, V148, P397

Dark Matter Subhalos in the Ursa Minor Dwarf Galaxy

Through numerical simulations, we study the dissolution timescale of the Ursa Minor cold stellar clump, due to the combination of phase-mixing and gravitational encounters with compact dark substructures in the halo of Ursa Minor. We compare two scenarios; one where the dark halo is made up by a smooth mass distribution of light particles and one where the halo contains 10% of its mass in the form of substructures (subhalos). In a smooth halo, the stellar clump survives for a Hubble time provided that the dark matter halo has a big core. In contrast, when the point-mass dark substructures are added, the clump survives barely for \sim 1.5 Gyr. These results suggest a strong test to the \Lambda-cold dark matter scenario at dwarf galaxy scale.Comment: accepted for publication in Ap