Rare

Potassium-40 is a widespread, naturally occurring isotope whose radioactivity impacts subatomic rare-event searches, nuclear structure theory, and estimated geological ages. A predicted electron-capture decay directly to the ground state of argon-40 has never been observed. The KDK (potassium decay) collaboration reports strong evidence of this rare decay mode. A blinded analysis reveals a nonzero ratio of intensities of ground-state electron-captures (I_{EC^{0}}) over excited-state ones (I_{EC^{*}}) of I_{EC^{0}}/I_{EC^{*}}=0.0095±[over stat]0.0022±[over sys]0.0010 (68% C.L.), with the null hypothesis rejected at 4σ. In terms of branching ratio, this signal yields I_{EC^{0}}=0.098%±[over stat]0.023%±[over sys]0.010%, roughly half of the commonly used prediction, with consequences for various fields [27L. Hariasz et al., companion paper, Phys. Rev. C 108, 014327 (2023)PRVCAN2469-998510.1103/PhysRevC.108.014327].

Impact of Modular Total Absorption Spectrometer measurements of ß decay of fission products on the decay heat and reactor ν[over ¯]_{e} flux calculation.

We report the results of a ß-decay study of fission products ^{86}Br, ^{89}Kr, ^{89}Rb, ^{90gs}Rb, ^{90m}Rb, ^{90}Kr, ^{92}Rb, ^{139}Xe, and ^{142}Cs performed with the Modular Total Absorption Spectrometer (MTAS) and on-line mass-separated ion beams. These radioactivities were assessed by the Nuclear Energy Agency as having high priority for decay heat analysis during a nuclear fuel cycle. We observe a substantial increase in ß feeding to high excited states in all daughter isotopes in comparison to earlier data. This increases the average γ-ray energy emitted by the decay of fission fragments during the first 10 000 s after fission of ^{235}U and ^{239}Pu by approximately 2% and 1%, respectively, improving agreement between results of calculations and direct observations. New MTAS results reduce the reference reactor ν[over ¯]_{e} flux used to analyze reactor ν[over ¯]_{e} interaction with detector matter. The reduction determined by the ab initio method for the four nuclear fuel components, ^{235}U, ^{238}U, ^{239}Pu, and ^{241}Pu, amounts to 0.976, 0.986, 0.983, and 0.984, respectively.

Decays of the Three Top Contributors to the Reactor ν[over ¯]_{e} High-Energy Spectrum,

We report total absorption spectroscopy measurements of ^{92}Rb, ^{96gs}Y, and ^{142}Cs ß decays, which are the most important contributors to the high energy ν[over ¯]_{e} spectral shape in nuclear reactors. These three ß decays contribute 43% of the ν[over ¯]_{e} flux near 5.5 MeV emitted by nuclear reactors. This ν[over ¯]_{e} energy is particularly interesting due to spectral features recently observed in several experiments including the Daya Bay, Double Chooz, and RENO Collaborations. Measurements were conducted at Oak Ridge National Laboratory by means of proton-induced fission of ^{238}U with on-line mass separation of fission fragments and the Modular Total Absorption Spectrometer. We observe a ß-decay pattern that is similar to recent measurements of ^{92}Rb, with a ground-state to ground-state ß feeding of 91(3)%. We verify the ^{96gs}Y ground-state to ground-state ß feeding of 95.5(20)%. Our measurements substantially modify the ß-decay feedings of ^{142}Cs, reducing the ß feeding to ^{142}Ba states below 2 MeV by 32% when compared with the latest evaluations. Our results increase the discrepancy between the observed and the expected reactor ν[over ¯]_{e} flux between 5 and 7 MeV, the maximum excess increases from ∼10% to ∼12%.

Evidence for Gamow-Teller Decay of

The ß-delayed neutron emission of ^{83,84}Ga isotopes was studied using the neutron time-of-flight technique. The measured neutron energy spectra showed emission from states at excitation energies high above the neutron separation energy and previously not observed in the ß decay of midmass nuclei. The large decay strength deduced from the observed intense neutron emission is a signature of Gamow-Teller transformation. This observation was interpreted as evidence for allowed ß decay to ^{78}Ni core-excited states in ^{83,84}Ge favored by shell effects. We developed shell model calculations in the proton fpg_{9/2} and neutron extended fpg_{9/2}+d_{5/2} valence space using realistic interactions that were used to understand measured ß-decay lifetimes. We conclude that enhanced, concentrated ß-decay strength for neutron-unbound states may be common for very neutron-rich nuclei. This leads to intense ß-delayed high-energy neutron and strong multineutron emission probabilities that in turn affect astrophysical nucleosynthesis models.

Large ß-delayed one and two neutron emission rates in the decay of 86Ga.

Beta decay of 86Ga was studied by means of ß-neutron-γ spectroscopy. An isotopically pure ^{86}Ga beam was produced at the Holifield Radioactive Ion Beam Facility using a resonance ionization laser ion source and high-resolution electromagnetic separation. The decay of 86Ga revealed a half-life of 43(-15)(+21) ms and large ß-delayed one-neutron and two-neutron branching ratios of P1n=60(10)% and P2n=20(10)%. The ßγ decay of 86Ga populated a 527 keV transition that is interpreted as the deexcitation of the first 2+ state in the N=54 isotone 86Ge and suggests a quick onset of deformation in Ge isotopes beyond N=50.

New half-lives of r-process Zn and Ga isotopes measured with electromagnetic separation.

The ß decays of neutron-rich nuclei near the doubly magic (78)Ni were studied at the Holifield Radioactive Ion Beam Facility using an electromagnetic isobar separator. The half-lives of (82)Zn (228±10 ms), (83)Zn (117±20 ms), and (85)Ga (93±7 ms) were determined for the first time. These half-lives were found to be very different from the predictions of the global model used in astrophysical simulations. A new calculation was developed using the density functional model, which properly reproduced the new experimental values. The robustness of the new model in the (78)Ni region allowed us to extrapolate data for more neutron-rich isotopes. The revised analysis of the rapid neutron capture process in low entropy environments with our new set of measured and calculated half-lives shows a significant redistribution of predicted isobaric abundances strengthening the yield of A>140 nuclei.

128Cs as the best example revealing chiral symmetry breaking.

The results of the Doppler-shift attenuation method lifetime measurements in partner bands of 128Cs and 132La are presented. Experimental reduced transition probabilities in 128Cs are compared with theoretical calculations done in the frame of the core-quasiparticle coupling model. The electromagnetic properties, energy and spin of levels belonging to the partner bands show that 128Cs is the best known example revealing the chiral symmetry breaking phenomenon.

On the holistic approach in cancer biology: tumor necrosis factor, colon cancer cells, chaos theory and complexity.

TNFalpha plays a role in the pathogenesis of septic shock, inflammatory diseases, autoimmune diseases, graft rejection reaction, acute, and chronic respiratory inefficiency among others. Its activity depends on the type of target cells and different regulating factors, but the effect of biological activity is conditioned by specific receptors such as p55 (type I, TNF R55) and p75 (type II, TNF R75). The aim of the study was to answer the following questions: 1) Is it possible to apply elements of non-linear dynamics to assess the level of expression of TNF, TNFRI, TNFRII genes in tumor cells, pathologically unchanged tissue and metastatically changed lymph nodes? 2) Is theoretically anticipated variability of cytokine and its receptors in colorectal carcinoma cells and the immediate vicinity justified in the developed mathematical model? The research material--specimens taken from tumor, unchanged tissue and metastatic lymph nodes--were histopathologically and molecularly analysed. Results of the molecular research were used to develop a mathematical model using the basic studies on the theory of chaos and biological system modelling.

[Evaluation of captopril levels in chronic congestive heart failure, stages NYHA III and IV]. / Ocena wartosci stosowania kaptoprylu w przewleklej zastoinowej niewydolnosci krazenia w III i IV okresie wg NYHA.

Thirty eight patients, aged between 25 and 81 years (mean age 56.9 years) with diagnosed chronic congestive heart failure of NYHA III and IV stages have been examined. The following phases of therapy have been distinguished depending on the used drugs: phase 0--digoxin in a daily dose of 0.25 mg and furosemide in a daily dose of 40-150 mg (mean value 72.4 mg) for 14 days; phase A1A2--nifedipine has been added in a daily dose of 40-80 mg (mean value 64.0 mg), lasting also for 14 days; phase B1B2--captopril (Lopirin--Squibb) has been added to the previous drugs in a daily dose of 25-150 mg (mean value 67.4 mg) in three divided portions for 28 days; phase C1C2--captopril has been withdrawn and drugs as in phase A1A2 have been administered for 14 days. Routine laboratory tests, ECG, a 24-hour ECG-records with Holter's technique, exercise ECG, chest X-ray, and 2D and M echocardiography were performed prior to and after 7 days as well as after each phase of the studies. A significant improvement in the left ventricle functioning assessed with Cubet's echo 2D has been observed in phase B1B2 in comparison with phase A1A2. These parameters have been the following: EF 42.61% vs 31.52%; CO 3.2 vs 2.9 L/min; SV 57.15 vs 44.24 mL (p < .001). Moreover, a decrease in heart volume (X-ray) from 1,145.25 mL to 1,088.25 mL, an increase in exercise tolerance (exercise ECG) in 52.6% of the patients, decrease in Lown's class in 11 out of 24 patients have been noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Computed tomographic findings in fresh (2nd to 4th week) myocardial infarction.

Thirty-seven patients, 2-4 weeks after transmural myocardial infarction, were investigated with ungated CT over a period of 120 min. after an i.v. contrast medium infusion + bolus injection of 0.6-0.9 iodine/kg body mass. Perfusion defect was found in 23/33 (70%) of technically adequate studies, delayed washout in 6/33 (18%) and local deformity of LV in 8/33 (24%). The mass of the perfusion defect assumed to represent the CT infarct size had a mean value of 10.2 g (3.5-25.8), infarct size estimated with CK-MB enzyme release method had a mean value of 14.1 g eq. (2.4-28.2). There was a r = 0.95 rectilinear correlation coefficient (p less than 0.001) between the CT and CK-MB method of infarct size estimation. Infarcts of size less than 6.0 g eq could not have been demonstrated with CT as a perfusion defect. Contrast enhancement of the infarct area was not a reliable feature of infarction.