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Combining the experimental a-decay energies and half-lives, the a-particle preformation factors for the nuclei around A' = Z = 50 are extracted within the generalized liquid drop model. It is found that the average order of magnitude of the preformation factor is 1.0 x 10-1. In addition, a detailed discussion on the odd-even effect of the preformation factor is performed. [ABSTRACT FROM AUTHOR]

The tensor force effect on the proton pseudospin orbital splittings of the 1d and 1f states in Sn isotopes is systematically analyzed with 36 sets of the TIJ interactions in the framework of the Hartree-Fock-Bogoliubov approach. It is shown that not all tensor parametrizations preserve the pseudospin symmetry. [ABSTRACT FROM AUTHOR]

In the framework of the Hartree-Fock-Bogoliubov (HFB) approach with Skyrme interactions SLy5+T, SLy5+Tw and several sets of the TIJ parametrizations, the evolution of the proton single-particle energy difference between the 2s 1/2 and 1d3/2 orbits in Ca isotopes is investigated for the cases with and without the tensor force. It is shown that the energy difference evolution trends by using different Skyrme interactions without the tensor force are similar to each other. However, the energy differences are obviously influenced by the tensor force. Meanwhile, it is found that the inversion between the two orbits (2s1/2-1d3/2 inversion) induced by the tensor force occurs around 48Ca (by SLy5+Tw) as well as in the nuclei very far from the stability. We understand the inversion phenomenon by analyzing the tensor contributions to the spin-orbit potentials and the radial wave functions of the two orbits. Finally, the proton density distributions of 46Ar and 206Hg are calculated by using several sets of Skyrme interactions with and without the tensor component. It is found that the parametrization SLy5+Tw favors the bubble structure of 46Ar resulting from the 2s1/2-1d3/2 inversion. However, for 206Hg any tensor parametrizations do not favor its bubble structure. [ABSTRACT FROM AUTHOR]

In the framework of the Hartree-Fock-Bogoliubov approach with the Skyrme interactions SLy5, SLy5+T, SLy5+Tw, and several sets of the TIJ parametrizations (Skyrme effective interaction parametrizations including the tensor terms), the effect of the tensor force on the shell evolution at Z,N=8, 20, and 28 is investigated. It is shown that the evolution of the gap (defined as the energy difference between the last occupied and first unoccupied single-particle orbits) with SLy5+T is similar to that with SLy5+Tw, and the gap values with SLy5+T are smaller than those with SLy5+Tw in the cases of Z,N=8, 20. At Z, N = 28, the gap values with SLy5 are smaller than those with SLy5+T and larger than those with SLy5+Tw. To understand these features, we analyze the spin-orbit potentials with and without the tensor contributions and the radial wave functions of relevant orbits. Meanwhile, we find that the deviation of the calculated gaps with SLy5+Tw from the experimental ones is larger than that with SLy5+T. This indicates that SLy5+Tw is not suitable for investigating the properties of the ground-state gap evolution. Finally, it is seen that the gap evolutions with different sets of the TIJ parametrizations are similar to each other except for the ones with T22, and there is almost no difference between the tensor effect in gap evolution with the perturbative method and the one with the complete fitting method. [ABSTRACT FROM AUTHOR]

In the framework of the generalized liquid drop model (GLDM) and improved Royer's formula, we investigate the branching ratios and half-lives of α-decay to the members of the ground-state rotational bands of heavy even-even Fm and No isotopes. The calculated results are in good agreement with the available experimental data and some useful predictions are provided for future experiments. [ABSTRACT FROM AUTHOR]

A novel Wilkinson power divider using complementary split ring resonators (CSRRs) for harmonic suppression is presented. CSRRs resonators cells are etched at the ground plane below the microstrip line of power divider. A demonstration power divider is designed, fabricated and measured. It agreed with the simulated results well. [ABSTRACT FROM AUTHOR]

The quadratic form of the isobaric multiplet mass equation (IMME), which was originally suggested by Wigner and has been generally regarded as valid, is seriously questioned by recent high-precision nuclear mass measurements. The usual resolution to this problem is to add empirically the cubic and quartic Tz terms to characterize the deviations from the IMME, but finding the origin of these terms remains an unsolved difficulty. Based on a strategy beyond Wigner's first-order perturbation, we derive explicitly the cubic and quartic Tz terms. These terms are shown to be generated by the effective charge-symmetry-breaking and charge-independence-breaking interactions in the nuclear medium combined with the Coulomb polarization effect. Calculations for the sd and lower fp shells explore a systematic emergence of the cubic Tz term, suggesting a general deviation from the original IMME. Intriguingly, the magnitude of the deviation exhibits an oscillation-like behavior with mass number, modulated by the shell effect. [ABSTRACT FROM AUTHOR]

Systematic calculations on the a-decay energies (Qa) and a-decay half-lives of the superheavy nuclei (SHN) with Z ≥ 100 are performed by using 20 models and 18 empirical formulas, respectively. According to the comparisons between the calculated results and experimental data, it is shown that the WS4 mass model is the most accurate one to reproduce the experimental Qa values of the SHN. Meanwhile it is found that the SemFIS2 formula is the best one to predict the a-decay half-lives of the SHN because the parameters in this formula are from the experimental a emitter data of transuranium nuclei including SHN (Z = 92-118). In addition, the UNIV2 formula with fewest parameters and the VSS, SP and NRDX formulas with fewer parameters work well in prediction on the SHN a-decay half-lives. Finally, the a-decay half-lives of Z = 110-120 isotopes are predicted within the above mentioned five formulas by inputting the WS4 Qa values. By analyzing the Qa values and the a-decay half-lives of this region, it is found that for Z = 110-114 isotopes N = 162 and N = 184 are the submagic number and magic number, respectively. However, for the isotopes of Z = 116-120 the submagic number is N = 178. [ABSTRACT FROM AUTHOR]

The proton density distribution of 206Hg is calculated in the framework of the Skyrme-Hartree-Fock approach with the SLy5, SLy5+T, and SLy5+Tw interactions. It is shown that the central density drops strongly with the SLy5 and SLy5+T interactions due to the vacancy of the 3s1/2 orbital. This means that the density depression in the interior of the nucleus is not so much influenced by the tensor force of the SLy5+T interaction. However, with the SLy5+Tw interaction the bubble structure does not exist because the tensor force effect of this interaction leads to the inversion between the single-proton states 3s1/2 and 1h11/2 (3s1/2-1h11/2 inversion) so that the 3s1/2 state is fully occupied by protons. In addition, a detailed discussion on the antibubble effect from the pairing interaction is performed by using the Skyrme-Hartree-Fock-Bogoliubov approach. It is found that a proton bubble structure in Hg206 is unlikely to appear because of the paring correlation. [ABSTRACT FROM AUTHOR]

Abstract: The low-spin part of the nucleus was investigated in radioactive decay of . The decay scheme was established and for a number of levels spin-parity assignments are suggested on the basis of logft values and γ-branching ratios. In order to discuss the band structures of this nucleus, the projected shell model is applied to the nucleus . The results of theoretical calculations about the excited positive-parity yrast states and the negative-parity ground-state band are compared with experimental data, and the best reproduction of the experiment has been given by this model. In addition, a band diagram calculated for the negative-parity g.s. band is used in order to extract physics out of the numerical results. [Copyright &y& Elsevier]

The generalized liquid drop model (GLDM) is first extended to study the two-proton (2p) radioactivity half-lives of the ground state of nuclei. According to the comparison between the calculated half-lives and the experimental data, it is shown that the GLDM describes the 2p radioactivity half-lives well. In addition, by comparing its accuracy with other models, it is found that the GLDM has a comparable accuracy with them. Finally, the 2p radioactivity half-lives of some of the most probable candidates are predicted with the GLDM by inputting the Q2p values (the released energy of the 2p radioactivity) from the updated 2016 Atomic Mass Evaluation mass table, which may be useful for future experiments. [ABSTRACT FROM AUTHOR]

The charge-symmetry-breaking (CSB) effect in a nuclear medium that gives rise to the first-order symmetry energy in finite nuclei is discussed in detail in the present paper. For heavy and superheavy nuclei with large neutron excesses, it should be nonnegligible in high-precision mass predictions, and importantly it affects the stability of these nuclei. Combined with this CSB effect, the Coulomb energy is constrained by using the experimental Coulomb displacement energy of mirror nuclei, and then the mass-dependent symmetry energy coefficients of heavy nuclei are reextracted with the experimental β--decay energies of heavy odd-A nuclei and with the experimental mass differences. Based on these results, we probe the neutron skin thickness ΔRnp of 208Pb and the density-dependent symmetry energy coefficient of nuclear matter. ΔRnp in 208Pb is found to be 0.158±0.014fm, and the slopes L of the symmetry energy coefficient at densities of ρ=0.16 and ρ=0.11fm-3 are estimated to be 42±8 and 42±3MeV, respectively. These results would be meaningful to discriminate between the models and the predictions that are relevant for the investigations on properties of nuclei and of neutron stars. [ABSTRACT FROM AUTHOR]

The Wigner isobaric multiplet mass equation (IMME) is the most fundamental prediction in nuclear physics with the concept of isospin. However, it was deduced based on the Wigner-Eckart theorem with the assumption that all charge-violating interactions can be written as tensors of rank two. In the present work, the charge-symmetry breaking (CSB) and charge-independent breaking (CIB) components of the nucleon-nucleon force, which contribute to the effective interaction in nuclear medium, are established in the framework of Brueckner theory with AV18 and AV14 bare interactions. Because such charge-violating components can no longer be expressed as an irreducible tensor due to density dependence, its matrix element cannot be analytically reduced by the Wigner-Eckart theorem. With an alternative approach, we derive a generalized IMME (GIMME) that modifies the coefficients of the original IMME. As the first application of GIMME, we study the long-standing question of the origin of the Nolen-Schiffer anomaly (NSA) found in the Coulomb displacement energy of mirror nuclei. We find that the naturally emerged CSB term in GIMME is largely responsible for explaining the NSA. [ABSTRACT FROM AUTHOR]

The α decay and proton radioactivity half-lives of some neutron-deficient nuclei are calculated using an effective liquid drop model (ELDM). It is found that the experimental half-lives of the two decay modes and the dominant decay mode can be well reproduced by the ELDM. Moreover, the predicted penetration probabilities (P) of proton radioactivity by the ELDM are in agreement with those by a microscopic model (MM). This allows us to make predictions on the competition of the two decay modes for nuclei whose experimental data are not available, which are useful for future measurements. In addition, the comparison between the predicted reduced proton radioactivity half-lives by the ELDM and the ones by a standard formula suggests that one is unlikely to observe large angular momentum transfers for nuclei with a very large Coulomb parameter χ. Last, we find that in most isotope chains the proton radioactivity is the dominant decay mode for nuclei that are very close to the proton drip line. But with increasing neutron number N the main decay mode is changed into α decay. With the decay energies the decay mode anomaly of 184Bi is discussed [ABSTRACT FROM AUTHOR]

A Comment on the Letter by U. Das and B. Mukhopadhyay, Phys. Rev. Lett. 110, 071102 (2013). The authors of the Letter offer a Reply. [ABSTRACT FROM AUTHOR]

A major obstacle in positional cloning is identifying the specific mutated gene from within a large physical contig. Here we describe the application of DNA microarray technology to a defined genomic region (physical map) to identify: (i) exons without a priori sequence data and (ii) the disease gene based on differential gene expression in a recessive disorder. The feasibility was tested using resources from the positional cloning of the Neimann-Pick Type C (NP-C) disease gene, NPC1. To identify NPC1 exons and optimize the technology, an array was generated from genomic fragments of the 110-kb bacterial artificial chromosome, 108N2, which encodes NPC1. First, as a test case for blindly identifying exons, fluorescently labeled NPC1 cDNA identified 108N2 fragments that contained NPC1 exons, many of which also contained intronic sequences and could be used to determine part of the NPC1 genomic structure. Second, to demonstrate that the NPC1 disease gene could be identified based upon differential gene expression, subarrays of 108N2 fragments were hybridized with fluorescently labeled cDNA probes generated from total RNA from hamster cell lines differentially expressing NPC1. A probe derived from the NP-C cell line CT60 did not detect NPC1 exons or other genomic fragments from 108N2. In contrast, several NPC1 exons were detected by a probe generated from the non-NP-C cell line 911D5A13, which was derived from CT60, and expressed NPC1 as a consequence of stable transduction with a YAC that contains NPC1 and encompasses 108N2. Thus, the array technology identified NPC1 as a candidate gene based on a physical contig and differential NPC1 expression between NP-C and non-NP-C cells. This technique should facilitate gene identification when a physical contig exists for a region of interest and mutations result in changes in the mRNA level of the disease gene or portions thereof., (Copyright 2000 Academic Press.)

Tangier disease (TD) is an autosomal co-dominant disorder in which homozygotes have a marked deficiency of high density lipoprotein (HDL) cholesterol and, in some cases, peripheral neuropathy and premature coronary heart disease (CHD). Homozygotes are further characterized by cholesteryl ester deposition in various tissues throughout the body, most notably in those of the reticuloendothelial system. Several studies have demonstrated that the excess lipid deposition in TD is due to defective apolipoprotein-mediated efflux of cellular cholesterol and phospholipids. Although much progress has been made in our understanding of the metabolic basis of TD, the precise molecular defect had remained elusive until very recently. By positional cloning methods, we: 1) confirm the assignment of TD to chromosome 9q31, 2) provide evidence that human ATP-binding cassette-1 (hABC-1) maps to a 250 kb region on 9q31, and 3) describe novel deletion, insertion, and missense mutations in the gene encoding hABC-1 in four unrelated TD kindreds. These results establish a causal role for mutations in hABC-1 in TD and indicate that this transporter has a critical function in the regulation of intracellular lipid trafficking that dramatically affects plasma HDL cholesterol levels.

An integrated human-mouse positional candidate approach was used to identify the gene responsible for the phenotypes observed in a mouse model of Niemann-Pick type C (NP-C) disease. The predicted murine NPC1 protein has sequence homology to the putative transmembrane domains of the Hedgehog signaling molecule Patched, to the cholesterol-sensing regions of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and SREBP cleavage-activating protein (SCAP), and to the NPC1 orthologs identified in human, the nematode Caenorhabditis elegans, and the yeast Saccharomyces cerevisiae. The mouse model may provide an important resource for studying the role of NPC1 in cholesterol homeostasis and neurodegeneration and for assessing the efficacy of new drugs for NP-C disease.

Niemann-Pick disease type C (NP-C) is an autosomal recessive lipidosis linked to chromosome 18q11-12, characterized by lysosomal accumulation of unesterified cholesterol and delayed induction of cholesterol-mediated homeostatic responses. This cellular phenotype is identifiable cytologically by filipin staining and biochemically by measurement of low-density lipoprotein-derived cholesterol esterification. The mutant Chinese hamster ovary cell line (CT60), which displays the NP-C cellular phenotype, was used as the recipient for a complementation assay after somatic cell fusions with normal and NP-C murine cells suggested that this Chinese hamster ovary cell line carries an alteration(s) in the hamster homolog(s) of NP-C. To narrow rapidly the candidate interval for NP-C, three overlapping yeast artificial chromosomes (YACs) spanning the 1 centimorgan human NP-C interval were introduced stably into CT60 cells and analyzed for correction of the cellular phenotype. Only YAC 911D5 complemented the NP-C phenotype, as evidenced by cytological and biochemical analyses, whereas no complementation was obtained from the other two YACs within the interval or from a YAC derived from chromosome 7. Fluorescent in situ hybridization indicated that YAC 911D5 was integrated at a single site per CT60 genome. These data substantially narrow the NP-C critical interval and should greatly simplify the identification of the gene responsible in mouse and man. This is the first demonstration of YAC complementation as a valuable adjunct strategy for positional cloning of a human gene.

To identify candidate genes for Branchio-oto-renal (BOR) syndrome, we have made use of a set of cosmids that map to 8q13.3, which has previously been shown to be involved in this syndrome. These cosmids were used as genomic clones in the attempts to isolate corresponding cDNAs using a modified hybrid selection technique. cDNAs from the region were identified and used to search for sequence similarity in human or other species. One cDNA clone was found to have 89% sequence similarity to the bovine B22 subunit of NADH-ubiquinone oxidoreductase, a mitochondrial protein in the respiratory electron transport chain. Given the history of other mitochondrial mutations being involved in hearing loss syndromes, this gene should be considered a strong candidate for involvement in BOR.

Genetic linkage analysis has previously mapped the locus for the autosomal dominant disorder branchio-oto-renal syndrome (BOR) to the pericentric region of chromosome 8q. A YAC contig spanning the putative BOR region, from D8S543 to D8S541, was constructed and confirmed by sequence-tagged site content mapping using microsatellite markers and by DNA hybridization analysis. YACs spanning the BOR interval were used as fluorescence in situ hybridization probes on a cell line from a patient with BO and tricho-rhino-phalangeal syndrome I that involves a chromosome 8q rearrangement. In addition to the cytogenetically defined direct insertion of material from 8q13.3-q21.13 into 8q24.11, a previously unidentified deletion of just under one megabase was found in 8q13.3. These data narrowed the most likely location of the BOR gene to a region corresponding to the proximal two-thirds of YAC 869E10 between D8S543 and D8S279.