Nonlocal correlations transmitted between quantum dots via short topological superconductor.

We study the quasiparticle states and nonlocal correlations of a hybrid structure, comprising two quantum dots interconnected through a short-length topological superconducting nanowire hosting overlaping Majorana modes. We show that the hybridization between different components of this setup gives rise to the emergence of molecular states, which are responsible for nonlocal correlations. We inspect the resulting energy structure, focusing on the inter-dependence between the quasiparticles of individual quantum dots. We predict the existence of nonlocal effects, which could be accessed and probed by crossed Andreev reflection spectroscopy. Our study would be relevant to a recent experimental realization of the minimal Kitaev model [T. Dvir et al., Nature 614, 445 (2023) ], by considering its hybrid structure with side-attached quantum dots.

Magnetic field effect on trivial and topological bound states of superconducting quantum dot.

We investigate the properties of a quantum dot embedded between the normal and superconducting leads which is additionally side-attached to the topological superconducting nanowire, hosting the Majorana modes. This setup enables formation of the trivial (finite-energy) bound states induced in the quantum dot through the superconducting proximity effect, coexisting/competing with the topological (zero-energy) mode transmitted from the topological superconductor. We analyze their interplay, focusing on a role played by the external magnetic field. To distinguish between these bound states we analyze the qualitative and quantitative features manifested in the subgap charge tunneling originating under nonequilibrium conditions from the Andreev (particle to hole) scattering processes.

Leakage of Majorana mode into correlated quantum dot nearby its singlet-doublet crossover.

We study quasiparticle spectrum of the correlated quantum dot (QD) deposited on superconducting (SC) substrate which is side-coupled to the Rashba nanochain, hosting Majorana end modes. Ground state of an isolated QD proximitized to SC reservoirs is represented either by the singly occupied site or BCS-type superposition of the empty and doubly occupied configurations. Quantum phase transition between these distinct ground states is spectroscopically manifested by the in-gap Andreev states which cross each other at the Fermi level. This qualitatively affects leakage of the Majorana mode from the side-attached nanowire. We inspect the spin-selective relationship between the trivial Andreev states and the leaking Majorana mode, considering (i) perfectly polarized case, when tunneling of one spin component is completely prohibited, and (ii) another one when both spins are hybridized with the nanowire but with different couplings.

Interplay between correlations and Majorana mode in proximitized quantum dot.

We study the low energy spectrum and transport properties of a correlated quantum dot coupled between normal and superconducting reservoirs and additionally hybridized with a topological superconducting nanowire, hosting the Majorana end-modes. In this setup the Majorana quasiparticle leaking into the quantum dot can be confronted simultaneously with the on-dot pairing and correlations. We study this interplay, focusing on the quantum phase transition from the spinless (BCS-type) to the spinful (singly occupied) configuration, where the subgap Kondo effect may arise. Using the selfconsistent perturbative treatment for correlations and the unbiased numerical renormalization group calculations we find that the Majorana mode has either constructive or destructive effect on the low-energy transport behavior of the quantum dot, depending on its spin. This spin-selective influence could be verified by means of the polarized STM spectroscopy.

Constructive influence of the induced electron pairing on the Kondo state.

Superconducting order and magnetic impurities are usually detrimental to each other. We show, however, that in nanoscopic objects the induced electron pairing can have constructive influence on the Kondo effect originating from the effective screening interactions. Such situation is possible at low temperatures in the quantum dots placed between the conducting and superconducting reservoirs, where the proximity induced electron pairing cooperates with the correlations amplifying the spin-exchange potential. The emerging Abrikosov-Suhl resonance, which is observable in the Andreev conductance, can be significantly enhanced by increasing the coupling to superconducting lead. We explain this intriguing tendency within the Anderson impurity model using: the generalized Schrieffer-Wolff canonical transformation, the second order perturbative treatment of the Coulomb repulsion, and the nonperturbative numerical renormalization group calculations. We also provide hints for experimental observability of this phenomenon.

Progress of local symptoms of superficial vein thrombosis vs. duplex findings.

BACKGROUND: Risk of subsequent deep vein thrombosis (DVT) following superficial vein thrombosis (SVT) is not fully appreciated. Mechanisms, time relations and risk factors for DVT arising upon earlier SVT remain unclear. The aim of this study was to analyze time relations between local symptoms of lower limb superficial vein thrombosis, duplex findings and onset of deep vein thrombosis during clinically evident course of SVT. PATIENTS AND METHODS: 46 patients with early (onset less than 72 hours prior to inclusion) clinical diagnosis of SVT, confirmed ultrasonographically were included in this prospective, multicenter study. Progress of pain, erythema and swelling in relation to subsequent ultrasound changes in size and localization of thrombus at 0, 7, 14 and 21 day of study has been recorded. RESULTS: Local symptoms subsided completely during 3 weeks. At that time thrombus disappeared completely only in 26% of cases, in remaining cases decreased in size from average 117.5 mm to 43.0 mm. Thrombus regression was similar to venous blood outflow direction--proximal to femoral area. Thrombus propagation was observed following regression of local symptoms of SVT. 4 cases of DVT (8.7%) were diagnosed at 2-11 days. CONCLUSIONS: Local, clinically detectable symptoms of SVT regress incomparably quicker than thrombus in affected veins. Risk of further thrombus propagation extends well beyond the period of intensive local symptoms of SVT. Regression of thrombus in femoral area requires significantly more time than in popliteal or calf segment. Thrombus propagation is directed with blood flow towards femoral segment.

Characterization of mouse fibronectin alternative mRNAs reveals an unusual isoform present transiently during liver development.

Fibronectins are found in many extracellular matrices as well as being abundant plasma proteins. The plasma isoforms of fibronectin, which are synthesized in the adult by liver hepatocytes, differ from those derived from most other cells and tissues due to alternative mRNA splicing. Studies in several vertebrates have indicated that FN alternative splicing is regulated spatially and temporally during development. The mouse represents an attractive organism in which to study the regulation of fibronectin splicing during development, but the patterns of fibronectin alternative splicing were not known for this species. Mouse fibronectin cDNA clones were isolated and sequenced, revealing > 95% identity with rat fibronectin at the amino acid level; all three segments that undergo alternative splicing are well conserved. RNase protection and RT-PCR were used to determine the patterns of alternative splicing that occur in fibroblasts and adult liver, sources of cellular and plasma fibronectins. Only A-B-mRNAs were detected in liver, and three V region variants were observed, corresponding to the protein isoforms V120, V95, and V0. Fibroblasts produced mRNAs that were heterogeneous for A and B splicing, but all RNAs contained V120. These patterns contrast with the embryonic form (B+A+V120). Characterization of fibronectin mRNAs from livers of fetal and newborn mice revealed that a significant level of B+ mRNA was present throughout late gestation, declining at birth. Little A+ mRNA was present, and the adult liver V region pattern was observed at all stages. Thus, fibronectin splicing changes during liver development are noncoordinate. One consequence of this temporal regulation is the transient synthesis of B+ mRNAs, including a novel isoform, B+A-V0.

[Results of intra-arterial administration of PGE1 prostaglandin]. / Wyniki dotetniczego podawania prostaglandyny PGE1.

On the basis of own clinical material the results are presented of intra-arterial administration of PGE1 prostaglandin (Prostavasin) to 18 patients with chronic lower limb ischaemia in II, III and IV stage of the disease according to Fontaine. In the group of 15 patients (four treated as outpatients) Prostavasin was administered in multiple infusions of 20 micrograms of the drug, according to the schema recommended by the producer. Three very good, six good and three poor results were observed. The best results were seen in young patients with persisting pulse over the popliteal artery. The presented method of treatment was assessed as safe, with the possibility of application, in selected cases, on outpatient basis.

Trisomy 14 in two cases of granulosa cell tumor of the ovary.

Cytogenetic analysis of granulosa cell tumor of the ovary was performed in two patients. G-banding analysis of cells cultured 3-5 days showed that the karyotype of each tumor contained normal diploid cells as well as cells with identical aberration: trisomy 14. This is the first report of trisomy 14 in two cases of granulosa cell tumor of the ovary. Flow cytometric DNA content analysis was also performed.

Alterations at the rel locus in human lymphoma.

The rel proto-oncogene has been mapped to chromosome region 2p11.2-14, a site associated with nonrandom rearrangements in non-Hodgkin's lymphoma. We have characterized an abnormal rel mRNA from a cell line derived from a diffuse large cell lymphoma, in which the evolutionarily conserved N-terminal half of the rel coding region was fused with the C-terminal coding region of an unrelated gene. In addition, rearrangement or amplification of the rel locus was found in the lymphomatous tissue of two follicular and one diffuse large cell lymphoma. The findings suggest involvement of rel in the pathogenesis of large cell lymphoma.

Effect of 8-methoxypsoralen in the dark on proliferation of stimulated lymphocytes.

The effect of 8-methoxypsoralen (8-MOP) in the dark on proliferation of phytohaemagglutinin-stimulated human lymphocytes has been examined, using total blood leucocytes, the lymphocyte fraction and the T-lymphocyte subpopulation. 8-MOP (1 microgram mL-1) increased [3H]TdR incorporation and caused a rise in the blastic and mitotic index in all experimental cultures. The lymphocyte proliferation in these experiments was effected by a comitogenic effect of 8-MOP on T-lymphocytes.

Increased proliferation of phytohaemagglutinin (PHA)-stimulated human leucocytes after 8-methoxypsoralen treatment.

The effect of 8-methoxypsoralen on human blood mononuclear cells cultured in darkness has been examined. 8-Methoxypsoralen (1 microgram mL-1, 4.6 microM) added to (phytohaemagglutinin-stimulated cells induced a two-fold increase in the number of mitoses. The number of blastic cells also increased. There was no effect on the formation of micronuclei and there was no chromosomal breakage.

Micronucleus formation in lymphocytes of patients with fraXq27 syndrome.

Human chromosome carry different fragile sites, but the most interesting one is the fragile X chromosome, especially in relation to mental retardation. In this report we present micronucleus formation in 5 individuals with the fragile X syndrome and 11 control subjects whose lymphocytes were cultured under 1) hydroxyurea treatment condition suitable for the increasing expression of the fraXq27, 2) control conditions. It has been found that hydroxyurea (HU) added to the final concentration 1.3 X 10(-5)M increases the frequency of the fraXq and micronucleus formation in comparison with culture without HU. The same concentration of HU has induced neither "nonspecific" "spontaneous" chromosomal breakage nor micronucleus formation in the control subjects.

Increased expression of fragile site Xq by hydroxyurea. Preliminary communication.

The addition of hydroxyurea in final concentration 1.3 X 10(-5) M increases the frequency of fraX in comparison with cultures without hydroxyurea. The same concentration of hydroxyurea did not induce fraX formation and "nonspecific" gaps in cultures of lymphocytes derive from healthy individuals. The possible explanation of this effect is discussed.

Interindividual phenotypic variations in CLL B lymphocyte maturation indication of different maturation blocks.

Peripheral blood lymphocytes from 8 patients with B-derived chronic lymphocytic leukaemia were stimulated by Staphylococcus aureus bacteria strain Cowan 1 with T cell mitogens PHA or PWM in 5-7 day suspension cultures. For the first group of patients proliferation and maturation tests were performed on T cell enriched and T cell depleted subpopulations, obtained from harvested lymphocytes at the end of cultures by the sheep red cell rosette technique. To re-examine mutual influences of cultivated T and B cells in the second group of experiments, lymphocytes from CLL patients and from 5 healthy individuals were investigated by the use of transmembrane cocultivation system after Feldman and Basten. The proliferative responses to lectin and to bacteria were assessed by 3HTdR-blastic and mitotic indices. The maturation process of B lymphocytes was examined by cytoplasmic Ig, studied by FITC-conjugated antisera. Results obtained with cocultivation system support the view that T cell replacing factor(s) were required for inducing prolonged growth and development of maturation of more numerous B lymphocytes in response to Staphylococcus aureus, a T cell independent, B specific polyclonal stimulator. Results analysed in different patients indicate various degrees of maturation of B cells including their differentiation towards a plasmacytoid cell, accompanied by various proliferative capacities of B and T lymphocytes. This functional analysis reflects the heterogeneity of B-CLL patients group.