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We propose a scheme for the generation of an ion vortex beam and we study the properties of its electromagnetic field on a plane transverse to its propagation direction. The ion vortex is created by the diffraction of an ionic beam by a light mask with a spiral-like transverse intensity pattern. The diffraction is a result of a short time optical dipole interaction between the light mask and the ion which results to a phase imprint on the ionic wave function. It is shown that as the order of the vortex states that are generated by the various diffraction gets higher the electromagnetic field components have reduced magnitudes. The properties of these fields are studied against the various parameters of the problem.

It is well established that the interaction of light with matter generally imparts mechanical forces and associated torques. Where laser light is involved, such effects can be deployed for the microscale and nanoscale manipulation of matter, giving rise to notable applications in wide areas of physics, chemistry, and the life sciences. The diversity of applications is enriched not only by the complexity of the constitution of matter, but also by the structure of the laser light itself, according to its polarisation, amplitude, and phase. This article reviews in comprehensive terms the origins of laser-based optical forces and their manifestations in a variety of current contexts and applications.

For radially extended Bessel modes, the helicity density distributions of magnetic fields associated with relativistic electron vortex beams are investigated for first time in the literature. The form of the distribution is defined by the electron beam’s cylindrically symmetric density flux, which varies with the winding number ℓ and the electron spin. Different helicity distributions are obtained for different signs of the winding number ±ℓ, confirming the chiral nature of the magnetic fields associated with the electron vortex beam. The total current helicity for the spin-down state is smaller than that of the spin-up state. The different fields and helicities associated with opposite winding numbers and/or spin values will play an important role in the investigation of the interaction of relativistic electron vortices with matter and especially chiral matter. A comparison of the calculated quantities with the corresponding ones in the case of non-relativistic spin-polarized electron beams is performed.

We investigate the interaction of atoms with a Laguerre-Gaussian beam near the vortex center where an annular nodal area exists on and around the beam propagation axis. To grasp the essential features related to the orbital angular momentum transfer to a bound electron, we first show that it suffices to include in the interaction Hamiltonian the leading (second) term in the usual expansion of e−ik.r to be associated with the transverse (longitudinal) field component of a beam with orbital angular momentum ℓ=±1. We compare the obtained results for the quadrupole transition 4S1/2 to 3D5/2 in Ca+ with published experimental data. For orbital angular momenta |ℓ|>1, this approach predicts that quadrupole transitions are only possible for the configuration where the orbital angular momentum with |ℓ|=2 is antiparallel to the spin degree of freedom. These results are confirmed by another approach based on the multipolar Hamiltonian which, additionally, provides rich information on the emergence of different selection rules for arbitrary value of ℓ including their spatial dependence in the region of interest. This work also extends the discussion of the excitation of target atoms by twisted light to two-electron atomic systems by deriving selection rules for single-electron transitions.

We report theoretical results for the transition amplitudes of two-photon transitions induced in a one-active-electron atomic system by a LG10 beam. We identify the excitation pathways for selected two-photon transitions starting from the ground state of the atomic system. We numerically evaluate these two-photon transition matrix elements for selected transitions in Ca+ employing the truncated summation method. We provide a comparison with corresponding transitions induced by a Gaussian beam and present an estimation of the relative strength when the two different types of light beams are employed.

Background: Chronic hepatitis B virus (HBV) infection is a common chronic liver disease that is closely associated with increased morbidity and mortality. Circulating cell-free DNA (cf-DNA) and global DNA methylation, expressed as circulating levels of 5-methyl-2′-deoxycytidine, are increasingly used to monitor chronic inflammatory diseases of several etiologies. This study attempts to investigate the serum levels of circulating cf-DNA and 5-methyl-2′-deoxycytidine in HBeAg-negative patients with chronic infection (carriers) and chronic hepatitis B (CHB), as well as their changes after treatment initiation in CHB. Methods: Serum samples from a total of 61 HBeAg-negative patients (30 carriers and 31 CHB patients) were included in order to quantify the levels of circulating cf-DNA and 5-methyl-2′-deoxycytidine. In addition, serum samples from 17 CHB patients in complete virological and biochemical remission after initiation of treatment with a nucleos(t)ide analogue were included. Results: Circulating cf-DNA concentration was significantly increased after the initiation of treatment (15 vs. 10 ng/mL, p = 0.022). There was a trend in higher mean levels of circulating 5-methyl-2′-deoxycytidine in carriers compared to CHB patients (211.02 vs. 175.66 ng/mL, p = 0.089), as well as a trend in increasing 5-methyl-2′-deoxycytidine levels after treatment initiation in CHB patients compared to pre-treatment levels (215 vs. 173 ng/mL, p = 0.079). Conclusions: Both circulating levels of cf-DNA and 5-methyl-2′-deoxycytidine might be useful biomarkers in order to monitor liver disease activity and response to antiviral treatment in HBeAg-negative chronic HBV patients, but further studies are essential in order to validate these intriguing findings.

Increased expression of interferon (IFN)-stimulated genes (ISGs) in peripheral blood, has been previously reported in viral infections, as well as in autoimmune disorders, in association with reduced leukocyte and platelet counts. Though cytopenias are common in patients with COVID-19 disease and predict severe outcomes, the underlying mechanisms have not been fully elucidated. In the current study, we aimed to determine the prevalence of hematological abnormalities in the setting of active COVID-19 infection and to explore whether they associate with disease outcomes and activation of type I IFN pathway. One-hundred-twenty-three consecutive SARS-CoV2 infected patients were included in the study. Clinical and laboratory parameters were recorded for all study participants. In 114 patients, total RNA was extracted from whole peripheral blood and subjected to real time PCR. The relative expression of three interferon stimulated genes (ISGs; IFIT1, MX-1, and IFI44) was determined and a type I IFN score reflecting peripheral type I IFN activity was calculated. The rates of anemia, leukopenia, and thrombocytopenia were 28.5, 14.6, and 24.4%, respectively. Among leukocytopenias, eosinopenia, and lymphopenia were the most prominent abnormalities being found in 56.9 and 43.1%, respectively. Of interest, patients with either eosinopenia and/or thrombocytopenia but no other hematological abnormalities displayed significantly increased peripheral type I IFN scores compared to their counterparts with normal/high eosinophil and platelet counts. While eosinopenia along with lymphopenia were found to be associated with increased risk for intubation and severe/critical disease, such an association was not detected between other hematological abnormalities or increased type I IFN scores. In conclusion, hematological abnormalities are commonly detected among patients with COVID-19 infection in association with severe disease outcomes and activation of the type I IFN pathway.

Abstract Background ERBB-2 is overexpressed in about 20% of breast cancers (BCs), indicating poor prognosis. The receptor activator of nuclear factor-κB (RANK) pathway is implicated in ERBB-2 (+) BC. The purpose of this study was to elucidate the underlying molecular mechanism of this interaction and the beneficial impact of dual targeting of RANK and ERBB-2 pathways. Methods We used SKBR3, MCF7, MDA-MB-453, and BT-474 human BC cell lines. We examined RANK and RANKL expression using RT-PCR, Western blot, and immunofluorescence. The evaluation of RANK expression in a cohort of BC patients was performed using immunohistochemistry. The interaction between RANK and ERBB family members was detected using proximity ligation assay (PLA), which enables the visualization of interacting proteins. We used inhibitors of both pathways [trastuzumab (T), pertuzumab (P), denosumab (D)]. NF-κB pathway activation was studied using Western blot. Cell growth and viability was evaluated using XTT, flow cytometry, and clonogenic assay. For cell migration evaluation, scratch assay was performed. Data were analyzed by one-way ANOVA. Results Cell lines express RANK and RANKL. RANK immunostaining was also detected in human BC tissue samples. RANK receptor dimerizes with ERBB family members. RANK/ERBB-2 dimer number seems to be associated with ERBB-2 expression (SKBR3, 5.4; BT-474, 8.2; MCF7, 0.7; MDA-MB-453, 0.3). RANK/ERBB-2 dimers were decreased in the presence of the inhibitors D, T, and P, while they were increased after RANKL (R) treatment in SKBR3 (m, 5.4; D, 1.2; T, 1.9; DT, 0.6; TP, 1; DTP, 0.4; R, 11.8) and BT-474 (m, 8.2; D, 3.1; T, 4.3; DT, 0.7; TP, 3.4; DTP, 3.2; R, 11.6). Combination targeting of SKBR3 further decreased NF-κB pathway activation compared to single targeting. In SKBR3, RANKL and ERBB-2 blockage resulted in reduced cell proliferation, increased apoptosis, and lower metastatic potential compared to mock cells (m) and reversed values in RANKL presence. The combination treatment of SKBR3 with D, T, and P had an advantage in functional traits compared to single targeting. Denosumab suppressed NF-κB signaling and diminished proliferation rate in MDA-MB-453 cells. MCF7 did not correspond to inhibitors. Conclusions The results indicate a novel physical and molecular association between ERBB-2 and RANK pathways that affects ERBB-2 (+) BC growth. We also present data suggesting that the combination of anti-ERBB-2 agents and RANKL inhibitors have a potential direct anti-tumor effect and should be further tested in certain BC patients.

“My main goal was to point out new phenomena and spread the ideas, which will become the starting points for new research” [...]

(1) Background: Hepatocellular carcinoma (HCC) is the most serious complication of chronic hepatitis B (CHB). Recently, the detection of circulating cell-free (cf) DNA and nucleosomes has found numerous applications in oncology. This study aimed to examine the levels of serum cfDNA markers and nucleosomes in CHB patients with and without HCC and assess their potential association with HCC patients’ survival. (2) Methods: Nineteen patients with CHB and HCC and 38 matched patients with CHB without cancer development during 5 years of antiviral therapy were included. Stored serum samples were analyzed for cfDNA species, including the cfDNA concentration and levels of Alu115, Alu247, and nucleosomes. DNA integrity was expressed as the Alu247/Alu115 ratio. (3) Results: Compared to controls, HCC patients had higher median Alu247 levels (64.2 vs. 23.2 genomic equivalent, p = 0.004) and DNA integrity (1.0 vs. 0.7, p < 0.001) and a trend for a higher median cfDNA concentration (36.0 vs. 19.5 ng/mL, p = 0.064). Increased DNA integrity (Alu247/Alu115 > 1) was associated with an increased risk of death during the first year after HCC diagnosis (p = 0.016). (4) Conclusions: Levels of Alu247 and DNA integrity in serum cfDNA are elevated in CHB patients with HCC, whereas increased DNA integrity seems to be associated with a worse short-term prognosis in this setting.

True-color holograms, as they are the most advanced and realistic three-dimensional images obtainable with current technologies, can become valuable tools for the preservation, documentation and diffusion of cultural heritage. In this respect, the transportable Z3RGB color holography system and the HoLoFoSTM illuminant developed by the Hellenic Institute of Holography have been successfully utilized for the in-situ recording and displaying of OptoClonesTM (Denisyuk-type color holograms) in four museums and two countries. The holographic image of an OptoCloneTM is characterized by a wide angle of view, full parallax and perspective, good color rendition and ultra-realistic reproduction of the optical properties of the materials of an artefact. In this paper, we report on our accumulated expertise in on-site holographic documentation of museum artworks of various types, already from four museums of world caliber and reputation (Athens and Thessaloniki Byzantine, Fabergé Museum of St. Petersburg and Diamond Fund of Russia). In one case, a world’s first, the in-situ recorded OptoClonesTM have been subsequently displayed as part of the permanent exhibition of the Byzantine & Christian Museum of Athens in replacement of the original artifacts while on loan. On another occasion involving State Treasures from the Diamond Fund of Russia, the recorded OptoClonesTM exhibited inside the Moscow Kremlin were highly appraised by officials and international experts as well as the general public allowing reasonable optimism for the prospects of Display Holography for museums.

We propose a scheme for the generation of an ion vortex beam and we study the properties of its electromagnetic field on a plane transverse to its propagation direction. The ion vortex is created by the diffraction of an ionic beam by a light mask with a spiral-like transverse intensity pattern. The diffraction is a result of a short time optical dipole interaction between the light mask and the ion which results to a phase imprint on the ionic wave function. It is shown that as the order of the vortex states that are generated by the various diffraction gets higher the electromagnetic field components have reduced magnitudes. The properties of these fields are studied against the various parameters of the problem. [ABSTRACT FROM AUTHOR]

The role of sodium-bicarbonate (Na+-HCO3-) cotransport in HCO3- secretion and membrane ion balance was investigated in guinea pig ileal crypt cells. Cells were depolarized or alkanized, depending on the nature of the medium used. However, gramicidin had a marked effect on intracellular pH, cell volume and rates of sodium efflux. An electrogenic Na+-HCO3- symport system was suggested to be present in pig ileal crypt cells.

Isolation of jejunal crypt epithelial cells using segmental perfusion with hyperosmolar Ca(2+)-free solution for electronic cell volume measurements reveals that 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP) induces a decrease in the isotonic volume of the cells and an increase in the efflux of 36Cl from the crypt cells. Administration of anthracene-9-carboxylate or Ba(2+) to the volume-reduced cells enables the cells to increase their volume again. Addition of 8-BrcAMP to the villi enterocytes does not cause isotonic volume reduction or high 36Cl efflux. Intestinal crypt cells do not mediate cell volume reduction in an isotonic medium.