1
|
A proposed index of myocardial staining for vein of Marshall ethanol infusion: an Italian single-center experience. J Interv Card Electrophysiol 2024:10.1007/s10840-023-01732-4. [PMID: 38206450 DOI: 10.1007/s10840-023-01732-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024]
Abstract
BACKGROUND Mitral isthmus (MI) conduction block is a fundamental step in anatomical approach treatment for persistent atrial fibrillation (PeAF). However, MI block is hardly achievable with endocardial ablation only. Retrograde ethanol infusion (EI) into the vein of Marshall (VOM) facilitates MI block. Fluorographic myocardial staining (MS) during VOM-EI could be helpful in predicting procedural alcoholization outcome even if its role is qualitatively assessed in the routine. The aim was to quantitatively assess MS during VOM-EI and to evaluate its association with MI block achievement. METHODS Consecutive patients undergoing catheter ablation for PeAF at Fondazione Toscana Gabriele Monasterio (Pisa, Italy) from February 2022 to May 2023 were considered. Patients with identifiable VOM were included. A proposed index of MS (MSI) was retrospectively calculated in each included patient. Correlation of MSI with low-voltage zones (LVZ) extension after VOM-EI and its association with MI block achievement were assessed. RESULTS In total, 42 patients out of 49 (85.8%) had an identifiable VOM. MI block was successfully achieved in 35 patients out of 42 (83.3%). MSI was significantly associated with the occurrence of MI block (OR 1.24 (1.03-1.48); p = 0.022). A higher MSI resulted in reduced ablation time (p = 0.014) and reduced radiofrequency applications (p = 0.002) to obtain MI block. MSI was also associated with MI block obtained by endocardial ablation only (OR 1.07 (1.02-1.13); p = 0.002). MSI was highly correlated with newly formed LVZ extension (r = 0.776; p = 0.001). CONCLUSIONS In our study cohort, optimal MSI predicts MI block and facilitates its achievement with endocardial ablation only.
Collapse
|
2
|
Sauter-Schwinger Effect in a Bardeen-Cooper-Schrieffer Superconductor. PHYSICAL REVIEW LETTERS 2021; 126:117001. [PMID: 33798345 DOI: 10.1103/physrevlett.126.117001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 12/01/2020] [Accepted: 02/18/2021] [Indexed: 06/12/2023]
Abstract
Since the 1960s a deep and surprising connection has followed the development of superconductivity and quantum field theory. The Anderson-Higgs mechanism and the similarities between the Dirac and Bogoliubov-de Gennes equations are the most intriguing examples. In this last analogy, the massive Dirac particle is identified with a quasiparticle excitation and the fermion mass energy with the superconducting gap energy. Here we follow further this parallelism and show that it predicts an outstanding phenomenon: the superconducting Sauter-Schwinger effect. As in the quantum electrodynamics Schwinger effect, where an electron-positron couple is created from the vacuum by an intense electric field, we show that an electrostatic field can generate two coherent excitations from the superconducting ground-state condensate. Differently from the dissipative thermal excitation, these form a new macroscopically coherent and dissipationless state. We discuss how the superconducting state is weakened by the creation of this kind of excitations. In addition to shedding a different light and suggesting a method for the experimental verification of the Sauter-Schwinger effect, our results pave the way to the understanding and exploitation of the interaction between superconductors and electric fields.
Collapse
|
3
|
The additional role of 18F-FDG PET/CT in prosthetic valve endocarditis. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2019; 22:1744-1751. [PMID: 29630121 DOI: 10.26355/eurrev_201803_14590] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The purpose of the present review is an update on the diagnosis of prosthetic valve endocarditis (PVE), evaluating the additional value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) to the standard modified DUKE criteria on which for a long time is based the diagnostic strategy of the disease. MATERIALS AND METHODS We did a comprehensive research on the studies reported in the literature and regarding the employment of 18F-FDG PET/CT in the early diagnosis of PVE in patients with suspected disease. Scientific databases have been examined such as Medline and PubMed, followed by a review of citations and reference lists. The research included the following terms: infective endocarditis, prosthetic heart valve and cardiac valve replacement infections, 18F-FDG PET/CT and endocarditis. RESULTS The recent studies reported in the literature on the PVE diagnostic approaches showed elevated sensitivity and specificity values of 18F-FDG PET/CT ranging from 73 to 96.6% and from 80 to 94%, respectively, reducing the number of misdiagnosed patients. The usefulness of the radioisotopic procedure is even more important when the other diagnostic conventional diagnostic tools, such as echocardiography, are inconclusive or negative in patients in whom the diagnosis of PVE is definitively ascertained. However, false negative and positive results of 18F-FDG PET/CT were also ascertained in some studies interfering with image interpretation even if such limitation can be reduced with an adequate patient preparation, with a better knowledge of clinical course of the disease, of the treatment in progress and of the different technical aspects of the method. CONCLUSIONS In different studies reported in the literature, 18F-FDG PET/CT proved to improve the diagnostic accuracy of the conventional modified DUKE criteria in patients with suspected IE, and in particular with PVE, giving the highest diagnostic performance and providing additional diagnostic benefits. Thus, the radioisotopic hybrid procedure should be included in the diagnostic protocol of PVE as complementary tool to modified DUKE criteria. Finally, the usefulness of 18F-FDG PET/CT in monitoring the response to antibiotic therapy, although the few data reported in the literature are encouraging, needs more numerous studies and with a major number of cases.
Collapse
|
4
|
Body fat changes in HIV patients on highly active antiretroviral therapy (HAART): a longitudinal DEXA study. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2019; 22:1852-1859. [PMID: 29630136 DOI: 10.26355/eurrev_201803_14606] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE We aimed to quantitatively evaluate body fat composition in a group of HIV patients treated with Highly Active Anti-retroviral Therapy (HAART) to ascertain both fat loss and fat distribution changes and to identify possible therapeutic and host related associated risk factors. PATIENTS AND METHODS A total of 180 patients with available total body DEXA scan were assigned to a) Group 1, with clinically evident body fat changes, (BFC) and b) Group 2, without BFC. Clinical and immunovirologic data were collected. We used Student t-test and x2 or Fisher exact test to compare the characteristics of the two groups. Paired t-test was used to compare basal and follow-up data. The relationships between variables were evaluated by calculating Pearson's correlation coefficient and its significance. RESULTS HAART duration was significantly (p<0.0001) higher for patients in Group 1 than in Group 2, as well as PI (p<0.02) and NRTI (p<0.002) therapy duration. Current CD4 count and CD4 rise from nadir resulted significantly higher in Group 1 than in Group 2 (p<0.02 and 0.006, respectively). Whole Body Fat (WBF), Peripheral Fat (PF) and Leg (L) fat negatively correlated with PI and NRTI therapy duration, while Trunk Fat (TF)/PF positively correlated with PI and NNRTI duration. No significant correlation was found, instead, with NNRTI therapy duration. At 5-year follow-up, we registered a further increase in TF, Arms (A) and L fat, especially in PI-treated patients. CONCLUSIONS Body fat changes should always be considered when dealing with HIV-affected patients on HAART. The fat loss seemed to involve mainly peripheral regions, while fat accumulation tendency occurred in the trunk.
Collapse
|
5
|
Abstract
Gate-tunable Josephson junctions (JJs) are the backbone of superconducting classical and quantum computation. Typically, these systems exploit low-charge-concentration materials and present technological difficulties limiting their scalability. Surprisingly, electric field modulation of a supercurrent in metallic wires and JJs has been recently demonstrated. Here, we report the realization of titanium-based monolithic interferometers which allow tuning both JJs independently via voltage bias applied to capacitively coupled electrodes. Our experiments demonstrate full control of the amplitude of the switching current (Is) and of the superconducting phase across the single JJ in a wide range of temperatures. Astoundingly, by gate-biasing a single junction, the maximum achievable total Is is suppressed down to values much lower than the critical current of a single JJ. A theoretical model including gate-induced phase fluctuations on a single junction accounts for our experimental findings. This class of quantum interferometers could represent a breakthrough for several applications such as digital electronics, quantum computing, sensitive magnetometry, and single-photon detection.
Collapse
|
6
|
Metallic supercurrent field-effect transistor. NATURE NANOTECHNOLOGY 2018; 13:802-805. [PMID: 29967460 DOI: 10.1038/s41565-018-0190-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 06/07/2018] [Indexed: 06/08/2023]
Abstract
In their original formulation of superconductivity, the London brothers predicted1 the exponential suppression of an electrostatic field inside a superconductor over the so-called London penetration depth2-4, λL. Despite a few experiments indicating hints of perturbation induced by electrostatic fields5-7, no clue has been provided so far on the possibility to manipulate metallic superconductors via the field effect. Here, we report field-effect control of the supercurrent in all-metallic transistors made of different Bardeen-Cooper-Schrieffer superconducting thin films. At low temperature, our field-effect transistors show a monotonic decay of the critical current under increasing electrostatic field up to total quenching for gate voltage values as large as ±40 V in titanium-based devices. This bipolar field effect persists up to ~85% of the critical temperature (~0.41 K), and in the presence of sizable magnetic fields. A similar behaviour is observed in aluminium thin-film field-effect transistors. A phenomenological theory accounts for our observations, and points towards the interpretation in terms of an electric-field-induced perturbation propagating inside the superconducting film. In our understanding, this affects the pairing potential and quenches the supercurrent. These results could represent a groundbreaking asset for the realization of all-metallic superconducting field-effect electronics and leading-edge quantum information architectures8,9.
Collapse
|
7
|
Abstract
Since its recent foundation, phase-coherent caloritronics has sparkled continuous interest giving rise to numerous concrete applications. This research field deals with the coherent manipulation of heat currents in mesoscopic superconducting devices by mastering the Josephson phase difference. Here, we introduce a new generation of devices for fast caloritronics able to control local heat power and temperature through manipulation of Josephson vortices, i.e., solitons. Although most salient features concerning Josephson vortices in long Josephson junctions were comprehensively hitherto explored, little is known about soliton-sustained coherent thermal transport. We demonstrate that the soliton configuration determines the temperature profile in the junction, so that, in correspondence of each magnetically induced soliton, both the flowing thermal power and the temperature significantly enhance. Finally, we thoroughly discuss a fast solitonic Josephson heat oscillator, whose frequency is in tune with the oscillation frequency of the magnetic drive. Notably, the proposed heat oscillator can effectively find application as a tunable thermal source for nanoscale heat engines and coherent thermal machines.
Collapse
|
8
|
Abstract
Superconducting field-effect transitor (SuFET) and Josephson field-effect transistor (JoFET) technologies take advantage of electric-field-induced control of charge-carrier concentration to modulate the channel superconducting properties. Despite the fact that the field-effect is believed to be ineffective for superconducting metals, recent experiments showed electric-field-dependent modulation of the critical current ( IC) in a fully metallic transistor. However, the grounding mechanism of this phenomenon is not completely understood. Here, we show the experimental realization of Ti-based Dayem bridge field-effect transistors (DB-FETs) able to control the IC of the superconducting channel. Our easy fabrication process for DB-FETs show symmetric full suppression of IC for applied critical gate voltages as low as VGC ≃ ±8 V at temperatures reaching about the 85% of the record critical temperature, TC ≃ 550 mK, for titanium. The gate-independent TC and normal-state resistance ( RN) coupled with the increase of resistance in the superconducting state ( RS) for gate voltages close to the critical value ( VGC) suggest the creation of field-effect induced metallic puddles in the superconducting sea. Our devices show extremely high values of transconductance (| gmMAX| ≃ 15 μA/V at VG ≃ ±6.5 V) and variations of Josephson kinetic inductance ( LK) with VG of 2 orders of magnitude. Therefore, the DB-FET appears as an ideal candidate for the realization of superconducting electronics, superconducting qubits, and tunable interferometers as well as photon detectors.
Collapse
|
9
|
0-π phase-controllable thermal Josephson junction. NATURE NANOTECHNOLOGY 2017; 12:425-429. [PMID: 28288120 DOI: 10.1038/nnano.2017.25] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 02/02/2017] [Indexed: 06/06/2023]
Abstract
Two superconductors coupled by a weak link support an equilibrium Josephson electrical current that depends on the phase difference ϕ between the superconducting condensates. Yet, when a temperature gradient is imposed across the junction, the Josephson effect manifests itself through a coherent component of the heat current that flows opposite to the thermal gradient for |ϕ| < π/2 (refs 2-4). The direction of both the Josephson charge and heat currents can be inverted by adding a π shift to ϕ. In the static electrical case, this effect has been obtained in a few systems, for example via a ferromagnetic coupling or a non-equilibrium distribution in the weak link. These structures opened new possibilities for superconducting quantum logic and ultralow-power superconducting computers. Here, we report the first experimental realization of a thermal Josephson junction whose phase bias can be controlled from 0 to π. This is obtained thanks to a superconducting quantum interferometer that allows full control of the direction of the coherent energy transfer through the junction. This possibility, in conjunction with the completely superconducting nature of our system, provides temperature modulations with an unprecedented amplitude of ∼100 mK and transfer coefficients exceeding 1 K per flux quantum at 25 mK. Then, this quantum structure represents a fundamental step towards the realization of caloritronic logic components such as thermal transistors, switches and memory devices. These elements, combined with heat interferometers and diodes, would complete the thermal conversion of the most important phase-coherent electronic devices and benefit cryogenic microcircuits requiring energy management, such as quantum computing architectures and radiation sensors.
Collapse
|
10
|
Energy Exchange in Driven Open Quantum Systems at Strong Coupling. PHYSICAL REVIEW LETTERS 2016; 116:240403. [PMID: 27367367 DOI: 10.1103/physrevlett.116.240403] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Indexed: 06/06/2023]
Abstract
The time-dependent energy transfer in a driven quantum system strongly coupled to a heat bath is studied within an influence functional approach. Exact formal expressions for the statistics of energy dissipation into the different channels are derived. The general method is applied to the driven dissipative two-state system. It is shown that the energy flows obey a balance relation, and that, for strong coupling, the interaction may constitute the major dissipative channel. Results in analytic form are presented for the particular value K=1/2 of strong Ohmic dissipation. The energy flows show interesting behaviors including driving-induced coherences and quantum stochastic resonances. It is found that the general characteristics persists for K near 1/2.
Collapse
|
11
|
Different impact of NNRTI and PI-including HAART on bone mineral density loss in HIV-infected patients. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2015; 19:4576-4589. [PMID: 26698255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
OBJECTIVE To evaluate the changes in Bone Mineral Density (BMD) and bone remodelling markers in a group of HIV patients treated with HAART and controlled in a long follow-up and to identify possible risk factors for accelerated bone mass loss. PATIENTS AND METHODS In a series of 172 HIV patients treated with HAART a total of 67 patients (44 males and 33 females) underwent repeated bone mineral density measurement by DEXA in lumbar spine and in femur; the patients were classified according to T-score WHO criteria. Serum bone alkaline phosphatase (BAP), by IRMA, and urine pyridinoline/deoxypyridinoline (PYD&DPD), by EIA, were also assayed in all cases. RESULTS At baseline, 62/67 patients were on HAART, while 5 were naïve; 44.8% were previous intravenous drug users (IVDU), 46.3% heterosexual and 8.9% homosexual, mean age being 40.2 ± 6.5 years, and 23.9% had previous AIDS diagnosis. Fifteen/67 (22.4%) of treated patients had osteoporosis and 25/67 (37.3%) osteopenia in spine and/or femur including 3 naïve, 27/67 (40.3%), including 2 naïve, had normal BMD in both sites. Fifty-one/67 patients were monitored during follow-up (56.8 ± 5.3 months); 27 (52.9%) of these (Group 1), received protease inhibitors (PI) and 24 (47.1%), including naïve, (Group 2) received not nucleoside reverse transcriptase inhibitors (NNRTI) for > 50% of follow-up period. In Group 1 patients, BMD reduction was observed after follow-up in respect of basal condition in both spine and femur, but significantly (p = 0.011) only for the latter. However, mean BMD values remained stable in both sites in Group 2 patients. Basal BAP and PYD&DPD levels were higher in Group 1 than Group 2, but not significantly. Moreover, only PYD&DPD levels at the follow-up evaluation were significantly (p = 0.031) higher in Group 1 than Group 2. Of the remaining 16/67 patients with osteoporosis/osteopenia, 10 received PI and 6 NNRTI and were treated with therapies that could increase bone density, in particular, 9 with Alendronate/Vitamin D/Calcium and 7 with only vitamin D/calcium; these patients were excluded from statistical analysis of 51 Group 1/Group 2 cases. In the 16 patients, after these specific treatments, mean spine and femur BMD increased over time, but significantly only in those cases including alendronate in their protocol. CONCLUSIONS The study showed that in HIV patients on HAART BMD decrease, even osteoporosis, can be present persisting over time, particularly in PI in respect of NNRTI treated patients. The pathogenesis is probably multifactorial, the different antiviral drugs seeming to differently affect bone metabolism. Alendronate/Vitamin D/Calcium therapy can be useful to slow down bone mass loss and also improve osteoporosis/osteopenia conditions, thus, reducing fracture risk also continuing HAART.
Collapse
|
12
|
Ultrastructural evidence of a secretory role for melatonin in the human parotid gland. JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY : AN OFFICIAL JOURNAL OF THE POLISH PHYSIOLOGICAL SOCIETY 2015; 66:847-853. [PMID: 26769834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 10/31/2015] [Indexed: 06/05/2023]
Abstract
In vivo animal studies show that pentagastrin, cholecystokinin and melatonin cause the secretion and synthesis of salivary proteins. Melatonin occurs in large amounts in the gut and is released into the blood on food intake. In vitro experiments suggest that pentagastrin exerts secretory activity in human salivary glands, as judged by ultrastructural changes, reflecting secretion, and an actual protein output. Currently, it is hypothesised that melatonin induces secretory exocytotic events in the human parotid gland. Human parotid tissues were exposed to a high single concentration of melatonin in vitro, processed for high resolution scanning electron microscopy and then assessed morphometrically with the emphasis on the membrane of the intercellular canaliculi, a site of protein secretion. Compared with controls and in terms of density, the melatonin-exposed parotid tissues displayed increases in protrusions (signalling anchored granules) and microbuds (signalling membrane recycling and/or vesicle secretion) and decreases in microvilli (signalling cytoskeletal re-arrangement related to exocytosis), phenomena abolished or very largely reduced by the melatonin receptor blocker, luzindole. In conclusion, acinar serous cells of parotid tissue displayed in vitro exocytotic activity to melatonin, signalling protein secretion. Whether, under physiological conditions, melatonin influences the secretion of human parotid glands remains to be explored, however.
Collapse
|
13
|
Full distribution of work done on a quantum system for arbitrary initial states. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:042150. [PMID: 26565211 DOI: 10.1103/physreve.92.042150] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Indexed: 06/05/2023]
Abstract
We propose an approach to define and measure the statistics of work, internal energy and dissipated heat in a driven quantum system. In our framework the presence of a physical detector arises naturally and work and its statistics can be investigated in the most general case. In particular, we show that the quantum coherence of the initial state can lead to measurable effects on the moments of the work done on the system. At the same time, we recover the known results if the initial state is a statistical mixture of energy eigenstates. Our method can also be applied to measure the dissipated heat in an open quantum system. By sequentially coupling the system to a detector, we can track the energy dissipated in the environment while accessing only the system degrees of freedom.
Collapse
|
14
|
Abstract
We propose the implementation of a Josephson Radiation Comb Generator (JRCG) based on a dc superconducting quantum interference device (SQUID) driven by an external magnetic field. When the magnetic flux crosses a diffraction node of the critical current interference pattern, the superconducting phase undergoes a jump of π and a voltage pulse is generated at the extremes of the SQUID. Under periodic drive this allows one to generate a sequence of sharp, evenly spaced voltage pulses. In the frequency domain, this corresponds to a comb-like structure similar to the one exploited in optics and metrology. With this device it is possible to generate up to several hundreds of harmonics of the driving frequency. For example, a chain of 50 identical high-critical-temperature SQUIDs driven at 1 GHz can deliver up to a 0.5 nW at 200 GHz. The availability of a fully solid-state radiation comb generator such as the JRCG, easily integrable on chip, may pave the way to a number of technological applications, from metrology to sub-millimeter wave generation.
Collapse
|
15
|
Lamb-shift enhancement and detection in strongly driven superconducting circuits. PHYSICAL REVIEW LETTERS 2014; 113:027001. [PMID: 25062221 DOI: 10.1103/physrevlett.113.027001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Indexed: 06/03/2023]
Abstract
It is shown that strong driving of a quantum system substantially enhances the Lamb shift induced by broadband reservoirs, which are typical for solid-state devices. By varying drive parameters the impact of environmental vacuum fluctuations with continuous spectral distribution onto system observables can be tuned in a distinctive way. This provides experimentally feasible measurement schemes for the Lamb shift in superconducting circuits based on Cooper pair boxes, where it can be detected either in shifted dressed transition frequencies or in pumped charge currents.
Collapse
|
16
|
Quantum driving and work. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 89:052128. [PMID: 25353760 DOI: 10.1103/physreve.89.052128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Indexed: 06/04/2023]
Abstract
As quantum systems become more experimentally accessible, we are forced to reconsider the notions of control and work to fully account for quantum effects. To this end, we identify the work injected into a quantum system during a general quantum-mechanical driving protocol and quantify the relevant heat flows. The known results that are applicable in the limit of a classical drive are shown to emerge from our equations as a special case. Using the established framework, we show that the Bochkov-Kuzovlev identity for the exclusive work distribution is modified in a nontrivial way by the accumulation of system-drive correlations resulting from quantum back action. Our results accentuate the conceptual and discernible differences between a fully quantum-mechanical and classical driving protocols of quantum systems.
Collapse
|
17
|
The antipsychotic amisulpride: ultrastructural evidence of its secretory activity in salivary glands. Oral Dis 2013; 20:796-802. [PMID: 24245711 DOI: 10.1111/odi.12209] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 11/05/2013] [Accepted: 11/12/2013] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Amisulpride is reported to inhibit clozapine-induced sialorrhea. Preclinically, clozapine evokes muscarinic-M1-type-mediated secretion that, however, amisulpride does not reduce. Instead, amisulpride, without causing any overt secretion per se, enhances both nerve- and autonomimetic-evoked salivation by unknown mechanism(s). Hypothesizing that amisulpride prepares the gland for secretion, we looked for ultrastructural events indicating secretory activity in intercellular canaliculi of serous/seromucous cells, that is, density increase in protrusions (reflecting anchored granules) and in microbuds (reflecting recycling membranes and/or vesicle secretion) and decrease in microvilli (reflecting the cytoskeletal re-arrangement related to exocytosis). MATERIAL AND METHODS Rat parotid and submandibular glands were exposed to amisulpride in vivo or in vitro. Glands were processed for transmission electron and scanning electron microscopy and then morphometrically assessed. RESULTS Cells were packed with secretory granules. The density of protrusions increased in both glands, whereas significant and parallel changes in microvilli and microbuds occurred only in parotid glands, and in vitro. CONCLUSIONS Amisulpride induced ultrastructural signs of secretory activity but to varying extent; in submandibular glands, in contrast to parotid glands, changes were not brought beyond the granular anchoring stage. Amisulpride may provide an overall readiness for secretion that will result in augmented responses to agonists, a phenomenon of potential interest in dry-mouth treatment.
Collapse
|
18
|
Subcellular distribution of melatonin receptors in human parotid glands. J Anat 2013; 223:519-24. [PMID: 23998562 DOI: 10.1111/joa.12105] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/06/2013] [Indexed: 12/29/2022] Open
Abstract
The hormone melatonin influences oral health through a variety of actions, such as anti-inflammatory, anti-oxidant, immunomodulatory and antitumour. Many of these melatonin functions are mediated by a family of membrane receptors expressed in the oral epithelium and salivary glands. Using immunoblotting and immunohistochemistry, recent studies have shown that the melatonin membrane receptors, MT1 and MT2, are present in rat and human salivary glands. To date, no investigation has dealt with the ultrastructural distribution of the melatonin receptors. This was the aim of the present study, using the immunogold method applied to the human parotid gland. Reactivity to MT1 and, with less intensity, to MT2 appeared in the secretory granules of acinar cells and in the cytoplasmic vesicles of both acinar and ductal cells. Plasma membranes were also stained, albeit slightly. The peculiar intracytoplasmic distribution of these receptors may indicate that there is an uptake/transport system for melatonin from the circulation into the saliva.
Collapse
|
19
|
Environment-governed dynamics in driven quantum systems. PHYSICAL REVIEW LETTERS 2013; 110:150403. [PMID: 25167233 DOI: 10.1103/physrevlett.110.150403] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Indexed: 06/03/2023]
Abstract
We show that the dynamics of a driven quantum system weakly coupled to the environment can exhibit two distinct regimes. While the relaxation basis is usually determined by the system+drive Hamiltonian (system-governed dynamics), we find that under certain conditions it is determined by specific features of the environment, such as, the form of the coupling operator (environment-governed dynamics). We provide an effective coupling parameter describing the transition between the two regimes and discuss how to observe the transition in a superconducting charge pump.
Collapse
|
20
|
Diabetes reduces statherin in human parotid: immunogold study and comparison with submandibular gland. Oral Dis 2011; 18:360-4. [DOI: 10.1111/j.1601-0825.2011.01884.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
21
|
Abstract
We propose a new type of interferometry, based on geometric phases accumulated by a periodically driven two-level system undergoing multiple Landau-Zener transitions. As a specific example, we study its implementation in a superconducting charge pump. We find that interference patterns appear as a function of the pumping frequency and the phase bias, and clearly manifest themselves in the pumped charge. We also show that the effects described should persist in the presence of realistic decoherence.
Collapse
|
22
|
|
23
|
|
24
|
Decoherence in adiabatic quantum evolution: application to cooper pair pumping. PHYSICAL REVIEW LETTERS 2010; 105:030401. [PMID: 20867746 DOI: 10.1103/physrevlett.105.030401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Revised: 05/03/2010] [Indexed: 05/29/2023]
Abstract
One of the challenges of adiabatic control theory is the proper inclusion of the effects of dissipation. Here we study the adiabatic dynamics of an open two-level quantum system deriving a generalized master equation to consistently account for the combined action of the driving and dissipation. We demonstrate that in the zero-temperature limit the ground state dynamics is not affected by environment. As an example, we apply our theory to Cooper pair pumping, which demonstrates the robustness of ground state adiabatic evolution.
Collapse
|
25
|
New findings on 3-D microanatomy of cellular structures in human tissues and organs. An HRSEM study. Eur J Histochem 2007; 51 Suppl 1:53-8. [PMID: 17703594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023] Open
Abstract
We present here findings obtained on a large number of human tissues over a period of more than ten years, by our modification of the Osmium maceration method for high resolution scanning electron microscopy (HRSEM). Data are documented by original pictures which illustrate both some 3-D intracellular features not previously shown in human tissues, and results obtained in our current studies on mitochondrial morphology and on the secretory process of salivary glands. We have demonstrated that mitochondria of cells of practically all human tissues and organs have usually tubular cristae, and that even the cristae that look lamellar are joined to the inner mitochondrial membrane by tubular connexions similar to the crista junctions later seen by electron tomography. Concerning salivary glands an important result is the development of a morphometric method that allows the quantitative evaluation of the secretory events.
Collapse
|
26
|
Bone mass loss and vitamin D metabolism impairment in HIV patients receiving highly active antiretroviral therapy. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF... 2004; 48:39-48. [PMID: 15195003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
AIM Given the few controversial data about the effect of highly active antiretroviral therapy (HAART) on bone mass in HIV patients, we investigated whether a relationship between osteopenia/osteoporosis risk and HAART exists. METHODS In 172 HIV patients, 152 on HAART, 92 including and 60 not including protease inhibitors (PI), 20 naïve and 64 controls, we measured spine/femur bone mineral density (BMD) by DEXA, and assayed serum osteocalcin (O), bone alkaline phosphatase (BAP), 1,25(OH)2 D, parathormone (PTH), calcium (Ca) and urinary pyridinium cross-links (PYD & DPD). RESULTS Following WHO BMD t-score criteria, osteopenia was ascertained in >35% of all HAART groups and in 30% of naive. Only HAART patients had osteoporosis, PI patients more frequently, significantly (p<0.03) in spine (21.7% vs 8.3%). Males, intravenous drug users and B-C stage patients have a higher risk for low bone mass. Mean t-score was significantly lower in both spine and femur and O and PYD & DPD higher in PI than non PI patients and controls; 1,25(OH)2 D was significantly lower in all HIV groups than controls, PI patients having the lowest values positively correlating with BMD and negatively with OC and PYD & DPD, and it decreased further in 27 non selected monitored patients continuing on HAART. PTH was higher and Ca lower in HAART patients than controls but not significantly, PTH negatively correlating with BMD. CONCLUSION HAART could be associated with osteopenia, even osteoporosis, and it could aggravate the loss in bone mass due to HIV infection itself. We hypothesize that HAART may directly affect bone remodelling and/or may indirectly affect vitamin D metabolism.
Collapse
|
27
|
Abstract
OBJECTIVES This study investigated the prognostic value of left ventricular (LV) mass at echocardiography in uncomplicated subjects with essential hypertension. BACKGROUND Only a few single-center studies support the prognostic value of LV mass in uncomplicated hypertension. METHODS The MAssa Ventricolare sinistra nell'Ipertensione study was a multicenter (45 centers) prospective study. The prespecified aim was to explore the prognostic value of LV mass in hypertension. Admission criteria included essential hypertension, no previous cardiovascular events, and age > or =50. There was central reading of echocardiographic tracings. Treatment was tailored to the single subject. RESULTS Overall, 1,033 subjects (396 men) were followed for 0 to 4 years (median, 3 years). Mean age at entry was 60 years, and systolic/diastolic blood pressure was 154/92 mm Hg. The rate of cardiovascular events (x100 patient-years) was 1.3 in the group with normal LV mass and 3.2 in the group (28.5% of total sample) with LV mass > or =125 g/body surface area (p = 0.005). After adjustment for age (p < 0.01), diabetes (p < 0.01), cigarette smoking (p < 0.01) and serum creatinine (p = 0.03), LV hypertrophy was associated with an increased risk of events (RR [relative risk] 2.08; 95% CI [confidence interval]: 1.22 to 3.57). For each 39 g/m(2) (1 SD) increase in LV mass there was an independent 40% rise in the risk of major cardiovascular events (95% CI: 14 to 72; p = 0.0013). CONCLUSIONS Our findings show a strong, continuous and independent relationship of LV mass to subsequent cardiovascular morbidity. This is the first study to extend such demonstration to a large nationwide multicenter sample of uncomplicated subjects with essential hypertension.
Collapse
|
28
|
99mTc-Tetrofosmin pinhole-SPECT (P-SPECT) and radioguided sentinel node (SN) biopsy and in breast cancer axillary lymph node staging. Cancer Biother Radiopharm 2001; 16:501-13. [PMID: 11789027 DOI: 10.1089/10849780152752100] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We compared 99mTc-Tetrofosmin P-SPECT with radioguided SN biopsy in 101 T1/T2 BC pts to predict axillary lymph node status. The day before surgery all pts underwent lymphoscintigraphy (LS) to mark the SN, following subdermal injection of 99mTc-colloidal sulphur surrounding the breast lesion. LS was combined with pre and intraoperative gamma probe. Previously, all pts had also undergone P-SPECT. ALND was performed in all cases. The SN(s) was detected in 97/101 cases (96%) by LS and gamma probe; in the 4 missed cases P-SPECT predicted lymph node status. In the 97 comparable cases, radioguided SN biopsy showed a slightly higher accuracy than P-SPECT (94.8% vs 93.8%), but a higher false-negative rate (14.3% vs 8.6%); P-SPECT had a higher NPV (95.2% vs 92.5%). The two procedures when combined achieved 100% accuracy. Radioguided SN biopsy alone had 100% accuracy only in pts with BC < 15 mm. P-SPECT had 3 false negative cases, 2 of which were micrometastatic SNs, and 3 false positives. P-SPECT identified 81.2% of cases with a single node, determined the exact number of nodes in 82.6% of cases with 1 to 3 node and correctly classified 93.7% of pts as having < or = 3 or > 3 metastatic nodes. Radioguided SN biopsy seems indicated in selected, early stage, small BC pts, while P-SPECT shows a high sensitivity independent of primary tumor size, giving additional important preoperative prognostic information. The two procedures combined provided a better axillary lymph node status prediction in T1/T2 carcinomas, and could thus improve ALND pt selection.
Collapse
MESH Headings
- Adult
- Aged
- Axilla/surgery
- Biopsy, Needle
- Breast Neoplasms/diagnostic imaging
- Breast Neoplasms/pathology
- Carcinoma, Ductal, Breast/diagnostic imaging
- Carcinoma, Ductal, Breast/secondary
- Carcinoma, Lobular/diagnostic imaging
- Carcinoma, Lobular/secondary
- Carcinoma, Medullary/diagnostic imaging
- Carcinoma, Medullary/secondary
- Female
- Humans
- Lymph Node Excision
- Lymph Nodes/diagnostic imaging
- Lymphatic Metastasis
- Male
- Middle Aged
- Neoplasm Staging
- Organophosphorus Compounds
- Organotechnetium Compounds
- Prospective Studies
- Radiopharmaceuticals
- Sentinel Lymph Node Biopsy/methods
- Tomography, Emission-Computed, Single-Photon/methods
Collapse
|
29
|
Delineation of the spectrum of Wilson disease mutations in the Greek population and the identification of six novel mutations. GENETIC TESTING 2001; 4:399-402. [PMID: 11216666 DOI: 10.1089/109065700750065162] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In this study, we report the further results of an ongoing project on the delineation of the spectrum of mutations on the ATP7B gene in Wilson disease (WD) patients of Greek origin. We have analyzed 24 additional families and detected 16 mutations (five frameshifts, two splice site, two nonsense, and seven missense), of which six are novel. On adding these results to the ones already published by us, we conclude that WD shows a marked allelic heterogeneity in the Greek population. Of the total number of mutations so far detected, the most common eight account for the molecular defect in 72.8% of the WD chromosomes. The most frequent mutation is the His0169Gln, which has a frequency of 28.5%, similar to those reported in North European populations. Using these data, an efficient strategy of mutation screening for WD is possible in this population, thus improving the possibility of preclinical diagnosis.
Collapse
|
30
|
Abstract
Immune function, T-lymphocyte subsets, serum quantitative immunoglobulin levels, serum lysozyme levels, and circulating immune complex levels were analyzed in patients with idiopathic dilated cardiomyopathy (IDCM). The percentage of helper/inducer T cells (OKT4) was higher and the percentage of suppressor/cytotoxic T cells (OKT8) was lower in IDCM patients than in healthy controls and in patients with ischemic heart disease. IDCM patients, in addition, have higher 5/9+ T cells, a T-cell subset known to give maximal helper activity in B-cell differentiation assays. Peripheral blood mononuclear cells (PBMC) from IDCM patients demonstrated a statistically greater ability to induce B-cell differentiation (helper T-cell function) into plasma cells and a hypofunctioning suppressor T-cell population in an in vitro pokeweed nitrogen (PWN)-driven B-cell differentiation assay. Serum immunoglobulin IgM levels were higher in IDCM patients, but serum lysozyme levels and serum immune complex levels in IDCM patients were normal. These data verify that an immunoregulatory defect exists in IDCM.
Collapse
|
31
|
[Nitrate isoconazole: a new topical use antimycotic]. GIORN ITAL DERMAT V 1986; 121:LV-LVIII. [PMID: 3530985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
32
|
Acute left ventricular filling time and rate changes in hypertrophic cardiomyopathy after verapamil and propranolol evaluated by nuclear stethoscope. GIORNALE ITALIANO DI CARDIOLOGIA 1985; 15:307-9. [PMID: 4040486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We have undertaken the present study to evaluate the acute effects of propranolol and verapamil on the diastolic function in patients with hypertrophic cardiomyopathy. We used a non imaging isotope device, the nuclear stethoscope, that has been so far mainly employed for assessment of systolic function, although fitted for detecting diastolic filling rates and times as well. Relative cardiac output, ejection fraction, rapid and slow filling times and rates were measured in five patients suffering from hypertrophic cardiomyopathy in basal conditions and 10.20 and 30 minutes after i.v. administration for either propranolol or verapamil, with a time interval of at least 24 hours between the two acute drug studies. With respect to the baseline values only verapamil showed a significant improvement in rapid and maximum filling rates, suggesting that diastolic function is more beneficially affected by Ca-entry blockers rather than beta-blockers in hypertrophic cardiomyopathy.
Collapse
|
33
|
[Mitral prolapse: critical review of 87 cases studied with the T-motion technic]. CARDIOLOGIA (ROME, ITALY) 1982; 27:55-59. [PMID: 6892373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
|
34
|
|
35
|
[A program of combined ECG and VCG automatic diagnosis. Note I. The atriogram]. Minerva Med 1976; 67:3129-38. [PMID: 792729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In this paper a new computer aided ECG and VCG data handling is analized. It is based on an optimum estimation of dipole moment, which is used as the main diagnosis parameter. Already known diagnostical methods (available in present literature) are compared with this new technique. The available diagnostical range has been increased widely. The sensitivity of such a program is being analyzed both for normal and abnormal cases.
Collapse
|
36
|
[Angiography and angiocardiography with radioisotopes]. CARDIOLOGIA PRATICA 1970; 21:277-82. [PMID: 5495420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
37
|
[Study of thyroid function in subjects with acquired cardiac valve defects]. CARDIOLOGIA PRATICA 1970; 21:273-6. [PMID: 5495419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
38
|
[Wegener's granulomatosis. Clinical contribution and review of the literature]. OMNIA MEDICA ET THERAPEUTICA 1968; 46:141-76. [PMID: 5739602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
39
|
[Idiopathic acute pericarditis. Critical review of the literature and clinical case contribution]. OMNIA MEDICA ET THERAPEUTICA 1965; 43:715-66. [PMID: 5882016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
40
|
[On two cases of acute benign idiopathic pericarditis in the course of infectious mononucleosis and herpes zoster]. LA RIFORMA MEDICA 1965; 79:1037-43. [PMID: 5852765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
41
|
[On two cases of acute benign idiopathic pericarditis in the course of infectious mononucleosis and herpes zoster]. LA RIFORMA MEDICA 1965; 79:1037-42. [PMID: 5852762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|