Optimal path for a quantum teleportation protocol in entangled networks

Bellman's optimality principle has been of enormous importance in the development of whole branches of applied mathematics, computer science, optimal control theory, economics, decision making, and classical physics. Examples are numerous: dynamic programming, Markov chains, stochastic dynamics, calculus of variations, and the brachistochrone problem. Here we show that Bellman's optimality principle is violated in a teleportation problem on a quantum network. This implies that finding the optimal fidelity route for teleporting a quantum state between two distant nodes on a quantum network with bi-partite entanglement will be a tough problem and will require further investigation.Comment: 4 pages, 1 figure, RevTeX

Mimicking the probability distribution of a two-dimensional Grover walk with a single-qubit coin

Multi-dimensional quantum walks usually require large coin spaces. Here we show that the non-localized case of the spatial density probability of the two-dimensional Grover walk can be obtained using only a two-dimensional coin space and a quantum walk in alternate directions. We present a formal proof of this correspondence and analyze the behavior of the coin-position entanglement as well as the x-y spatial entanglement in our scheme with respect to the Grover one. We show that our experimentally simpler scheme allows to entangle the two orthogonal directions of the walk more efficiently.Comment: 5 pages, 2 figures, RevTeX

On the Gauge/Gravity Correspondence and the Open/Closed String Duality

In this article we review the conditions for the validity of the gauge/gravity correspondence in both supersymmetric and non-supersymmetric string models. We start by reminding what happens in type IIB theory on the orbifolds C^2/Z_2 and C^3/(Z_2 x Z_2), where this correspondence beautifully works. In these cases, by performing a complete stringy calculation of the interaction among D3 branes, it has been shown that the fact that this correspondence works is a consequence of the open/closed duality and of the absence of threshold corrections. Then we review the construction of type 0 theories with their orbifolds and orientifolds having spectra free from both open and closed string tachyons and for such models we study the validity of the gauge/gravity correspondence, concluding that this is not a peculiarity of supersymmetric theories, but it may work also for non-supersymmetric models. Also in these cases, when it works, it is again a consequence of the open/closed string duality and of vanishing threshold corrections.Comment: Invited review article for Int. J. Mod. Phys. A, 95 pages, 2 figures, 3 tables, LaTeX. References and acknowledgements adde

POS1464-HPR ASSESSMENT OF EMOTIONAL WELL-BEING IN RHEUMATIC PATIENTS DURING COVID-19 LOCKDOWN THROUGH A WEB-BASED SURVEY APPROACH

Background:The severe measures of lockdown imposed in Italy to limit the SARS coronavirus 2 disease (COVID-19) spread caused an increase of reported anxiety, depression and suicidal rate among general population. Patients affected by rheumatic disorders feature an increased risk of mood disorders for the chronic course of the disease itself and for the related disability.Objectives:Aim of this study was to investigate the impact of COVID-19 lockdown on emotional well-being of a large cohort of rheumatic patients through a telemedicine approach.Methods:Patients in follow-up in rheumatologic out-patient clinics of our hospital were invited to participate to an online survey. They were asked also to invite their best friend, matched for age and sex, to participate the survey, as control group. The online survey included demographic questions and validated, psychometric scales for stress vulnerability (Stress Vulnerability Scale-SVS), resilience (Resilience Scale-RS), depression (Zung's depression questionnaire-Zung-D) and anxiety (Zung's anxiety questionnaire-Zung-A) evaluation.Results:The cohort was composed by 484 subjects (84,1% F, 15,9% M). The number of subjects and the frequency of various diagnosis are shown in Table 1. According to the psychometric scales, 55,5% and 43,3% of subject showed respectively an increased stress vulnerability and a reduced resiliency. Moreover, 64% and 40,5% of the enrolled subjects reported respectively anxiety and depressive symptoms worthy of psychiatric attention. There was a significant different distribution of scores for SVS (p<0,0001), Zung-A (p<0,0001) and Zung-D (p<0,0001) among the various diagnosis. In comparison with controls, higher scores of SVS were present in connective tissue diseases (CTD) (p=0,007), Sjogren's Syndrome (SSJ) (p=0,0029) and fibromyalgia (FM) (p<0,0001) patients, higher scores of Zung-A were present in SSJ (p=0,006) and FM (p<0,0001) patients and higher scores of Zung-D were present in FM (p<0,0001) patients (Figure 1). Ordinal regression analysis showed that higher classes of anxiety were independently predicted by the Tension (β=0,32;CI=0,13-0,52;p=0,003) and Demoralization (β=0,22;CI=0,04-0,44;p=0,046) components of SVS and by the Zung-D score (β=0,09;CI=0,05-0,1;p<0,001), while higher classes of depression were independently predicted by SVS total (β=0,17;CI=0,03-0,30;p=0,012), by its subcomponent Demoralization (β=0,22;CI=0,01-0,43;p=0,038), by a lower absolute RS score (β=-0,083;CI=-0,1--0,06;p<0,001) and by the Zung-A score (β=0,11;CI=0,06-0,15;p<0,001). In both cases, a specific diagnosis was not associated to a higher risk of advanced anxiety and depression classes.Conclusion:Rheumatic patients developed a high frequency of anxiety and depressive symptoms following COVID-19 lockdown, of which a large part should be referred for specialist attention according to their severity. There was a large variability of the symptoms reported among the various diagnosis. CTD, SSJ and FM patients were the most susceptible to the development of anxiety, depression and stress vulnerability. The application of psycometric scales through a telemedicine approach represents a useful tool to identify patients with higher levels of anxiety and depression.Table 1.DIAGNOSISFrequencyPercentControls459,3RA8216,9PSA214,3UA40,8SPA71,4CTD7014,5FM7916,3Myositis81,7Behcet's112,3Vasculitis163,3APS61,2Other AID132,7SSJ12225,2Total484100RA: Rheumatoid Arthritis, PSA: Psoriatic Arthritis; UA: Undifferentiated Arthritis; SPA: Spondyloarthritis; CTD: Connective tissues diseases (including Systemic Lupus Erythematosus, Scleroderma, Undifferentiated Connettivitis, Mixed Connettivitis); FM: Fibromyalgia; APS: Anti-phospholipid syndrome; Other AID: Other autoimmune/inflammatory disorders (including Adult-onset Still disease, IgG4 related disease); SSJ: Sjogren SyndromeFigure 1.Disclosure of Interests:None declare

FRI0376 EFFECT OF CARBAMYLATED LOW-DENSITY LIPOPROTEINS ON BONE CELLS HOMEOSTASIS

Background:Carbamylation is a post-translational modification occurring under several conditions such as uremia, smoking and chronic inflammation as in rheumatoid arthritis (RA). Low-density lipoproteins (LDL) represent a target of carbamylation. Carbamylated-LDL (cLDL) have an increased inflammatory and atherogenic potential. Growing evidence supports an influence of modified lipids on bone cells homeostasis. However, the role of cLDL on bone cells physiology is still unknown.Objectives:Considering the rate of carbamylation and the role of anti-carbamylated proteins antibodies as markers of erosive disease in RA, the purpose of this study is to investigate the effect of cLDL on bone homeostasis.Methods:In-vitrocarbamylation of LDL was performed as previously described by Ok et al. (Kidney Int. 2005). Briefly, native LDL (nLDL) were treated with potassium cyanate (KOCN) for 4 hours, followed by excessive dialysis for 36 hours to remove KOCN. Both osteoclasts (OCs) and osteoblasts (OBLs) were treated at baseline with 20 μg/ml, 100 μg/ml and 200 μg/ml of cLDL or nLDL. To induce osteoclast differentiation, CD14+ monocytes were isolated from peripheral blood of healthy donors by magnetic microbeads separation and then cultured on a 96-wells plate in DMEM media supplemented with RANKL and M-CSF. After 10 days cells were fixed, stained for tartrate-resistant acid phosphatase (TRAP), a marker of OC differentiation, and counted. OBLs were isolated from bone specimens of 3 patients who had undergone to knee or hip arthroplasty for osteoarthritis and treated for 5 days with different concentrations of cLDL and nLDL. OBLs were fixed and stained for alkaline phosphatase positive activity (ALP), a marker of osteogenic differentiation. Total RNA was extracted from cell lysates. Copies of single-stranded complementary DNA (cDNA) were synthesized and analyzed by real-time PCR to evaluate RANKL and Osteoprotegerin (OPG) mRNA expression levels.Results:In OCLs culture, cLDL significantly decreased the number of OC compared to untreated cells (200 μg/ml p=0,0015) and nLDL treated cells (200 μg/ml p= 0,011; 20 μg/ml p= 0,0014) (Fig 1). Moreover, treatment with cLDL induced an increase of not terminally differentiated OCs, reduced dimensions of OCs, less intense TRAP staining and vacuolization (Fig 2). In OBLs culture, cLDL (20, 100 μg/ml) significantly reduced the ALP activity of OBLs compared with untreated cells (p<0.05) (Fig 3). nLDL did not affect the ALP expression. Treatment with cLDL stimulated RANKL mRNA expression in osteoblasts increasing the RANKL/OPG ratio (Fig 4).Fig 1.Fig 2.Fig 3.Fig 4.Conclusion:cLDL induce a significant depression of OC and OBL differentiation. Moreover, cLDL increase RANKL expression in OBL, unbalancing bone tissue turnover towards bone resorption. Accordingly, cLDL could be implicated in the bone loss characterizing several conditions associated to an increased carbamylation, such as RADisclosure of Interests:Bruno Lucchino: None declared, Martina Leopizzi: None declared, Tania Colasanti: None declared, Valeria Di Maio: None declared, cristiano alessandri Grant/research support from: Pfizer, Guido Valesini: None declared, fabrizio conti Speakers bureau: BMS, Lilly, Abbvie, Pfizer, Sanofi, Manuela Di Franco: None declared, Francesca Romana Spinelli Grant/research support from: Pfizer, Consultant of: Novartis, Gilead, Lilly, Sanofi, Celgene, Speakers bureau: Lill

Impact of SARS-CoV-2 on dentistry: a review of literature.

OBJECTIVE: SARS-CoV-2 is a new Coronavirus identified as the cause of Corona- virus disease in 2019 (COVID-19). The epidemic spread in China and beyond its borders, involv- ing 114 countries with more than 5 million dead. On March 11, the WHO declared the spread of SARS-CoV-2 to be a pandemic and encouraged nations to adopt harsh restrictive measures. Therefore, patients more and more often turn to dental offices only for emergencies. Healthcare professionals, including dentists, are at high in- fectious risk. In fact, the closeness to the oral cavity and nasopharynx and the use of drills or ultrasonic devices that cause aerosol release, make dental professions at high risk of bacterial and viral infections. The way patients are treat- ed has changed. In fact, it should be mandato- ry to carry out a pre-treatment telephone triage and the use of mouthwashes to reduce bacterial load. In the current pandemic, it is necessary to adopt specific safety protocols that can protect dental operators as well as limit the spread of the virus. The purpose of this review is to pres- ent an overview on ways to reduce the risk of SARS-CoV-2 contagion in dentistry by focusing on the immediate situation as well as by look- ing towards the future. MATERIALS AND METHODS: To reach the review purpose, we selected a series of studies using keywords “COVID-19” OR “SARS-CoV-2” in association with “dentistry” AND “safety proto- cols” AND “healthcare procedures” AND “individ- ual protection dispositive” AND “air transmission” AND “droplet”. We selected papers exclusively in English language, up to 1st January 2022. RESULTS: During future phases of the pan- demic, everywhere in the World, it is necessary to impose all dentistry team both a serological screening and the vaccination, as already estab- lished for all health staff in Italy. CONCLUSIONS: For own safety, it is an import- ant for the whole dentistry category constantly update the devices and the protocols adopted, as well as monitoring the real infectious threats, which may occur

Gauge/Gravity Correspondence from Open/Closed String Duality

We compute the annulus diagram corresponding to the interaction of a fractional D3 brane with a gauge field on its world-volume and a stack of N fractional D3 branes on the orbifolds C^2 /Z_2 and C^3/Z_2 x Z_2. We show that its logarithmic divergence can be equivalently understood as due either to massless open string states circulating in the loop or to massless closed string states exchanged between two boundary states. This follows from the fact that, under open/closed string duality, massless states in the open and closed string channels are matched into each other without mixing with massive states. This explains why the perturbative properties of many gauge theories living on the worldvolume of less supersymmetric and nonconformal branes have been recently obtained from their corresponding supergravity solution.Comment: LaTeX, 28 page

Eta photoproduction off the neutron at GRAAL: Evidence for a resonant structure at W=1.67 GeV

New (preliminary) data on eta photoproduction off the neutron are presented. These data reveal a resonant structure at W=1.67 GeV.Comment: 8 pages, 4 figures. Published in Proceedings of Workshop on the Physics of Excited Nucleons NSTAR2004, Grenoble, France, March 24 - 27, pg.19