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Now showing items 1 - 15 of 15

  • X-ray Detectors for Kaonic Atoms Research at DA Phi NE

    Curceanu, Catalina   Amirkhani, Aidin   Baniahmad, Ata   Bazzi, Massimiliano   Bellotti, Giovanni   Berucci, Carolina   Bosnar, Damir   Bragadireanu, Mario   Cargnelli, Michael   Clozza, Alberto   Del Grande, Raffaele   Fiorini, Carlo   Ghio, Francesco   Guaraldo, Carlo   Iliescu, Mihail   Iwasaki, Masaiko   Sandri, Paolo Levi   Marton, Johann   Miliucci, Marco   Moskal, Pavel   Niedzwiecki, Szymon   Okada, Shinji   Pietreanu, Dorel   Piscicchia, Kristian   Scordo, Alessandro   Shi, Hexi   Silarski, Michal   Sirghi, Diana   Sirghi, Florin   Skurzok, Magdalena   Spallone, Antonio   Tatsuno, Hideyuki   Doce, Oton Vazquez   Widmann, Eberhard   Zmeskal, Johann  

    This article presents the kaonic atom studies performed at the INFN National Laboratory of Frascati (Laboratori Nazionali di Frascati dell'INFN, LNF-INFN) since the opening of this field of research at the DA Phi NE collider in early 2000. Significant achievements have been obtained by the DA Phi NE Exotic Atom Research (DEAR) and Silicon Drift Detector for Hadronic Atom Research by Timing Applications (SIDDHARTA) experiments on kaonic hydrogen, which have required the development of novel X-ray detectors. The 2019 installation of the new SIDDHARTA-2 experiment to measure kaonic deuterium for the first time has been made possible by further technological advances in X-ray detection.
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  • Scintillator Pixel Detectors for Measurement of Compton Scattering

    Makek, Mihael   Bosnar, Damir   Pavelić, Luka  

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  • A simple setup for cosmic muon lifetime measurements

    Bosnar, Damir   Matic, Zoran   Friscic, Ivica   Zugec, Petar   Janci, Hrvoje  

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  • Recent Studies of Hypernuclei Formation with Electron Beams at MAMI

    Achenbach, Patrick   Gayoso, Carlos Ayerbe   Boehm, Ralph   Borodina, Olga   Bosnar, Damir   Bozkurt, Vakkas   Debenjak, Luka   Distler, Michael O.   Esser, Anselm   Friscic, Ivica   Fujii, Yuu   Gogami, Toshiyuki   Rodriguez, Mar Gomez   Hashimoto, Osamu   Hirose, Satoshi   Kanda, Hiroki   Kaneta, Masashi   Kim, Eunhee   Kusaka, Junichiro   Margaryan, Amur   Merkel, Harald   Mueller, Ulrich   Nagao, Sho   Nakamura, Satoshi N.   Pochodzalla, Josef   Rappold, Christophe   Reinhold, Joerg   Saito, Takehiko R.   Lorente, Alicia Sanchez   Majos, Salvador Sanchez   Schlimme, B. Soeren   Schoth, Matthias   Schulz, Florian   Sfienti, Concettina   Sirca, Simon   Tang, Liguang   Thiel, Michaela   Tsukada, Kyo  

    At the Mainz Microtron MAMI exploratory experiments on the spectroscopy of mesonic weak decays (MWD) of electroproduced I >-hypernuclei were performed. A unique setup was realized to use the broad momentum-band kaon spectrometer Kaos at zero degree angle with respect to the high-intensity electron beam direction to tag strangeness producing processes. A sample of order 10(3) MWD from a beryllium target was collected by the coincidence technique with the high-resolution multi-spectrometer facility of the A1 Collaboration. It is conjectured that this sample contains monochromatic two-body decays from stopped hyperfragment decays as well as a wide momentum distribution of quasi-free produced I >- and I -hyperon pound decays and three-body decays from hyperfragments. Stopped hyperfragments will be identified as monochromatic peaks in the pi (-) momentum spectrum from which their masses can be extracted with a precision of 50 keV/c (2).
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  • Histopathological changes in involutional lower eyelid entropion: the tarsus is thickened!

    Miletic, Daliborka   Kuzmanovic Elabjer, Biljana   Busic, Mladen   Biscan Tvrdi, Ana   Petrovic, Zvonko   Bosnar, Damir   Bjelos, Mirjana  

    OBJECTIVE: Evaluation of histopathological changes in lower eyelid involutional entropion.; DESIGN: Case-control, comparative study at a single institution.; PARTICIPANTS: A total of 20 consecutive patients with previously untreated involutional lower eyelid entropion and 20 matching patients with lateral lower eyelid basal cell carcinoma (BCC).; METHODS: Patients with involutional entropion were operated using our modified surgical method, and patients with BCC underwent full-thickness pentagonal excision with 3-mm surgical margins. Histopathological analysis of the full-thickness eyelid specimens of both groups included measurements of tarsal thickness and height, thickness of the pretarsal orbicularis oculi muscle, diameter of muscle fibres, and qualitative changes in lower eyelid retractor attachment.; RESULTS: The tarsus was significantly thicker in the entropion group (p =3D 0.006). The mean tarsal thickness was 1.40 =C2=B1 0.32 mm, whereas in the BCC group it was 1.16 =C2=B1 0.19 mm. There was no statistically significant difference in the tarsal height and the thickness of the pretarsal orbicularis oculi muscle between the 2 groups. In the entropion group, 60% of the lids had total and 35% partial dehiscence of the retractor, whereas in the BCC group, dehiscence was found in only 45% of the lids. The difference was statistically significant (p =3D 0.002).; CONCLUSIONS: To the best of our knowledge, this is the first histopathological study documenting thickening of the tarsus in involutional lower eyelid entropion. Moreover, dehiscence of the lower eyelid retractor was proven histopathologically in 95% of the entropic lids. With this in mind, correction of vertical instability should be mandatory in involutional lower eyelid entropion repair. Copyright =C2=A9 2016 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.
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  • Single-layer Compton detectors for measurement of polarization correlations of annihilation quanta

    Makek, Mihael   Bosnar, Damir   Pavelic, Luka   Senjug, Pavla   Zugec, Petar  

    Measurement of gamma-ray polarization can provide valuable insight in different areas of physics research. One possible application is in Positron Emission Tomography, where the annihilation quanta with orthogonal polarizations are emitted. Since polarization can be measured via Compton scattering, the initial orthogonality of polarizations can be translated to correlation of azimuthal scattering angles, and this correlation may be exploited as an additional handle to identify the true coincidence events. In order to examine the concept of utilizing the polarization correlations in PET, we have used a system of two compact, position and energy-sensitive Compton scattering detectors in coincidence mode. Each consists of a single matrix of scintillation pixels, read-out by a matching array of Silicon photomultipliers on the back side. The Compton events in each module are clearly identified and the scattering angles are reconstructed from the energy deposition and event topology. We have extracted the polarimetric modulation factors from the measured azimuthal scattering angles of the two Compton-scattered gammas and studied their dependence on Compton scattering angles theta and on azimuthal resolution Delta phi. For scattering angles around theta(1,2) =3D 82 degrees, where the maximum modulation is expected, the modulation factors from mu =3D 0.15 +/- 0.01 to mu =3D 0.27 +/- 0.02 have been measured, depending on the azimuthal resolution, which is governed by event topology in the detectors. Analogously, for scattering around theta(1,2) =3D 70 degrees, modulation factors from mu =3D 0.12 +/- 0.01 to mu =3D 0.21 +/- 0.02 have been obtained. The results show that the measurement of the polarization correlations of annihilation quanta are feasible with compact single-layer, single-side read-out detectors, which may be used to build cost-efficient systems for various applications where gamma-ray polarization information is of interest.
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    Elabjer, Biljana Kuzmanovic   Miletic, Daliborka   Busic, Mladen   Tvrdi, Ana Biscan   Bosnar, Damir   Bjelos, Mirjana  

    Dermis-fat graft has been proven as a useful replacement tissue for eyelid and orbit reconstruction, but there is no evidence in the literature that it can be used for correction of upper eyelid retraction.This is the first report that presents two cases (four eyelids) of dermis-fat graft usage as a spacer in the treatment of severe recurrent upper eyelid retraction due to Graves' orbitopathy. Improvement was achieved with minimum complications, patient symptoms were reduced, and the results were stable almost three years after the procedure.
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  • Cystoid macular lesions are resistant to topical dorzolamide treatment in enhanced S-cone syndrome child

    Busic, Mladen   Bjelos, Mirjana   Bosnar, Damir   Ramic, Senad   Busic, Iva  

    Purpose To evaluate whether cystoid macular lesions respond to treatment with dorzolamide 2 % drops in the enhanced S-cone syndrome (ESCS) child, as several case reports document favorable efficacy in adults. Methods Seven-year-old boy with ESCS and cystoid macular lesions was treated with dorzolamide 2 % in both eyes three times a day for a period of 7 months. The efficacy of treatment was analyzed by visual acuity assessment (ETDRS), multifocal electroretinography and SD-OCT central foveal thickness (CFT) measurement. Results Baseline RE CFT was 540 and 453 mu min the LE, with amplitude of P1-wave density 39.8 and 50.4 nV/deg(2), respectively. Best corrected visual acuity (BCVA) was 0.3 logMAR RE and 0.3 logMAR LE at distance. At 7-month follow-up examination, CFT showed no reduction in thickness (RE 599 mu m, LE 521 mu m). P1-wave density increased (RE 49.1 nV/deg(2), LE 84.9 nV/deg(2)), with BCVA 0.3 logMAR RE and 0.2 logMAR LE. Conclusions To the best of our knowledge, this is the youngest ESCS patient treated with dorzolamide drops and the first report recording that cystoid macular lesions are resistant to topical dorzolamide treatment. Furthermore, these data are in favor of the hypothesis that microcystoid changes in ESCS appear due to defects in cell-to-cell adhesion rather than the disintegration of the retinal barrier. The marked differences in treatment response to carbonic anhydrase inhibitors between the adults and the child here presented suggest that the breakdown of the blood-retinal barrier may play a more important role later in life.
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  • Comparison of optical low-coherence reflectometry and applanation ultrasound biometry on intraocular lens power calculation

    Busic, Mladen   Cima, Ivan   Elabjer, Biljana Kuzmanovic   Bosnar, Damir   Miletic, Daliborka  

    The aim of the study was to determine whether the innovative non-contact optical low-coherence reflectometry method utilized by the Lenstar LS 900A (R) agrees sufficiently with applanation ultrasound A-scan technique in routine biometric measurement and intraocular lens power calculation to replace it.Twenty-two patients hospitalized at our eye clinic undergoing cataract surgery were assigned to have five consecutive measurements of axial length by two examiners in a single session using applanation ultrasound and the Lenstar. The applanation ultrasound intraocular lens power calculation was based on automated keratometry and applanation ultrasound axial length measurements. The Lenstar intraocular lens power calculation was based on its measurement of keratometry and axial length. Bland-Altman analysis was used to assess interobserver repeatability of applanation ultrasound and the Lenstar as well as agreement between the Lenstar and applanation ultrasound for axial length measurement and intraocular lens power calculation.Thirty-two eyes of 22 patients were analyzed. In 95% of the observations, predicted refractive error corresponded to -0.26 +/- 0.62 D and 0.01 +/- 0.20 D obtained with applanation ultrasound and the Lenstar, respectively.Based on excellent repeatability of the Lenstar and acceptable repeatability of applanation ultrasound, two techniques may be used interchangeably. The predicted refractive error of +/- 0.20 D in 95% of the observations has never been achieved. Optical low-coherence reflectometry might become a new standard method for biometric measurement needed for intraocular lens-power calculation in patients with cataract.
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  • Zagreb Amblyopia Preschool Screening Study: near and distance visual acuity testing increase the diagnostic accuracy of screening for amblyopia

    Bušić, Mladen   Bjeloš, Mirjana   Petrovečki, Mladen   Kuzmanović Elabjer, Biljana   Bosnar, Damir   Ramić, Senad   Miletić, Daliborka   Andrijašević, Lidija   Kondža Krstonijević, Edita   Jakovljević, Vid   Bišćan Tvrdi, Ana   Predović, Jurica   Kokot, Antonio   Bišćan, Filip   Kovačević Ljubić, Mirna   Motušić Aras, Ranka  

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  • Single-Stage Orbital Socket Reconstruction Using the Oversized Dermis Fat Graft and the 22mm Silicone Orbital Implant after an Extended Enucleation

    Elabjer, Biljana Kuzmanovic   Busic, Mladen   Miletic, Daliborka   Bjelos, Mirjana   Saric, Borna   Bosnar, Damir  

    We would like to present a surgical technique of orbital socket reconstruction using oversized dermis fat graft and 22mm silicone orbital implant in a single-stage after extended enucleation in two patients with massive local recurrence of anteriorly located choroidal melanoma previously treated with endoresection. Orbital tissues en bloc were removed leaving conjunctival lining only at the fornices. Simultaneously, the 22mm silicone sphere was implanted deeply into the orbit and covered with the oversized dermis fat graft of 30mm in height and 35mm in length with 20mm of the fat thickness. The graft was sutured to the residual forniceal conjunctiva with interrupted 6/0 absorbable sutures overlapping conjunctiva with the graft edge for 2mm to facilitate the epithelization. Epithelization was completed in two months, leaving well-formed fornices with good fitting of the prosthesis. The key point of orbital socket reconstruction after extended enucleation is to restore conjunctival lining prior to volume. Thus, whenever facing a massive volume and conjunctival lining loss, simultaneous insertion of the 22mm silicone sphere deep into the orbit combined with oversized dermis fat graft is, in our opinion, the method of choice. It proved to be safe and effective with favourable long-term results.
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  • Single-Stage Orbital Socket Reconstruction Using the Oversized Dermis Fat Graft and the 22 mm Silicone Orbital Implant after an Extended Enucleation

    Kuzmanović Elabjer, Biljana   Bušić, Mladen   Miletić, Daliborka   Bjeloš, Mirjana   Šarić, Borna   Bosnar, Damir  

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    Janjetovic, Zeljka   Busic, Mladen   Bosnar, Damir   Barac, Josip   Genda, Ivanka  

    The aim of the study was to assess biometric factor aberrations and differences among groups of eyes with cataract and pseudoexfoliative syndrome, cataract and pseudoexfoliative glaucoma, and cataract and primary open-angle glaucoma (POAG), and to determine biometric factors of the eye specific for the group of glaucomatous patients with pseudoexfoliative syndrome by use of optical low-coherence reflectometry. This retrospective study included 72 patients, and the study sample of 102 eyes was divided into the following three groups according to diagnosis: 29 eyes with pseudoexfoliative syndrome and cataract; 36 eyes with POAG and cataract; and 37 eyes with pseudoexfoliative glaucoma and cataract. Data on biometric measurements (central corneal thickness, pupillary diameter, anterior chamber depth, lens thickness, axial length, retinal thickness, astigmatism and white-to-white) obtained by use of optical low-coherence reflectometry on a Lenstar LS 900 (R) (HaagStreit International) were collected and analyzed by thorough survey of medical documentation of patients scheduled for cataract surgery at Department of Ophthalmology, Sveti Duh University Hospital in Zagreb, Croatia. Comparative analysis of the groups yielded statistically significant differences in central corneal thickness (F2/99=3D7.066; p=3D0.001) and lens thickness (F2/96=3D5.133; p=3D0.008). The group of eyes diagnosed with pseudoexfoliative glaucoma and cataract had a significantly thinner cornea as compared with the other two groups and a significantly thicker lens as compared with the group of eyes with POAG and cataract. In conclusion, optical low-coherence reflectometry revealed differences in biometric factors among the three groups of eyes, with a statistically significantly thinner cornea and thicker lens in the group of glaucomatous patients with pseudoexfoliative syndrome.
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  • Intravitreal Bevacizumab and Cardiovascular Risk in Patients with Age-Related Macular Degeneration:Systematic Review and Meta-Analysis of Randomized Controlled Trials and Observational Studies

    Bosnar, Damir  

    Introduction Intravitreal bevacizumab (IVTB) is used to treat age-related macular degeneration (ARMD), although its use is off-label and its cardiovascular safety has not been unequivocally established.Objective Our objective was to assess the cardiovascular safety of IVTB in patients with ARMD.Methods We conducted a systematic review and meta-analysis of published randomized controlled trials (RCTs) and observational studies.Results Of the 2028 non-duplicate records, five RCTs versus ranibizumab (N =3D 3038, 12/24 months), four RCTs comparing different regimens (N =3D 809, 12/23 months), one RCT versus pegaptanib, photodynamic therapy (PDT), or sham (N =3D 131, 12 months), and three observational studies versus PDT, ranibizumab, or pegaptanib (similar to 150,000 or 1666 patients/12 months and 317 patients/1-2 years, respectively) had a low risk of bias/high quality and a parts per thousand yen20 patients per arm with a parts per thousand yen6 months and a parts per thousand yen3 injections of treatment. RCT-based comparisons with PDT or pegaptanib are negligible. Observational data have not demonstrated differences [all-cause mortality, myocardial infarction (MI), stroke], but the level of evidence is "very low" (imprecise, indirect). RCT-based comparisons with ranibizumab did not demonstrate differences regarding some outcomes, although certain point estimates were at the level of a relevant harm/benefit [all-cause mortality odds ratio (OR) 1.103, 95 % confidence interval (CI) 0.641-1.898; vascular mortality OR 1.380, 95 % CI 0.476-3.997; MI OR 0.551, 95 % CI 0.265-1.146; stroke OR 0.657, 95 % CI 0.260-1.660; transitory ischemic attack OR 1.536, 95 % CI 0.444-5.313; atherothrombotic events (ATEs) OR 1.007, 95 % CI 0.641-1.593; venous thromboembolism OR 2.325, 95 % CI 0.963-5.612] or suggested a higher risk with bevacizumab (hypertension OR 7.512, 95 % CI 1.056-52.3), but estimates were based on sparse data, were extremely imprecise, and commonly exhibited considerable heterogeneity/inconsistency. The level of evidence per outcome was "low" or "very low". Observational data did not demonstrate difference (all-cause mortality, MI, stroke), or suggested a higher risk with bevacizumab (ATE), but were imprecise and indirect (level of evidence "very low"). RCT-based comparisons of different IVTB regimens suffered from the same limitations.Conclusion Published data on IVTB in AMRD provide only a low level of evidence on its cardiovascular safety and do not support any finite conclusions.
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  • Kaon Tagging at 0 degrees Scattering Angle for High-Resolution Decay-Pion Spectroscopy

    Esser, Anselm   Achenbach, Patrick   Arai, Naoki   Gayoso, Carlos Ayerbe   Boehm, Ralph   Borodina, Olga   Bosnar, Damir   Bozkurt, Vakkas   Debenjak, Luka   Distler, Michael O.   Friscic, Ivica   Fujii, Yuu   Gogami, Toshiyuki   Rodriguez, Mar Gomez   Hashimoto, Osamu   Hirose, Satoshi   Kanda, Hiroki   Kaneta, Masashi   Kim, Eunhee   Kusaka, Junichiro   Maeda, Kazushige   Margaryan, Amur   Merkel, Harald   Mueller, Ulrich   Nagao, Sho   Nakamura, Satoshi N.   Pochodzalla, Josef   Rappold, Christophe   Reinhold, Joerg   Saito, Takehiko R.   Lorente, Alicia Sanchez   Majos, Salvador Sanchez   Schlimme, Bjoern Soeren   Schoth, Matthias   Schulz, Florian   Sfienti, Concettina   Sirca, Simon   Tang, Liguang   Thiel, Michaela   Tsukada, Kyo  

    At the Mainz Microtron hypernuclei can be studied by (e, e'K) reactions. By detecting the kaon which is emitted in forward direction, with the KAOS spectrometer placed at 0 degrees scattering angle, reactions involving open strangeness production are tagged. High-resolution magnetic spectrometers are then used to coincidentally detect the mono-energetic decay-pions from mesonic two-body weak decays of light hypernuclei at rest. As a pioneering experiment has confirmed, the KAOS spectrometer is exposed to a large flux of background particles, mostly positrons from bremsstrahlung pair production. In order to increase the efficiency of kaon identification the KAOS spectrometer was modified to suppress background particles at the cost of a high momentum resolution, which is less important for this experiment. This was achieved by placing up to 14 cm of lead absorbers in front of the detectors, in which positrons are blocked by forming electromagnetic showers while the effect on kaons is limited. An additional time-of-flight wall and a new threshold Cerenkov detector help to increase the detection efficiency of kaons.
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