Dvofotonska fizika u MAMI

The structure of the nucleon can be described by the electromagnetic form factors GE and GM. These form factors can be determined by elastic electron-proton scattering with the well-known Rosenbluth technique. Alternatively, the ratio of the electric and the magnetic form factors GE/GM can be determined by the socalled polarization-transfer technique. The measurements reveal a large discrepancy between the two methods at large momentum transfers. There is evidence that twophoton exchange contributions to the elastic scattering have been underestimated. While the two-photon exchange amplitude is difficult to compute from theory due to the excited intermediate hadronic states, its imaginary part can be accessed experimentally by measuring the asymmetry A⊥ in the cross section of elastic ep scattering where the electrons are transversely polarized parallel or antiparallel to the normal of the scattering plane, respectively. The PVA4 experiment at MAMI is currently performing such measurements covering a large range of momentum transfers.Struktura nukleona opisuje se elektromagnetskim faktorima oblika GE i GM. Ti se faktori oblika određuju elastičnim raspršenjem elektrona na protonima poznatom Rosenbluthovom metodom. Druga metoda je određivanje omjera električnog i magnetskog faktora oblika GE/GM primjenom takozvane metode prijenosa polarizacije. Mjerenja pokazuju velike razlike ove dvije metode pri velikim prijenosima impulsa. Neki podaci ukazuju da su doprinosi dvofotonske izmjene elastičnom raspršenju bili podcijenjeni. Teorijsko određivanje amplitude dvofotonske izmjene je vrlo teško zbog uzbudnih hadronskih međustanja. Međutim, imaginarni dio amplitude može se odrediti mjerenjem asimetrije A⊥ udarnog presjeka elastičnog ep raspršenja, u kojemu su elektroni poprečno polarizirani u smjeru odnosno suprotno u odnosu na okomicu na ravninu raspršenja. Eksperiment PVA4 u MAMI provodi ta mjerenja za široko područje prijenosa impulsa

Dvofotonska fizika u MAMI

The structure of the nucleon can be described by the electromagnetic form factors GE and GM. These form factors can be determined by elastic electron-proton scattering with the well-known Rosenbluth technique. Alternatively, the ratio of the electric and the magnetic form factors GE/GM can be determined by the socalled polarization-transfer technique. The measurements reveal a large discrepancy between the two methods at large momentum transfers. There is evidence that twophoton exchange contributions to the elastic scattering have been underestimated. While the two-photon exchange amplitude is difficult to compute from theory due to the excited intermediate hadronic states, its imaginary part can be accessed experimentally by measuring the asymmetry A⊥ in the cross section of elastic ep scattering where the electrons are transversely polarized parallel or antiparallel to the normal of the scattering plane, respectively. The PVA4 experiment at MAMI is currently performing such measurements covering a large range of momentum transfers.Struktura nukleona opisuje se elektromagnetskim faktorima oblika GE i GM. Ti se faktori oblika određuju elastičnim raspršenjem elektrona na protonima poznatom Rosenbluthovom metodom. Druga metoda je određivanje omjera električnog i magnetskog faktora oblika GE/GM primjenom takozvane metode prijenosa polarizacije. Mjerenja pokazuju velike razlike ove dvije metode pri velikim prijenosima impulsa. Neki podaci ukazuju da su doprinosi dvofotonske izmjene elastičnom raspršenju bili podcijenjeni. Teorijsko određivanje amplitude dvofotonske izmjene je vrlo teško zbog uzbudnih hadronskih međustanja. Međutim, imaginarni dio amplitude može se odrediti mjerenjem asimetrije A⊥ udarnog presjeka elastičnog ep raspršenja, u kojemu su elektroni poprečno polarizirani u smjeru odnosno suprotno u odnosu na okomicu na ravninu raspršenja. Eksperiment PVA4 u MAMI provodi ta mjerenja za široko područje prijenosa impulsa

Latissimus dorsi rotational flap combined with a custom-made scapular prosthesis after oncological surgical resection: A report of two patients

BACKGROUND: Sarcomas that arise from the scapula or periscapular soft tissues often require a total scapulectomy. This often implies a large complex tissue defect that needs adequate reconstruction of both bone and soft tissue. Although various methods have been developed, no optimal procedure has emerged. Postoperative complications are common and functional recovery is not always satisfactory. This study aims to present a new surgical technique that combines a custom-made scapular prosthesis with a functional latissimus dorsi flap. CASE PRESENTATION: Two patients diagnosed with malignant tumour of the scapular region were surgically treated after proper multidisciplinary evaluation. The first patient underwent the procedure as a first surgery, the second as revision surgery. The new technique comprises three surgical stages: excisional surgery with soft tissue resection and scapulectomy, bone reconstruction with custom-made prosthesis, and soft tissue reconstruction using a latissimus dorsi rotational flap overturned on the prosthesis. The goal is to set up a new functional unit combining an anatomically shaped implant (manufactured using latest three-dimensional printing technology) and a muscular flap, and to maintain the neurovascular supply. The patients were followed up to evaluate functional outcome and complications. Both patients were alive with no evidence of disease. Functional results were satisfactory and the Musculoskeletal Tumor Society scores were 87% and 63%, respectively. No surgical complications such as implant breakage, joint collapse, wound dehiscence, or infection were observed. CONCLUSIONS: This new technique upgrades the role of the latissimus dorsi flap to a functional tool in combination with an anatomical, three-dimensionally printed, custom-made prosthesis, and provides adequate well-vascularized and healthy tissue to maximize the likelihood of successful limb salvage

Isospin breaking in the vector current of the nucleon

Extraction of the nucleon's strange form factors from experimental data requires a quantitative understanding of the unavoidable contamination from isospin violation. A number of authors have addressed this issue during the past decade, and their work is reviewed here. The predictions from early models are largely consistent with recent results that rely as much as possible on input from QCD symmetries and related experimental data. The resulting bounds on isospin violation are sufficiently precise to be of value to on-going experimental and theoretical studies of the nucleon's strange form factors.Comment: 5 pages, 3 figures. Presented at the International Workshop "From Parity Violation to Hadronic Structure and more...", Milos, Greece, 16-20 May 2006. Version 2 is only to update Refs. [21] and [25

Incidence and outcome of peripartum cardiomyopathy in a tertiary care hospital

AIMS AND OBJECTIVES OF THE STUDY: To study the incidence, assess the risk factors and study the clinical profile of patients with peripartum cardiomyopathy and the outcome of peripartum cardiomyopathy. Methods : A prospective study and retrospective study of PPCM was conducted at Prathima Institute of Medical Sciences, Karimnagar, Telangana, India over a period of 4 years. Prospective data was collected during the period of January, 2017 to October, 2018. Retrospective data was collected from hospital records from January, 2015 to December, 2016. A total of 92 patients were identified during the study period that fulfilled the inclusion criteria. Results: Overall incidence of PPCM in our institution was 9 per 1000 deliveries. Patient age range was between 20 and 35 years. Mean age was 26 ± 4 years. Out of 92 cases, 40 cases were in the age group of 20-25yrs, 32 in 25-30yrs and 20 in 30-35yrs age group. 72 patients were of =30years of age and 20 were of advanced maternal age (>30 years). 70 cases were primiparous (76.08%) and 22 were multiparous (23.91%). Two patients had twin foetuses. 37 patients (40.21%) developed PPCM during pregnancy and 55 patients (59.78%) during postpartum period. There were 12 (13.04%) maternal deaths. All the 12 cases were aged less than 30 years and had severe LV dysfunction. Conclusion: Incidence of PPCM is not uncommon in southern India. The incidence was 9 per 1000 deliveries in the study. PPCM is not the disease of advanced maternal age and multiparity as majority of the cases in the study were of age <30years and primiparous

Future Directions in Parity Violation: From Quarks to the Cosmos

I discuss the prospects for future studies of parity-violating (PV) interactions at low energies and the insights they might provide about open questions in the Standard Model as well as physics that lies beyond it. I cover four types of parity-violating observables: PV electron scattering; PV hadronic interactions; PV correlations in weak decays; and searches for the permanent electric dipole moments of quantum systems.Comment: Talk given at PAVI 06 workshop on parity-violating interactions, Milos, Greece (May, 2006); 10 page

Handmade clay bricks: chemical, physical and mechanical properties

The clay brick masonry that is much used in historical structures often is in a rather poor state of conservation. In order to intervene correctly in these buildings, it is convenient to characterize the old material. For this purpose, a large sample of clay brick specimens from the 12th to 19th century were collected from six Portuguese monasteries, and were characterized chemically, physically and mechanically. A large variability of the properties was found. Additionally, a sample of handmade new bricks, which are commonly used as replacing material, was also analysed. The results were compared to the old bricks and could be possibly adequate as substitution bricks. Still, significant differences were found in chemical composition, and in water absorption and porosity, which are much lower in modern handmade bricks. With respect to mechanical properties, the range of values found in old bricks was rather high and the degree of deterioration exhibited a large scatter, meaning that a conclusion is hardly possible.The authors gratefully acknowledge the Instituto de Gestao do Patrimonio Arquitectonico e Arqueologico (IGESPAR) for providing the old clay bricks used in the present work. The first author acknowledges the partial funding of this work by the FCT through the following scholarships POCTI SFRH/BD/6409/2001 and POCTI SFRH/BPD/26706/2005

Apremilast retention rate in clinic practice:observations from an Italian multi-center study

Objective There are few real-world setting studies focused on apremilast efectiveness (i.e., retention rate) in psoriatic arthritis (PsA). The main aim of this retrospective observational study is the assessment of apremilast 3-year retention ratein real-world PsA patients. Moreover, the secondary objective is to report the reasons of apremilast discontinuation and thefactors related to treatment persistence. Methods In ffteen Italian rheumatological referral centers, all PsA consecutive patients who received apremilast were enrolled. Anamnestic data, treatment history, and PsA disease activity (DAPSA) at baseline were recorded. The Kaplan–Meier curve and the Coxanalysis computed the apremilast retention rate and treatment persistence-related risk factors. A p-value&lt;0.05 was considered statistically signifcant. Results The 356 enrolled patients (median age 60 [interquartile range IQR 52–67] yrs; male prevalence 42.7%) median observation period was 17 [IQR 7–34] months (7218 patients-months). The apremilast retention rate at 12, 24, and 36 months was, respectively, 85.6%, 73.6%, and 61.8%. The main discontinuation reasons were secondary inefcacy (34% of interruptions), gastro-intestinal intolerance (24%), and primary inefcacy (19%). Age and oligo-articular phenotype were related to treatment persistence (respectively hazard ratio 0.98 IQR 0.96–0.99; p=0.048 and 0.54 IQR 0.31–0.95; p=0.03). Conclusion Almost three-ffths of PsA patients receiving apremilast were still in treatment after 3 years. This study confrmed its efectiveness and safety profle. Apremilast appears as a good treatment choice in all oligo-articular PsA patients and in those ones burdened by relevant comorbiditi

Psycho-educational group therapy in acute psychiatric units: creating a psychosocial culture. An update of spread and effectiveness of a psychosocial intervention in Italian psychiatric wards

The implementation of a Cognitive-Behavioural Group Intervention (CBGI) in Italian general hospital psychiatric units started in the years 2000-2001 in two Italian regions. Over the years it has became more and more popular also in other psychiatric units located in the rest of the country. Based on the "stress-vulnerability-coping" theory, the CBGI is a replicable and innovative psychosocial intervention that promotes the active involvement of inpatients in decisions concerning their individual objectives and care. In the present article, the authors briefly describe this intervention and the main findings regarding its implementation in several psychiatric units in different Regions of Italy. The authors emphasize that such a psychosocial approach to inpatient care is needed because it can produce improved clinical outcomes, reduction in untoward events and increased staff and inpatient satisfaction. However, its introduction and use still represent a major cultural and managerial challenge in our country