291 research outputs found
Structure and Form: The Theory of ‘Minimal Surfaces’ and the Bridge over the Basento River by Sergio Musmeci
Sergio Musmeci occupies a very important position in the history of late 20th century Italian engineering. Born in Rome in 1926, he initially graduated in civil engineering and later in aeronautical engineering. Following an apprenticeship with Pier Luigi Nervi, in whose office he worked from 1949 to 1951, and with Riccardo Morandi, he later opened his own engineering and architecture office together with his wife, the architect Zenaide Zanini. He taught at the University of Rome, initially as an assistant to the course in Rational Mechanics and Graphic Statics, and later as professor of Bridges and Large Structures
Laparoscopic adjustable gastric banding’s multiple complications: when complications arise even after 30 years, a case report.
Laparoscopic adjustable gastric banding (LAGB) is a popular bariatric surgical procedure. The introduction of laparoscopy has increased the use of this procedure, making it the most commonly performed bariatric surgery. Patients undergoing LAGB have achieved satisfactory results in terms of weight loss, a reduction in co-morbidities, and improved quality of life. Nonetheless, complications with LAGB are well documented and include migration, erosion, prolapse, infection, pouch dilation, gastric perforation, and most commonly, lack of weight loss following the failure of the procedure. This case report presents a patient with slippage and pouch dilation, erosion of the stomach, and port site problems, including infection, occurring 28 years after LAGB
Trinodal Self-Penetrating Versus cds 3-Dimensional Networks Using Bis(3,2' : 6',3''-terpyridine) Building Blocks: the Solvent Makes the Difference
Reactions between Co(NCS)2 and 24,24-[2,5-bis(cyclohexyloxy)-1,4-phenylene]di(13,22 :26,33-terpyridine) (1), 24,24-[2,5-bis(cyclohexylmethoxy)-1,4-phenylene]di(13,22 :26,33-terpyridine) (2), and 24,24-[2,5-bis(2-phenylethoxy)- 1,4-phenylene]di(13,22 :26,33-terpyridine) (3) under conditions of crystal growth by layering at room temperature lead to 3-dimensional nets with either a cds or trinodal self-penetrating topology depending upon the solvents (MeOH/C6H5Cl, MeOH/1,2-Cl2C6H5, or MeOH/CHCl3) used in the crystallization experiments. The cds network was found for [Co(NCS)2(1)]n.2nC6H4Cl2, [Co(NCS)2(2)]n.4nC6H4Cl2, and [Co(NCS)2(3)]n.2.5nC6H5Cl, while a trinodal selfpenetrating net was observed in [Co2(NCS)4(2)2]n.5.5nCHCl3.0.2nMeOH. Preliminary structural data for single crystals from the reactions of Co(NCS)2 and 1 or Co(NCS)2 and 3 from MeOH/CHCl3 solvent combinations also evidenced the assemblies of trinodal self-penetrating nets. Both net topologies assemble from a combination of planar, 4-connecting metal and ligand nodes. The role of the solvent in directing the network type is investigated
Dosimetrical evaluation of rotation errors in the patient set-up in lung SBRT treatments
EnStereotactic body radiation therapy (SBRT) is a noninvasive, well-tolerated technique in the management of lung malignancies. SBRT requires a high degree of accuracy in target localization and treatment delivery to achieve tumor control while minimizing normal tissue toxicity. Through volumetric imaging, it is possible to obtain comprehensive assessment of patient positioning uncertainties before every treatment delivery. The purpose of this study was to quantify the magnitude of the rotational setup errors in lung SBRT using CBCT and to investigate the dosimetric impact of uncorrected rotational uncertainty. The dosimetric study was conducted on a thorax phantom. The retrospective analysis of CBCT set-up images shows that rotational errors detected in the patient's set-up are on average small in amplitude, although a certain variability index has been observed which can't be considered negligible in the evaluation of the dosimetric impact on the target coverage. The dosimetric study on phantom shows that the effect of uncorrected rotations on target coverage can't always be considered irrelevant and their clinical significance depends on the entity of rotation and target size. In conclusion, the presence of rotations in the positioning of the patient must be carefully investigated before every treatment delivery, especially for small targets size.ItLa stereotassi corporea (SBRT) è una terapia radioterapica non invasiva utilizzata nella cura dei tumori al polmone. SBRT richiede un alto grado di accuratezza nella localizzazione del tumore per ottenere un maggiore controllo della malattia minimizzando la tossicità ai tessuti sani. Mediante l'uso di immagini volumetriche, è possibile valutare gli errori di posizionamento del paziente prima del trattamento. Lo scopo di questo studio è quello di quantificare gli errori rotazionali di set up usando immagini CBCT di pazienti e valutare l'impatto dosimetrico di tali errori simulandoli su un fantoccio antropomorfo. L'analisi retrospettiva delle immagini di set up mostra che gli errori rotazionali rilevati sono in media piccoli in ampiezza, tuttavia l'indice di variabilità osservato può incidere sull'accuratezza della copertura dosimetrica del target. Lo studio dosimetrico sul fantoccio mostra che gli effetti di errori di rotazione dal punto di vista dosimetrico dipendono dalla entità di rotazione e dalle dimensioni del target. L'errore di rotazione dovrebbe essere valutato e corretto prima di ogni trattamento, soprattutto in presenza di lesioni di piccole dimensioni
Isomeric 4,2′:6′,4″- and 3,2′:6′,3″-Terpyridines with Isomeric 4′-Trifluoromethylphenyl Substituents: Effects on the Assembly of Coordination Polymers with [Cu(hfacac)2] (Hhfacac = Hexafluoropentane-2,4-dione)
The isomers 4′-(4-(trifluoromethyl)phenyl)-4,2′:6′,4″-terpyridine (1), 4′-(3-(trifluoromethyl) phenyl)-4,2′:6′,4″-terpyridine (2), 4′-(4-(trifluoromethyl)phenyl)-3,2′:6′,3″-terpyridine (3), and 4′-(3-(trifluoromethyl)phenyl)-3,2′:6′,3″-terpyridine (4) have been prepared and characterized. The single crystal structures of 1 and 2 were determined. The 1D-polymers [Cu2(hfacac)4(1)2]n.2nC6H4Cl2 (Hhfacac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione), [Cu(hfacac)2(2)]n.2nC6H5Me, [Cu2(hfacac) 4(3)2]n.nC6H4Cl2, [Cu2(hfacac)4(3)2]n.nC6H5Cl, and [Cu(hfacac)2(4)]n.nC6H5Cl have been formed by reactions of 1, 2, 3 and 4 with [Cu(hfacac)2].H2O under conditions of crystal growth by layering and four of these coordination polymers have been formed on a preparative scale. [Cu2(hfacac) 4(1)2]n.2nC6H4Cl2 and [Cu(hfacac)2(2)]n.2nC6H5Me are zig-zag chains and the different substitution position of the CF3 group in 1 and 2 does not affect this motif. Packing of the polymer chains is governed mainly by C-F...F-C contacts, and there are no inter-polymer π-stacking interactions. The conformation of the 3,2′:6′,3″-tpy unit in [Cu2(hfacac)4(3)2]n.nC6H4Cl2 and [Cu(hfacac)2(4)]n.nC6H5Cl differs, leading to different structural motifs in the 1D-polymer backbones. In [Cu(hfacac) 2(4)]n.nC6H5Cl, the peripheral 3-CF3C6H4 unit is accommodated in a pocket between two {Cu(hfacac) 2} units and engages in four C-Hphenyl...F-Chfacac contacts which lock the phenylpyridine unit in a near planar conformation. In [Cu2(hfacac)4(3)2]n.nC6H4Cl2 and [Cu(hfacac)2(4)]n.nC6H5Cl, π-stacking interactions between 4′-trifluoromethylphenyl-3,2′:6′,3″-tpy domains are key packing interactions, and this contrasts with the packing of polymers incorporating 1 and 2. We use powder X-ray diffraction to demonstrate that the assemblies of the coordination polymers are reproducible, and that a switch from a 4,2′:6′,4″- to 3,2′:6′,3″-tpy metal-binding unit is accompanied by a change from dominant C-F...F-C and C-F...H-C contacts to π-stacking of arene domains between ligands 3 or 4
Dosimetric verification of vmat dose distribution with DELTA4 Phantom
Radiation Oncology, has changed a great deal, undergoing an innovation and technical development; there has been an evolution from conformal radiotherapy techniques (3D-CRT), through advanced modalities like intensity-modulated radiation therapy (IMRT) and next volumetric modulated arc therapy (VMAT). VMAT technique requires a dedicated QA (Quality Assurance) procedure for dosimetric verification of a planned dose distribution to check for the agreement between a dose distribution calculated by the Treatment Planning System (TPS) and the corresponding measured dose distribution. Since November 2010, in Radiation Therapy Department of “V. Fazzi” hospital in Lecce (Italy), 257 patients were treated with VMAT and the corresponding dose distribution were verified with the Delta4 diode array phantom. Parameters used in the comparison between calculated e measured dose are the dose agreement (DA), the distance to agreement (DTA) and the -index. The phantom measurements closely match the planned dose distributions in high and low dose-gradient region
PCV15 MANAGEMENT EFFECTIVENESS AND COST/UTILITY RATIO IN CHRONIC HEART FAILURE: COMPARISON BETWEEN HEART FAILURE MANAGEMENT PROGRAM DELIVERED BY DAY-HOSPITAL AND USUAL CARE
Pentraxin-3 predicts functional recovery and 1-year major adverse cardiovascular events after rehabilitation of cardiac surgery patients.
Performance of Delta4 Phantom+ using Flattening-Filter and Flattening Filter-Free beams
EnThe goal of this study was to evaluate the performances of the new pre-treatment system Delta4 Phantom+ in terms of a stable and sensitive tool for achieving a reliable verification. Delta4+ was evaluated for verification with 6FFFMV beams using static beam arrangement. The accelerator output was monitored with the ionization chamber. The device was tested for dose-rate dependence, linearity and stability using its daily output correction. The response of Delta4+ was evaluated for energy 6FFFMV, measuring the gamma index of four Volumetric Modulated Arc Therapy (VMAT) plan. The response of Delta4+ as a function of accelerator dose rate is in agreement with the ionization chamber with a difference smaller than 0,1%. The output is constant for different MU. VMAT plan analysis show values within 98,3%-100% with a threshold of 3%-3mm, while with a threshold of 2%-2mm the values are within 93,5%-97,5%. Delta4+ is an accurate device. For all the measurements made, uncertainties below 1% were obtained.ItLo scopo di questo studio è stato quello di valutare la risposta in termini di stabilità e sensibilità del nuovo sistema pre-trattamento Delta4 Phantom+. La risposta del sistema è stato studiata utilizzando fasci di fotoni da 6MVsenza filtro di flattening (6FFFMV). L'output dell'acceleratore è stato monitorato con una camera a ionizzazione. La dipendenza dal dose rate, la linearità e la stabilità sono state verificate utilizzando il fattore di correzione giornaliera fornito dal sistema. La risposta è stata verificata su 4 piani di trattamento con tecnica VMAT. La risposta del Delta4+ al variare del dose rate è in accordo con quella della camera a ionizzazione con una scarto minore dello 0.1%. La risposta al variare delle UM è costante con una differenza entro lo 0.4%. L'analisi dei piani VMAT mostra valori di indice gamma per soglia 3%-3mm compresi tra 98.3%-100%, mentre per 2%-2mm i valori sono tra 93,5%-97,5%. Il Delta4+ risulta essere un sistema accurato in quanto l'incertezza ottenuta su tutte le misure non supera l'1%
Prevalence and Persistence of Breathing Disorders in Chronic Heart Failure Patients: Preliminary Results from Home Telemonitoring in the HHH Study
In this paper we present preliminary results of the European Community multicountry trial HHH (Home or Hospital in Heart Failure), which assessed the prevalence and persistence of nocturnal breathing disorders in mild-to-moderate CHF patients. All subjects (465) carried out a baseline respiratory recording in the hospital, followed by 12 recordings (one per month) at home. The latter were totally self-managed by the patients, and data were transmitted to the referring hospital through telephone lines. We found that 43 % of the patients had a periodic breathing pattern (PB, waxing and waning of ventilation with or without apneas) during the night lasting ≥ 1 hour, and the apnea-hypopnea index (AHI) was ≥ 5 events/hour in 51 % of them. During the 1-year follow-up, a PB ≥ 1 hour and an AHI ≥ 5 events/hour were persistent (i.e., occurred in> 50 % of the recordings) in 43 % and 52 % of the patients. These findings confirm the high prevalence of nocturnal breathing disorders in CHF patients and show that in a large proportion of patients they tend to persist over time. 1
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