28 research outputs found
Fluorine-based color centers in diamond
We report on the creation and characterization of the luminescence properties
of high-purity diamond substrates upon F ion implantation and subsequent
thermal annealing. Their room-temperature photoluminescence emission consists
of a weak emission line at 558 nm and of intense bands in the 600 - 750 nm
spectral range. Characterization at liquid He temperature reveals the presence
of a structured set of lines in the 600 - 670 nm spectral range. We discuss the
dependence of the emission properties of F-related optical centers on different
experimental parameters such as the operating temperature and the excitation
wavelength. The correlation of the emission intensity with F implantation
fluence, and the exclusive observation of the afore-mentioned spectral features
in F-implanted and annealed samples provides a strong indication that the
observed emission features are related to a stable F-containing defective
complex in the diamond lattice.Comment: 10 pages, 5 figure
Efficient fabrication of high-density ensembles of color centers via ion implantation on a hot diamond substrate
Nitrogen-Vacancy (NV) centers in diamond are promising systems for quantum
technologies, including quantum metrology and sensing. A promising strategy for
the achievement of high sensitivity to external fields relies on the
exploitation of large ensembles of NV centers, whose fabrication by ion
implantation is upper limited by the amount of radiation damage introduced in
the diamond lattice. In this works we demonstrate an approach to increase the
density of NV centers upon the high-fluence implantation of MeV N2+ ions on a
hot target substrate (>550 {\deg}C). Our results show that, with respect to
room-temperature implantation, the high-temperature process increases the
vacancy density threshold required for the irreversible conversion of diamond
to a graphitic phase, thus enabling to achieve higher density ensembles.
Furthermore, the formation efficiency of color centers was investigated on
diamond substrates implanted at varying temperatures with MeV N2+ and Mg+ ions
revealing that the formation efficiency of both NV centers and
magnesium-vacancy (MgV) centers increases with the implantation temperature.Comment: 12 pages, 5 figure
Postoperative outcomes in oesophagectomy with trainee involvement
BACKGROUND: The complexity of oesophageal surgery and the significant risk of morbidity necessitates that oesophagectomy is predominantly performed by a consultant surgeon, or a senior trainee under their supervision. The aim of this study was to determine the impact of trainee involvement in oesophagectomy on postoperative outcomes in an international multicentre setting. METHODS: Data from the multicentre Oesophago-Gastric Anastomosis Study Group (OGAA) cohort study were analysed, which comprised prospectively collected data from patients undergoing oesophagectomy for oesophageal cancer between April 2018 and December 2018. Procedures were grouped by the level of trainee involvement, and univariable and multivariable analyses were performed to compare patient outcomes across groups. RESULTS: Of 2232 oesophagectomies from 137 centres in 41 countries, trainees were involved in 29.1 per cent of them (n = 650), performing only the abdominal phase in 230, only the chest and/or neck phases in 130, and all phases in 315 procedures. For procedures with a chest anastomosis, those with trainee involvement had similar 90-day mortality, complication and reoperation rates to consultant-performed oesophagectomies (P = 0.451, P = 0.318, and P = 0.382, respectively), while anastomotic leak rates were significantly lower in the trainee groups (P = 0.030). Procedures with a neck anastomosis had equivalent complication, anastomotic leak, and reoperation rates (P = 0.150, P = 0.430, and P = 0.632, respectively) in trainee-involved versus consultant-performed oesophagectomies, with significantly lower 90-day mortality in the trainee groups (P = 0.005). CONCLUSION: Trainee involvement was not found to be associated with significantly inferior postoperative outcomes for selected patients undergoing oesophagectomy. The results support continued supervised trainee involvement in oesophageal cancer surgery
On the Properties of Iterated Binomial Transforms for the Padovan and Perrin Matrix Sequences
Differential cross section measurements of the 9Be(3He,p)11B reaction for NRA applications
The differential cross sections of the 9Be(3He,pi)11B reactions for i = 0–6 were determined within the laboratory energy range 1.24–2.87 MeV and for backward angles from 107° to 164° with 2° steps using two double sided silicon strip detectors. The obtained cross sections covered the angle and energy ranges typically used for the analysis of beryllium targets with the nuclear reaction analysis technique. The experiments were carried out at the Ruđer Bošković Institute and the determined cross sections were benchmarked with the measurement of thick target reaction yields from a pure beryllium target at two beam energies, 1.8 and 2.7 MeV. The results are presented in graphical form and for 134° and 164° are also given as tables in the Appendix. The correctness of the data, verified through the comparison of thick target spectra as well as the observed discrepancies with previous data are discussed and analyzed
Re-engineering process in a food factory: an overview of technologies and approaches for the design of pasta production processes
Pleurodese: técnica e indicações Pleurodesis: technique and indications
O derrame pleural recidivante Ă© uma situação clĂnica comum que compromete a qualidade de vida dos pacientes, em especial dos portadores de doença oncolĂłgica em estágio avançado. A abordagem terapĂŞutica do espaço pleural Ă© variada, incluindo procedimentos agressivos como a pleurectomia. A pleurodese Ă© a tĂ©cnica mais freqĂĽentemente utilizada, podendo ser induzida tanto atravĂ©s da inserção de cateteres pleurais, como por procedimentos cirĂşrgicos amplos (toracotomia). SĂŁo vários os agentes esclerosantes indicados, incluindo o talco, que Ă© o mais utilizado, o nitrato de prata e recentemente as citocinas proliferativas. Este artigo resume as principais abordagens do derrame pleural recidivante e particularmente da pleurodese, suas indicações, vantagens e desvantagens para a aplicação na prática diária do pneumologista.<br>Recurrent pleural effusion, which is commonly seen in clinical practice, compromises patient quality of life, especially in patients with advanced malignant disease. The therapeutic approach to the pleural space involves a wide range of techniques, including aggressive procedures such as pleurectomy. Among such techniques, pleurodesis is the most frequently used. Pleurodesis can be induced through the insertion of pleural catheters, as well as through major surgical procedures (such as thoracotomy). There are various recommended sclerosing agents, including talc (which is the most widely used), silver nitrate and, recently, proliferative cytokines. This article summarizes the principal approaches to the treatment of recurrent pleural effusion, pleurodesis in particular, addressing the indications for, as well as the advantages and disadvantages of, their application in daily pulmonology practice