405 research outputs found
A comparison between state-specific and linear-response formalisms for the calculation of vertical electronic transition energy in solution with the CCSD-PCM
The calculation of vertical electronic transition energies of molecular systems in solution with accurate quantum mechanical methods requires the use of approximate and yet reliable models to describe the effect of the solvent on the electronic structure of the solute. The polarizable continuum model (PCM) of solvation represents a computationally efficient way to describe this effect, especially when combined with coupled cluster (CC) methods. Two formalisms are available to compute transition energies within the PCM framework: State-Specific (SS) and Linear-Response (LR). The former provides a more complete account of the solute-solvent polarization in the excited states, while the latter is computationally very efficient (i.e., comparable to gas phase) and transition properties are well defined. In this work, I review the theory for the two formalisms within CC theory with a focus on their computational requirements, and present the first implementation of the LR-PCM formalism with the coupled cluster singles and doubles method (CCSD). Transition energies computed with LR- and SS-CCSD-PCM are presented, as well as a comparison between solvation models in the LR approach. The numerical results show that the two formalisms provide different absolute values of transition energy, but similar relative solvatochromic shifts (from nonpolar to polar solvents). The LR formalism may then be used to explore the solvent effect on multiple states and evaluate transition probabilities, while the SS formalism may be used to refine the description of specific states and for the exploration of excited state potential energy surfaces of solvated systems
Performance of the diamond active target prototype for the PADME experiment at the DANE BTF
The PADME experiment at the DANE Beam-Test Facility (BTF) is designed
to search for the gauge boson of a new interaction in the process
ee+, using the intense positron beam hitting a
light target. The , usually referred as dark photon, is assumed to
decay into invisible particles of a secluded sector and it can be observed by
searching for an anomalous peak in the spectrum of the missing mass measured in
events with a single photon in the final state. The measurement requires the
determination of the 4-momentum of the recoil photon, performed by a
homogeneous, highly segmented BGO crystals calorimeter. A significant
improvement of the missing mass resolution is possible using an active target
capable to determine the average position of the positron bunch with a
resolution of less than 1 mm. This report presents the performance of a real
size PADME active target made of a thin (50 m) diamond
sensor, with graphitic strips produced via laser irradiation on both sides. The
measurements are based on data collected in a beam test at the BTF in November
2015.Comment: 7 pages, 10 figure
A five-year survey for plastic surgery malpractice claims in Rome, Italy
(1) Introduction: Medical malpractice claims against both health institutions and physicians are a crucial topic in Italy, as well as in other countries, particularly regarding civil proceedings. Our study reports an analysis of all of the malpractice judgments concerning plastic surgery decided in the Civil Court of Rome between 2012 and 2016. (2) Methods: the database of the Observatory Project on Medical Responsibility (ORMe) was analyzed, which collects all of the judgments of the Civil Court of Rome, that is, the first instance district court. Therefore, neither the jurisprudence of the second level court nor that of the Supreme Court was taken into account. (3) Results: 144 judgments concerning plastic surgery were delivered in the five-year period of 2012–2016 (corresponding to 10.6% of total professional liability verdicts of the Civil Court of Rome in the same period). In 101/144 cases (70.14%), the claim was accepted. A total of €4,727,579.00 was paid in compensation for plastic surgery malpractice claims, with a range from a minimum amount of €1555.96 to a maximum amount of €1,425,155.00 and an average compensation of €46,807.71 per claim that was significantly lower compared to other surgical disciplines. (4) Conclusions: Our data confirm that the analyzed branch has a high litigation rate, with a prevalence of convictions for cosmetic procedures over reconstructive ones, both for malpractice and for violation of the informed consent. Plastic surgery is also confirmed among those branches in which the professionals are more frequently sued compared to health institutions
Radiation Damage of Polycrystalline CVD Diamond with Graphite Electrical Contacts
In this work we show preliminary results of radiation damage for a polycrystalline diamond with graphite contacts in terms of time response after 62 MeV protons irradiation for a total fluence of (2.0±0.08)×1015 protons/cm2. In addition, we describe the realization of a new type of device made with graphite micro-strips by laser micro-writing on diamond surface. In this way we made 20 graphite micro-strips of width about 87 m and spacing between each other of about 60 m
Study of a metal-halide perovskite CsPbBr3 thin film deposited on a 10B layer for neutron detection
Metal halide perovskite materials have received significant attention in recent years due to their
promising properties and potential applications, particularly their use as scintillator detectors,
which is rapidly emerging due to their promising advantages as detectors, such as low costs, fast
response, high quantum yield, strong absorption, scalability, flexibility, and emission
wavelength tunability. Given the effectiveness of perovskites as α particle detectors and the
potential of 10B as a neutron converter, in this paper a 10B converting layer was coupled with an
all-inorganic lead halide perovskite (CsPbBr3) layer aiming to create a thermal neutron detector.
Specifically, a 1 μm thin film of 10B and a 1 μm thin layer of CsPbBr3 were deposited on a
suitable substrate using a laser ablation process. The fabricated detector was subjected to a
comprehensive characterization, including structural, morphological, and detection properties.
As output, the films exhibit macroscopically uniform behavior and good adhesion to the
substrate. In terms of thermal neutron efficiency, an efficiency of (7.9 ± 0.3)% was determined
with respect to a commercial detector (EJ-426), which corresponds to an intrinsic efficiency of
(2.5 ± 0.1)%. Also, Monte Carlo simulations were conducted, and the optimum value of the 10B
layer thickness was found to be 2.5 μm
Bevacizumab in association with de Gramont 5-fluorouracil/folinic acid in patients with oxaliplatin-, irinotecan-, and cetuximab-refractory colorectal cancer: a single-center phase 2 trial.
BACKGROUND: The aim of the current study was the investigation of the value of bevacizumab+5-fluorouracil(5-FU)/folinic acid in patients with advanced colorectal cancers who have exhausted standard chemotherapy options. METHODS: The authors included 48 heavily pretreated patients (colon:rectum, 33:15; men:women, 23:25; median age, 63 years; range, 27-79 years) whose disease had progressed during or within an oxaliplatin-based first-line chemotherapy, an irinotecan-based second-line regimen, and a third-line treatment with cetuximab plus weekly irinotecan. Bevacizumab was given at a dose of 5 mg/kg. 5-FU/folinic acid was administered according to the de Gramont schedule. RESULTS: The response rate was 6.25%, and 30.4% of patients demonstrated stable disease as the best response. The median time to disease progression was 3.5 months (95% confidence interval [95% CI], 2.3-6.9 months), and the median survival time was 7.7 months (95% CI, 3.9-11.9 months). The most common grade 3 to 4 side toxicities (graded according to the National Cancer Institute Common Toxicity Criteria [version 2.0]) were: diarrhea (20.8%), fatigue (14.5%), and stomatitis (12.5%). Grade 3 to 4 hemorrhage occurred in 8 patients (16.6%), including 4 cases of bleeding in the gastrointestinal tract. Other relatively common adverse events such as hypertension, thrombosis, and bowel perforation were reported in 50%, 18.7%, and 4.16%, of patients respectively. CONCLUSIONS: The data from the current study suggest a modest but significant clinical benefit of bevacizumab+de Gramont schedule in heavily pretreated colorectal cancer patients. Copyright (c) 2009 American Cancer Society
Stereospecific generation of homochiral helices in coordination polymers built from enantiopure binaphthyl-based ligands
The novel enantiopure spacer 2,2′-dimethoxy-1,1′-binaphthyl-3,3′-bis(4-pyridyl-amido) has been designed to prepare helical coordination polymers here investigated by means of experimental and theoretical data
Thermal neutron conversion by high purity 10B-enriched layers: PLD-growth, thickness-dependence and neutron-detection performances
Neutron applications and detection are of paramount importance in industry, medicine, scientific research, homeland security, production of extreme UV optics and so on. Neutron detection requires a converter element that, as a result of its interaction with neutrons, produces reaction products (mainly charged particles) whose detection can be correlated with the neutron flux. Reduced availability and increased cost of the most used converter element, 3He, have triggered research efforts for alternative materials, proper deposition methods and new detector architectures. 10B converter is a valid alternative to 3He thanks to its high thermal neutron cross section and relatively high Q value. In this paper we report on the room temperature Pulsed Laser Deposition (PLD) of high quality and uniform 10B films with the expected density, different thickness values (0.5, 1.0, 1.2, 1.5 and 2.0 μm) and uniform thickness over a circular area of about 30 mm in diameter. Additionally, they are adherent to the substrate with a negligible presence of contaminants. The conversion properties of such 10B coatings coupled to a Si solid state detector are studied upon exposure to a neutron flux from an Am-Be neutron source (2.2·106 n/s). The experimental results, compared with spectra simulated by using a GEANT4 code, present a good agreement and efficiencies of the order of a few percent
Characterization of Spectral Entanglement of Spontaneous Parametric-Down Conversion Biphotons
We verified operational approach based on direct measurement of entanglement
degree for bipartite systems. In particular spectral distributions of single
counts and coincidence for pure biphoton states generated by train of short
pump pulses have been measured and entanglement quantifier calculated. The
approach gives upper bound of entanglement stored in total biphoton states,
which can reach extremely high value up to
Interrogating colorectal cancer metastasis to liver: a search for clinically viable compounds and mechanistic insights in colorectal cancer Patient Derived Organoids
Approximately 20-50% of patients presenting with localized colorectal cancer progress to stage IV metastatic disease (mCRC) following initial treatment and this is a major prognostic determinant. Here, we have interrogated a heterogeneous set of primary colorectal cancer (CRC), liver CRC metastases and adjacent liver tissue to identify molecular determinants of the colon to liver spreading. Screening Food and Drug Administration (FDA) approved drugs for their ability to interfere with an identified colon to liver metastasis signature may help filling an unmet therapeutic need
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