525 research outputs found
A contribution to breast cancer cell proteomics: detection of new sequences
Ductal infiltrating carcinoma (DIC) of the breast is the most common and potentially aggressive form of cancer. Knowledge of proteomic profiles, attained both in vivo and in vitro, is fundamental to acquire as much information as possible on the proteins expressed in these pathologic conditions. We used the breast cancer cell line 8701-BC, established from a primary DIC, with the aim of contributing to the databases on mammary cancer cells, which in turn will be very useful for the identification of differentially expressed proteins in normal and neoplastic cells. Within an analysis window comprising about 1750 discernible spots, we have at present catalogued 84 protein spots. The proteins for which an identity was assigned were identified essentially using gel comparison, N-terminal (Nt) microseqencing and immune detection. Among the protein spots Nt-microsequenced, sixteen corresponded to known proteins, four resulted as modified, relative to matching sequences deposited on databases, and seven were unknown. These modified or novel sequences are thus of potential interest to the knowledge of breast cancer proteomics and its applications
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
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
Accurate Assignments of Excited-State Resonance Raman Spectra: A Benchmark Study Combining Experiment and Theory
This is an unofficial translation of an article that appeared in an ACS publication. ACS has not endorsed the content of this translation or the context of its use.Femtosecond stimulated Raman scattering (FSRS) probes the structural dynamics of molecules in electronically excited states by following the evolution of the vibrational spectrum. Interpreting the dynamics requires accurate assignments to connect the vibrational bands with specific nuclear motions of an excited molecule. However, the assignment of FSRS signals is often complicated by mode-specific resonance enhancement effects that are difficult to calculate for molecules in electronically excited states. We present benchmark results for a series of eight aryl-substituted thiophene derivatives to show that calculated off-resonance Raman spectra can be used to assign experimental bands on the basis of a comparison of structurally similar compounds and careful consideration of the resonance condition. Importantly, we show that direct comparison with the off-resonant calculations can lead to incorrect assignments of the experimental spectrum if the resonance condition is neglected. These results highlight the importance of resonance enhancement effects in assigning FSRS spectra
Diamond detectors with electrodes graphitized by means of laser
In the last years there has been an increase of interest in diamond devices because of the promising applications in different field, such as high-energy physics, radiotherapy and biochemical applications. In particular, a new frontier is represented by the realization of full-carbon detectors characterized by graphite electrodes, which give to the devices considerable advantages like high radiation hardness, perfect mechanical adhesion and good charge collection properties. In this paper the manufacturing of full-carbon devices and their detection performances are illustrated and compared to a reference diamond detector characterized by traditional electrodes
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
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
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
Radiofrequency Ablation of Hepatic Tissue: a New Experimental Animal Model.
BACKGROUND/AIMS: Experimental radiofrequency ablation has already been performed
in healthy livers of porcine models, but not in less expensive and easy-to-manage
rats, with devices capable of delivering radiofrequency ablation in the 20-30 g
liver of such small animals being so far unavailable. METHODOLOGY: We
experimented with a modified system of radiofrequency ablation of liver tissue in
rat models developing a custom-made needle-microelectrode of very small
dimensions (0.3x2 mm) and an electrode-tip cooling technique, based on saline
solution infusion. We adjusted duration (seconds) and power (watts) of
radiofrequency ablation letting them range between 5-50 seconds and 5-25 W,
respectively, to obtain the greatest lesions with the least side effects. After
sacrificing the animals, an accurate histological examination of the liver was
made. RESULTS: It is possible to establish beforehand the diameter of thermal
liver lesion on the basis of joules of applied energy. The greatest increase of
liver thermal lesion diameter (8 mm) is obtained with a 250-joule (10 W for 25
seconds) thermal energy cooling the electrode-tissue interface. CONCLUSIONS:
Experimental radiofrequency ablation in rat liver is an effective and cheap way
to study its effects on healthy hepatic tissues. It might be the first step to
treat experimentally caused liver tumors
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