The conversion of photon energy into other energetic forms in molecules is accompanied by charge moving on ultrafast timescales. We directly observe the charge motion at a specific site in an ...electronically excited molecule using time-resolved x-ray photoelectron spectroscopy (TR-XPS). We extend the concept of static chemical shift from conventional XPS by the excited-state chemical shift (ESCS), which is connected to the charge in the framework of a potential model. This allows us to invert TR-XPS spectra to the dynamic charge at a specific atom. We demonstrate the power of TR-XPS by using sulphur 2p-core-electron-emission probing to study the UV-excited dynamics of 2-thiouracil. The method allows us to discover that a major part of the population relaxes to the molecular ground state within 220-250 fs. In addition, a 250-fs oscillation, visible in the kinetic energy of the TR-XPS, reveals a coherent exchange of population among electronic states.
The expected increase of the particle flux at the high-luminosity phase of the LHC (HL-LHC) with instantaneous luminosities up to L=7.5×1034 cm−1s−1 will have a severe impact on the ATLAS detector ...performance. The pile-up is expected to increase on average to 200 interactions per bunch crossing. The reconstruction and trigger performance for electrons, photons as well as jets and transverse missing energy will be severely degraded in the end-cap and forward region, where the liquid Argon based electromagnetic calorimeter has coarser granularity and the inner tracker has poorer momentum resolution compared to the central region. A High Granularity Timing Detector (HGTD) is proposed in front of the liquid Argon end-cap calorimeters for pile-up mitigation and for bunch per bunch luminosity measurements. This device should cover the pseudo-rapidity range of 2.4 to about 4.0. Two Silicon sensors double-sided layers are foreseen to provide a precision timing information for minimum ionizing particle with a time resolution better than 50 pico-seconds per hit (i.e. 30 pico-seconds per track) in order to assign the particle to the correct vertex. Each readout cell has a transverse size of 1.3mm×1.3 mm leading to a highly granular detector with about 3 millions of readout electronics channels. Low-Gain Avalanche Detector (LGAD) technology has been chosen as it provides an internal gain good enough to reach large signal over noise ratio needed for excellent time resolution. Extensive LGAD research and development (R&D) campaigns are carried out to investigate the suitability of this new technology as timing sensors for HGTD. The related readout ASIC is also being studied extensively.
Experimental Study of Acceptor Removal in UFSD Jin, Y.; Ren, H.; Christie, S. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2020, Letnik:
983, Številka:
C
Journal Article
Recenzirano
Odprti dostop
The performance of the Ultra-Fast Silicon Detectors (UFSD) after irradiation with neutrons and protons is compromised by the removal of acceptors in the thin layer below the junction responsible for ...the gain. This effect is tested both with capacitance–voltage, C–V, measurements of the doping concentration and with measurements of charge collection, CC, using charged particles. We find a perfect linear correlation between the bias voltage to deplete the gain layer determined with C–V and the bias voltage to collect a defined charge, measured with charge collection. An example for the usefulness of this correlation is presented.
► The cyclic deformation response of AISI 316L at 20°C is exhaustively studied. ► Internal stresses and microstructural evolution are comprehensively characterised. ► The relations of internal ...stresses to microstructural development are established. ► Physically-based evolutionary constitutive model is successfully developed. ► The model accurately describes the cyclic elasto-plastic deformation behaviour.
Deformation (e.g. cyclic hardening, softening and saturation) response and the corresponding microstructural evolution of AISI 316L during cyclic loading at room temperature are exhaustively studied. In particular, the physical interpretation and the role of internal stresses are thoroughly evaluated in order to better comprehend the relationship between microstructural evolution and cyclic deformation response. The understanding obtained provides a basis for the development of a physically-based evolutionary constitutive model which aims to accurately represent the complex cyclic deformation response of the material. The developed constitutive model represents the change in microstructural condition and its relationship with internal stress variables. The model parameters are identified by a systematic evaluation of mechanical and microstructural observations from a number of experimental tests. The proposed model is shown to effectively represent the complex cyclic elasto-plastic deformation behaviour of the material for a range of strain amplitudes.
Summary
The influence of ultrasound power (1000–3000 W/L), citric acid concentration (0–3%) and solid:liquid ratio (1:5–1:15) on the phenolic compounds recovery and antioxidant capacity of Syrah ...grape skin extracts were evaluated. Total phenolic compounds varied from 6485 to 11732 mg gallic acid/100 g and monomeric anthocyanin content from 453 to 685 mg malvidin‐3‐glucoside/100 g. The antioxidant capacity measured by ORAC and ABTS methods ranged from 230 to 516 μmol Trolox/g and from 442 to 939 μmol Trolox/g, respectively. The most suitable conditions chosen for extraction, within the studied ranges, were 3000 W/L of power, 2.5% citric acid and solid:liquid ratio of 1:15. The extraction yield was satisfactory, with a recovery of 59% of the quantified phenolic compounds, with only 3 min of processing. Ultrasound was considered a suitable method as compared to the conventional extraction, improving the extraction of phenolic acids and facilitating their release.
Ultrasound‐assisted extraction resulted in an extract rich in phenolic compounds, mainly malvidin‐3‐O‐glucoside, quercetin, rutin, epicatechin and catechin.
The impact of tuberculosis and of anti-tuberculosis therapy on composition and modification of human lung microbiota has been the object of several investigations. However, no clear outcome has been ...presented so far and the relationship between M. tuberculosis pulmonary infection and the resident lung microbiota remains vague. In this work we describe the results obtained from a multicenter study of the microbiota of sputum samples from patients with tuberculosis or unrelated lung diseases and healthy donors recruited in Switzerland, Italy and Bangladesh, with the ultimate goal of discovering a microbiota-based biomarker associated with tuberculosis. Bacterial 16S rDNA amplification, high-throughput sequencing and extensive bioinformatic analyses revealed patient-specific flora and high variability in taxon abundance. No common signature could be identified among the individuals enrolled except for minor differences which were not consistent among the different geographical settings. Moreover, anti-tuberculosis therapy did not cause any important variation in microbiota diversity, thus precluding its exploitation as a biomarker for the follow up of tuberculosis patients undergoing treatment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Purpose There are few clinical studies focusing on the lip cancer treatment outcomes. This study aims to investigate the clinicopathological variables profile of a large sample of lip ...squamous cell carcinoma (LSCC) patients treated in a head and neck cancer reference center for the last 25 years, and to analyze the influence of these variables on the treatment outcomes. Materials and Methods In this retrospective cohort study, we reviewed the clinical records of LSCC patients. The epidemiological data were age, gender, ethnicity, type of occupation, tobacco smoking, alcohol consumption, comorbid conditions and family cancer history. Clinicopathological features included the lip location of the tumor, TNM classification, clinical staging, histopathological grade, surgical margin analysis and treatment modality. Local recurrence, second primary tumor and survival were the outcome variables. Statistics was performed by Chi-square, Fisher exact test and Binary Logistic Regression. Survival analysis was assessed through the Kaplan and Meier curve. Level of statistical significance was set at p<0.05 for all tests. Results A total of 144 LSCC patients were studied. There were 117 men (81.25%) and 27 women (18.75%), with mean age of 60.21 years. One hundred thirty-four patients (93.05%) were considered of white ethnicity and in 57 cases (39.58%) the patients presented an occupation that was related to chronic solar exposure. Most cancers had initial clinical staging of I/II (84.02%). Microscopically, lesions were predominantly well- (43.05%) and moderately- (40.96%) differentiated tumors. The clinical staging was related to a specific higher survival rate (p=0.0049). One hundred twelve cases (77.78%) were submitted to surgical treatment and only six patients (4.80%) had local recurrence, which was directly associated with compromised surgical margins (p=0.0320). Conclusion A high success rate in LSCC treatment was observed in this study. Compromised surgical margin was associated to tumor recurrence and is a critical event in lip cancer treatment.
Abstract
Advances in timing detector technology require new specialized readout electronics. Applications demand below 10 ps time of arrival resolution and low power for a low repetition rate. A ...possible path to achieve O(10 ps) time resolution is an integrated chip using Silicon Germanium (SiGe) technology. Using DoE SBIR funding, Anadyne, Inc., in collaboration with UC Santa Cruz, has developed a prototype SiGe front-end readout chip optimized for low power and timing resolution. Two versions of the chip were produced with performance in simulation: a more power version with 10 ps resolution at 5 fC with 1.1 mW/channel, and a less power version with 10 ps resolution at 8 fC with 0.6 mW/channel.
The chip was produced at Tower Semiconductor with 350 nm technology. The ASIC from the prototype run shows good performance: a rise time of 0.7–1 ns and 25 mV per fC response with RMS noise <1 mV. Simulation and results from the prototype will be reported in this paper.
During the last decade, X-ray free-electron lasers (XFELs) have enabled the study of light-matter interaction under extreme conditions. Atoms which are subject to XFEL radiation are charged by a ...complex interplay of (several subsequent) photoionization events and electronic decay processes within a few femtoseconds. The interaction with molecules is even more intriguing, since intricate nuclear dynamics occur as the molecules start to dissociate during the charge-up process. Here, we demonstrate that by analyzing photoelectron angular emission distributions and kinetic energy release of charge states of ionic molecular fragments, we can obtain a detailed understanding of the charge-up and fragmentation dynamics. Our novel approach allows for gathering such information without the need of complex
ab initio
modeling. As an example, we provide a detailed view on the processes happening on a femtosecond time scale in oxygen molecules exposed to intense XFEL pulses.
The X-ray-induced charge-up and fragmentation process of a small molecule is examined in great detail by measuring the molecular-frame photoelectron interference pattern in conjunction with other observables in coincidence.
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