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We introduce a versatile high-repetition-rate solid tape target system suitable for relativistic laser-plasma driven secondary sources. We demonstrate the operation and stability monitoring based on a petawatt laser focused at 1 Hz. Experiments were carried out at the VEGA-3 laser system of the Centro de Láseres Pulsados facility where results for different tape materials and thicknesses are presented. Experimental proton spectra were recorded by a Thomson parabola spectrometer and a time-of-flight detector. In addition, non-invasive detectors, such as a target charging monitor and ionization chamber detectors, were tested as metrology for the stability of the source. Degradation of the proton signal at high-repetition-rate operation was observed and it was solved by online optimization of the relative focus position of the target and laser beam parameters. We report the use of the tape target for bursts of 1000 shots at 1 Hz with mean cut-off energies of about 10 MeV in optimized interaction conditions.
OBJECTIVES/GOALS: While the evolving treatment paradigm for Glioblastoma (GBM) leverages different modalities to improve outcomes, treatment access might be limited by cost and disparities. This study explores the influence of race and social determinants of health (SDoH) on healthcare access and outcomes of GBM patients in a large metropolitan area over a decade. METHODS/STUDY POPULATION: Our institution’s tumor registry (2009-2019) was queried to identify our GBM cohort. Data were supplemented by electronic health records to include demographics, outcome, NCI Comorbidity Index, and the Agency for Healthcare Research and Quality (AHRQ) socioeconomic status (SES) index. RESULTS/ANTICIPATED RESULTS: Of the 559 GBM records, 361 unique patients met the inclusion criteria, and 43% were Non-White. Non-White patients predominantly comprised the lowest AHRQ SES index quartile and had longer hospital stays (LOS; p<0.001). White patients accounted for 61% of privately insured patients (p<0.001). Private insurance (p= 0.02) and age < 65 years (p= 0.039) were associated with a higher rate of home discharge. Patients diagnosed with GBM in the emergency department were more likely to be discharged to acute rehab than home (p<0.001). At 2 years, privately insured patients had longer OS (HR= 1.46; p= 0.04). DISCUSSION/SIGNIFICANCE: In contrast to previous studies, the study demonstrates that GBM affected a higher proportion of Non-White patients. Our data show that SDoH influences multiple outcomes in GBM patients. Efforts to identify and correct these barriers are needed to improve the care of all GBM patients.
We report the first high-repetition-rate generation and simultaneous characterization of nanosecond-scale return currents of kA-magnitude issued by the polarization of a target irradiated with a PW-class high-repetition-rate titanium:sapphire laser system at relativistic intensities. We present experimental results obtained with the VEGA-3 laser at intensities from $5\times {10}^{18}$ to $1.3\times {10}^{20}$ W cm${}^{-2}$. A non-invasive inductive return-current monitor is adopted to measure the derivative of return currents of the order of kA ns${}^{-1}$ and analysis methodology is developed to derive return currents. We compare the current for copper, aluminium and Kapton targets at different laser energies. The data show the stable production of current peaks and clear prospects for the tailoring of the pulse shape, which is promising for future applications in high-energy-density science, for example, electromagnetic interference stress tests, high-voltage pulse response measurements and charged particle beam lensing. We compare the target discharge of the order of hundreds of nC with theoretical predictions and a good agreement is found.
The advent of COVID-19 vaccination meant a moment of hope after months of crisis communication. However, the context of disinformation on social media threatened the success of this public health campaign. This study examines how heads of government and fact-checking organizations in four countries managed communications on Twitter about the vaccination. Specifically, we conduct a content analysis of their discourses through the observation of propaganda mechanisms. The research draws on a corpus of words related to the pandemic and vaccines in France, Spain, the United Kingdom, and the United States (n = 2,800). The data were captured for a five-month period (January–May 2021), during which COVID-19 vaccines became available for elderly people. The results show a trend of clearly fallacious communication among the political leaders, based on the tools of emphasis and appeal to emotion. We argue that the political messages about the vaccination mainly used propaganda strategies. These tweets also set, to a certain extent, the agendas of the most relevant fact-checking initiatives in each country.
DNA dynamics can only be understood by taking into account its complex mechanical behavior at different length scales. At the micrometer level, the mechanical properties of single DNA molecules have been well-characterized by polymer models and are commonly quantified by a persistence length of 50 nm (~150 bp). However, at the base pair level (~3.4 Å), the dynamics of DNA involves complex molecular mechanisms that are still being deciphered. Here, we review recent single-molecule experiments and molecular dynamics simulations that are providing novel insights into DNA mechanics from such a molecular perspective. We first discuss recent findings on sequence-dependent DNA mechanical properties, including sequences that resist mechanical stress and sequences that can accommodate strong deformations. We then comment on the intricate effects of cytosine methylation and DNA mismatches on DNA mechanics. Finally, we review recently reported differences in the mechanical properties of DNA and double-stranded RNA, the other double-helical carrier of genetic information. A thorough examination of the recent single-molecule literature permits establishing a set of general ‘rules’ that reasonably explain the mechanics of nucleic acids at the base pair level. These simple rules offer an improved description of certain biological systems and might serve as valuable guidelines for future design of DNA and RNA nanostructures.
Recently, artificial intelligence-powered devices have been put forward as potentially powerful tools for the improvement of mental healthcare. An important question is how these devices impact the physician-patient interaction.
Aims
Aifred is an artificial intelligence-powered clinical decision support system (CDSS) for the treatment of major depression. Here, we explore the use of a simulation centre environment in evaluating the usability of Aifred, particularly its impact on the physician–patient interaction.
Method
Twenty psychiatry and family medicine attending staff and residents were recruited to complete a 2.5-h study at a clinical interaction simulation centre with standardised patients. Each physician had the option of using the CDSS to inform their treatment choice in three 10-min clinical scenarios with standardised patients portraying mild, moderate and severe episodes of major depression. Feasibility and acceptability data were collected through self-report questionnaires, scenario observations, interviews and standardised patient feedback.
Results
All 20 participants completed the study. Initial results indicate that the tool was acceptable to clinicians and feasible for use during clinical encounters. Clinicians indicated a willingness to use the tool in real clinical practice, a significant degree of trust in the system's predictions to assist with treatment selection, and reported that the tool helped increase patient understanding of and trust in treatment. The simulation environment allowed for the evaluation of the tool's impact on the physician–patient interaction.
Conclusions
The simulation centre allowed for direct observations of clinician use and impact of the tool on the clinician–patient interaction before clinical studies. It may therefore offer a useful and important environment in the early testing of new technological tools. The present results will inform further tool development and clinician training materials.
Describe and validate the CHROME (CHemical Restraints avOidance MEthodology) criteria.
Design:
Observational prospective longitudinal study.
Setting:
Single nursing home in Las Palmas de Gran Canaria, Spain.
Participants:
288 residents; mean age: 81.6 (SD 10.6). 77.4% had dementia.
Intervention:
Multicomponent training and consultancy program to eliminate physical and chemical restraints and promote overall quality care. Clinicians were trained in stringent diagnostic criteria of neuropsychiatric syndromes and adequate psychotropic prescription.
Measurements:
Psychotropic prescription (primary study target), neuropsychiatric syndromes, physical restraints, falls, and emergency room visits were semi-annually collected from December 2015 to December 2017. Results are presented for all residents and for those who had dementia and participated in the five study waves (completer analysis, n=107).
Results:
For the study completers, atypical neuroleptic prescription dropped from 42.7% to 18.7%, long half-life benzodiazepines dropped from 25.2% to 6.5%, and hypnotic medications from 47.7% to 12.1% (p<0.0005). Any kind of fall evolved from 67.3 to 32.7 (number of falls by 100 residents per year). Physicians’ diagnostic confidence increased, while the frequency of diagnoses of neuropsychiatric syndromes decreased (p<0.0005).
Conclusions:
Implementing the CHROME criteria reduced the prescription of the most dangerous medications in institutionalized people with dementia. Two independent audits found no physical or chemical restraint and confirmed prescription quality of psychotropic drugs. Adequate diagnosis and independent audits appear to be the keys to help and motivate professionals to optimize and reduce the use of psychotropic medication. The CHROME criteria unify, in a single compendium, neuropsychiatric diagnostic criteria, prescription guidelines, independent audit methodology, and minimum legal standards. These criteria can be easily adapted to other countries.
We present a new tool for the analysis of the optical emission lines of the gas in the Narrow Line Region (NLR) around Active Galactic Nuclei (AGNs). This new tool can be used in large samples of objects in a consistent way using different sets of optical emission-lines taking into the account possible variations from the O/H - N/O relation. The code compares certain observed emission-line ratios with the predictions from a large grid of photoionization models calculated under the most usual conditions in the NLR of AGNs to calculate the total oxygen abundance, nitrogen-to-oxygen ratio and ionization parameter. We applied our method to a sample of Seyfert 2 galaxies with optical emission-line fluxes from the literature. Our results confirm the high metallicity of the objects of the sample and provide consistent values with the direct method. The usage of models to calculate precise ICFs is mandatory when only optical emission lines are available to derive chemical abundances using the direct method in NLRs of AGN.
Hii regions in galaxy disks can be used as a powerful tool to trace the radial distribution of several of their properties and shed some light on the different relevant processes on galaxy formation and evolution. Among the properties that can be extracted from the study of the ionized gas are the metallicity, the excitation and the hardness of the ionizing field of radiation. In this contribution we focus on the determination of both the ionization parameter (U) and the effective temperature of the ionizing clusters (T) by means of a bayesian-like comparison between the observed relative fluxes of several emission-lines with the predictions from a set of photoionization models. We also show the implications that the use of our method has for the study of the radial variation of both U and T in some very well-studied disk galaxies of the Local Universe.
Leishmaniasis is one of the world's most neglected diseases, and it has a worldwide prevalence of 12 million. There are no effective human vaccines for its prevention, and treatment is hampered by outdated drugs. Therefore, research aiming at the development of new therapeutic tools to fight leishmaniasis remains a crucial goal today. With this purpose in mind, we present 20 arylaminoketone derivatives with a very interesting in vitro and in vivo efficacy against Trypanosoma cruzi that have now been studied against promastigote and amastigote forms of Leishmania infantum, Leishmania donovani and Leishmania braziliensis strains. Six out of the 20 Mannich base-type derivatives showed Selectivity Index between 39 and 2337 times higher in the amastigote form than the reference drug glucantime. These six derivatives affected the parasite infectivity rates; the result was lower parasite infectivity rates than glucantime tested at an IC25 dose. In addition, these derivatives were substantially more active against the three Leishmania species tested than glucantime. The mechanism of action of these compounds has been studied, showing a greater alteration in glucose catabolism and leading to greater levels of iron superoxide dismutase inhibition. These molecules could be potential candidates for leishmaniasis chemotherapy.
Based on the nature of the links and interactions existing at the hybrid interface, hybrid materials can be broadly classified in two main designations: a) Hybrid compounds Class I, that include all systems with electrostatic forces, hydrogen bonding or Van der Waals interactions and b) Hybrid compounds Class II, showing that the inorganic and organic components are linked through strong covalent or ionic-covalent bonds. The physico–chemical properties of nanostructured copolymer acrylates based on butyl acrylate (BA), methyl methacrylate (MMA) and acrylic acid (AA) has been investigated employing un-modified SiO2 (Class I) and modified SiO2 particles (Class II) using 3-(trimethoxysilyl) propyl methacrylate (MPS) as compatibilizing agent. The synthesis was carried out using seeded batch emulsion polymerization system. Metastable nanostructured emulsions containing 1 wt% nanoparticles were obtained. Films casted from the in-situ nanostructured latex exhibited excellent optical transparency suggesting good nanoparticles dispersion. However, the mechanical properties showed by SiO2-MPS nanocomposite, are better than the Class I hybrid compounds. Therefore, SiO2-MPS surface treatment prior to polymerization enhances the physical properties of copolymer BA-MMA-AA film. The mass loss derivative traces for the polyacrylic nanocomposites and the neat polymer obtained by thermogravimetric analysis showed that the onset temperature for thermal decomposition was shifted towards a higher temperature than the neat polyacrylic, indicating the enhancement of thermal stability of the un-modified SiO2 nanocomposite. However, there is a decrease of 40°C in the decomposition temperature for the modified polyacrylic nanocomposite. The results obtained so far have shown that weak Van der Waals and H-bonding interactions may be sufficient to enable improvement of the physical properties of the acrylate nanocomposites.
The incorporation of layered nano-silicates in polymer matrix greatly enhances the properties of the polymer. At present, there are many applications of polymer nanocomposites including coatings and architectural, they are also parts of automotive and construction industry among others. The acrylics employed at the present study were based on butyl acrylate (BA), styrene (STY), and methacrylic acid (MAA), and the nano-clay was Na-montomorillonite (MMT). The MMT clay was added to the polymer, which is the mixing matrix in a physical state solution called blend. Furthermore, their mechanical, thermal and wettability of especially prepared acrylic montmorillonite (MMT) nanocomposites were performed. By increasing the MMT in the polymer matrix concentration the Young’s modulus tends to increase it by an order of magnitude. However, by Differential Scanning Calorimetry (DSC), the thermograms show an increase in the glass transition temperature of nanocomposites for all weight percentages of MMT. Also, the wetting angle was determined, in order to know how much water is retained on the surface of the nanocomposite; the results showed that by increasing the particle of nano clay in the polymer matrix will induce a hydrophobic property to the nanocomposite.
The field of composites materials has evolved from the use of traditional fillers (e.g. carbon and glass fibers) to nanoscale fillers that add unique and often multifunctional properties to the neat polymer. Because nanoparticles have extremely high surface to volume ratios, that alter the mobility of polymer chains near their interfaces, even a small addition of nanoparticles. These components have the potential to drastically transform the properties of the host polymers. While the last decade has observed several advances in the field of nanocomposites, some recent reviews have made it clear that definitive structure-property relationships are insufficient in the literature. The influence of inorganic TiO2 nanoparticles on the dynamic mechanical properties and microstructure of copolymer based on Butyl acrylate - Methyl methacrylate - Acrylic Acid has been investigated. The mechanical relaxations of the reinforced copolymer/TiO2 composites were studied under tension mode. Addition of TiO2 nanoparticles to acrylic copolymer produced a decrease in the glass transition temperature. Dynamic mechanical analysis (DMA) showed that the local motions associated with the alpha-transition (40°C) are enhanced as the frequency of oscillation increases, i.e. the tan d maximum increases at higher frequencies. The addition of TiO2 nanoparticles reduces significantly the strength of the alpha-transition. Thus, the cooperative molecular motions involving segments of the molecular chains associated with the alpha-transition were compromised by the presence of TiO2 nanoparticles resulting in a decrement of the storage modulus.
We study the radial distribution of oxygen and nitrogen abundances in H ii regions in 350 galaxies observed in the CALIFA survey using the semi-empirical N-sensitive code Hii-Chi-mistry. A separate analysis of N/O when using [N ii] is justified as the dispersion in the O/H-N/O diagram is very large. In fact different O/H and N/O slope distributions and flattening in the outskirts are obtained.On the other hand there is a tight correlation between O/H and N/O when the values of the fittings at the effective radius are considered as representative of each galaxy.
As is well known, the corrosion of embedded steel reinforced depends strongly of the concrete resistivity, which is related directly with the water contained into its porous network. Environment plays an important role on resistivity, due to have a direct correspondence with the relative humidity and temperature. In these terms, ingress or output of water is favored or hampered by the environmental parameters, as well as its fluctuations. This work presents a proposal of instrumented system to generate a map of electrical resistivity at concrete samples by using superficial and embedded electrodes. Mathematical analysis of equivalent circuit revealed the importance of the impedance of electrodes utilized, to simplify measures. Concrete samples were exposed to different relative humidity focused to try to obtain the relation between relative humidity and resistivity. An array of two electrodes distributed in a matrix was manufactured to apply a signal of direct current at first electrode and measure the resultant current at second electrode. The system applies a programmed sequence of switch to turn on and turn off to realize measurements over established zone and, in this form, allows identify zones with potentials gradients. Also, do easy the monitoring of concrete resistivity evolution in function of time and humidity conditions.
The addition of nanoparticles into polymeric materials has changed dramatically the properties of the host polymers, promising a novel class of composite materials with different properties and added functionalities. This research focuses on the influence of inorganic nanospheres particles such as SiO2, Al2O3, Fe2O3, TiO2 and nanoplatelets, such as Bentonite nanoclay, on the thermo-mechanical properties of a polyacrylic latex (utilized in commercial coatings). The analysis of the thermal and mechanical properties showed a decrease of Young's modulus and glass transition temperature Tg in the presence of spherical nanoparticles. However, there was an increase of these properties in the presence of nanoplatelets (Bentonite), as demonstrated by the dynamic mechanical analysis and uniaxial tensile analysis. Moreover, water contact angle measurements demonstrated significant increase in hydrophobic behavior when incorporating nanosphere particles as compared to nanoplatelets. These results showed that the metallic oxides nanoparticles greatly influenced the physical and mechanical properties of the neat polyacrylic matrix.
The Calar Alto Legacy Integral Field Area (CALIFA) project is an ongoing 3D spectroscopic survey of 600 nearby galaxies of all kinds. This pioneer survey is providing valuable clues on how galaxies form and evolve. Processed through spectral synthesis techniques, CALIFA datacubes allow us to, for the first time, spatially resolve the star formation history of galaxies spread across the color-magnitude diagram. The richness of this approach is already evident from the results obtained for the first ~ 1/6 of the sample. Here we show how the different galactic spatial sub-components (“bulge” and “disk”) grow their stellar mass over time. We explore the results stacking galaxies in mass bins, finding that, except at the lowest masses, galaxies grow inside-out, and that the growth rate depends on a galaxy's mass. The growth rate of inner and outer regions differ maximally at intermediate masses. We also find a good correlation between the age radial gradient and the stellar mass density, suggesting that the local density is a main driver of galaxy evolution.
Central neurocytoma is a rare intraventricular brain tumour that affects young people and presents with increased intracranial pressure secondary to obstructive hydrocephalus. Typically, it has a favourable prognosis after complete resection. In some cases the clinical course could be more aggressive. In this report, we describe a case of recurrent central neurocytoma treated with radiosurgery after two consecutive relapses. An asymptomatic radionecrosis developed after that. At the moment the patient is in complete recovery. Finally, we discuss the role of postoperative irradiation in the treatment of this rare tumour.
The layered oxide LiVO2 recently has received more attention due to its interesting structural and magnetic behaviors involving the two-dimensional magnetic frustration in these systems. We synthesized a series of F-doped LiVO2 samples, and reported the F-doping effect on the structure and transition temperature Tt. The samples LiVO2-xFx (x=0, 0.1, 0.2 and 0.3) were characterized by X-ray diffraction, scanning electron microscope (SEM), differential scanning calorimetry (DSC), magnetic susceptibility and specific heat measurement. The structural analysis shows that with increasing x, the ratio of lattice parameter c/a increasing, i.e. in the a-b plane the lattice is compressed while in the c-axis direction the lattice expands. The DSC measurements show that a first-order phase transition happens at around 500 K, and the thermal hysteresis around phase transition temperature Tt increases with increasing x. Substitution of O with F ions results in a change of two dimensional characteristics and the distortion of the VO6 block in structure, which significantly influence the magnetic ordering transition temperature Tt.