We report the integration of a ferroelectric (FE) silicon-doped hafnium oxide material in ferroelectric field-effect transistor (FeFET) devices fabricated with an optimized interfacial layer in a ...gate-first scheme. The effect of increasing the permittivity (k) value of the interface layer on the performance of the metal-ferroelectric-insulator-semiconductor (MFIS)-FE-HfO 2 FeFET is studied in terms of its switching characteristics, endurance, and retention. In contrast to the previous work, the FE Si:HfO 2 -integrated FeFET devices show a low-power operation capability as well as an improved endurance characteristics without jeopardizing high-temperature retention. The utilization of an optimized SiON interface layer for MFIS-HfO 2 FeFET stack is discussed, and the improvements are outlined with reference to a standard low-k SiO 2 interface.
In spite of the increasing use of machine learning techniques, in-memory computing and hardware have increased the interest to accelerate neural network operation. Henceforth, novel embedded ...nonvolatile memories (eNVMs) for highly scaled technology nodes, like ferroelectric field effect transistors (FeFETs), are heavily studied and very promising. Furthermore, inference and on-chip learning can be fostered by further eNVM technology options, such as multibit operation and linear switching. In this article, we present the advantages of hafnium oxide-based FeFETs for such purposes due to their basic three-terminal structure, which allows to selectively activate or deactivate selected devices as well as tune linearity and dynamic range for certain applications. Furthermore, we discuss the impact of the material properties of the ferroelectric layer, the interface layer thickness, and scaling on the device performance. Here, we demonstrate good device properties even for highly scaled devices (<inline-formula> <tex-math notation="LaTeX">100\,\,nm \times 100 </tex-math></inline-formula> nm).
•Inhibiting left temporo-parietal cortex (TPC) does not affect reading performance.•Effective stimulation alters left inferior frontal cortex activation during pseudoword reading.•Coupling between ...left TPC and occipito-temporal cortex is crucial for short-term reorganization.
The left temporo-parietal cortex (TPC) is crucial for phonological decoding, i.e., for learning and retaining sound-letter mappings, and appears hypoactive in dyslexia. Here, we tested the causal contribution of this area for reading in typical readers with transcranial magnetic stimulation (TMS) and explored the reading network's response with fMRI. By investigating the underlying neural correlates of stimulation-induced modulations of the reading network, we can help improve targeted interventions for individuals with dyslexia. 28 typical adult readers overtly read simple and complex words and pseudowords during fMRI after effective and sham TMS over the left TPC. To explore differences in functional activation and effective connectivity within the reading network, we performed univariate and multivariate analyses, as well as dynamic causal modeling. While TMS-induced effects on reading performance and brain activation showed large individual variability, multivariate analyses revealed a shift in activation in the left inferior frontal cortex for pseudoword reading after effective TMS. Furthermore, TMS increased effective connectivity from the left ventral occipito-temporal cortex to the left TPC. In the absence of effects on reading performance, the observed changes in task-related activity and the increase in functional coupling between the two core reading nodes suggest successful short-term compensatory reorganization in the reading network following TMS-induced disruption. This study is the first to explore neurophysiological changes induced by TMS to a core reading node in typical readers while performing an overt reading task. We provide evidence for remote stimulation effects and emphasize the relevance of functional interactions in the reading network.
Display omitted
We use data from the Multi-Unit Spectroscopic Explorer (MUSE), recently commissioned at the Very Large Telescope (VLT), to study the kinematics and stellar population content of NGC 4371, an ...early-type massive barred galaxy in the core of the Virgo cluster. We integrate this study with a detailed structural analysis using imaging data from the Hubble and Spitzer Space Telescopes, which allows us to perform a thorough investigation of the physical properties of the galaxy. We show that the rotationally supported inner components in NGC 4371, i.e. an inner disc and a nuclear ring – which, according to the predominant scenario, are built with stars formed from gas brought to the inner region by the bar – are vastly dominated by stars older than 10 Gyr. Our results thus indicate that the formation of the bar occurred at a redshift of about \hbox{$z=1.8^{+0.5}_{-0.4}$}z=1.8-0.4+0.5 (error bars are derived from 100 Monte Carlo realisations). NGC 4371 thus testifies to the robustness of bars. In addition, the mean stellar age of the portion of the major disc of the galaxy that is covered by our MUSE data is above 7 Gyr with a small contribution from younger stars. This suggests that the quenching of star formation in NGC 4371, which is very likely an environmental effect, was already occurring at a redshift of about \hbox{$z=0.8^{+0.2}_{-0.1}$}z=0.8-0.1+0.2. Our results suggest that bar-driven secular evolution processes may have an extended impact on the evolution of galaxies, and thus on the properties of galaxies as observed today, and not necessarily be restricted to more recent cosmic epochs.
The Largest M Dwarf Flares from ASAS-SN Schmidt, Sarah J.; Shappee, Benjamin J.; van Saders, Jennifer L. ...
The Astrophysical journal,
05/2019, Letnik:
876, Številka:
2
Journal Article
Recenzirano
Odprti dostop
The All-sky Automated Survey for Supernovae (ASAS-SN) is the only project in existence to scan the entire sky in optical light approximately every day, reaching a depth of g ∼ 18 mag. Over the course ...of its first 4 yr of transient alerts (2013-2016), ASAS-SN observed 53 events classified as likely M dwarf flares. We present follow-up photometry and spectroscopy of all 53 candidates, confirming flare events on 47 M dwarfs, one K dwarf, and one L dwarf. The remaining four objects include a previously identified T Tauri star, a young star with outbursts, and two objects too faint to confirm. A detailed examination of the 49 flare star light curves revealed an additional six flares on five stars, resulting in a total of 55 flares on 49 objects ranging in V-band contrast from ΔV = −1 to −10.2 mag. Using an empirical flare model to estimate the unobserved portions of the flare light curve, we obtain lower limits on the V-band energy emitted during each flare, spanning -35, which are among the most energetic flares detected on M dwarfs. The ASAS-SN M dwarf flare stars show a higher fraction of H emission, as well as stronger H emission, compared to M dwarfs selected without reference to activity, consistent with belonging to a population of more magnetically active stars. We also examined the distribution of tangential velocities, finding that the ASAS-SN flaring M dwarfs are likely to be members of the thin disk and are neither particularly young nor old.
Quality of life (QoL) impairment is a well-known consequence of chronic kidney disease (CKD). The factors influencing QoL and late life functional health are poorly examined.
Using questionnaires ...combined with neuropsychological examinations, we prospectively evaluated physical, cognitive, and emotional factors influencing QoL, functional health and participation in community dwelling in 119 patients with CKD stages 3-5 including hemodialysis (61.5±15.7years; 63% men) and 54 control patients of the same age without CKD but with similar cardiovascular risk profile.
Compared with control patients, CKD patients showed impairment of the physical component of QoL and overall function, assessed by the SF-36 and LLFDI, whereas disability, assessed by LLFDI, was selectively impaired in CKD patients on hemodialysis. Multivariable linear regressions (forced entry) confirmed earlier findings that CKD stage (β = -0.24; p = 0.012) and depression (β = -0.30; p = 0.009) predicted the QoL physical component. Hitherto unknown, CKD stage (β = -0.23; p = 0.007), cognition (β = 0.20; p = 0.018), and depression (β = -0.51; <0.001) predicted disability assessed by the LLFDI, while age (β = -0.20; p = 0.023), male gender (B = 5.01; p = 0.004), CKD stage (β = -0.23; p = 0.005), stroke history (B = -9.00; p = 0.034), and depression (β = -0.41; p<0.001) predicted overall function. Interestingly, functional health deficits, cognitive disturbances, depression, and anxiety were evident almost only in CKD patients with coronary heart disease (found in 34.2% of CKD patients). The physical component of QoL and functional health decreased with age and depressive symptoms, and increased with cognitive abilities.
In CKD, QoL, functional health, and participation in community dwelling are influenced by physical, cognitive, and emotional factors, most prominently in coronary heart disease patients.
Huntington's disease (HD) is an autosomal dominantly inherited, and currently untreatable, neuropsychiatric disorder. This progressive and ultimately fatal disease is named after the American ...physician George Huntington and according to the underlying molecular biological mechanisms is assigned to the human polyglutamine or CAG‐repeat diseases. In the present article we give an overview of the currently known neurodegenerative hallmarks of the brains of HD patients. Subsequent to recent pathoanatomical studies the prevailing reductionistic concept of HD as a human neurodegenerative disease, which is primarily and more or less exclusively confined to the striatum (ie, caudate nucleus and putamen) has been abandoned. Many recent studies have improved our neuropathological knowledge of HD; many of the early groundbreaking findings of neuropathological HD research have been rediscovered and confirmed. The results of this investigation have led to the stepwise revision of the simplified pathoanatomical and pathophysiological HD concept and culminated in the implementation of the current concept of HD as a multisystem degenerative disease of the human brain. The multisystem character of the neuropathology of HD is emphasized by a brain distribution pattern of neurodegeneration (i) which apart from the striatum includes the cerebral neo‐and allocortex, thalamus, pallidum, brainstem and cerebellum, and which (ii) therefore, shares more similarities with polyglutamine spinocerebellar ataxias than previously thought.
Purpose
The purpose of this study was to assess the prevalence of male infertility and treatment-related risk factors in childhood cancer survivors.
Methods
Within the Childhood Cancer Survivor ...Study, 1,622 survivors and 274 siblings completed the Male Health Questionnaire. The analysis was restricted to survivors (938/1,622; 57.8 %) and siblings (174/274; 63.5 %) who tried to become pregnant. Relative risks (RR) and 95 % confidence intervals (CI) for the prevalence of self-reported infertility were calculated using generalized linear models for demographic variables and treatment-related factors to account for correlation among survivors and siblings of the same family. All statistical tests were two-sided.
Results
Among those who provided self-report data, the prevalence of infertility was 46.0 % in survivors versus 17.5 % in siblings (RR = 2.64, 95 % CI 1.88–3.70,
p
< 0.001). Of survivors who met the definition for infertility, 37 % had reported at least one pregnancy with a female partner that resulted in a live birth. In a multivariable analysis, risk factors for infertility included an alkylating agent dose (AAD) score ≥3 (RR = 2.13, 95 % CI 1.69–2.68 for AAD ≥3 versus AAD <3), surgical excision of any organ of the genital tract (RR = 1.63, 95 % CI 1.20–2.21), testicular radiation ≥4 Gy (RR = 1.99, 95 % CI 1.52–2.61), and exposure to bleomycin (RR = 1.55, 95 % CI 1.20–2.01).
Conclusion
Many survivors who experience infertility father their own children, suggesting episodes of both fertility and infertility. This and the novel association of infertility with bleomycin warrant further investigation.
Implications for Cancer Survivors
Though infertility is common, male survivors reporting infertility often father their own children. Bleomycin may pose some fertility risk.
We report a detailed characterization of the fluorite-structure-based Si:HfO2 (HSO) and Zr:HfO2 (HZO) ferroelectric (FE) materials integrated into a metal-FE-insulator-semiconductor (MFIS) FE ...field-effect transistors (FeFETs) gate-stack with the silicon oxynitride (SiON) interface layer. The pressing issue in the emerging FeFET concept is the limited endurance range (104-105) of program/erase cycles and is attributed to the gate-stack degradation. In a gate-first scheme, the effect of dopant type on the endurance performance of the fluorite structure-based FeFETs is investigated. The zirconium (Zr)-doped FeFETs show faster memory window (MW) degradation when compared with silicon (Si)-doped hafnium dioxide (HfO2) FeFETs. The physical mechanism responsible for endurance degradation is identified and attributed to the higher number of traps in the HZO-based FeFETs compared with the HSO ones.
PDF
