302 research outputs found
Dirac points with giant spin-orbit splitting in the electronic structure of two-dimensional transition-metal carbides
Two-dimensional (2D) materials, especially their most prominent member,
graphene, have greatly influenced many scientific areas. Moreover, they have
become a base for investigating the relativistic properties of condensed matter
within the emerging field of Dirac physics. This has ignited an intense search
for new materials where charge carriers behave as massless or massive Dirac
fermions. Here, we theoretically show the existence of Dirac electrons in a
series of 2D transition-metal carbides, known as MXenes. They possess twelve
conical crossings in the 1st Brillouin zone with giant spin-orbit splitting.
Our findings indicate that the 2D band structure of MXenes is protected against
external perturbations and preserved even in multilayer phases. These results,
together with the broad possibilities to engineer the properties of these
materials phases, make Dirac MXenes a potential candidate for studying and
developing novel Dirac-physics-based technologies.Comment: 4 figures and supplementar
Gas identification based on bias induced hysteresis of a gas-sensitive SiC field effect transistor
In this work dynamic variation of gate bias is used on a gas-sensitive SiC
field effect transistor ("GasFET") to optimize its sensitivity and
increase its selectivity. Gate bias ramps introduce strong hysteresis in the
sensor signal. The shape of this hysteresis is shown to be an appropriate
feature both for the discrimination of various gases (ammonia, carbon
monoxide, nitrogen monoxide and methane) as well as for different gas
concentrations (250 and 500 ppm). The shape is very sensitive to ambient
conditions as well as to the bias sweep rate. Thus, the influences of oxygen
concentration, relative humidity, sensor temperature and cycle duration,
i.e., sweep rate, are investigated and reasons for the observed signal
changes, most importantly the existence of at least two different and
competing processes taking place simultaneously, are discussed. Furthermore,
it is shown that even for very fast cycles, in the range of seconds, the
gas-induced shape change in the signal is strong enough to achieve a
reliable separation of gases using gate bias cycled operation and linear
discriminant analysis (LDA) making this approach suitable for practical
application
Методика вивчення контрольно-вимірювальних приладів у курсі «Технології» основної школи
(uk) У статті запропонована методика вивчення контрольно-вимірювальних приладів при вивчені шкільного курсу «Технології» з використанням сучасного електронного вимірювального обладнання.(en) In the article the technique of studying instrumentation to teach school course "Technology" using modern electronic measuring equipment
P03-06. Preserved cellular and humoral immune responses in macaques infected with SIVmac239 and subjected to early antiretroviral therapy
P19-05. Use of autologous apoptotic pseudovirus infected cells for vaccination against HIV, evaluation in macaques
California's Minimum Nurse Staffing Legislation: Results from a Natural Experiment
To determine whether, following implementation of California's minimum nurse staffing legislation, changes in acuity-adjusted nurse staffing and quality of care in California hospitals outpaced similar changes in hospitals in comparison states without such regulations
Ohmic contact properties of magnetron sputtered Ti3SiC2 on n- and p-type 4H-silicon carbide
Changes in the Immune Phenotype and Gene Expression Profile Driven by a Novel Tuberculosis Nanovaccine: Short and Long-Term Post-immunization.
Deciphering protection mechanisms against Mycobacterium tuberculosis (Mtb) remains a critical challenge for the development of new vaccines and therapies. We analyze the phenotypic and transcriptomic profile in lung of a novel tuberculosis (TB) nanoparticle-based boosting mucosal vaccine Nano-FP1, which combined to BCG priming conferred enhanced protection in mice challenged with low-dose Mtb. We analyzed the vaccine profile and efficacy at short (2 weeks), medium (7 weeks) and long term (11 weeks) post-vaccination, and compared it to ineffective Nano-FP2 vaccine. We observed several changes in the mouse lung environment by both nanovaccines, which are lost shortly after boosting. Additional boosting at long-term (14 weeks) recovered partially cell populations and transcriptomic profile, but not enough to enhance protection to infection. An increase in both total and resident memory CD4 and CD8 T cells, but no pro-inflammatory cytokine levels, were correlated with better protection. A unique gene expression pattern with differentially expressed genes revealed potential pathways associated to the immune defense against Mtb. Our findings provide an insight into the critical immune responses that need to be considered when assessing the effectiveness of a novel TB vaccine
- …