56 research outputs found
Growth performance, organ-level ionic relations and organic osmoregulation of Elaeagnus angustifolia in response to salt stress
Elaeagnus angustifolia is one of the most extensively afforested tree species in environment-harsh regions of northern China. Despite its exceptional tolerance to saline soil, the intrinsic adaptive physiology has not been revealed. In this study, we investigated the growth, organ-level ionic relations and organic osmoregulation of the seedlings hydroponically treated with 0, 100 and 200 mM NaCl for 30 days. We found that the growth characteristics and the whole-plant dry weight were not obviously stunted, but instead, were even slightly stimulated by the treatment of 100 mM NaCl. In contrast, these traits were significantly inhibited by 200 mM NaCl treatment. Interestingly, as compared with the control (0 mM NaCl), both 100 and 200 mM NaCl treatments had a promotional effect on root growth as evidenced by 26.3% and 2.4% increases in root dry weight, respectively. Roots had the highest Na+ and Cl- concentrations and obviously served as the sink for the net increased Na+ and Cl-, while, stems might maintain the capacity of effective Na+ constraint, resulting in reduced Na+ transport to the leaves. K+, Ca2+ and Mg2+ concentrations in three plant organs of NaCl-treated seedlings presented a substantial decline, eventually leading to an enormously drop of K+/Na+ ratio. As the salt concentration increased, proline and soluble protein contents continuously exhibited a prominent and a relatively tardy accumulation, respectively, whereas soluble sugar firstly fell to a significant level and then regained to a level that is close to that of the control. Taken together, our results provided quantitative measures that revealed some robust adaptive physiological mechanisms underpinning E. angustifolia’s moderately high salt tolerance, and those mechanisms comprise scalable capacity for root Na+ and Cl- storage, effectively constrained transportation of Na+ from stems to leaves, root compensatory growth, as well as an immediate and prominent leaf proline accumulation
In situ electron paramagnetic resonance spectroscopy using single nanodiamond sensors
An ultimate goal of electron paramagnetic resonance (EPR) spectroscopy is to
analyze molecular dynamics in place where it occurs, such as in a living cell.
The nanodiamond (ND) hosting nitrogen-vacancy (NV) centers will be a promising
EPR sensor to achieve this goal. However, ND-based EPR spectroscopy remains
elusive, due to the challenge of controlling NV centers without well-defined
orientations inside a flexible ND. Here, we show a generalized zero-field EPR
technique with spectra robust to the sensor's orientation. The key is applying
an amplitude modulation on the control field, which generates a series of
equidistant Floquet states with energy splitting being the
orientation-independent modulation frequency. We acquire the zero-field EPR
spectrum of vanadyl ions in aqueous glycerol solution with embedded single NDs,
paving the way towards \emph{in vivo} EPR
High-fidelity single-shot readout of single electron spin in diamond with spin-to-charge conversion
High fidelity single-shot readout of qubits is a crucial component for
fault-tolerant quantum computing and scalable quantum networks. In recent
years, the nitrogen-vacancy (NV) center in diamond has risen as a leading
platform for the above applications. The current single-shot readout of the NV
electron spin relies on resonance fluorescence method at cryogenic temperature.
However, the the spin-flip process interrupts the optical cycling transition,
therefore, limits the readout fidelity. Here, we introduce a spin-to-charge
conversion method assisted by near-infrared (NIR) light to suppress the
spin-flip error. This method leverages high spin-selectivity of cryogenic
resonance excitation and high flexibility of photonionization. We achieve an
overall fidelity 95% for the single-shot readout of an NV center electron
spin in the presence of high strain and fast spin-flip process. With further
improvements, this technique has the potential to achieve spin readout fidelity
exceeding the fault-tolerant threshold, and may also find applications on
integrated optoelectronic devices
Single rare-earth ions as atomic-scale probes in ultra-scaled transistors
Continued dimensional scaling of semiconductor devices has driven information
technology into vastly diverse applications. As the size of devices approaches
fundamental limits, metrology techniques with nanometre resolution and
three-dimensional (3D) capabilities are desired for device optimisation. For
example, the performance of an ultra-scaled transistor can be strongly
influenced by the local electric field and strain. Here we study the spectral
response of single erbium ions to applied electric field and strain in a
silicon ultra-scaled transistor. Stark shifts induced by both the overall
electric field and the local charge environment are observed. Further, changes
in strain smaller than are detected, which is around two
orders of magnitude more sensitive than the standard techniques used in the
semiconductor industry. These results open new possibilities for
non-destructive 3D mapping of the local strain and electric field in the
channel of ultra-scaled transistors, using the single erbium ions as
ultra-sensitive atomic probes.Comment: 10+5 pages, 4+3 figure
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