683 research outputs found
(E)-N′-[4-(DimethylÂamino)ÂbenzylÂidene]-4-methylÂbenzohydrazide methanol monosolvate
In the title compound, C17H19N3O·CH3OH, the hydrazone molÂecule exists in a trans geometry with respect to the methylÂidene unit and the dihedral angle between the two substituted benzene rings is 42.6 (2)°. In the crystal, the components are linked through N—H⋯O and O—H⋯O hydrogen bonds, forming [100] chains of alternating hydrazone and methanol molÂecules
Pressure-induced melting of magnetic order and emergence of new quantum state in alpha-RuCl3
Here we report the observation of pressure-induced melting of
antiferromagnetic (AFM) order and emergence of a new quantum state in the
honeycomb-lattice halide alpha-RuCl3, a candidate compound in the proximity of
quantum spin liquid state. Our high-pressure heat capacity measurements
demonstrate that the AFM order smoothly melts away at a critical pressure (Pc)
of 0.7 GPa. Intriguingly, the AFM transition temperature displays an increase
upon applying pressure below the Pc, in stark contrast to usual phase diagrams,
for example in pressurized parent compounds of unconventional superconductors.
Furthermore, in the high-pressure phase an unusual steady of magnetoresistance
is observed. These observations suggest that the high-pressure phase is in an
exotic gapped quantum state which is robust against pressure up to ~140 GPa.Comment: 20 pages, 4 figure
Coexistence of superconductivity with exotic ferromagnetic state in pressurized non-superconducting UTe
The discovery of superconductivity in heavy Fermion UTe, a candidate
topological and triplet-paired superconductor, has aroused widespread interest.
However, to date, superconductivity has only been reported in nonstoichiometric
crystals of UTe with a Te deficit. Here, we demonstrate that the
application of uniaxial pressure induces superconductivity in stoichiometric
UTe crystals. Measurements of resistivity, magnetoresistance and
susceptibility reveal that uniaxial pressure results in a suppression of the
Kondo coherent state seen at ambient pressure, leading to the emergence of
superconductivity initially at 1.5 GP, followed by the development of bulk
superconductivity at 4.8 GPa. The superconducting state coexists with an exotic
ferromagnetically ordered (FM) state that develops just below the onset
temperature of the superconducting transition. High-pressure synchrotron x-ray
diffraction measurements performed at 20 K indicate that no structural phase
transition occurs over the measured pressure range. Our results not only
demonstrate the coexistence of superconductivity with an exotic ferromagnetic
state in pressurized stoichiometric UTe, but also highlight a vital role of
Te deficiency in developing superconductivity at ambient pressures.Comment: 17 pages, 4 figure
Pressure-induced coevolution of transport properties and lattice stability in CaK(Fe1-xNix)4As4 (x= 0.04 and 0) superconductors with and without spin-vortex crystal state
Here we report the first investigation on correlation between the transport
properties and the corresponding stability of the lattice structure for
CaK(Fe1-xNix)4As4 (x=0.04 and 0), a new type of putative topological
superconductors, with and without a spin-vortex crystal (SVC) state in a wide
pressure range involving superconducting to non-superconducting transition and
the half- to full-collapse of tetragonal (h-cT and f-cT) phases, by the
complementary measurements of high-pressure resistance, Hall coefficient and
synchrotron X-ray diffraction. We identify the three critical pressures, P1
that is the turn-on critical pressure of the h-cT phase transition and it
coincides with the critical pressure for the sign change of Hall coefficient
from positive to negative, a manifestation of the Fermi surface reconstruction,
P2 that is the turn-off pressures of the h-cT phase transition, and P3 that is
the critical pressure of the f-cT phase transition. By comparing the
high-pressure results measured from the two kinds of samples, we find a
distinct left-shift of the P1 for the doped sample, at the pressure of which
its SVC state is fully suppressed, however the P2 and the P3 remain the same as
that of the undoped one. Our results not only provide a consistent
understanding on the results reported before, but also demonstrate the
importance of the Fe-As bonding in stabilizing the superconductivity of the
iron pnictide superconductors through the pressure window
Evaluation of Tolerability, Pharmacokinetics and Pharmacodynamics of Vicagrel, a Novel P2Y12 Antagonist, in Healthy Chinese Volunteers
Background: Vicagrel is a novel anti-platelet drug and hydrolyzed to the same intermediate as clopidogrel via esterase, instead of CYP2C19. Here we report the first clinical trial on the tolerability, pharmacokinetics and pharmacodynamics of different doses of vicagrel, and comparison with clopidogrel in healthy Chinese volunteers.Methods: This study was conducted in two parts. Study I was a dose-escalating (5–15 mg) study. For each dose, 15 participants were randomized into three groups (total n = 45); nine participants were given vicagrel, three were given clopidogrel, and three were given a placebo. Study II was conducted to assess interactions between vicagrel and aspirin in 15 healthy participants. The plasma concentrations of the metabolites of vicagrel and clopidogrel were determined using a LC-MS/MS method. Platelet aggregation was assessed using the VerifyNow-P2Y12 assay.Results: Vicagrel (5–15 mg per day) dosing for 10 days or addition of aspirin was well tolerated in healthy volunteers. The exposure of the active metabolite increased proportionally across the dose range and was higher (~10-fold) than clopidogrel. The levels of IPA dosing 75 mg clopidogrel were between the responses of 5 mg and 10 mg vicagrel. After a single loading dose of vicagrel (30 mg) and a once-daily maintenance dose (7.5 mg) for 8 days, the maximum inhibition of platelet aggregation was similar to that seen with the combined use of vicagrel and aspirin (100 mg/day).Conclusion: Oral vicagrel demonstrated a favorable safety profile and excellent anti-platelet activity, which could be a promising P2Y12 antagonist as anti-platelet drug and can be further developed in phase II/III studies, and marketing for the unmet medical needs of cardiovascular diseases. The study was registered at http://www.chictr.org.cn (ChiCTR-IIR-16009260)
A COVID-19 Risk Score Combining Chest CT Radiomics and Clinical Characteristics to Differentiate COVID-19 Pneumonia From Other Viral Pneumonias
With the continued transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) throughout the world, identification of highly suspected COVID-19 patients remains an urgent priority. In this study, we developed and validated COVID-19 risk scores to identify patients with COVID-19. In this study, for patient-wise analysis, three signatures, including the risk score using radiomic features only, the risk score using clinical factors only, and the risk score combining radiomic features and clinical variables, show an excellent performance in differentiating COVID-19 from other viral-induced pneumonias in the validation set. For lesion-wise analysis, the risk score using three radiomic features only also achieved an excellent AUC value. In contrast, the performance of 130 radiologists based on the chest CT images alone without the clinical characteristics included was moderate as compared to the risk scores developed. The risk scores depicting the correlation of CT radiomics and clinical factors with COVID-19 could be used to accurately identify patients with COVID-19, which would have clinically translatable diagnostic and therapeutic implications from a precision medicine perspective
Performance of a novel solar driven ventilation of smoke from moxibustion therapy
In this paper, a novel solar driven smoke ventilation system was proposed for the moxibustion therapy. A mathematical model is developed based on heat balance and fluid flow, and the performance of the ventilation system is studied. Sensitivity analyses of solar radiation intensity from 100 to 1000Â W/m2, collector length from 1 to 10Â m, solar system width from 0.5 to 3Â m, and chimney width from 0.1 to 0.3Â m, and chimney height from 0.5 to 3Â m are also performed. For stronger solar radiation, larger collector or higher chimney, the effective heat flux of the solar system increases and the flow rate increases. For the solar radiation of larger than 210Â W/m2, the velocity at the smoke pipe entrance is larger than the critical velocity of 0.5Â m/s. Higher chimney also leads to the increase of the driving force besides receiving more solar radiation. For reaching the pipe entrance velocity of larger than the critical velocity, a solar radiation of larger than 210Â W/m2, a chimney height of higher than 0.89Â m, a collector length of larger than 1.9Â m, or a collector width of larger than 0.198Â m is needed. The conclusions are obtained under the absent parametric values: the solar radiation intensity of 600Â W/m2, the chimney height of 2Â m, the solar collector length of 8Â m, and the widths of solar collector and chimney of 0.25Â m. This work lays a solid foundation for application of this solar driven smoke ventilation system to the moxibustion therapy
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