691 research outputs found
1,4-Bis(5-methyl-1H-1,2,4-triazol-3-yl)benzene tetrahydrate
In the title compound, C12H12N6·4H2O, the two triazole rings adopt a cis configuration with a crystallographic twofold axis passing through the central benzene group. The benzene and triazole rings are almost coplanar with a dihedral angle of 5.5 (1)°. In the crystal, water molecules are joined together by OW—H⋯OW hydrogen bonds to form a one-dimensional zigzag chain. These water chains are further connected to the organic molecule, forming a three-dimensional network by intermolecular OW—H⋯N and N—H⋯OW hydrogen bonds. Moreover, π–π stacking interactions between triazole rings [centroid–centroid distances = 3.667 (1)–3.731 (1) Å] are observed. One of the water molecules shows one of the H atoms to be disordered over two positions
Bis(5-phenyl-1H-1,2,4-triazol-3-yl) disulfide dihydrate
A crystallographic twofold axis passing through the centre of the disulfide linkage in the title compound, C16H12N6S2·2H2O, results in one-half of the molecule and one uncoordinated water molecule described in the asymmetric unit. In the molecule, the mean planes of the benzene and triazole rings are close to being coplanar and are separated by a dihedral angle of 2.08 (15)°. The triazole rings are twisted by a dihedral angle of 37.67 (6)° from the disulfide linkage. The crystal packing is stabilized by intermolecular N—H⋯O and O—H⋯N hydrogen bonds with the water molecules, forming a three-dimensional supramolecular network
Study of pharmacokinetics and tissue distribution of liposomal brucine for dermal administration
Bai-Can Yang1, Zhi-Feng Chu1, Sha Zhu1, Li-Jun Wang1, Yu-Hong Feng1, Feng-Hua Li1, Chang-Sheng Liu2, Yuan Yuan21Pharmacy Department of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, People’s Republic of China; 2Key Laboratory for Ultrafine Materials of Ministry of Education, and Engineering Research Center for Biomedical Materials of Ministry of Education, East China University of Science and Technology, Shanghai, People’s Republic of ChinaObjective: To evaluate the pharmacokinetics and tissue distribution of liposomal brucine (LB) for dermal application.Methods: Pharmacokinetics and tissue distribution were studied by in vivo animal testing. High performance liquid chromatography (HPLC) was used to detect the concentration of brucine in rats’ skin, plasma and various tissues.Results: After dermal administration, LB was absorbed rapidly in the skin and could be detected after 0.5 hours. After 36 hours, levels were too low to be detected. In plasma, levels were also too low to be detected after 36 hours. The concentration of LB reached 50% of the maximum in all tissues except the brain, peaking after 1.5 hours but still detectable after 12 hours.Conclusion: The concentration of LB was high in skin at the application site. LB was quickly absorbed into tissues through the blood circulation and widely distributed throughout the whole body. There was no obvious toxicity and LB did not readily accumulate in tissues and organs. It showed local potency but low overall systemic toxicity.Keywords: liposomal brucine, dermal administration, pharmacokinetics, tissue distributio
A SWAP Gate for Spin Qubits in Silicon
With one- and two-qubit gate fidelities approaching the fault-tolerance
threshold for spin qubits in silicon, how to scale up the architecture and make
large arrays of spin qubits become the more pressing challenges. In a scaled-up
structure, qubit-to-qubit connectivity has crucial impact on gate counts of
quantum error correction and general quantum algorithms. In our toolbox of
quantum gates for spin qubits, SWAP gate is quite versatile: it can help solve
the connectivity problem by realizing both short- and long-range spin state
transfer, and act as a basic two-qubit gate, which can reduce quantum circuit
depth when combined with other two-qubit gates. However, for spin qubits in
silicon quantum dots, high fidelity SWAP gates have not been demonstrated due
to the requirements of large circuit bandwidth and a highly adjustable ratio
between the strength of the exchange coupling J and the Zeeman energy
difference Delta E_z. Here we demonstrate a fast SWAP gate with a duration of
~25 ns based on quantum dots in isotopically enriched silicon, with a highly
adjustable ratio between J and Delta E_z, for over two orders of magnitude in
our device. We are also able to calibrate the single-qubit local phases during
the SWAP gate by incorporating single-qubit gates in our circuit. By
independently reading out the qubits, we probe the anti-correlations between
the two spins, estimate the operation fidelity and analyze the dominant error
sources for our SWAP gate. These results pave the way for high fidelity SWAP
gates, and processes based on them, such as quantum communication on chip and
quantum simulation by engineering the Heisenberg Hamiltonian in silicon.Comment: 25 pages, 5 figures
Syntropic spin alignment at the interface between ferromagnetic and superconducting nitrides
The magnetic correlations at the superconductor/ferromagnet (S/F) interfaces
play a crucial role in realizing dissipation-less spin-based logic and memory
technologies, such as triplet-supercurrent spin-valves and "{\pi}" Josephson
junctions. Here we report the coexistence of an induced large magnetic moment
and a crypto ferromagnetic state at high-quality nitride S/F interfaces. Using
polarized neutron reflectometry and d. c. SQUID measurements, we quantitatively
determined the magnetization profile of S/F bilayer and confirmed the induced
magnetic moment in the adjacent superconductor only exists below TC.
Interestingly, the direction of the induced moment in the superconductors was
unexpectedly parallel to that in the ferromagnet, which contrasts with earlier
findings in S/F heterostructures based on metals or oxides. The
first-principles calculations verify the observed unusual interfacial spin
texture is caused by the Heisenberg direct exchange coupling through d orbital
overlapping and severe charge transfer across the interfaces. Our work
establishes an incisive experimental probe for understanding the magnetic
proximity behavior at S/F interfaces and provides a prototype epitaxial
building block for superconducting spintronics.Comment: 21 pages, 5 figures, supplementary file with 14 figure
Metal-to-insulator transition in oxide semimetals by anion doping
Oxide semimetals exhibiting both nontrivial topological characteristics stand
as exemplary parent compounds and multiple degrees of freedom, offering great
promise for the realization of novel electronic states. In this study, we
present compelling evidence of profound structural and transport phase shifts
in a recently uncovered oxide semimetal, SrNbO3, achieved through effective
in-situ anion doping. Notably, a remarkable increase in resistivity of more
than three orders of magnitude at room temperature is observed upon
nitrogen-doping. The extent of electronic modulation in SrNbO3 is strongly
correlated with the misfit strain, underscoring its phase instability to both
chemical doping and crystallographic symmetry variations. Using
first-principles calculations, we discern that elevating the level of nitrogen
doping induces an upward shift in the conductive bands of SrNbO3-dNd.
Consequently, a transition from a metallic state to an insulating state becomes
apparent as the nitrogen concentration reaches a threshold of 1/3. This
investigation sheds light on the potential of anion engineering in oxide
semimetals, offering pathways for manipulating their physical properties. These
insights hold promise for future applications that harness these materials for
tailored functionalities.Comment: 18 pages, 4 figure
SOX40L: An Important Infl ammatory Mediator in Adult Bronchial Asthma
Abstract Introduction: The role of soluble OX40 ligand (sOX40L) in adult bronchial asthma is unclear. This study aims to determine the serum concentrations of sOX40L in adult patients with bronchial asthma, and discussed its relationship with pulmonary function. Materials and Methods: We measured the pulmonary function using the spirometer and detected the serum concentrations of sOX40L by enzyme linked immunosorbent assay (ELISA) in 19 healthy persons in the control group, 58 acute asthmatic adult patients who were grouped according to their disease severity: 18 mild grade, 24 moderate grade, 16 severe grade, and 24 persons in a stable asthmatic group. Results: The serum concentrations of sOX40L in asthmatic adult patients (6.80 ± 4.95 ng/L) were distinctly higher than those in the control group (3.98 ± 2.83 ng/L, P <0.05), and they were negatively correlated with pulmonary function indexes (FEV1%, FVC%, FEV1/FVC) (r = -0.754, P <0.01, r = -0.557, P <0.01, r = -0.457, P <0.01, respectively). Moreover, the serum concentrations of sOX40L showed obvious differences among control, mild, moderate, and severe groups (3.98 ± 2.83, 4.87 ± 1.89, 6.97 ± 5.91, 8.71 ± 5.18 ng/L, respectively; P <0.01). The concentrations of sOX40L decreased to the same extent as the control group after therapeutic treatments were provided to the asthmatic adult patients. Conclusion: The concentrations of sOX40L were found to be high in adult asthmatic patients and were associated with the severity of the disease. Therefore, sOX40L could be a potential infl ammatory mediator in the pathogenesis of asthma
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