885 research outputs found
2-(Hydroxymethyl)pyridin-3-ol
In the crystal structure of the title compound, C6H7NO2, the molecules are are linked by intermolecular O—H⋯N and O—H⋯O hydrogen bonds; π–π stacking is observed between parallel pyridine rings of adjacent molecules [centroid-to-centroid distance = 3.7649 (12) Å]
rac-Methyl 2-(2-formyl-4-nitrophenoxy)hexanoate
In the racemic title compound, C14H17NO6, the plane of the ester group of the methyl hexanoate side chain makes a dihedral angle of 80.0 (2)° with the benzene ring, while the nitro group is approximately coplanar with the benzene ring [dihedral angle = 10.3 (2)°]. In the crystal, molecules form weak aromatic C—H⋯Onitro hydrogen-bonding interactions, giving inversion dimers [graph set R
2
2(8)]
5-Methyl-N-[2-(trifluoromethyl)phenyl]isoxazole-4-carboxamide
In the title compound, C12H9F3N2O2, the benzene ring is nearly perpendicular to the isoxazole ring, making a dihedral angle of 82.97 (2)°. In the crystal, molecules are linked by N—H⋯O hydrogen bonds into a supramolecular chain running along the c axis
Recent advances in the repair of degenerative intervertebral disc for preclinical applications
The intervertebral disc (IVD) is a load-bearing, avascular tissue that cushions pressure and increases flexibility in the spine. Under the influence of obesity, injury, and reduced nutrient supply, it develops pathological changes such as fibular annulus (AF) injury, disc herniation, and inflammation, eventually leading to intervertebral disc degeneration (IDD). Lower back pain (LBP) caused by IDD is a severe chronic disorder that severely affects patients’ quality of life and has a substantial socioeconomic impact. Patients may consider surgical treatment after conservative treatment has failed. However, the broken AF cannot be repaired after surgery, and the incidence of re-protrusion and reoccurring pain is high, possibly leading to a degeneration of the adjacent vertebrae. Therefore, effective treatment strategies must be explored to repair and prevent IDD. This paper systematically reviews recent advances in repairing IVD, describes its advantages and shortcomings, and explores the future direction of repair technology
Quasi-Solid-State Ion-Conducting Arrays Composite Electrolytes with Fast Ion Transport Vertical-Aligned Interfaces for All-Weather Practical Lithium-Metal Batteries
The rapid improvement in the gel polymer electrolytes (GPEs) with high ionic conductivity brought it closer to practical applications in solid-state Li-metal batteries. The combination of solvent and polymer enables quasi-liquid fast ion transport in the GPEs. However, different ion transport capacity between solvent and polymer will cause local nonuniform Li distribution, leading to severe dendrite growth. In addition, the poor thermal stability of the solvent also limits the operating-temperature window of the electrolytes. Optimizing the ion transport environment and enhancing the thermal stability are two major challenges that hinder the application of GPEs. Here, a strategy by introducing ion-conducting arrays (ICA) is created by vertical-aligned montmorillonite into GPE. Rapid ion transport on the ICA was demonstrated by Li solid-state nuclear magnetic resonance and synchrotron X-ray diffraction, combined with computer simulations to visualize the transport process. Compared with conventional randomly dispersed fillers, ICA provides continuous interfaces to regulate the ion transport environment and enhances the tolerance of GPEs to extreme temperatures. Therefore, GPE/ICA exhibits high room-temperature ionic conductivity (1.08 mS cm) and long-term stable Li deposition/stripping cycles (> 1000 h). As a final proof, Li||GPE/ICA||LiFePO cells exhibit excellent cycle performance at wide temperature range (from 0 to 60 °C), which shows a promising path toward all-weather practical solid-state batteries
Approaching the standard quantum limit of a Rydberg-atom microwave electrometer
The development of a microwave electrometer with inherent uncertainty
approaching its ultimate limit carries both fundamental and technological
significance. Recently, the Rydberg electrometer has garnered considerable
attention due to its exceptional sensitivity, small-size, and broad tunability.
This specific quantum sensor utilizes low-entropy laser beams to detect
disturbances in atomic internal states, thereby circumventing the intrinsic
thermal noise encountered by its classical counterparts. However, due to the
thermal motion of atoms, the advanced Rydberg-atom microwave electrometer falls
considerably short of the standard quantum limit by over three orders of
magnitude. In this study, we utilize an optically thin medium with
approximately 5.2e5 laser-cooled atoms to implement heterodyne detection. By
mitigating a variety of noises and strategically optimizing the parameters of
the Rydberg electrometer, our study achieves an electric-field sensitivity of
10.0 nV/cm/Hz^1/2 at a 100 Hz repetition rate, reaching a factor of 2.6 above
the standard quantum limit and a minimum detectable field of 540 pV/cm. We also
provide an in-depth analysis of noise mechanisms and determine optimal
parameters to bolster the performance of Rydberg-atom sensors. Our work
provides insights into the inherent capacities and limitations of Rydberg
electrometers, while offering superior sensitivity for detecting weak microwave
signals in numerous applications.Comment: 12 page
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Cortical structural differences in major depressive disorder correlate with cell type-specific transcriptional signatures
Abstract: Major depressive disorder (MDD) has been shown to be associated with structural abnormalities in a variety of spatially diverse brain regions. However, the correlation between brain structural changes in MDD and gene expression is unclear. Here, we examine the link between brain-wide gene expression and morphometric changes in individuals with MDD, using neuroimaging data from two independent cohorts and a publicly available transcriptomic dataset. Morphometric similarity network (MSN) analysis shows replicable cortical structural differences in individuals with MDD compared to control subjects. Using human brain gene expression data, we observe that the expression of MDD-associated genes spatially correlates with MSN differences. Analysis of cell type-specific signature genes suggests that microglia and neuronal specific transcriptional changes account for most of the observed correlation with MDD-specific MSN differences. Collectively, our findings link molecular and structural changes relevant for MDD
Functional building blocks for scalable multipartite entanglement in optical lattices
Featuring excellent coherence and operated parallelly, ultracold atoms in
optical lattices form a competitive candidate for quantum computation. For
this, a massive number of parallel entangled atom pairs have been realized in
superlattices. However, the more formidable challenge is to scale-up and detect
multipartite entanglement due to the lack of manipulations over local atomic
spins in retro-reflected bichromatic superlattices. Here we developed a new
architecture based on a cross-angle spin-dependent superlattice for
implementing layers of quantum gates over moderately-separated atoms
incorporated with a quantum gas microscope for single-atom manipulation. We
created and verified functional building blocks for scalable multipartite
entanglement by connecting Bell pairs to one-dimensional 10-atom chains and
two-dimensional plaquettes of atoms. This offers a new platform
towards scalable quantum computation and simulation
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