3,164 research outputs found
Application of prenatal ultrasonography and magnetic resonance imaging on fetal agenesis of corpus callosum
Objectives: To evaluate the diagnostic value and clinical application of prenatal ultrasonography (US) and Magnetic Resonance Imaging (MRI) for different types of fetal Agenesis of the Corpus Callosum (ACC). Material and methods: There were 42 cases of fetal ACC discovered by routine US, including complete ACC 18 cases and partial ACC 24 cases, checked by MRI within 1 week. The results were confirmed by head ultrasound after birth or brain biopsy after labor induction. Results: From prenatal ultrasonic diagnosis, 18 cases were complete ACC and 24 cases were partial ACC. MRI was able to find complete ACC in 11 cases, partial ACC in 16 cases, and non-ACC in 15 cases. Labor induction or birth confirmed that, 11 cases were complete ACC, 14 cases were partial ACC, and 17 cases were non-ACC.The results of different types of ACC were detected by ultrasound and MRI were statistically significant (p < 0.05).MRI examination was superior to ultrasound in specificity, positive predictive value, negative predictive value, Youden index, and diagnostic index. Conclusions: MRI is high specific degrees, diagnostic performance is satisfactory, should be use as a necessary method for prenatal definitive diagnosis of ACC. However, prenatal ultrasound can be tested repeatedly and can be combined with blood flow imaging detection in real time, and it is still the preferred method for screening fetal structural malformation in a comprehensive way, which is suitable for general screening of ACC
Spin-flip reflection at the normal metal-spin superconductor interface
We study spin transport through a normal metal-spin superconductor junction.
A spin-flip reflection is demonstrated at the interface, where a spin-up
electron incident from the normal metal can be reflected as a spin-down
electron and the spin will be injected into the spin
superconductor. When the (spin) voltage is smaller than the gap of the spin
superconductor, the spin-flip reflection determines the transport properties of
the junction. We consider both graphene-based (linear-dispersion-relation) and
quadratic-dispersion-relation normal metal-spin superconductor junctions in
detail. For the two-dimensional graphene-based junction, the spin-flip
reflected electron can be along the specular direction (retro-direction) when
the incident and reflected electron locates in the same band (different bands).
A perfect spin-flip reflection can occur when the incident electron is normal
to the interface, and the reflection coefficient is slightly suppressed for the
oblique incident case. As a comparison, for the one-dimensional
quadratic-dispersion-relation junction, the spin-flip reflection coefficient
can reach 1 at certain incident energies. In addition, both the charge current
and the spin current under a charge (spin) voltage are studied. The spin
conductance is proportional to the spin-flip reflection coefficient when the
spin voltage is less than the gap of the spin superconductor. These results
will help us get a better understanding of spin transport through the normal
metal-spin superconductor junction.Comment: 11 pages, 9 figure
catena-Poly[[[bis(acetato-κ2 O,O′)aquacadmium]-μ-[(pyridin-3-yl)(pyridin-4-yl)methanone]-κ2 N:N′] dihydrate]
In the title complex, {[Cd(CH3COO)2(C11H8N2O)(H2O)]·2H2O}n, the CdII ion adopts an O5N2 pentagonal–bipyramidal coordination geometry with four acetate O atoms and one water O atom at the equatorial sites and two pyridine N atoms at the axial sites. The (pyridin-3-yl)(pyridin-4-yl)methanone ligand acts in a μ2-bridging mode, linking the metal atoms, leading to an infinite chain along [-110]. O—H⋯O hydrogen bonds involving the lattice water molecules connect these chains into a three-dimensional network
2-(2-Amino-5-methylthiazol-4-yl)phenol
In the title compound, C10H10N2OS, the benzene ring is nearly co-planar with the thiazole ring, making a dihedral angle of 2.1 (2)°. The crystal structure is stabilized by intermolecular N—H⋯O hydrogen bonds. An intramolecular O—H⋯N hydrogen bond is also present
3,3′-Carbonyldipyridinium bis(perchlorate)
In the title molecular salt, C11H10N2O2+·2ClO4
−, the complete cation is generated by crystallographic twofold symmetry. The dihedral angle between the pyridyl rings is 67.07 (7)°. The crystal structure features N—H⋯Cl hydrogen bonds, forming sheets in the ab plane
Effect of siRNA interference on nerve growth factor in intervertebral disc inflammation rats
AbstractObjectiveTo investigate the inhibition effect of siRNA interference on NGF induced by inflammatory factor IL-6, and IL-1 so as to provide novel targets for clinical treatment of discogenic low back pain.MethodsThe intervertebral disc nucleus and annulus fibrosus cells of rats were separated. The cells were co-cultured with different concentrations (10 nmol/L, 20 nmol/L, 50 nmol/L, 100 nmol/L) of IL-6 and IL-1β. The NGF-siRNA was leaded into the co-cultured cells with its import ability assessed by flow cytometry instrument tests, before and after which the NGF mRNA expression was detected by real-time Q-PCR and the NGF content was detected by ELISA.ResultsFlow cytometry instrument test results showed that the NGF-siRNA cell conversion rate was 99.8%. Real-time Q-PCR detection results showed that compared with negative control group, the NGF mRNA expression of co-cultured cells treated by 10 nmol/L, 20 nmol/L, 50 nmol/L, 100 nmol/L IL-6 and IL-1β were respectively raised 3.4, 3.7, 4.7, 3.7 times which were all significantly down-regulated after the import of NGF-siRNA. EILSA detection results showed that compared with negative control group, the NGF content of co-cultured medium treated by 10 nmol/L, 20 nmol/L, 50 nmol/L, 100 nmol/L I-L6 and IL-1β were respectively raised 2.9, 3.3, 4.5, 7.4 times which were all significantly decreased after the import of NGF-siRNA.ConclusionsThese molecular biological results suggest that inflammatory factor IL-6 and IL-1β could stimulate NGF on intervertebral disc cells in vitro culture model and its efficiency is concentration dependent, while siRNA interference can inhibit the stimulation effect of IL-6 and IL-1β on intervertebral disc cell, which provides a new targets for the clinical treatment of discogenic low back pain
A Situation-aware Enhancer for Personalized Recommendation
When users interact with Recommender Systems (RecSys), current situations,
such as time, location, and environment, significantly influence their
preferences. Situations serve as the background for interactions, where
relationships between users and items evolve with situation changes. However,
existing RecSys treat situations, users, and items on the same level. They can
only model the relations between situations and users/items respectively,
rather than the dynamic impact of situations on user-item associations (i.e.,
user preferences). In this paper, we provide a new perspective that takes
situations as the preconditions for users' interactions. This perspective
allows us to separate situations from user/item representations, and capture
situations' influences over the user-item relationship, offering a more
comprehensive understanding of situations. Based on it, we propose a novel
Situation-Aware Recommender Enhancer (SARE), a pluggable module to integrate
situations into various existing RecSys. Since users' perception of situations
and situations' impact on preferences are both personalized, SARE includes a
Personalized Situation Fusion (PSF) and a User-Conditioned Preference Encoder
(UCPE) to model the perception and impact of situations, respectively. We
conduct experiments of applying SARE on seven backbones in various settings on
two real-world datasets. Experimental results indicate that SARE improves the
recommendation performances significantly compared with backbones and SOTA
situation-aware baselines.Comment: Accepted at the International Conference on Database Systems for
Advanced Applications (DASFAA 2024
- …