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•A bi-layer scaffold consists of electrospinning membrane and 3D printing scaffold.•The upper layer membrane could promote L929 fibroblast adhesion and proliferation.•The lower layer ...porous scaffold could promote osteogenic differentiation of BMSCs.•In vivo studies confirm the beneficial features of the bi-layer scaffold for GBR.
The guided bone regeneration (GBR) concept has been extensively utilized to treat periodontal defects in clinical practice. However, the repair efficacy of the currently available GBR membranes is often compromised by their limited alveolar bone regeneration potential, insufficient mechanical strength and inadequate space maintenance duration. In this paper, a novel hybrid bi-layer scaffold was fabricated using electrospun polycaprolactone/gelatine (PCL/Gel) nanofibre membranes combined with 3D printed PCL/Gel/nano-hydroxyapatite (n-HA) scaffolds. Their manipulation parameters and microstructures were investigated, and biological studies of in vitro and in vivo bone regeneration were carried out. The heparin-conjugated PCL/Gel fibrous membrane could significantly promote L929 fibroblast adhesion and proliferation. The PCL/Gel/n-HA (PGH) scaffold could promote attachment, growth and osteogenic differentiation of BMSCs. After 20 weeks, the defect sites in the hybrid bi-layer scaffold group showed a higher degree of new bone formation than that in the control group, indicating that this is a promising material combination for GBR.
When a polarized light beam is incident upon the surface of a magnetic material, the reflected light undergoes a polarization rotation
. This magneto-optical Kerr effect (MOKE) has been intensively ...studied in a variety of ferro- and ferrimagnetic materials because it provides a powerful probe for electronic and magnetic properties
as well as for various applications including magneto-optical recording
. Recently, there has been a surge of interest in antiferromagnets (AFMs) as prospective spintronic materials for high-density and ultrafast memory devices, owing to their vanishingly small stray field and orders of magnitude faster spin dynamics compared to their ferromagnetic counterparts
. In fact, the MOKE has proven useful for the study and application of the antiferromagnetic (AF) state. Although limited to insulators, certain types of AFMs are known to exhibit a large MOKE, as they are weak ferromagnets due to canting of the otherwise collinear spin structure
. Here we report the first observation of a large MOKE signal in an AF metal at room temperature. In particular, we find that despite a vanishingly small magnetization of
~0.002 µ
/Mn, the non-collinear AF metal Mn
Sn
exhibits a large zero-field MOKE with a polar Kerr rotation angle of 20 milli-degrees, comparable to ferromagnetic metals. Our first-principles calculations have clarified that ferroic ordering of magnetic octupoles in the non-collinear Néel state
may cause a large MOKE even in its fully compensated AF state without spin magnetization. This large MOKE further allows imaging of the magnetic octupole domains and their reversal induced by magnetic field. The observation of a large MOKE in an AF metal should open new avenues for the study of domain dynamics as well as spintronics using AFMs.
An ultimate goal of spintronics is to control magnetism via electrical means. One promising way is to utilize a current-induced spin-orbit torque (SOT) originating from the strong spin-orbit coupling ...in heavy metals and their interfaces to switch a single perpendicularly magnetized ferromagnetic layer at room temperature. However, experimental realization of SOT switching to date requires an additional in-plane magnetic field, or other more complex measures, thus severely limiting its prospects. Here we present a novel structure consisting of two heavy metals that delivers competing spin currents of opposite spin indices. Instead of just canceling the pure spin current and the associated SOTs as one expects and corroborated by the widely accepted SOTs, such devices manifest the ability to switch the perpendicular CoFeB magnetization solely with an in-plane current without any magnetic field. Magnetic domain imaging reveals selective asymmetrical domain wall motion under a current. Our discovery not only paves the way for the application of SOT in nonvolatile technologies, but also poses questions on the underlying mechanism of the commonly believed SOT-induced switching phenomenon.
Abstract
A supercurrent flowing in a superconductor meets no resistance. Yet an electric field may still be established within the superconductor in the presence of dissipative processes, such as ...vortex motion. Here we report the observation of a transverse voltage drop in superconducting
β-
Bi
2
Pd thin films. Unlike the Hall effect in general or in other superconductors, the sign of the observed transverse voltage does not depend on the external magnetic field. Instead, it is dictated by the broken inversion symmetry on the film interfaces. This anomalous transverse voltage, or transverse resistance, is indicative of a chirality that likely resonates with the topological surface states reported in
β-
Bi
2
Pd.
Control of magnetization direction is essential for the wide application of ferromagnets; it defines the signal size of memory and sensor. However, the magnetization itself causes a dilemma. While ...its size matters to obtain strong responses upon its reversal, the large magnetization concomitantly suppresses the range of its directional control because of the demagnetizing field. On the other hand, realization of the desired magnetic anisotropy requires careful engineering of crystalline and interfacial effects to overcome the demagnetization barrier. Thus, it would be ideal if one could find alternative magnets that carry no magnetization but strong responses. The discovery of a topological metallic state in the antiferromagnet Mn3Sn is significant; they host a large Berry curvature in momentum space, enabling the observation of disproportionately large transverse responses such as anomalous Hall and Nernst effects, the key functionalities for replacing ferromagnets in the magnetic devices. Here, the experimental realization of omnidirectional control of the large responses in an antiferromagnet is reported. In particular, it is demonstrated that the absence of shape anisotropy enables the omnidirectional control, and lifts the shape constraint in designing the magnetic devices. This work lays the technological foundation for developing simple‐structured high‐performance devices including multi‐level memory and heat flux sensor.
As the topological antiferromagnet Mn3Sn only carries a negligibly small demagnetizing field unlike ferromagnetic materials, the Berry curvature induces large electrical outputs such as anomalous Hall and Nernst effects can be controlled without considering the shape anisotropy, which is a newly demonstrated promising magnetic property for developing simple‐structured high‐performance devices including multi‐level memory and heat‐flux sensor.
We report a pair of dichorionic diamniotic (DCDA) twin pregnancy affected by Noonan syndrome (NS) with a novel mutation of LZTR1 determined by genetic analysis.
A pregnant woman with monozygotic ...twins (DCDA) at 12 + 2 weeks gestation was referred to our center. This was her second pregnancy following a previous delivery of a healthy infant. Nuchal translucency of two fetuses was 11.2 mm (CRL 62.0 mm) and 6.9 mm (CRL 62.1 mm) respectively. Ultrasound examination indicated cystic hygroma and hypoplastic ear. The couple was not consanguineous, and both had normal phenotype. Familial hereditary disease was also excluded. Under ultrasound guidance, 30 mg of chorionic villi was obtained for karyotyping, quantitative fluorescent polymerase chain reaction (QF-PCR), chromosomal microarray analysis(CMA), and Trio-whole-exome sequencing(WES) examination. We used the "target region capture and sequencing" for WES, and the BWA (Burrows Wheeler Aligner) Multi-Vision software package for the data analysis. The results of all these tests were normal except WES detected a c.427 A > G mutation in the exonic region of the LZTR1 gene and a p. Asn143Asp novel heterozygous mutation associated with NS in this pair of twins. In addition, WES suggested that the mutation in the twin fetuses originated from the mother. When the mother got the genetic test report, she came to our fetal medicine department for genetic counseling and she declined the appointment with a clinical geneticist. The couple opted to terminate the pregnancy. Because the patient did not choose to terminate the pregnancy at our hospital, we were unable to take further examination. With the help of colleagues in another hospital, photos of the fetuses were taken. Compared with the prenatal ultrasound results, the appearance of the "cystic hygroma" and "hypoplastic ear" was consistent with the ultrasound. The couple were depressed after knowing this pathogenic result and although we advised the mother to take further investigation, they refused.
The mutant locus might be incompletely dominant, which led to an abnormal fetal phenotype such as cystic hygroma and hypoplastic ear.
To investigate the efficacy and safety of dexmedetomidine (DEX) for postoperative patient controlled intravenous analgesia (PCIA).
Two investigators independently searched Pubmed, Embase, Scopus, ...Cochrane Library and CBM for randomized controlled trials of DEX for PCIA.
Thirty-seven studies with a total of 5,409 patients were included in this meta-analysis. Compared with analgesics alone, DEX for PCIA reduced pain score at 24 h mean difference (MD) = -0.70; 95% confidence interval (CI): -0.85, -0.54;
< 0.00001,
= 90% and 48 h postoperatively (MD = -0.43; 95% CI: -0.52, -0.34;
< 0.00001,
= 96%). Moreover, DEX reduced analgesics consumption during the first 24 h standardized mean difference (SMD) = -0.25; 95% CI: -0.34, -0.16;
< 0.00001,
= 91% and the number of resuscitation analgesics administered odds ratio (OR) = 0.54; 95% CI: 0.44, 0.66;
< 0.00001,
= 72%. Furthermore, DEX improved patient satisfaction (OR = 3.55; 95% CI: 2.36, 5.35;
< 0.00001,
= 60%), and reduced incidence of side effects, such as postoperative nausea and vomiting (PONV) (OR = 0.47; 95% CI: 0.39, 0.57;
< 0.00001,
= 59%) and pruritus after surgery (OR = 0.45; 95% CI: 0.30, 0.68;
= 0.0001,
= 0%). Besides, DEX attenuates inflammatory cytokine levels, such as IL-6 (MD = -5.73; 95% CI: -8.34, -3.12;
< 0.00001,
= 91%) and TNF-α (MD = -0.63; 95% CI: -0.76, -0.50;
< 0.00001,
= 89%). Finally, DEX increased the risk of bradycardia (OR = 1.66; 95% CI: 1.12, 2.45;
= 0.01,
= 15%), but the complication of hypotension did not differ between the two groups (OR = 1.30; 95% CI: 0.84, 2.04;
= 0.25,
= 0%).
DEX is used for postoperative PCIA analgesia, which can significantly improve the analgesic effect, effectively control postoperative inflammatory response, reduce the dosage and adverse reactions of analgesics, and improve postoperative patient satisfaction. Of course, the impact of the immunosuppressive effect of DEX on the prognosis of patients needs further study.
CRD42022340933, https://www.crd.york.ac.uk/prospero/.
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