Perpendicular magnetic anisotropy and magnetization dynamics in oxidized CoFeAl films

Half-metallic Co-based full-Heusler alloys with perpendicular magnetic anisotropy (PMA), such as Co₂FeAl in contact with MgO, are receiving increased attention recently due to its full spin polarization for high density memory applications. However, the PMA induced by MgO interface can only be realized for very thin magnetic layers (usually below 1.3 nm), which would have strong adverse effects on the material properties of spin polarization, Gilbert damping parameter, and magnetic stability. In order to solve this issue, we fabricated oxidized Co₅₀Fe₂₅Al₂₅ (CFAO) films with proper thicknesses without employing the MgO layer. The samples show controllable PMA by tuning the oxygen pressure (P_O2) and CFAO thickness (t_CFAO), large perpendicular anisotropy field of ~8.0 kOe can be achieved at P_O2 = 12% for the sample of t_CFAO= 2.1 nm or at P_O2= 7% for t_CFAO= 2.8 nm. The loss of PMA at thick t_CFAO or high P_O2 results mainly from the formation of large amount of CoFe oxides, which are superparamagnetic at room temperature but become hard magnetic at low temperatures. The magnetic CFAO films, with strong PMA in a relatively wide thickness range and small intrinsic damping parameter below 0.028, would find great applications in developing advanced spintronic devices.

Folic acid supplementation and dietary folate intake, and risk of preeclampsia

BACKGROUND/OBJECTIVES

Folic acid supplementation has been suggested to reduce the risk of preeclampsia. However, results from few epidemiologic studies have been inconclusive. We investigated the hypothesis that folic acid supplementation and dietary folate intake before conception and during pregnancy reduce the risk of preeclampsia.

SUBJECTS/METHODS

A birth cohort study was conducted in 2010-2012 at the Gansu Provincial Maternity & Child Care Hospital in Lanzhou, China. A total of 10,041 pregnant women without chronic hypertension or gestational hypertension were enrolled.

RESULTS

Compared with nonusers, folic acid supplement users had a reduced risk of preeclampsia (OR=0.61, 95% CI: 0.43-0.87). A significant dose-response of duration of use was observed among women who used folic acid supplemention during pregnancy only (P-trend=0.007). The reduced risk associated with folic acid supplement was similar for mild or severe preeclampsia and for early- or late-onset preeclampsia, although the statistical significant associations were only observed for mild (OR=0.50, 95% CI: 0.30-0.81) and late-onset (OR=0.60, 95% CI: 0.42-0.86) preeclampsia. The reduced risk associated with dietary folate intake during pregnancy was only seen for severe preeclampsia (OR=0.52, 95% CI: 0.31-0.87, for the highest quartile of dietary folate intake compared with the lowest).

CONCLUSIONS

Our study results suggest that folic acid supplementation and higher dietary folate intake during pregnancy reduce the risk of preeclampsia. Future studies are needed to confirm the associations.

Transposon variation by order during allopolyploidisation between Brassica oleracea and Brassica rapa

Although many studies have shown that transposable element (TE) activation is induced by hybridisation and polyploidisation in plants, much less is known on how different types of TE respond to hybridisation, and the impact of TE-associated sequences on gene function. We investigated the frequency and regularity of putative transposon activation for different types of TE, and determined the impact of TE-associated sequence variation on the genome during allopolyploidisation. We designed different types of TE primers and adopted the Inter-Retrotransposon Amplified Polymorphism (IRAP) method to detect variation in TE-associated sequences during the process of allopolyploidisation between Brassica rapa (AA) and Brassica oleracea (CC), and in successive generations of self-pollinated progeny. In addition, fragments with TE insertions were used to perform Blast2GO analysis to characterise the putative functions of the fragments with TE insertions. Ninety-two primers amplifying 548 loci were used to detect variation in sequences associated with four different orders of TE sequences. TEs could be classed in ascending frequency into LTR-REs, TIRs, LINEs, SINEs and unknown TEs. The frequency of novel variation (putative activation) detected for the four orders of TEs was highest from the F1 to F2 generations, and lowest from the F2 to F3 generations. Functional annotation of sequences with TE insertions showed that genes with TE insertions were mainly involved in metabolic processes and binding, and preferentially functioned in organelles. TE variation in our study severely disturbed the genetic compositions of the different generations, resulting in inconsistencies in genetic clustering. Different types of TE showed different patterns of variation during the process of allopolyploidisation.

Association between IRF5 polymorphisms and autoimmune diseases: a meta-analysis

In this study, we investigated the association between 5 interferon regulatory factor-5 (IRF5) single nucleotide polymorphisms (SNPs) and autoimmune diseases using the Medline citation index. Twenty-eight studies with 74 comparisons, including 16 rheumatoid arthritis (RA), 43 systemic lupus erythematous (SLE), 2 juvenile idiopathic arthritis (JIA), 6 multiple sclerosis (MS), and 5 systemic sclerosis (SSc) studies, were examined in the meta-analysis. The SNP rs2004640 was significantly associated with SLE, MS, and SSc, but not with JIA [odds ratio (OR)=1.06, 95% confidence interval (CI)=0.90-1.24, P=0.48] or RA (OR=1.03, 95%CI=0.95-1.11, P=0.44). A significant association was observed between rs2280714 and SLE, MS, and SSc, but not RA (OR=1.01, 95%CI=0.94-1.09, P=0.80). Rs10954213 was associated with the pathogenesis of SLE, RA, MS, and SSc. rs2070197 and the exon 6 insertion were significantly associated with SLE. Haplotypes containing rs2004640T and rs2280714T were significantly associated with an increased risk of SLE, but not with RA. This meta-analysis certified that IRF5 polymorphisms confer susceptibility to SLE, MS, and SSc. To further confirm the correlations between polymorphisms of IRF5 and autoimmune disease susceptibility, studies involving a larger number of patients worldwide are necessary.

Mussel-inspired protein-mediated surface functionalization of electrospun nanofibers for pH-responsive drug delivery

pH-responsive drug delivery systems could mediate drug releasing rate by changing the pH values at specific times as per the pathophysiological need of the disease. This paper demonstrates that a mussel-inspired protein polydopamine coating can tune the loading and releasing rate of charged molecules from electrospun poly(ε-caprolactone) (PCL) nanofibers in solutions with different pH values. In vitro release profiles show that the positive charged molecules release significantly faster in acidic than those in neutral and basic environments within the same incubation time. The results of fluorescein diacetate staining and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays show the viability of cancer cells after treatment with doxorubicin-released media at different pH values qualitatively and quantitatively, indicating that the media containing doxorubicin that were released in solutions at low pH values could kill a significantly higher number of cells than those released in solutions at high pH values. Together, the pH-responsive drug delivery systems based on polydopamine-coated PCL nanofibers could have potential application in the oral delivery of anticancer drugs for treating gastric cancer and in vaginal delivery of anti-viral drugs or anti-inflammatory drugs, which could raise their efficacy, deliver them to the specific target and minimize their toxic side effects.

A study comparing three different laser-assisted hatching techniques

PURPOSE OF INVESTIGATION

Laser-assisted hatching (LAH) is recognized as a useful technology to improve clinical pregnancy rates and implantation rates. This study reports the differences between a new LAH method and two conventional LAH techniques.

MATERIALS AND METHODS

The authors studied 151 patients with repeated implantation failure, who were divided into three groups.

RESULTS

In group 1, the zona pellucida (ZP) was opened using LAH (n = 52). In group 2, laser-assisted thinning was performed to dissolve the outer layer of the ZP (n = 49). In group 3, laser-assisted thinning was performed to dissolve the inner layer of the ZP (n = 50). The clinical pregnancy rates and implantation rates among the groups were compared. The results demonstrate that there are significant differences in the clinical pregnancy rates and implantation rates between group 3 and the other two groups.

CONCLUSION

Performing laser-assisted thinning to dissolve the inner layer of the ZP markedly increases the pregnancy rates and implantation rates of patients with repeated implantation failure.