Scaling of the anomalous Hall effect in SrRuO3_{3}

We measure the anomalous Hall effect (AHE) resistivity $\rho_{xy}$ in thin films of the itinerant ferromagnet SrRuO$_{3}$. At low temperatures, the AHE coefficient $R_{s}$ varies with $\rho_{xx}^2$, and at higher temperatures, $R_{s}$ reaches a peak and then changes sign just below $T_{c}$. We find that for all films studied $R_{s}$ scales with resistivity in the entire ferromagnetic phase. We attribute the observed behavior to the contribution of the extrinsic side jumps mechanism and the intrinsic Karplus-Luttinger (Berry phase) mechanism including the effect of finite scattering rates.Comment: arXiv admin note: substantial text overlap with arXiv:1105.305

Imaging and tuning polarity at SrTiO3 domain walls.

Electrostatic fields tune the ground state of interfaces between complex oxide materials. Electronic properties, such as conductivity and superconductivity, can be tuned and then used to create and control circuit elements and gate-defined devices. Here we show that naturally occurring twin boundaries, with properties that are different from their surrounding bulk, can tune the LaAlO3/SrTiO3 interface 2DEG at the nanoscale. In particular, SrTiO3 domain boundaries have the unusual distinction of remaining highly mobile down to low temperatures, and were recently suggested to be polar. Here we apply localized pressure to an individual SrTiO3 twin boundary and detect a change in LaAlO3/SrTiO3 interface current distribution. Our data directly confirm the existence of polarity at the twin boundaries, and demonstrate that they can serve as effective tunable gates. As the location of SrTiO3 domain walls can be controlled using external field stimuli, our findings suggest a novel approach to manipulate SrTiO3-based devices on the nanoscale

Anisotropic transport at the LaAlO₃ /SrTiO₃ interface explained by microscopic imaging of channel-flow over SrTiO₃ domains

Oxide interfaces, including the LaAlO3/SrTiO3 interface, have been a subject of intense interest for over a decade due to their rich physics and potential as low dimensional nanoelectronic systems. The field has reached the stage where efforts are invested in developing devices. It is critical now to understand the functionalities and limitations of such devices. Recent scanning probe measurements of the LaAlO3/SrTiO3 interface have revealed locally enhanced current flow and accumulation of charge along channels related to SrTiO3 structural domains. These observations raised a key question regarding the role these modulations play in the macroscopic properties of devices. Here we show that the microscopic picture, mapped by scanning superconducting quantum interference device, accounts for a substantial part of the macroscopically measured transport anisotropy. We compared local flux data with transport values, measured simultaneously, over various SrTiO3 domain configurations. We show a clear relation between maps of local current density over specific domain configurations and the measured anisotropy for the same device. The domains divert the direction of current flow, resulting in a direction dependent resistance. We also show that the modulation can be significant and that in some cases up to 95% of the current is modulated over the channels. The orientation and distribution of the SrTiO3 structural domains change between different cooldowns of the same device or when electric fields are applied, affecting the device behavior. Our results, highlight the importance of substrate physics, and in particular, the role of structural domains, in controlling electronic properties of LaAlO3/SrTiO3 devices. Further, these results point to new research directions, exploiting the STO domains ability to divert or even carry current.Comment: in ACS Appl. Mater. Interfaces, Article ASAP, 201

Recurrent De Novo Dominant Mutations in SLC25A4 Cause Severe Early-Onset Mitochondrial Disease and Loss of Mitochondrial DNA Copy Number

Mutations in SLC25A4 encoding the mitochondrial ADP/ATP carrier AAC1 are well-recognized causes of mitochondrial disease. Several heterozygous SLC25A4 mutations cause adult-onset autosomal-dominant progressive external ophthalmoplegia associated with multiple mitochondrial DNA deletions, whereas recessive SLC25A4 mutations cause childhood-onset mitochondrial myopathy and cardiomyopathy. Here, we describe the identification by whole-exome sequencing of seven probands harboring dominant, de novo SLC25A4 mutations. All affected individuals presented at birth, were ventilator dependent and, where tested, revealed severe combined mitochondrial respiratory chain deficiencies associated with a marked loss of mitochondrial DNA copy number in skeletal muscle. Strikingly, an identical c.239G>A (p.Arg80His) mutation was present in four of the seven subjects, and the other three case subjects harbored the same c.703C>G (p.Arg235Gly) mutation. Analysis of skeletal muscle revealed a marked decrease of AAC1 protein levels and loss of respiratory chain complexes containing mitochondrial DNA-encoded subunits. We show that both recombinant AAC1 mutant proteins are severely impaired in ADP/ATP transport, affecting most likely the substrate binding and mechanics of the carrier, respectively. This highly reduced capacity for transport probably affects mitochondrial DNA maintenance and in turn respiration, causing a severe energy crisis. The confirmation of the pathogenicity of these de novo SLC25A4 mutations highlights a third distinct clinical phenotype associated with mutation of this gene and demonstrates that early-onset mitochondrial disease can be caused by recurrent de novo mutations, which has significant implications for the application and analysis of whole-exome sequencing data in mitochondrial disease

The outcomes of blastocyst versus cleavage stage embryo biopsy for preimplantation genetic testing for monogenic diseases

In recent years, the application of blastocyst biopsy in PGT has been gradually rising, mainly due to the assumed detrimental effect of blastomere biopsy on the embryo implantation potential and the widespread application of PGT for aneuploidy. In contrast to complete chromosomal testing (CCT) cycles, for which trophectoderm (TE) biopsy has become the well-established preferred method due to higher diagnostic reliability, evidences for the purpose of PGT-M are still lacking. Therefore, we conducted a retrospective cohort study including 147 PGT-M cycles with at least eight high quality embryos (HQE) suitable for biopsy at the cleavage stage, 83 and 64 in the blastocyst and cleavage stage biopsy groups, respectively. Our results showed no significant differences in implantation rates (32.8% vs. 33.6%, p=0.9), clinical pregnancy rates (CPR) per transfer (30.3% vs. 33.0%, p=0.7), as well as cumulative CPR (46.2% vs. 38.3%, p=0.4). This study is the largest so far, demonstrating that blastocyst biopsy has higher cost-effectiveness over cleavage stage biopsy in good prognosis patient population. Moreover, our data is the first to show that blastomere biopsy does not compromise the reproductive outcomes, which merits further investigation regarding its cost-effectiveness in the poor prognosis patient population, having a small number of embryos for biopsy and transfer. Further large prospective randomized studies are needed to elucidate the preferred biopsy strategy in specific patient populations in order to provide a tailored treatment that will ensure the best prognosis for each patient

IL-12 RB1 Genetic Variants Contribute to Human Susceptibility to Severe Acute Respiratory Syndrome Infection among Chinese

BACKGROUND: Cytokines play important roles in antiviral action. We examined whether polymorphisms of interleukin (IL)-12 receptor B1 (IL-12RB1) affect the susceptibility to and outcome of severe acute respiratory syndrome (SARS). METHODS: A case-control study was carried out in Chinese SARS patients and healthy controls. The genotypes of 4SNPs on IL-12 RB1 gene, +705A/G,+1158T/C, +1196G/C and +1664 C/T, were determined by PCR-RFLP. Haplotypes were estimated from the genotype data using the expectation-maximisation algorithm. RESULTS: Comparison between patients and close contacts showed that individuals with the +1664 C/T (CT and TT) genotype had a 2.09-fold (95% confidence interval [CI], 1.90-7.16) and 2.34-fold (95% CI, 1.79-13.37) increased risk of developing SARS, respectively. For any of the other three polymorphisms, however, no significant difference can be detected in allele or genotype frequencies between patients and controls. Additionally, estimation of the frequencies of multiple-locus haplotypes revealed potential risk haplotypes (GCCT) for SARS infection. CONCLUSIONS: Our data indicate that genetic variants of IL12RB1confer genetic susceptibility to SARS infection, but not necessary associated with the progression of the disease in Chinese population

Late vs. early intrauterine blood transfusion in fetal anemia: impact on maternal and neonatal outcomes

IntroductionOptimal timing of final intrauterine transfusion (IUT) and delivery in fetal anemia remains controversial, balancing procedural risks against prematurity complications. Our objective is to evaluate the safety and effectiveness of extending IUT beyond 34 weeks gestation in appropriately selected cases.MethodsRetrospective cohort study comparing pregnancies receiving late IUT (≥34 weeks, n = 21) versus early IUT (<34 weeks, n = 31) at a single tertiary center (2005–2024). We analyzed 200 IUT procedures in 52 pregnancies. Late IUT was offered to stable cases without hydrops or previous significant complications. Primary outcomes included procedure-related complications and prematurity-related outcomes.ResultsLate IUT showed no increase in procedure-related complications (0% vs. 20.0%, p = 0.069). Mean gestational age at delivery was higher in the late IUT group (37.2 ± 1.06 vs. 34.1 ± 3.6 weeks, p < 0.001), with reduced emergency cesarean rates (19% vs. 45%), higher birth weights (2,960 ± 399 g vs. 2,350 ± 620 g, p < 0.001), and lower NICU admission rates (29% vs. 71%, p < 0.05). These benefits persisted after adjusting for maternal characteristics. Subgroup analysis of hemolytic disease cases showed similar improvements with additional benefits in neonatal outcomes.DiscussionExtending IUT beyond 34 weeks in selected cases is safe and associated with improved obstetric and neonatal outcomes, supporting reconsideration of traditional gestational age limits for IUT

Engineering of Iron-Based Magnetic Activated Carbon Fabrics for Environmental Remediation

Magnetic Fe3O4, Fe and Fe/Pd nanoparticles embedded within the pores of activated carbon fabrics (ACF) were prepared by impregnation of the ACF in iron acetylacetanoate (Fe(acac)3) ethanol solution, followed by thermal decomposition of the embedded iron precursor at 200, 400 and 600 °C in an inert atmosphere. The effect of the annealing temperature on the chemical composition, shape, crystallinity, surface area, pore volume, and magnetic properties of the various functionalized ACF was elucidated. The Fe nanoparticles within the ACF were also doped with tinier Pd nanoparticles, by impregnation of the Fe/ACF in palladium acetate ethanol solution. The potential use of the functionalized ACF for removal of a model azo-dye, orange II, was demonstrated. This study illustrated the enhanced removal of the dye from an aqueous solution according to the following order: Fe/Pd/ACF > Fe/ACF > ACF. In addition, the enhanced activity of Fe3O4/ACF in the presence of increasing concentrations of H2O2 (Fenton catalysts) was also illustrated