A magnetic heterostructure of topological insulators as a candidate for an axion insulator

The axion insulator which may exhibit an exotic quantized magnetoelectric effect is one of the most interesting quantum phases predicted for the three-dimensional topological insulator (TI). The axion insulator state is expected to show up in magnetically doped TIs with magnetizations pointing inwards and outwards from the respective surfaces. Towards the realization of the axion insulator, we here engineered a TI heterostructure in which magnetic ions (Cr) are modulation-doped only in the vicinity of the top and bottom surfaces of the TI ((Bi,Sb)₂Te₃) film. A separation layer between the two magnetic layers weakens interlayer coupling between them, enabling the magnetization reversal of individual layers. We demonstrate the realization of the axion insulator by observing a zero Hall plateau (ZHP) (where both the Hall and longitudinal conductivity become zero) in the electric transport properties, excluding the other possible origins for the ZHP. The manifestation of the axion insulator can lead to a new stage of research on novel magnetoelectric responses in topological matter.

Dynamic Viscoelasticity of Soft Liners and Masticatory Function

Soft denture liners are used for edentulous patients to cushion functional forces. We hypothesized that the application of soft liners having viscoelastic properties would lead to the most marked improvement in masticatory function. The shear storage modulus ( G′), shear loss modulus ( G′′), and loss tangent (tan δ) were determined for 6 materials by means of a dynamic viscoelastometer. Masticatory function of ten subjects was evaluated by measurements of maximum bite forces and chewing times and frequencies for 2 food samples, and by the use of visual analogue scales. The acrylic materials exhibited viscoelastic behavior, while the silicones exhibited elastic behavior. The improvement in masticatory function compared with hard resin was found to be in the order: acrylic permanent materials > silicone > acrylic temporary materials. The results suggest that the use of materials with higher tan δ and G′ provides the most optimum masticatory function for patients requiring the provision of soft liners on their dentures.

Development of a simple and quick immunochromatography method for detection of anti-HPV-16/-18 antibodies

Immunochromatography (IC) is widely used to detect target molecules in biological fluids. Since this method can be performed without a special technique or device, IC is a convenient way to assess the existence of antibodies or pathogens such as viruses and bacteria, simply and quickly. In this study, we established an IC method to detect serum antibodies against oncogenic human papillomavirus (HPV)-16 and HPV-18 L1 proteins using recombinant L1 proteins produced by silkworms as antigens. Infection of oncogenic HPVs is a major risk factor of cervical cancer, which is one of the most common cancers in women worldwide. We first measured blood sera of two groups by magnetic beads enzyme-linked immunosorbent assay (MB-ELISA). For the first group, sera were collected prospectively from young women who planned to receive HPV vaccination. The second group consisted of children under 20 years of age, non-vaccinated healthy women, vaccinated healthy women, dysplasia, cervical intraepithelial neoplasia III, and cervical cancer patients. We confirmed that standard vaccination doses significantly increased serum HPV antibody concentrations, and the level was sustained at least more than 30 months after vaccination. In contrast, an increase in antibody concentration was not observed in patients with precancerous cervical changes and cervical cancer. We next measured the samples in both groups using the IC method we originally developed, and found that the measurement values of IC highly correlated with those of MB-ELISA. The simple and quick IC method would be a useful tool for rapid monitoring of L1 specific antibody levels in a non-laboratory environment. With less than one drop of serum, our IC can easily detect serum HPV-16/-18 antibodies within 15 minutes, without the need for electronic devices or techniques.

Observation of Zeeman effect in topological surface state with distinct material dependence

Manipulating the spins of the topological surface states represents an essential step towards exploring the exotic quantum states emerging from the time reversal symmetry breaking via magnetic doping or external magnetic fields. The latter case relies on the Zeeman effect and thereby we need to estimate the g-factor of the topological surface state precisely. Here, we report the direct observations of the Zeeman effect at the surfaces of Bi₂Se₃ and Sb₂Te₂Se by spectroscopic-imaging scanning tunnelling microscopy. The Zeeman shift of the zero mode Landau level is identified unambiguously by appropriately excluding the extrinsic effects arising from the nonlinearity in the band dispersion of the topological surface state and the spatially varying potential. Surprisingly, the g-factors of the topological surface states in Bi₂Se₃ and Sb₂Te₂Se are very different (+18 and −6, respectively). Such remarkable material dependence opens up a new route to control the spins of the topological surface states.

The knowledge of how electrons behave under magnetic field provides inherent information for exotic quantum states. Here, Fu et al. find different g-factors of topological surface states in Bi₂Se₃ and Sb₂Te₂Se, which suggests possible control of such states in spin-related applications.

P450 oxidoreductase deficiency with maternal virilization during pregnancy

PURPOSE

The authors report on a rare case of maternal virilization during pregnancy caused by autosomal recessive P450 oxidore- ductase (POR) deficiency.

MATERIALS AND METHODS

A 24-year-old primigravida developed a deepening voice and hirsutism in the second trimester. Prenatal ultrasonography failed to detect any fetal abnormality and fetal growth was normal. POR deficiency was suspected, but the mother declined fetal genetic testing. A female neonate was delivered by cesarean section at 41 weeks' gestation.

RESULTS

The neonate had skeletal abnormalities. Mutational analysis of the POR gene demonstrated homozygosity for c.1370 G>A and p.R457H in the patient and heterozygosity in her parents. POR deficiency was confirmed in the neonate.

CONCLUSION

POR deficiency should be suspected in cases of maternal virilization. Maternal urinary estriol, fetal magnetic resonance imaging, and parental genetic testing should be performed. Parental consent for fetal genetic testing should be sought to ensure prompt diagnosis and early treatment.

Identification of SPAG9 as a novel JAK2 fusion partner gene in pediatric acute lymphoblastic leukemia with t(9;17)(p24;q21)

We have identified a novel SPAG9-JAK2 fusion in a B-cell precursor acute lymphoblastic leukemia (ALL) with t(9;17)(p24;q21) and a poor outcome, using paired-end transcriptome sequencing. Homozygous and hemizygous deletions of CDKN2A/2B, and hemizygous deletions of PAX5, BTG1, CDK6, ADARB2, and IKZF1 were also identified by multiple ligation-dependent probe amplification and single nucleotide polymorphism array analyses. Having both a tyrosine kinase-activating rearrangement and genomic lesions affecting lymphoid transcription factors suggested that the leukemia was of the Philadelphia chromosome (Ph)/BCR-ABL1-like ALL subtype and that JAK2 inhibitors might be able to overcome this aggressive ALL with SPAG9-JAK2.

[Incidental detection of congenital Robertsonian translocation at diagnosis of Philadelphia chromosome-positive acute lymphocytic leukemia]

A man in his early forties who had undergone 3 years of unsuccessful treatment for infertility due to oligospermia and asthenospermia developed fever and bone pain in December 20XX. He was subsequently diagnosed with acute lymphocytic leukemia. Conventional cytogenetic analysis revealed Robertsonian translocation (RT) with der(13;14)(q10;q10) in addition to the Philadelphia (Ph) chromosome. Dasatinib and prednisolone induced complete remission (CR) with disappearance of the Ph chromosome. However, RT persisted despite achieving CR. We speculate that RT is possibly congenital in our present case and might also have been responsible for the aforementioned infertility. Hematologists should be aware of the possibility that congenital chromosomal disorders might be found incidentally through diagnostic chromosome analysis for leukemia.

Alteration of sialoglycoprotein in the glomerular basement membrane of diabetic glomerulosclerosis

The alteration of glycoprotein in the glomerular basement membrane in diabetic glomerulosclerosis was studied with preparative polyacrylamide gel electrophoresis by Uniphor column. Normal glomerular basement membrane was fractionated into 32 glycoprotein fractions. Decrease in sialic acid residue of sialoprotein was the characteristic finding observed in diabetic glomerulosclerosis. A hypothesis which explains the alteration of sialoglycoprotein is proposed.

Conversion to mycophenolate mofetil from azathioprine shows significant positive effect on graft function in long-term past-kidney transplantation stable-state patients

OBJECTIVES

A number of reports have shown that the efficacy of mycophenolate mofetil (MMF) is superior to that of azathioprine (AZP) for long-term kidney allograft survival. We conducted a retrospective single-center study to evaluate renal function more than 2 years after conversion from AZP to MMF in kidney transplant recipients several years after transplantation.

METHODS

AZP was converted to MMF in 51 recipients at 17.0 ± 0.8 years after kidney transplantation who were followed up for more than 2 years after conversion. Estimated glomerular filtration rate (eGFR) was determined using the Formula of the Japanese Society of Nephrology.

RESULTS

The eGFR was significantly greater at 1 year before conversion (41.72 ± 1.91 mL/min/1.73 m(2)) as compared with the day of conversion (39.04 ± 1.82 mL/min/1.73 m(2); P < .05). After conversion, eGFR plateaued to 39.30 ± 2.01 mL/min/1.73 m(2) at 1 year and 38.24 ± 2.42 mL/min/1.73 m(2) at 2 years after conversion. The average eGFR slopes were -2.96 ± 0.36 mL/min/1.73 m(2) per year for AZP and 1.22 ± 0.10 mL/min/1.73 m(2) per year for MMF (P < .0001). Cyclosporine (CSA) was reduced from 176 ± 9.3 to 165 ± 9.8 mg/d (P = .0394) after the switch, whereas the CSA trough level was increased from 77.3 ± 6.6 to 118 ± 9.8 ng/mL (P = .0017). Furthermore, the daily dose of tacrolimus (TAC) was decreased from 3.5 ± 0.3 to 3.1 ± 0.3 mg/d (P = .0083).

CONCLUSIONS

Our findings demonstrated the safety of conversion from AZP to MMF even in the patients who underwent renal transplantation several years prior. In addition, these short-term results indicated the improvement in allograft function following conversion.

Aerobic fitness and skewness of frequency distribution of continuously measured heart rate in adults with brain injury

BACKGROUND

Determinant factors of aerobic fitness have not been clearly demonstrated in individuals with brain injury.

AIM

To investigate the relationship between aerobic fitness and gender, age, intensity and total duration of aerobic physical activity, and skewness of the frequency distribution of 6-h continuous heart rate values in a larger sample of adults with brain injury.

DESIGN

Cross-sectional and correlative study.

SETTING

Research laboratory setting.

POPULATION

Thirteen adult women and 20 adult men with cerebral palsy or stroke participated in this study.

METHOD

VO2max was estimated using the multistage submaximal cycle ergometer test. Heart rate was recorded continuously for 6 h on a weekday. Relationships between predicted VO2max and gender, age, intensity and total duration of aerobic physical activity, skewness of frequency distribution, and average heart rate over 6 h were determined.

RESULTS

Significant differences were seen in predicted VO2max between genders (P < 0.05). Predicted VO2max correlated significantly only with the skewness of the frequency distribution of values for continuous heart rate (r = -0.53, P < 0.01).

CONCLUSION AND CLINICAL REHABILITATION IMPACT

The results suggest that brief and frequent physical activity may also improve aerobic fitness in adults with brain injury.