Critical properties of S=1/2 Heisenberg ladders in magnetic fields

The critical properties of the $S=1/2$ Heisenberg two-leg ladders are investigated in a magnetic field. Combining the exact diagonalization method and the finite-size-scaling analysis based on conformal field theory, we calculate the critical exponents of spin correlation functions numerically. For a strong interchain coupling, magnetization dependence of the critical exponents shows characteristic behavior depending on the sign of the interchain coupling. We also calculate the critical exponents for the $S=1/2$ Heisenberg two-leg ladder with a diagonal interaction, which is thought as a model Hamiltonian of the organic spin ladder compound ${Cu}_2({1,4-diazacycloheptane})_2{Cl}_4$. Numerical results are compared with experimental results of temperature dependence of the NMR relaxation rate $1/T_1$.Comment: REVTeX, 10 pages, 8 figures, accepted for Phys. Rev.

CNVs in Three Psychiatric Disorders

BACKGROUND: We aimed to determine the similarities and differences in the roles of genic and regulatory copy number variations (CNVs) in bipolar disorder (BD), schizophrenia (SCZ), and autism spectrum disorder (ASD). METHODS: Based on high-resolution CNV data from 8708 Japanese samples, we performed to our knowledge the largest cross-disorder analysis of genic and regulatory CNVs in BD, SCZ, and ASD. RESULTS: In genic CNVs, we found an increased burden of smaller (500 kb) exonic CNVs in SCZ/ASD. Pathogenic CNVs linked to neurodevelopmental disorders were significantly associated with the risk for each disorder, but BD and SCZ/ASD differed in terms of the effect size (smaller in BD) and subtype distribution of CNVs linked to neurodevelopmental disorders. We identified 3 synaptic genes (DLG2, PCDH15, and ASTN2) as risk factors for BD. Whereas gene set analysis showed that BD-associated pathways were restricted to chromatin biology, SCZ and ASD involved more extensive and similar pathways. Nevertheless, a correlation analysis of gene set results indicated weak but significant pathway similarities between BD and SCZ or ASD (r = 0.25–0.31). In SCZ and ASD, but not BD, CNVs were significantly enriched in enhancers and promoters in brain tissue. CONCLUSIONS: BD and SCZ/ASD differ in terms of CNV burden, characteristics of CNVs linked to neurodevelopmental disorders, and regulatory CNVs. On the other hand, they have shared molecular mechanisms, including chromatin biology. The BD risk genes identified here could provide insight into the pathogenesis of BD

Generation of THz Radiation by Excitation of InAs with a Free Electron Laser

Terahertz (THz) radiation is generated by exciting an un-doped InAs wafer with a femtosecond free-electron laser (FEL) at the Thomas Jefferson National Accelerator Facility. A microwatt level of THz radiation is detected from the unbiased InAs emitter when it is excited with the femtosecond FEL pulses operated at a wavelength of 1.06 {mu}-m and 10 W average power

Rationale, Design, and Baseline Characteristics of the CURRENT AS Registry-2

BACKGROUND: There is scarce data evaluating the current practice pattern and clinical outcomes for patients with severe aortic stenosis (AS), including both those who underwent surgical aortic valve replacement (SAVR) or transcatheter aortic valve implantation (TAVI) and those who were managed conservatively in the TAVI era.Methods and Results: The Contemporary outcomes after sURgery and medical tREatmeNT in patients with severe Aortic Stenosis (CURRENT AS) Registry-2 is a prospective, physician-initiated, multicenter registry enrolling consecutive patients who were diagnosed with severe AS between April 2018 and December 2020 among 21 centers in Japan. The rationale for the prospective enrollment was to standardize the assessment of symptomatic status, echocardiographic evaluation, and other recommended diagnostic examinations such as computed tomography and measurement of B-type natriuretic peptide. Moreover, the schedule of clinical and echocardiographic follow up was prospectively defined and strongly recommended for patients who were managed conservatively. The entire study population consisted of 3, 394 patients (mean age: 81.6 years and women: 60%). Etiology of AS was degenerative in 90% of patients. AS-related symptoms were present in 60% of patients; these were most often heart failure symptoms. The prevalence of high- and low-gradient AS was 58% and 42%, respectively, with classical and paradoxical low-flow low-gradient AS in 4.5% and 6.7%, respectively. CONCLUSIONS: The CURRENT AS Registry-2 might be large and meticulous enough to determine the appropriate timing of intervention for patients with severe AS in contemporary clinical practice