Time-, spin-, and angle-resolved photoemission spectroscopy with a 1-MHz 10.7-eV pulse laser

We describe a setup of time-, spin-, and angle-resolved photoemission spectroscopy (tr-SARPES) employing a 10.7 eV (λ = 115.6 nm) pulse laser at a 1 MHz repetition rate as a probe photon source. This equipment effectively combines the technologies of a high-power Yb:fiber laser, ultraviolet-driven harmonic generation in Xe gas, and a SARPES apparatus equipped with very-low-energy-electron-diffraction spin detectors. A high repetition rate (1 MHz) of the probe laser allows experiments with the photoemission space-charge effects significantly reduced, despite a high flux of 1013 photons/s on the sample. The relatively high photon energy (10.7 eV) also brings the capability of observing a wide momentum range that covers the entire Brillouin zone of many materials while ensuring high momentum resolution. The experimental setup overcomes the low efficiency of spin-resolved measurements, which gets even more severe for the pump-probed unoccupied states, and affords the opportunity to investigate ultrafast electron and spin dynamics of modern quantum materials with energy and time resolutions of 25 meV and 360 fs, respectively.

Clinical findings of triglyceride deposit cardiomyovasculopathy

Background

Triglyceride (TG) deposit cardiomyovasculopathy (TGCV) is a novel cardiovascular disorder and was recently encoded as an orphan disease in Europe (ORPHA code: 565612). Defective intracellular lipolysis results in TG accumulation in the myocardium and coronary arteries in TGCV. The myocardial washout rate (WR) of iodine-123-β-methyl-p-iodophenylpentadecanoic acid (BMIPP) is an essential indicator to evaluate myocardial lipolysis in vivo, and decreased WR (<10%) of BMIPP is one of the essential items of diagnostic criteria for TGCV.

Purpose

To clarify clinical findings of TGCV including comorbid conditions and laboratory findings.

Methods

We enrolled 234 patients who underwent BMIPP scintigraphy between September 2015 and July 2019. The distributions of TGCV in each comorbidity, cardiac functions and laboratory findings were investigated.

Results

In total, 104 patients were diagnosed with definitive TGCV. The BMIPP WR of TGCV patients was −1.37±10.6%. TGCV patients had various comorbid conditions, including coronary artery disease (75%), diabetes mellitus (56%), and heart failure (21%). Left ventricular ejection fraction (LVEF) of TGCV patients was significantly lower than that of non-TGCV patients (38.1±18.0% vs. 43.6±18.9%, p-value=0.026). Moreover, among those who did not take lipid-lowering drugs, there was no difference in the serum TG level between TGCV and non-TGCV patients (TGCV: n=44, 127±84.6 mg/dL, non-TGCV: n=66, 133±70.7 mg/dL, p-value=0.73).

Conclusions

TGCV patients showed multiple coexistence of coronary artery disease, diabetes mellitus, or heart failure with lower LVEF. Serum TG level was not significantly different between TGCV and non-TGCV patients. Serum TG did not affect the intracellular TG accumulation in TGCV patients directly, and this result was consistent with the pathophysiological hypothesis that the TG accumulation in the myocardial cytoplasm is due to intracellular lipase dysfunction.

Funding Acknowledgement

Type of funding sources: None.

SPECT-guided myocardial perfusion and metabolic fatty acid planar imaging to assess the severity of the pulmonary hypertension in patients with chronic thromboembolic pulmonary hypertension

Background

Patients with chronic thromboembolic pulmonary hypertension (CTEPH) represent right ventricular (RV) enlargement and hypertrophy, which consequently increase the RV myocardial perfusion. Although the main energy source of myocardium is fatty acid, it remains unknown whether myocardial fatty acid metabolism is altered in loaded RV. Herein, we report a novel approach to assess the RV perfusion and fatty acid metabolism, which is called SPECT-guided planar imaging.

Purpose

To evaluate if SPECT-guided myocardial perfusion and metabolic fatty acid planar imaging reflects the severity of the pulmonary hypertension in patients with chronic thromboembolic pulmonary hypertension.

Methods

The study groups included 30 patients with CTEPH and 20 healthy controls. In these patients with CTEPH, 15 patients underwent pulmonary thromboendarterectomy (PEA). Mean pulmonary artery pressure (mPAP) by right heart catheterization was obtained in all CTEPH patients. 201Thallium (201Tl) and iodine-123-beta-methyl iodophenyl pentadecanoic acid (123I-BMIPP) planar myocardial imaging was performed in all participants. For the patients undergoing PEA, repetitive SPECT-guided 201Tl and 123I-BMIPP planar imaging was performed one year after the procedure. To assess the RV overload, the planar images were performed in left anterior oblique position, optimized to separate the RV from the left ventricular (LV) using SPECT-guided transverse imaging. We measured the total counts of 201Tl and 123I-BMIPP in both the RV and LV. Moreover, we calculated their relative counts of the RV to LV (abbreviated as HR/HL (Tl) and HR/HL (BMIPP), respectively) to determine the indices of myocardial perfusion and fatty acid metabolism, respectively.

Results

Both HR/HL (Tl) and HR/HL (BMIPP) were elevated in the CTEPH patients compared with control (0.62±0.14 vs. 0.36±0.07, p<0.01 and 0.57±0.14 vs. 0.34±0.06, p<0.01, respectively). In the CTEPH patients, average mPAP was 44.0±9.52 mmHg, which was correlated with HR/HL (Tl) (r=0.675, p<0.001) and HR/HL (BMIPP) (r=0.685, p<0.01). Furthermore, the decrease of average mPAP 1 year after PEA was positively associated with the decrease of HR/HL (Tl) (r=0.646, p<0.01) and HR/HL (BMIPP) (r=0.504, p<0.05) 1 year after PEA.

Conclusions

In patients with CTEPH, RV myocardial perfusion and fatty acid metabolism was upregulated and moderately correlated with mPAP. SPECT-guided 201Tl and 123I-BMIPP planar imaging is a novel and noninvasive imaging modality to assess the severity of PH.

Funding Acknowledgement

Type of funding sources: None.

Proving Nontrivial Topology of Pure Bismuth by Quantum Confinement

The topology of pure Bi is controversial because of its very small (∼10  meV) band gap. Here we perform high-resolution angle-resolved photoelectron spectroscopy measurements systematically on 14-202 bilayer Bi films. Using high-quality films, we succeed in observing quantized bulk bands with energy separations down to ∼10  meV. Detailed analyses on the phase shift of the confined wave functions precisely determine the surface and bulk electronic structures, which unambiguously show nontrivial topology. The present results not only prove the fundamental property of Bi but also introduce a capability of the quantum-confinement approach.

An atomic seesaw switch formed by tilted asymmetric Sn-Ge dimers on a Ge (001) surface

When tin (Sn) atoms are deposited on a clean germanium (Ge) (001) surface at room temperature, buckled dimers originating from the Sn atoms are formed at the Ge-dimer position. We identified the dimer as a heterogeneous Sn-Ge dimer by reversing its buckling orientation with a scanning tunneling microscope (STM) at 80 kelvin. An atomic seesaw switch was formed for one-dimensional electronic conduction in the Ge dimer-row direction by using the STM to reversibly flip the buckling orientation of the Sn-Ge dimer and to set up standing-wave states.

"Physiological" age as an outcome predictor for abdominal surgery in elderly patients

It would seem that a large discrepancy exists between the "chronological" age and "apparent" age of elderly patients, and we often observe that the latter reflects the results of surgical procedures very well. In the present study, we reviewed 258 patients aged 70 years or older who underwent elective abdominal operations under general anesthesia, to evaluate an outcome predictor representing their "physiological" age. A total of 24 preoperative variables were compared between patients who left the hospital in a satisfactory condition, being survivors, and those who died in hospital despite the operative procedure performed, being nonsurvivors. In the group of patients aged between 70 and 79 years, there was no significant difference between the survivor and nonsurvivor groups for any of the variables examined; however, in the group of patients aged over 80 years old, the oldest of whom was 93 years, there were significant differences in the total lymphocyte count (TLC) and the performance status (PS), as well as in age, between the survivor and nonsurvivor groups. Utilizing the three variables of age, PS, and TLC, a computer-generated discriminant function analysis yielded an equation which discriminated survival with 97% accuracy, and mortality with 83% accuracy. These findings indicate that the PS and TLC scores added to the chronological age should be considered when deciding whether a surgical procedure is appropriate for an elderly patient.

1-Acetyl-7-deacetylforskolin: a potential non-specific inactive analog of forskolin for estimation of its specific high-affinity binding and adenylyl cyclase stimulation in vitro

Labeled and unlabeled 1-acetyl-7-deacetylforskolin and forskolin were synthesized by acetylation of 7-deacetylforskolin with labeled and unlabeled acetyl chloride. The binding of 1-acetyl[1-acetyl-11C]-7-deacetylforskolin ([11C]1-acetyl-7-deacetylforskolin) and [7-acetyl-11C]forskolin ([11C]forskolin) to rat brain membranes was studied using filtration assay. The [11C]forskolin binding was decreased with an increasing load of unlabeled forskolin, whereas [11C]1-acetyl-7-deacetyl-forskolin binding was always very low, the level of which agreed with that of the non-specific binding in forskolin. However, binding of [7-acetyl-11C]1,9-dideoxyforskolin, which has been used as a non-specific inactive analog of forskolin, had a higher binding ratio than that of the non-specific binding of forskolin. The binding of [11C]forskolin was not affected by an increased load of cold 1-acetyl-7-deacetylforskolin. Forskolin activated adenylyl cyclase (AC) in cultured human endothelial cells, whereas 1-acetyl-7-deacetylforskolin did not. These data show that the 1-acetyl-7-deacetylforskolin lacks specific binding affinity and the ability to stimulate AC, while it has similar physical properties with forskolin. The compound 1-acetyl-7-deacetylforskolin would be a suitable "non-specific inactive analog" of forskolin with which to estimate its specific high-affinity binding capacity and to validate forskolin-specific AC stimulation in vitro.

Conformational rigidity of specific pyrimidine residues in tRNA arises from posttranscriptional modifications that enhance steric interaction between the base and the 2'-hydroxyl group

In order to elucidate roles of the 2'-O-methylation of pyrimidine nucleotide residues of tRNAs, conformations of 2'-O-methyluridylyl(3'----5')uridine (UmpU), 2'-O-methyluridine 3'-monophosphate (Ump), and 2'-O-methyluridine (Um) in 2H2O solution were analyzed by one- and two-dimensional proton NMR spectroscopy and compared with those of related nucleotides and nucleoside. As for UpU and UmpU, the 2'-O-methylation was found to stabilize the C3'-endo form of the 3'-nucleotidyl unit (Up-/Ump-moiety). This stabilization of the C3'-endo form is primarily due to an intraresidue effect, since the conformation of the 5'-nucleotidyl unit (-pU moiety) was only slightly affected by the 2'-O-methylation of the 3'-nucleotide unit. In fact even for Up and Ump, the 2'-O-methylation significantly stabilizes the C3'-endo form by 0.8 kcal/.mol-1. By contrast, for nucleosides (U and Um), the C3'-endo form is slightly stabilized by 0.1 kcal/.mol-1. Accordingly, the stabilization of the C3'-endo form by the 2'-O-methylation is primarily due to the steric repulsion among the 2-carbonyl group, the 2'-O-methyl group and the 3'-phosphate group in the C2'-endo form. For some tRNA species, 2-thiolation of pyrimidine residues is found in positions where the 2'-O-methylation is found for other tRNA species.(ABSTRACT TRUNCATED AT 250 WORDS)