Case report on an extremely rare type of ependymoma arising from the thigh

INTRODUCTION

Ependymomas are neuroepithelial neoplasms of the central nervous system that arise from the precursor cells lining the ventricular system and the central canal of the spinal cord. Herein, we report a case of an extremely rare type of ependymoma arising from the thigh. Then, a literature review was performed.

PRESENTATION OF CASE

An 87-year-old female Japanese patient presented with a chief complaint of a mass on the medial aspect of her right thigh. Pathology revealed a grade 2 extra-neural ependymoma. PET-CT and brain MRI showed no neoplastic lesions in the central nervous system, and the tumor was localized only in the right thigh. The tumor was growing and was treated as a low-grade tumor with extensive resection and postoperative adjuvant radiotherapy. The patient has been alive for 3 years, without postoperative recurrence or complications.

DISCUSSION

This case presents a rare extra-neural ependymoma of central nervous system origin arising in the thigh. The pathogenesis is unknown, but a search for neoplastic lesions in the cerebrospinal cord is warranted. Extra-neural ependymomas should be treated as low-grade tumors because they are more prone to recurrence and metastasis than ordinary ependymomas.

CONCLUSION

We experienced an extremely rare extra-neural ependymoma arising in the thigh. A search for tumors in the central nervous system region of the cerebrospinal cord, previous literature, and clinical, imaging, and pathological findings should be consulted to determine a treatment strategy.

Cooling positronium to ultralow velocities with a chirped laser pulse train

When laser radiation is skilfully applied, atoms and molecules can be cooled1-3, allowing the precise measurements and control of quantum systems. This is essential for the fundamental studies of physics as well as practical applications such as precision spectroscopy4-7, ultracold gases with quantum statistical properties8-10 and quantum computing. In laser cooling, atoms are slowed to otherwise unattainable velocities through repeated cycles of laser photon absorption and spontaneous emission in random directions. Simple systems can serve as rigorous testing grounds for fundamental physics-one such case is the purely leptonic positronium11,12, an exotic atom comprising an electron and its antiparticle, the positron. Laser cooling of positronium, however, has hitherto remained unrealized. Here we demonstrate the one-dimensional laser cooling of positronium. An innovative laser system emitting a train of broadband pulses with successively increasing central frequencies was used to overcome major challenges posed by the short positronium lifetime and the effects of Doppler broadening and recoil. One-dimensional chirp cooling was used to cool a portion of the dilute positronium gas to a velocity distribution of approximately 1 K in 100 ns. A major advancement in the field of low-temperature fundamental physics of antimatter, this study on a purely leptonic system complements work on antihydrogen13, a hadron-containing exotic atom. The successful application of laser cooling to positronium affords unique opportunities to rigorously test bound-state quantum electrodynamics and to potentially realize Bose-Einstein condensation14-18 in this matter-antimatter system.

R-Spondin1 protects gastric stem cells and mitigates gastric GVHD in allogeneic hematopoietic stem cell transplantation

ABSTRACT

Graft-versus-host disease (GVHD) is the major obstacle to performing allogeneic hematopoietic cell transplantation (allo-HCT). We and others have shown that intestinal stem cells are targeted in lower gastrointestinal GVHD. A leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5)-expressing gastric stem cells (GSCs) reside at the base of the gastric glands in mice. After experimental allo-HCT, Lgr5+ GSCs significantly decreased. Parietal cells, which underwent continuous renewal by GSCs, were injured in gastric GVHD, leading to failure of gastric acidification and aerobic bacterial overgrowth in the duodenum. Fate-mapping analysis demonstrated that administration of R-Spondin1 (R-Spo1) that binds to Lgr5 for 6 days in naïve mice significantly increased proliferating epithelial cells derived from Lgr5+ GSCs. R-Spo1 administered on days -3 to -1 and from days +1 to +3 of allo-HCT protected GSCs, leading to amelioration of gastric GVHD and restoration of gastric acidification, and suppression of aerobic bacterial overgrowth in the duodenum. In conclusion, Lgr5+ GSCs were targeted by gastric GVHD, resulting in disruption of the gastric homeostasis, whereas R-Spo1 protected Lgr5+ GSCs from GVHD and maintained homeostasis in the stomach.

[Kidney transplantation for end-stage renal disease after third allogeneic hematopoietic stem cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia]

An 18-year-old man underwent allogenic bone marrow transplantation (BMT) for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL). Ph+ALL relapsed 3 months after the first BMT, and the patient underwent a second BMT. However, Ph+ALL relapsed 4 months after the second BMT, and he received a haploidentical peripheral blood stem cell transplantation (haplo-PBSCT) from his father. Molecular complete remission was confirmed 29 days after haplo-PBSCT. However, the patient needed dialysis for end-stage renal disease due to thrombotic microangiopathy 3 years and 2 months after haplo-PBSCT. He received a kidney transplantation from his father 7 years and 10 months after haplo-PBSCT, and got off dialysis after the kidney transplantation. Immunosuppressive therapy with methylprednisolone, tacrolimus, and mycophenolate mofetil was started for kidney transplantation, but the dose of immunosuppressive agents was reduced successfully without rejection soon after kidney transplantation. The patient has maintained long-term remission since the haplo-PBSCT, and his kidney function was restored by the kidney transplantation from his father.

Metastatic patellar bone tumor due to gastric cancer resembling a primary or secondary aneurysmal bone cyst: A case report

INTRODUCTION AND IMPORTANCE

Patellar bone tumors are very rare, and most are benign or of intermediate type. In this report, we describe our experience of a metastatic patellar bone tumor caused by gastric cancer, which resembled a very rare primary or secondary aneurysmal bone cyst and review the literature.

CASE PRESENTATION

A 65-year-old man presented with severe pain in the patellar region and marked limitation of the knee joint range of motion. He had a history of gastric cancer; however, epidemiological, clinical, and imaging findings led us to strongly suspect an aneurysm-like bone cyst. Thus, we performed bone tumor curettage and autologous artificial bone grafting without biopsy because of the severe pain. Pathology results showed gastric cancer metastasis; hence, patellectomy and patellar tendon augmentation with femoral fascia were performed. The Musculoskeletal Tumor Society (MSTS) score was taken postoperatively to assess pain and function.

CLINICAL DISCUSSION

We experienced a very rare gastric cancer-related metastatic patellar bone tumor, which resembled a primary or secondary aneurysmal bone cyst in frequency and imaging findings. Patellectomy was ultimately performed, and the patient's MSTS score improved markedly.

CONCLUSION

Despite its very low frequency, patellar metastatic bone tumors must be taken into account without being misled by the frequency or imaging findings and a biopsy should necessarily be performed.

Observation of Bose-Einstein condensates of excitons in a bulk semiconductor

An unambiguous observation of the Bose-Einstein condensation (BEC) of excitons in a photoexcited bulk semiconductor and elucidation of its inherent nature have been longstanding problems in condensed matter physics. Here, we observe the quantum phase transition and a Bose-Einstein condensate appearing in a trapped gas of 1s paraexcitons in bulk Cu₂O below 400 mK, by directly visualizing the exciton cloud in real space using mid-infrared induced absorption imaging that we realized in a dilution refrigerator. Our study shows that the paraexciton condensate is undetectable by conventional luminescence spectroscopy. We find an unconventionally small condensate fraction of 0.016 with the spatial profile of the condensate well described by mean-field theory. Our discovery of this new type of BEC in the purely matter-like exciton system interacting with a cold phonon bath could pave the way for the classification of its long-range order, and for essential understanding of quantum statistical mechanics of non-equilibrium open systems.

Bose-Einstein condensate of excitons is expected in photo-excited bulk semiconductors, but a direct experimental evidence has been lacking. Here the authors report the observation of a condensate of 1s paraexcitons in Cu₂O using real-space mid-infrared absorption imaging realized in a dilution refrigerator.

Research Note: Expression of IGF-1 and IGF-1 Receptor Proteins in Skeletal Muscle Fiber Types in Chickens with Hepatic Fibrosis

We investigated the expression of insulin-like growth factor 1 (IGF-1) and IGF-1 type 1 receptor (IGF-1R) in skeletal muscle fiber types in chickens with hepatic fibrosis induced by bile duct ligation (BDL). Eleven hens, approximately 104 weeks old, were randomly assigned to BDL (n = 4) and sham surgery (SHAM; n = 7) groups. In BDL hens, histopathology revealed marked bile duct proliferation and liver fibrosis. The cross-sectional area (CSA) of myofibers from both the pectoralis (PCT) muscles significantly decreased in the BDL group compared with the SHAM group (P < 0.01). In contrast, the CSA of myofibers from the femorotibialis lateralis (FTL) muscle did not decrease in the BDL group. Type I fibers were large, round, and hypertrophic. Elongated type IIA and IIB fibers were also present. For IGF-1 immunostaining, the immunoreaction intensity was higher in the PCT in the BDL group than the SHAM group. Within the BDL group, type I fibers from FTL had a stronger immunoreaction intensity than the type II fibers. For IGF-1R immunostaining, the intensity of the immunoreactions was similar within the PCT in the BDL group compared with the SHAM group. For FTL, type I fibers had stronger reactions to IGF-1R than type II fibers in the BDL group. These results suggest that type I fibers express both IGF-1 and IGF-1R and become hypertrophic in chickens with hepatic fibrosis.

Dual optical frequency combs with ultra-low relative phase jitters from 550 nm to 1020 nm for precision spectroscopy

Here, ultra-low relative phase jitters over a wide optical spectrum were achieved for dual Ti:Sapphire optical frequency combs. The two optical frequency combs were independently phase-locked to a Sr optical lattice clock laser delivered through a commercial optical fiber network. We confirmed that the relative phase jitters between the two combs integrated from 8.3 mHz to 200 kHz were below 1 rad, corresponding to a relative linewidth of below 8.3 mHz, over the entire wavelength of the optical frequency combs ranging from 550 nm to 1020 nm. Our work paves the way for ultrahigh-precision dual-comb spectroscopy covering a wide optical spectral range with a simple setup, and provides an absolute optical frequency reference with great stability over a wide range of wavelengths.

Pebbles and sand on asteroid (162173) Ryugu: In situ observation and particles returned to Earth

The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and subsurface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample location. Surface pebbles at both landing sites show morphological variations ranging from rugged to smooth, similar to Ryugu's boulders, and shapes from quasi-spherical to flattened. The samples were returned to Earth on 6 December 2020. We describe the morphology of >5 grams of returned pebbles and sand. Their diverse color, shape, and structure are consistent with the observed materials of Ryugu; we conclude that they are a representative sample of the asteroid.

[Late-onset refractory autoimmune hemolytic anemia following autologous hematologic recovery after allo-HSCT in aplastic anemia-PNH syndrome]

A 31-year-old man underwent allogeneic bone marrow transplantation (BMT) for the treatment of transfusion-dependent aplastic anemia (AA) after conditioning with a regimen including fludarabine, cyclophosphamide, and antithymocyte globulin. The patient developed a late graft rejection on day 103 and showed autologous hematologic recovery not requiring transfusions on day 76. Peripheral blood leukocytes were of 100% recipient origin on day 103, and paroxysmal nocturnal hematuria (PNH)-type granulocytes were detected 5 months after BMT. The patient suddenly experienced hemolytic symptoms triggered by cold stimulation, and was diagnosed with autoimmune hemolytic anemia (AIHA) 37 months after BMT. Although anemia was ameliorated by prednisolone (PSL), hemolytic attacks repeatedly occurred, which became refractory to corticosteroids. Moreover, the patient underwent a splenectomy for the steroid-resistant AIHA and achieved AIHA remission without the need for PSL at 53 months after BMT. The immune tolerance breakdown to erythrocyte antigens was thought to have occurred due to various factors including immune AA, medication, cold stimulation, and infection, leading to AIHA development in this case.

Chirped pulse amplification of an ultrahigh-repetition-rate Ti:sapphire frequency comb using a tapered semiconductor amplifier

Chirped pulse amplification of a 1.6 GHz Ti:sapphire femtosecond frequency comb was achieved using a GaAs-based tapered semiconductor amplifier. The spectral component of 855-865 nm was coherently amplified up to 379 mW at 2.5 A, corresponding to a peak power of 1.48 kW and an average power of 150 µW per mode. A chirped Bragg grating was used for pulse stretching and compression, resulting in a 150mm×200mm compact amplification system. Competition between the amplified spontaneous emission and the coherent signal was observed at high driving currents. A numerical analysis was presented to account for the observed gain suppression. This amplification method is useful for the realization of high repetition rate frequency combs with a wider spectral range, including the UV and mid-infrared regions.

Diagnostic Accuracy of Screening Arterial Spin-Labeling MRI Using Hadamard Encoding for the Detection of Reduced CBF in Adult Patients with Ischemic Moyamoya Disease

BACKGROUND AND PURPOSE

Adult patients with ischemic Moyamoya disease are advised to undergo selective revascularization surgery based on cerebral hemodynamics. The purpose of this study was to determine the diagnostic accuracy of arterial spin-labeling MR imaging using Hadamard-encoded multiple postlabeling delays for the detection of reduced CBF in such patients.

MATERIALS AND METHODS

Thirty-seven patients underwent brain perfusion SPECT and pseudocontinuous arterial spin-labeling MR imaging using standard postlabeling delay (1525 ms) and Hadamard-encoded multiple postlabeling delays. For Hadamard-encoded multiple postlabeling delays, based on data obtained from the 7 sub-boluses with combinations of different labeling durations and postlabeling delays, CBF corrected by the arterial transit time was calculated on a voxel-by-voxel basis. Using a 3D stereotaxic template, we automatically placed ROIs in the ipsilateral cerebellar hemisphere and 5 MCA territories in the symptomatic cerebral hemisphere; then, the ratio of the MCA to cerebellar ROI was calculated.

RESULTS

The area under the receiver operating characteristic curve for detecting reduced SPECT-CBF ratios (<0.686) was significantly greater for the Hadamard-encoded multiple postlabeling delays-CBF ratios (0.885) than for the standard postlabeling delay-CBF ratios (0.786) (P = .001). The sensitivity and negative predictive value for the Hadamard-encoded multiple postlabeling delays-CBF ratios were 100% (95% confidence interval, 100%-100%) and significantly higher than the sensitivity (95% CI, 44%-80%) and negative predictive value (95% CI, 88%-97%) for the standard postlabeling delay-CBF ratio, respectively.

CONCLUSIONS

ASL MR imaging using Hadamard-encoded multiple postlabeling delays may be applicable as a screening tool because it can detect reduced CBF on brain perfusion SPECT with 100% sensitivity and a 100% negative predictive value in adult patients with ischemic Moyamoya disease.

Outcome of allogeneic hematopoietic stem cell transplantation for T-cell lymphoblastic leukemia/lymphoma: A single-center study

Although the indications for allogeneic hematopoietic stem cell transplantation (allo-HSCT) as a treatment for T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) and Philadelphia chromosome (Ph)-negative B-cell acute lymphoblastic leukemia (B-ALL) are similar, few studies have compared its outcomes for T-ALL/LBL and Ph-negative B-ALL. The clinical data of 28 patients with T-ALL, 16 with T-LBL, and 99 with Ph-negative B-ALL who underwent the first allo-HSCT from 2000 to 2019 were retrospectively analyzed. Complete remission (CR) rates at allo-HSCT were 79 %, 63 %, and 75 % for T-ALL, T-LBL, and B-ALL, respectively; the 3-year overall survival (OS) rates were 55.7 %, 56.2 %, and 58.6 %, respectively (p = 0.92). Univariate analysis revealed that disease subtypes were not significantly associated with OS (B-ALL vs. T-ALL: hazard ratio [HR]=0.89, p = 0.70; T-LBL vs. T-ALL: HR=0.87, p = 0.75), and CR at allo-HSCT was the only prognostic factor for OS (HR=0.25, p < 0.001). Multivariate analysis demonstrated that CR at allo-HSCT was the only predictor of OS (HR=0.24, p < 0.001). In all three disease subtypes, patients in CR at allo-HSCT tended to have a lower cumulative incidence of relapse than did those in non-CR (T-ALL: 13.6 % vs. 50.0 %, p = 0.10; T-LBL: 20.0 % vs. 50.0 %, p = 0.21; B-ALL: 10.0 % vs. 56.0 %, p < 0.01). Thus, the outcomes of allo-HSCT for T-ALL/LBL were comparable to those of Ph-negative B-ALL. Irrespective of the disease subtypes, achieving CR before allo-HSCT was associated with a favorable OS. Further advances in chemotherapy before allo-HSCT and defining the optimal timing of allo-HSCT would improve the prognosis of patients with T-ALL/LBL.

Intentional Stent Stenosis to Prevent Hyperperfusion Syndrome after Carotid Artery Stenting for Extremely High-Grade Stenosis

BACKGROUND AND PURPOSE

Intracranial hemorrhage due to hyperperfusion syndrome is a severe carotid artery stent placement complication of extremely high-grade stenosis, causing hemodynamic insufficiency. To prevent hyperperfusion syndrome, we attempted intentional residual stent stenosis and implemented "gentle" carotid artery stent placement, defined as carotid artery stent placement using a closed-cell stent coupled with slight balloon predilation, without balloon postdilation. Gradual stent expansion was expected. We investigated the incidence of hyperperfusion syndrome and long-term outcomes after gentle carotid artery stent placement.

MATERIALS AND METHODS

We included patients who underwent carotid artery stent placement for extremely high-grade stenosis from January 2015 to March 2019. We defined extremely high-grade stenosis as carotid stenosis with conventional angiographic "slow flow" and a reduced MCA signal intensity on MRA. A reduced MCA signal intensity was defined as MCA with a relative signal intensity of <0.9 in the ipsilateral compared with the contralateral MCA. We evaluated the stent diameter, CBF on SPECT, hyperperfusion syndrome, and intracranial hemorrhage. We defined hyperperfusion syndrome as a triad of ipsilateral headache, seizure, and hemiparesis.

RESULTS

Twenty-eight of the 191 patients met our inclusion criteria. After carotid artery stent placement, their median minimal stent diameter was 2.9 mm, which expanded to 3.9 mm at 4 months. Neither cerebral hyperperfusion syndrome nor intracranial hemorrhage occurred.

CONCLUSIONS

The gentle carotid artery stent placement strategy for intentional residual stent stenosis may prevent hyperperfusion syndrome in high-risk patients. Stents spontaneously dilated in 4 months.

Prognostic value of noninvasive combined anatomic/functional assessment by cardiac ct in patients with suspected coronary heart disease

Background

Noninvasive evaluation of patients with stable angina is preferable over invasive testing if it leads to similar patient outcome. The combination of coronary angiography and vasodilator challenge myocardial perfusion imaging by computed tomography allows fast, comprehensive assessment of patients with suspected coronary heart disease.

Purpose

To compare the long-term prognostic value of combined computed tomography angiography (CTA) and myocardial CT perfusion imaging (CTP) with invasive coronary angiography (ICA) and single photon emission tomography (SPECT) in patients with suspected hemodynamically significant coronary heart disease.

Methods

At 16 centres, 381 patients were followed for major adverse cardiac events (MACE) for the CORE320 study. All patients underwent coronary CTA, CTP, and SPECT before ICA. Prognostic performance according binary results (normal/abnormal) was assessed by 5-year major cardiovascular events (MACE) free survival and area under the receiver-operating-characteristic curve (AUC).

Results

Follow up beyond 2-years was available in 323 patients. MACE-free survival rate was greater among patients with normal combined CTA/CTP findings compared to ICA/SPECT: 85 vs. 80% (95% confidence interval [CI] for difference 0.1, 11.3) though event-free survival time was similar (4.54 vs. 4.37 years, 95% CI for difference: 0.03, 0.36). Abnormal results by combined CTA/CTP was associated with 3.83 years event-free survival vs. 3.66 years after abnormal combined ICA/SPECT (95% CI for difference: 0.05, 0.39, CI −1.0, 11.1) (Figure). Predicting MACE by AUC also was similar: 65 vs. 65 (difference 0.1; 95% CI: −4.6, 4.9). When MACE was restricted to death, myocardial infarction, or stroke, AUC for CTA/CTP was 66 vs. 61 by ICA/SPECT (difference 5.1; 95% CI: −7.1, 12.9).

Conclusions

Combined CTA/CTP yield similar 5-year prognostic performance as joined ICA/SPECT assessment in patients presenting with suspected coronary heart disease and thus may represent a fast, non-invasive alternative to the traditional diagnostic approach.

Figure 1. 5-year event-free survival

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): National Institutes of Health

Basic mechanism of atrial and ventricular arrhythmia suppression by heavy ion irradiation in hypercholesterolemic elderly rabbits

Background

Recent development of electrophysiology-guided noninvasive cardiac radioablation therapy for ventricular tachycardia attracts a great deal of attention as a novel antiarrhythmic strategy (Robinson CG, Circulation 2019). As to underlying mechanisms, however, much remains to be clarified. We reported before that a single targeted heavy ion irradiation (THIR 15Gy) to rabbit hearts increased connexin43 (Cx43) expression, and a reduction of vulnerability to ventricular arrhythmias after myocardial infarction.

Purpose

We investigated the effects of THIR on in-vivo cardiac electrophysiology and vulnerability to atrial and ventricular tachyarrhythmias in aged rabbits with hypercholesterolemia.

Methods

Sixteen three-year old rabbits were fed with high fat/cholesterol chow (0.5% cholesterol and 10% coconut oil) for 14 weeks. A single THIR 15Gy was applied to 8 rabbits (HC+THIR) with a heavy ion medical accelerator. Eight rabbits without THIR were used as control (HC).

Results

Serum cholesterol levels in the HC and HC+THIR were 1545+386 and 1569+328 mg/dl (n=8, NS). Atrial (P-wave) late potential in signal-averaged ECG in HC+THIR showed a significantly larger root mean square voltage (RMS) than those in HC (12+0.5 vs. 2+0.5μV, n=4, p&lt;0.01). Ventricular late potentials in HC+THIR showed significantly less fQRS-D than HC (81+5 vs. 89+7 ms); less LAS40 (21+7 vs. 30+4 ms), and larger RMS (99+27 vs. 44+13μV) (n=4, p&lt;0.04). Atrial tachycardia or fibrillation (AT/AF) was induced spontaneously or by programmed/burst pacing of the left atria (LA) in 4 out of 4 HC, whereas in only 1 out of 4 HC+THIR. Ventricular tachycardia or fibrillation (VT/VF) was induced spontaneously or by programmed pacing or left stellate stimulation in 4 out of 4 HC rabbits, whereas in only 1 out of 4 HC+THIR. Immunolabeled Cx40 densities in LA and RA tissue from HC+THIR rabbits were significantly higher than those from HC rabbits by 44% and 60%, respectively (n=4, p&lt;0.01). Comparable upregulation of immunoreactive Cx43 was observed in LV and RV tissue from HC+THIR rabbits. Sympathetic nerve densities in LA, RA, LV and RV tissues, which was labeled with anti-neuronal growth-associated protein 43 (GAP43) antibody and tyrosine hydroxylase (TH) antibody were both significantly less in HC+THIR than those in HC.

Conclusion

These results suggest that THIR may improve cardiac conductivity of HC rabbits in favor of reduction of vulnerability to atrial and ventricular tachycardia/fibrillation, and that this antiarrhythmic effect is attributed to upregulation of gap junction protein (Cx40 and Cx43) and in part to prevention of sympathetic nerve sprouting.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): KAKENHI KIBAN (C) 53020

Measurement of complex refractive index with tunable extreme ultraviolet high harmonic source

We report a broadband refractive index measurement method based on a higher harmonic generation tabletop coherent extreme ultraviolet source. We measured the complex refractive index of a sample material by measuring the interference pattern produced by a bare double slit and comparing this with the pattern produced by another double slit with one slit covered by the sample material. We validated the method by measuring the complex refractive index of aluminum in the photon energy range of 63-78 eV using a neon gas jet. The measurement system had errors of less than 0.02%.

An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2's Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu's surface age.

162 Detection of ovulation disorders and normal ovulation using wireless sensors of ventral tail surface temperature and neck acceleration data in Japanese Black cows

The present study aimed to clarify the possibility of detection of ovulation disorders and normal ovulation in Japanese Black cows using wearable wireless sensors based on continuous measurements of body surface temperature (ST) and neck acceleration data. For cows with normal ovulation (n=19, 8.5 years old, 476.2kg), controlled internal drug release (CIDR) and gonadotrophin-releasing hormone were administered on arbitrary days of the oestrous cycle (Day −10), and oestrus was induced by CIDR removal and prostaglandin F2α administration (Day −3). Ovulation (Day 0) was induced by gonadotrophin-releasing hormone administration on estimated oestrus day (Day −1) and was detected based on the disappearance of ≥8mm follicles using ultrasonography at 1- to 2-h intervals. For cows with spontaneous ovarian cysts (n=11, 8.6 years old, 471.2kg), oestrus and the next day were defined as Days −1 and 0, respectively. Plasma concentrations of progesterone (P4) and oestradiol-17β (E2) were measured on Days −9, −6, −2, −1, 0, 1, 5, and 8. The body ST sensor was attached to the ventral tail base (Day −16), and ST was measured every 10min for 24 days. For analysis of ST, after extracting hourly maximum ST values, the values were expressed as residual ST (RST; ST − mean ST for the same hour on the previous 3 days) for removal of circadian rhythm (Miura et al. 2017 Anim. Reprod. Sci. 180, 50-57; https://doi.org/10.1016/j.anireprosci.2017.03). The acceleration sensor (Farmnote Color, Farmnote Inc.) was attached to the neck (Day −16). Hourly oestrus level (amount of oestrus activity) was obtained from the amount of activity; the difference between the residual oestrus level (REL; same calculation as RST) and measured values of each day was used. To identify RST and REL of cows with normal ovulation and cows with ovarian cysts, the mean values and standard deviations for the same hours for 3-7 days before oestrus were calculated. Mean RST and REL for 3-7 days before oestrus were assumed according to the normal distribution. The 95% confidence range was determined using×1 standard deviation of all hours. Values over the 95% confidence range for ≥5h were considered to be different from the mean 4 days and the 5% level. For RST, no difference was found in both groups due to the large influence of environment, particularly low temperature. However, for REL, a difference was indicated for oestrus in all cows (P&lt;0.05). A large peak of REL appeared once on oestrus (&gt;14.4 REL for 20h) in normal cows, and three peaks occurred in &lt;21 days (&gt;16.2 REL for 21, 15, and 15h) in cows with ovulation disorders (P&lt;0.05). The REL rapidly increased following peaking E2 and decreasing P4 to oestrus (Day −1) in normal cows. In cows with an ovulation disorder, REL increased on oestrus; however, E2 and P4 remained high and low stable to oestrus, respectively. In conclusion, oestrus activity and the characteristics of normal cows and those with an ovulation disorder can be detected by the neck acceleration sensor using the correction value. This research was supported by The Research Project for the Future Agriculture Production Utilising Artificial Intelligence.

P295 Impact of Pre-existing Mitral Regurgitation on the Mid-Term Left Ventricular Mass Regression following Transcatheter Aortic Valve Implantation for Aortic Valve Stenosis

Background

Transcatheter aortic valve implantation (TAVI) results in an immediate and greater aortic pressure gradient improvement in patients with severe aortic valve stenosis (AS), and induces early left ventricular (LV) mass regression, which may be related to favorable effects on the mid to long term outcomes. However, the extent of LV mass regression after unloading of chronic pressure overload is varying, and its determinants are still unknown. Thus, the study aims to identify echocardiographic determinants of LV mass regression following TAVI.

Methods

We retrospectively screened all TAVI procedures in symptomatic AS from 2017 to 2019, and selected 74 successful TAVI cases that had serial echocardiographic studies both at the baseline and at the mid-term follow-up (4 to 6 months after the procedure). Through the digitalized medical records, clinical and echocardiographic data as well as angiographic grading (0-3) of post-procedure paravalvular leakage (PVL) were obtained. LV mass was calculated by using Cube formula. Thus, the extent of LV mass regression was defined as the differences of left ventricular mas index (LVMI) between at the baseline and at the follow-up (ΔLVMI). Quantification of the baseline mitral valve regurgitant volume was performed by stroke volume method with pulmonic site measurement on the assumption of no pre-existing intra/extra cardiac shunt. Cases with prior mitral valve replacement were excluded.

Results

At the post-procedure angiogram, only 3 cases had significant PVL (grade 2≤). At the mid-term follow–up, average LVMI decreased significantly from the baseline (165 ± 38 g/m2vs 140 ± 37 mg/ m2, P &lt; 0.0001) and 57 cases (70%) experienced the reduction of LVMI, although average relative wall thickness (2 × posterior wall thickness/left ventricular diastolic dimension) did not change (0.565 ± 0.135 vs 0.586 ± 0.168, P = 0.314). Among the baseline clinical and echocardiographic variables, the baseline peak A wave velocity, E/A ratio, mitral valve regurgitant volume and LVMI revealed simple correlation with ΔLVMI (γ=-0.298, p = 0.0188;γ=0.251, P = 0.0417;γ=0.354, p = 0.0041;γ=0.375, p &lt; 0.0010; respectively), whereas no correlation was observed in angiographic PVL grade. Stepwise multiple regression analysis demonstrated baseline mitral valve regurgitant volume and LVMI as the determinants of ΔLVMI (β=0.344, p = 0.032; β=0.335 P &lt; 0.0001; respectively).

Conclusions

Pre-existing mitral regurgitation has an impact on the mid–term left ventricular mass regression following TAVI. In severe AS, mitral regurgitation might be functioning as an afterload adjuster, and thus, produces protective effects on LV structure.

Gigahertz-repetition-rate, narrowband-deep-ultraviolet light source for minimization of acquisition time in high-resolution angle-resolved photoemission spectroscopy

Ultrahigh-repetition-rate (1.1 GHz), deep-ultraviolet coherent light at 208.8 nm is generated by applying an external Fabry-Pérot cavity for repetition-rate multiplication to the fourth harmonics of a 10-ps, mode-locked Ti:sapphire laser. Its small pulse energy minimizes the unwanted space charge effect, while its high repetition rate drastically reduces the acquisition time in high-energy resolution angle-resolved photoemission spectroscopy using hemispherical electron analyzers. The absence of the space charge effect in the photoemission spectrum near the Fermi edge of polycrystalline Au at 8 K demonstrates this idea.