Catalytic NH3 oxidation affected by the nanometric roughness of the platinum overlayer

Pulsed cathodic arc-plasma deposition was employed to create a few nanometre-thick Pt overlayer on a 50 μm-thick Fe-Cr-Al metal (SUS) foil, resulting in an effective NH3 oxidation catalyst fabrication. This catalyst exhibited a turnover frequency (TOF) exceeding 100 times that of Pt nanoparticles. In this study, Pt overlayer catalysts with varying degrees of surface roughness were fabricated using different metal foil substrates: mirror-polished (Pt/p-SUS), unpolished (Pt/SUS) and roughened by the formation of a surface oxide layer (Pt/Al2O3/SUS). The nanoscale roughness was comprehensively analysed using electron microscopy, laser scanning confocal microscopy and chemisorption techniques. NH3 oxidation activity, measured at 200 °C, followed an increasing trend in the order of Pt/Al2O3/SUS < Pt/SUS < Pt/p-SUS, despite a decrease in the apparent Pt surface area in the same order. Consequently, the calculated TOF was markedly higher for Pt/p-SUS (267 min-1) compared to Pt/SUS (107 min-1) and Pt/Al2O3/SUS (≤22 min-1). The smooth Pt overlayer surface also favoured N2 yield over N2O at this temperature. This discovery enhances our fundamental understanding of high-TOF NH3 oxidation over Pt overlayer catalysts, which holds significance for the advancement and industrial implementation of selective NH3 oxidation processes.

Risk factors for surgical site infection following orthopaedic surgery for fracture by trauma: a nested case-control study

BACKGROUND

Surgical site infection (SSI) is associated with higher medical expenses and lower patient quality of life.

AIM

To identify specific modifiable risk factors for SSI after orthopaedic surgery for fractures caused by trauma.

METHODS

This nested case-control study used a nationwide trauma registry, the Japan Trauma Data Bank (JTDB) database. Patient data from 280 hospitals between January 2004 and May 2019 were retrieved from the JTDB. Patients with SSI and identified patients without SSI as control subjects were included, using propensity score matching adjusted for unmodifiable factors. Risk factors associated with SSI after orthopaedic trauma surgery were assessed using multi-level mixed-effects logistic regression models.

FINDINGS

In total, 15,910 patients were included in the analysis. Of these patients, 377 (2.4%) had SSI. After propensity score matching, 258 patients with SSI and 2580 matched patients without SSI were selected. In the multi-level mixed-effects logistic regression analysis, blood transfusion within 24 h (odds ratio (OR): 1.51; 95% confidence interval (CI): 1.06-2.13) was a significant risk factor for SSI following orthopaedic fracture surgery. The OR (95% CI) values for external fixation, transcatheter arterial embolization, and tourniquet for SSI following orthopaedic fracture surgery were 1.40 (0.96-2.03), 1.66 (0.81-3.38), and 2.99 (0.60-14.87), respectively.

CONCLUSION

These findings highlight the necessity of exercising caution when implementing blood transfusion within 24 h as a risk factor associated with SSI following orthopaedic trauma surgery.

Radiographic and clinical comparisons between loose-fit and press-fit stems in monopolar radial head arthroplasty for comminuted radial head fractures

PURPOSE

Few clinical studies have compared the operative outcomes between loose- and press-fit stems in radial head arthroplasty (RHA). We aimed to evaluate the radiographic and clinical results of the two radial head implant concepts.

METHODS

In this retrospective multicenter study, 32 patients (24 women and 8 men) with a mean age of 63.1 years who underwent RHA for comminuted radial head fractures were reviewed between 2005 and 2021. Seventeen patients underwent RHA with a loose-fit stem (L-group), whereas the remaining fifteen patients underwent RHA with a press-fit stem (P-group). The mean follow-up period was 40.1 ± 9.9 months, with the minimum follow-up duration of 12 months. The radiographic findings were evaluated for periprosthetic osteolysis; furthermore, clinical outcomes were analyzed to measure the range of motion of the elbow. The rate of reoperations and prosthesis removal were also reviewed.

RESULTS

The general characteristics of the patients were similar in the two groups. The rate of periprosthetic osteolysis was 17.6% in the L-group, whereas it was 53.3% in the P-group. The mean elbow flexions were 128° and 133° in the L- and P-groups, respectively. The mean elbow extensions were -12° and -9° in the L- and P-groups, respectively. The rate of reoperation was 23.5% in the L-group and 15.2% in the P-group. One patient in the L-group had the prosthesis removed because of surgical site infection, whereas one patient in the P-group had the prosthesis removed owing to painful loosening.

CONCLUSIONS

No significant differences in the clinical outcomes and reoperation rate were observed between the two radial head implant concepts in this study. However, osteolysis occurred more frequently in the P-group. Although patients with periprosthetic osteolysis are currently asymptomatic, they should be carefully followed up for the symptoms in the long term.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Iodine contrast volume reduction in preoperative transcatheter aortic valve implantation computed tomography: Comparison with 64- and 256-multidetector row computed tomography

INTRODUCTION

This study aimed to compare the vascular enhancement and radiation dose in preoperative transcatheter aortic valve implantation (TAVI) computed tomography (CT) with a reduced contrast medium (CM) using volume scans in 256-multidetector row CT (MDCT) with a standard CM using 64-MDCT.

METHODS

This study included 78 patients with preoperative TAVI CT with either 64- or 256-MDCT. The CM was injected at 1.5 mL/kg in the 64-MDCT group and 1.0 mL/kg in the 256-MDCT group. We compared vascular enhancement of the aortic root and access routes, image quality (IQ) scores, and radiation dose in both groups.

RESULTS

Despite the reduced CM (by 33 %) in the 256-MDCT group, the mean vascular enhancement of the right and left subclavian arteries was significantly higher than that in the 64-MDCT group [284 and 267 Hounsfield units (HU) vs. 376 and 359 HU; p < 0.05]; however, no significant differences in the mean vascular enhancement in the ascending aorta, abdominal aorta at the celiac level, and bilateral common femoral arteries were observed between the two groups (p > 0.05 for all). The median IQ scores at the aortic root were higher in the 256-MDCT group than in the 64-MDCT group (3 vs. 4; p < 0.05), and those at the femoral access routes were comparable (4 vs. 4; p = 0.33). The mean effective dose was significantly reduced by 30 % in the 256-MDCT group (23.6 vs. 16.3 mSv; p < 0.05).

CONCLUSION

In preoperative TAVI CT, volume scans using 256-MDCT provide comparable or better vascular enhancement and IQ with a 30 % reduction in CM and radiation dose than those using 64-MDCT.

IMPLICATIONS FOR PRACTICE

Volume scan using 256-MDCT for preoperative TAVI CT may reduce CM and radiation dose in TAVI patients with renal dysfunction.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

[A Case of Conversion Surgery after SOX plus Nivolumab for Unresectable Advanced Gastric Cancer]

A 63-year-old woman came to our hospital complaining of anemia and weight loss. The abdominal CT showed wall thickening from the upper to lower the body of stomach, and peritoneal dissemination. The EGD revealed a type 3 large tumor extending about 2/3 of the circumference. Adenocarcinoma was detected as a result of biopsy. The patient was diagnosed with unresected gastric cancer(cT4aN+M1, cStage Ⅳ). SOX plus nivolumab was selected as a first-line chemotherapy because of HER2 expression negative. Symptoms such as diarrhea developed, and the treatment was completed until 5 courses. Laparoscopic distal gastrectomy was performed after the disappearance of abdominal dissemination by CT scan and PET. Pathological examination revealed cancer cells were completely disappeared in the tumor, regional lymph nodes and white nodules in the peritoneum, and final diagnosis was ypT0N0M0, ypStage 0(histological effect determination is Grade 3). Six months after the operation, the patient has been free of recurrence.

[A Case of Early Pancreatic Cancer Diagnosed from the Finding of Partial Pancreatic Parenchymal Atrophy]

A man in his 80s was referred to our hospital for further examination of partial pancreatic atrophy that was detected incidentally. Various imaging examinations including CT, MRI, and EUS did not reveal any obvious abnormal findings other than the partial pancreatic atrophy. However, cytological examination of serial pancreatic juice aspiration showed atypical cells. The presence of pancreatic intraepithelial carcinoma in the atrophy site was considered, and the patient underwent laparoscopic distal pancreatectomy. Pathological examination of the excised specimen confirmed the presence of high-grade pancreatic intraepithelial neoplasia consistent with the atrophy site, and the patient was diagnosed with pTisN0M0, Stage 0 pancreatic cancer. For the detection of early pancreatic cancer, it is important to be aware of partial pancreatic atrophy on imaging studies.

Antiferromagnetic topological insulator with selectively gapped Dirac cones

Antiferromagnetic (AF) topological materials offer a fertile ground to explore a variety of quantum phenomena such as axion magnetoelectric dynamics and chiral Majorana fermions. To realize such intriguing states, it is essential to establish a direct link between electronic states and topology in the AF phase, whereas this has been challenging because of the lack of a suitable materials platform. Here we report the experimental realization of the AF topological-insulator phase in NdBi. By using micro-focused angle-resolved photoemission spectroscopy, we discovered contrasting surface electronic states for two types of AF domains; the surface having the out-of-plane component in the AF-ordering vector displays Dirac-cone states with a gigantic energy gap, whereas the surface parallel to the AF-ordering vector hosts gapless Dirac states despite the time-reversal-symmetry breaking. The present results establish an essential role of combined symmetry to protect massless Dirac fermions under the presence of AF order and widen opportunities to realize exotic phenomena utilizing AF topological materials.

A case of carotid-axillary bypass for subclavian steal syndrome in an 83-year-old female undergoing hemodialysis

INTRODUCTION

Patients undergoing hemodialysis exhibit a high incidence of subclavian steal syndrome. Many cases of endovascular treatment for subclavian artery stenosis were only reported recently; however, the long-term results of surgical treatment are also important. Herein, we report a case of subclavian steal syndrome treated with common carotid-axillary bypass surgery in a patient undergoing hemodialysis.

PRESENTATION OF CASE

An 83-year-old woman experienced dizziness and pain in her left hand during hemodialysis. Computed tomography and angiography revealed severe stenosis and calcified lesions in the left subclavian artery. Ultrasonography revealed a retrograde blood flow waveform in the left vertebral artery. The patient was diagnosed with subclavian steal syndrome. We performed common carotid-axillary bypass for lesions that were difficult to revascularize via endovascular therapy. The post-operative course was uneventful, and the dizziness and numbness in the patient's left hand during dialysis disappeared. Post-operative ultrasonography revealed an antegrade blood flow waveform in the left vertebral artery.

DISCUSSION

Subclavian steal syndrome is an indication for revascularization in symptomatic patients. Endovascular treatment should be considered the first choice; however, surgery should be considered for patients in whom endovascular treatment is difficult, such as those with severe calcification. We chose common carotid-axillary artery bypass because the subclavian approach is a more familiar technique. Until 1 year post-operatively, the patient had not experienced any symptom recurrence, and the shunt flow was well maintained.

CONCLUSION

Common carotid-axillary bypass can be useful for revascularization of lesions for which endovascular therapy is considered difficult in patients with subclavian steal syndrome.

Targeted Pubic Neoantigen Immunotherapy Using Encapsulated Nanoparticles, Directed by Radiation

PURPOSE/OBJECTIVE(S)

We tested a treatment combining radiotherapy with pubic neoantigen nanoparticles of CAND1 and ADGRF5-II (120 ± 56 nm) in nanocapsules detectable by computed tomography (CT) (545± 24 nm) with IFN γ or PD-L1 antibody (Ab), which released their contents upon radiation exposure. We performed two radiotherapy sessions: 1) induction of MHC-I and II in tumor cells and dendritic cells (DC) by the first round of radiation with concurrently released IFN γ from nanoparticles; 2) targeted neoantigen immunotherapy with PD-L1 blockade by the second round of radiation, elicited by CAND1-specific CD8+T-cell and ADGRF5-II-specific CD4+T-cell, related to induced MHC-I and MHC-II in session 1, respectively.

MATERIALS/METHODS

For session one, nanocapsules were generated by mixing iopamiron and 15 mg IFN γ with a 1.0 mL solution containing 4.0% alginate, 3.0% hyaluronate, and 1 μg/mL P-selectin. This mixture was sprayed into 0.5 mmol/l FeCl2 supplemented with 1 µg/mL anti-VEGFR-1/2 Ab. For session two, Mixture of 110 fmol CAND1 and fmol ADGRF5-II, were encapsulated into poly lactic-co-Glycolic acid (PLGA) particle, using nanoprecitation method. Those particles were encapsulated by mixing into above alginate-hyaluronate cocktail with 400 mg PD-L1 antibody (Ab), then sprayed into 0.5 mmol/l FeCl2 supplemented with P-selectin Ab. In session one, 1 × 1010 nanocapsules were intravenously injected into BALB/c mice exhibiting primary 4TI mammary carcinoma in the left hind leg and lung metastases. Tumor accumulation was monitored by CT. Subsequently, 10 or 20 Gy 60Co γ-radiation was administered to primary tumors and lung metastasis. In session two, 1 × 1010 nanocapsules were injected i.v. and allowed to interact with P-selectin for 24 h; a further 10 or 20 Gy 60Co γ-radiation was administered to tumors and lung metastasis.

RESULTS

In session one, CT imaged the accumulation of anti-VEGFR-1/2 nanocapsules around primary and metastatic tumors, which helped determine the timing of the first radiation. The nanocapsules released P-selectin and IFN γ in response to first radiation. P-selectin was deposited on tumor vessels. Radiation and released IFN γ elicited MHC-I and II on tumor cells and DCs. In session two, released CAND1 and ADGRF5-II from PLGA particle, which were emitted from nanocapsules upon second radiation, were loaded onto MHC-I and II. Subsequently, two kinds of tertiary complex were formed on tumor cells and DC: 1) MHC-I-CAND1-CD8+T-cell receptor (TCR); and 2) MHC-II- ADGRF5-II-CD4+TCR, which destroyed tumor cells, in collaboration with released PD-L1 Ab. Those T-cell mediated cell killing was magnified via enhanced DC-mediated T-cell priming by the two kinds of tertiary complex on DC. Those treatments resulted in EF 1.5 and 86% reduction of new metastasis formation.

CONCLUSION

Our encapsulated pubic neoantigen particle will lead to quick and effective neoantigen immunotherapy.

Whole-genome sequencing analysis of molecular epidemiology and silent transmissions causing meticillin-resistant Staphylococcus aureus bloodstream infections in a university hospital

BACKGROUND

The emergence of novel genomic-type clones, such as community-associated meticillin-resistant Staphylococcus aureus (MRSA) and livestock-associated MRSA, and their invasion into hospitals have become major concerns worldwide; however, little information is available regarding the prevalence of MRSA in Japan. Whole-genome sequencing (WGS) has been conducted to analyse various pathogens worldwide. Therefore, it is important to establish a genome database of clinical MRSA isolates available in Japan.

AIM

A molecular epidemiological analysis of MRSA strains isolated from bloodstream-infected patients in a Japanese university hospital was conducted using WGS and single-nucleotide polymorphism (SNP) analysis. Additionally, through a review of patients' clinical characteristics, the effectiveness of SNP analysis as a tool for detecting silent nosocomial transmission that may be missed by other methods was evaluated in diverse settings and various time points of detection.

METHODS

Polymerase-chain-reaction-based staphylococcal cassette chromosome mec (SCCmec) typing was performed using 135 isolates obtained between 2014 and 2018, and WGS was performed using 88 isolates obtained between 2015 and 2017.

FINDINGS

SCCmec type II strains, prevalent in 2014, became rare in 2018, whereas the prevalence of SCCmec type IV strains increased from 18.75% to 83.87% of the population, and became the dominant clones. Clonal complex (CC) 5 CC8 and CC1 were detected between 2015 and 2017, with CC1 being dominant. In 88 cases, SNP analyses revealed nosocomial transmissions among 20 patients which involved highly homologous strains.

CONCLUSIONS

Routine monitoring of MRSA by whole-genome analysis is effective not only for gaining knowledge regarding molecular epidemiology, but also for detecting silent nosocomial transmission.

Data-driven cascade control system: Response estimation and controller design

In this study, we propose a data-driven design method for a cascade control system with inner and outer control loops. First, the input-output response of a controlled plant, which varies with the controller parameters of a fixed-structure inner-outer control law, is estimated directly from open-loop input-output data. Next, based on the estimated response, the controller parameters are optimized to minimize the difference between a reference model with a controlled closed-loop system. In the proposed method, the response of a fictitious reference input, which varies with the controller parameters, is estimated, and then the closed-loop response is estimated. Therefore, a closed-loop input-output data is not required, and the controller parameters are determined directly from an open-loop input-output data. Furthermore, the time constant of a reference model is also optimized so as to reduce the control error. The proposed method is compared with both conventional single-loop and cascade data-driven methods by means of numerical examples.

GC-MS analysis of exhaled gas for fine detection of inflammatory diseases

Exhaled gas analysis is a non-invasive test ideal for continuous monitoring of biological metabolic information. We analyzed the exhaled gas of patients with inflammatory diseases for trace gas components that could serve as biomarkers that enable early detection of inflammatory diseases and assessment of treatment efficacy. Furthermore, we examined the clinical potential of this method. We enrolled 34 patients with inflammatory disease and 69 healthy participants. Volatile components from exhaled gas were collected and analyzed by a gas chromatography-mass spectrometry system, and the data were examined for gender, age, inflammatory markers, and changes in markers before and after treatment. The data were tested for statistical significance through discriminant analysis by Volcano plot, Analysis of variance test, principal component analysis, and cluster analysis comparing healthy and patient groups. There were no significant differences in the trace components of exhaled gas by gender or age. However, we found differences in some components of the exhaled gas between healthy and untreated patients. In addition, after treatment, gas patterns including the patient-specific components changed to a state closer to the inflammation-free status. We identified trace components in the exhaled gas of patients with inflammatory diseases and found that some of these regressed after treatment.

Search for the Pair Production of Dark Particles X with K_{L}^{0}→XX, X→γγ

We present the first search for the pair production of dark particles X via K_{L}^{0}→XX with X decaying into two photons using the data collected by the KOTO experiment. No signal was observed in the mass range of 40-110  MeV/c^{2} and 210-240  MeV/c^{2}. This sets upper limits on the branching fractions as B(K_{L}^{0}→XX)<(1-4)×10^{-7} and B(K_{L}^{0}→XX)<(1-2)×10^{-6} at the 90% confidence level for the two mass regions, respectively.

[A Case of Giant Abdominal Desmoid Tumor in a Young Man]

Desmoid tumor is a rare tumor of the soft tissue. The frequency of occurrence is 2.4 to 4.3 cases per year per million people, which is a very rare disease. We experienced a huge intra-abdominal desmoid tumor which is thought to be the primary mesentery. The case was a male in his 20s. He visited a nearby doctor with a complaint of abdominal bloating and abdominal pain. Abdominal contrast CT revealed a huge abdominal mass with a clear boundary of 35×25 cm in size extending from the upper right abdomen to the pelvis. Surgery was performed with a diagnosis of an intra-abdominal mass. Open abdominal tumor resection. Due to infiltration into the duodenum, transverse colon, and pancreas, right hemicolectomy and duodenal combined resection were performed. The pathological diagnosis was a diagnosis of desmoid tumor.

Chromatin Immunoprecipitation Sequencing (ChIP-seq) for Detecting Histone Modifications and Modifiers

Chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) is the most widely used method for analyzing genome-wide DNA-protein interactions. Because there is considerable variation in the modes and strengths of DNA-protein interactions, chromatin immunoprecipitation (ChIP) protocols have been diversified and optimized for different needs. Here, we describe protocols for detecting histone modifications and modifiers using various crosslinking and immunoprecipitation conditions. We provide a complete ChIP-seq workflow covering sample preparation, immunoprecipitation, next-generation sequencing (NGS) library preparation, and data analyses.

Giant spin polarization and a pair of antiparallel spins in a chiral superconductor

Chiral molecules can exhibit spin-selective charge emission, which is known as chirality-induced spin selectivity^1,2. Despite the constituent light elements of the molecules, their spin polarization can approach or even exceed that of typical ferromagnets. This powerful capability may lead to applications in the chiral spintronics² field. Although the origin of spin selectivity is elusive, two microscopic phenomena have been suggested based on experimental results: effective enhancement of spin-orbit interactions³ and chirality represented by a pair of oppositely polarized spins^4,5. However, the hypotheses remain to be verified. Here we report the simultaneous observation of these two phenomena in an organic chiral superconductor by magnetoresistance measurements in the vicinity of the superconducting transition temperature. A pair of oppositely polarized spins is demonstrated by spatially mapping the spin polarity in an electric alternating current excitation. The obtained spin polarization exceeds that of the Edelstein effect^6-10 by several orders of magnitude, which indicates an effective enhancement of the spin-orbit interaction. Our results demonstrate a solid-state analogue of spin accumulations assumed for chiral molecules, and may provide clues to the origin of their molecular counterparts. In addition, the innovative capability of spin-current sourcing will invigorate superconducting spintronics research¹¹.

[A Case of Primary Hepatic Mucosa-Associated Lymphoid Tissue Lymphoma]

A 74-year-old man with no chronic liver disease was admitted for an incidental liver tumor by computed tomography. Serological examinations for hepatitis B and C virus were negative and tumor markers, including carcinoembryonic antigen, α-fetoprotein, carbohydrate antigen 19-9, and des-gamma-carboxy prothrombin, were within the normal range. The contrast- enhanced magnetic resonance imaging revealed that the 26 mm in diameter patchy tumor occupied the S7 in the liver. The tumor boundary was enhanced slightly in the arterial phase and inside gradually in the portal phase, and the enhancement was faded in the late phase. As a characteristic finding, vessels penetrated the tumor. The tumor was diagnosed as cholangiocarcinoma, and the patient underwent right lateral sectionectomy. After 19 days postoperatively, the patient was discharged. The diagnosis of hepatic mucosa-associated lymphoid tissue(MALT)lymphoma was made by pathological examination. Currently, the patient has no recurrence for 5 months without adjuvant chemotherapy. The primary hepatic MALT lymphoma is a rare disease among primary hepatic malignant lymphomas. The patient must be followed up carefully because 2 cases were reported as recurrent cases after several years postoperatively although the disease has a good prognosis.

[A Case of Giant Pancreatic Mucinous Cystic Neoplasm That Was Difficult to Preoperative Diagnosis]

A 43-year-old woman with about abdominal distension was referred to our hospital for a more detailed examination. Abdominal CT showed 27 cm-sized cystic lesion with the calcification along the partition wall and a nodular hyperplasia. We suspected pancreatic pseudocyst, primary retroperitoneal tumor and we performed tumorectomy. The resected specimen had a maximum diameter of 27 cm. The histopathological diagnosis was mucinous cystadenocarcinoma of the pancreas with ovarian-type stroma. The adjuvant chemotherapy treated with gemcitabine was selected for 3 courses. She continues to do well without any recurrences 7 months later.

[A Case of Laparoscopically Resected Sigmoid Colon Cancer and Transverse Colon Mesentery Primary Solitary Fibrous Tumor]

The patient is a 52-year-old woman who visited the general practitioner because of positive fecal occult blood test by medical examination. The patient underwent colonoscopy at the hospital, which revealed sigmoid colon cancer. Therefore, the patient was referred to our hospital for surgery. Preoperative CT scan revealed a well-defined and lobulated 54 mm tumor on the caudal side of the duodenal third portion. On MRI, the tumor showed low T1-weighted image signal and high T2-weighted and diffusion-weighted images signal, with low ADC. For preoperative diagnosis, we diagnosed sigmoid colon cancer and transverse colon mesenteric and performed laparoscopic sigmoid colon and transverse colon mesenteric tumor resections. The histopathological tumor diagnoses were sigmoid colon cancer(S, type 2, 30×30 mm, 1/2 circumference, moderately differentiated adenocarcinoma, pT3[SS], INF b, Ly1a, V1a, pN1b[#252: 2/4], sM0, fStage Ⅲb)and transverse colon mesentery primary solitary fibrous tumor. The patient was treated with XELOX as the adjuvant chemotherapy and survived without recurrence until present.

Expected resolution limits of x-ray free-electron laser single-particle imaging for realistic source and detector properties

The unprecedented intensity of x-ray free-electron laser sources has enabled single-particle x-ray diffraction imaging (SPI) of various biological specimens in both two-dimensional projection and three dimensions (3D). The potential of studying protein dynamics in their native conditions, without crystallization or chemical staining, has encouraged researchers to aim for increasingly higher resolutions with this technique. The currently achievable resolution of SPI is limited to the sub-10 nanometer range, mainly due to background effects, such as instrumental noise and parasitic scattering from the carrier gas used for sample delivery. Recent theoretical studies have quantified the effects of x-ray pulse parameters, as well as the required number of diffraction patterns to achieve a certain resolution, in a 3D reconstruction, although the effects of detector noise and the random particle orientation in each diffraction snapshot were not taken into account. In this work, we show these shortcomings and address limitations on achievable image resolution imposed by the adaptive gain integrating pixel detector noise.

Teaching Control during the COVID-19 Pandemic

This paper aims to analyze some different solutions that were adopted in control education activities during the pandemic. The authors of this paper are educators in the control education field from different countries on all the continents, who have developed a questionnaire with the idea of collecting data about the COVID-19 pandemic impact on the control education activities. The main objective is to study the diverse alternatives that were used worldwide to perform the online educational activities during that period, such as methodologies, tools, learning management systems (LMS), theoretical exercises, laboratory experiments, types of exams, simulators, software for online lecturing, etc. As a result, comparisons between pre-and during-pandemic educational resources and methods are performed, where useful ideas and discussions are given for the control education community.

Nuclear accumulation of MLKL induces necroptosis in cardiomyocytes: potential implication in Doxorubicin-induced cardiotoxicity

Background

The treatment with doxorubicin, a powerful chemotherapeutic agent, has been shown to be associated with an increased risk of lethal heart failure. Although various types of cell death pathway such as apoptosis and ferroptosis have been shown to be involved in the development of doxorubicin-induced cardiotoxicity, DIC, the involvement of necroptosis, a novel programmed necrosis induced by translocation of activated mixed lineage kinase domain-like protein, MLKL, to plasma membrane, remains unclear.

Purpose

The aim of this study was to determine whether necroptosis is involved in the development of DIC.

Methods and results

DIC was induced in C57BL/6J mice by intraperitoneal injection of doxorubicin at a dose of 10 mg/kg 3 times for a week. Eight days after the commencement of injection, echocardiographic analyses showed that left ventricular ejection fraction assessed by echocardiography was significantly lower in the doxorubicin-treated mice than in the vehicle-treated mice (44.0±13.7 vs. 70.5±3.7%), indicating the development of DIC. Immunoblot analysis showed that MLKL protein level was higher by 1.6 fold in the doxorubicin-treated mice than in the vehicle-treated mice. Interestingly, immunohistochemical analysis showed that signals of phospho-Ser345-MLKL, an activated form of MLKL, was found in the nuclei in addition to cytosol and intercalated discs of cardiomyocytes in the doxorubicin-treated mice. To get novel insight into significance of nuclear MLKL accumulation, a leucine-rich nuclear export signal (NES) spanning amino acids 280–284 of rat MLKL was identified by site-directed mutation analyses, and H9c2 cells, cultured rat cardiomyoblasts, were transfected with expression constructs for nucleus-directed MLKL (FLAG-mtNES-MLKL) or its wild type (FLAG-WT-MLKL). Percentage of FLAG-positive cells stained with Zombie Red, a fluorescent dye that is non-permeant to live cells, was higher in FLAG-mtNES-MLKL-transfected cells than in FLAG-WT-MLKL-transfected cells (80.0±3.5% vs. 6.3±1.3%, p&lt;0.05), whereas percentage of cells immunostained with cleaved caspase-3 to FLAG-positive cells was similar in the two groups. The effect of the MLKL mutant on necroptosis was attenuated by treatment with GppNHp, an inhibitor of Ran-mediated nuclear protein import.

Conclusion

Nuclear accumulation of MLKL induces necroptosis in cardiomyocytes, which may contribute to progression of DIC.

Funding Acknowledgement

Type of funding sources: None.

Clinical trajectory and outcomes of patients with heart failure with preserved ejection fraction with normal or indeterminate diastolic function

Background

Heart failure (HF) with preserved ejection fraction (HFpEF) is a chronic and progressive disease, but limited therapeutic strategies are currently available. Although left ventricular diastolic dysfunction (DD) is a prominent mechanism of HFpEF, a certain number of patients with HFpEF have a normal diastolic function (ND) or indeterminate diastolic function (ID). With the progressive nature of HFpEF, diastolic function may change over time. However, the change of diastolic function, its predictor and prognosis in patients with clinically established HFpEF remains unknown.

Purpose

To investigate the clinical trajectory and outcomes of patients with HFpEF with ND or ID and to identify factors associated with progression from ND or ID at discharge to DD at 1-year follow-up.

Methods

Using data from a prospective multicenter observational study of patients with HFpEF, we extracted 289 patients with HFpEF with ND or ID at discharge who had echocardiographic data at 1-year follow-up for the re-evaluation of diastolic function. Diastolic function was assessed according to the 2016 American Society of Echocardiography recommendations. Patients were classified according to the absence or presence of progression from ND or ID to DD at 1 year. The primary endpoint was a composite of all-cause death and HF rehospitalization.

Results

Median age was 81 years, and 138 (47.8%) patients were female. At 1 year, 107 (37%) patients progressed to DD. During a median follow-up of 709 days, the composite endpoint occurred in 90 (31.1%) patients. Compared to patients without progression to DD, those with progression to DD had a significantly higher cumulative incidence rate of the composite endpoint (incidence rate: 11.7/100 person-year versus 23.3/100 person-year, P&lt;0.001). Progression to DD (adjusted HR: 2.014, 95% CI: 1.239–3.273, P=0.005) was independently associated with the composite endpoint. Age (adjusted OR: 1.046, 95% CI: 1.008–1.087, P=0.018), body mass index (BMI) (adjusted OR: 1.107, 95% CI: 1.029–1.192, P=0.006), and serum albumin (adjusted OR: 0.459, 95% CI: 0.216–0.974, P=0.042) were independently associated with progression from ND or ID to DD at 1 year.

Conclusion

More than one-third of patients with HFpEF with ND or ID progressed to DD at 1 year and had poor clinical outcomes. Age, BMI, and serum albumin were independently associated with this progression.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by grants from Japan Society for the Promotion of Science KAKENHI (No. JP 17K09496) and Japan Agency for Medical Research and Development (No. JP16lk1010013).

Impact of right ventricular reserve on exercise capacity and quality of life in patients with left ventricular assist device

Background

Right heart failure following left ventricular assist device (LVAD) implantation is a major complication which significantly impairs functional capacity and quality of life (QoL). Right ventricular (RV) reserve function may limit exercise capacity and QoL in LVAD patients; however, most patients show normal RV haemodynamics at rest.

Purpose

The aim of this study was to investigate whether RV reserve assessed by the changes of RV function during exercise is correlated with exercise capacity and QoL in patients with LVAD.

Methods

We prospectively examined 20 consecutive LVAD patients who were admitted to our university hospital between June 2020 and November 2021 after excluding those who were unable to perform exercise (n=8). All patients underwent invasive exercise right heart catheterisation with simultaneous echocardiography in the supine position. RV stroke work index (RVSWI) was calculated as 0.0136 × stroke volume index × (mean pulmonary artery pressure [mPAP] − right atrial pressure [RAP]) at rest and during exercise. Exercise capacity and QoL were assessed by 6-minute walk distance (6MWD) and peak oxygen consumption (VO2) in cardiopulmonary exercise testing, and the EuroQol visual analogue scale (EQ-VAS), respectively. The patients were divided into two groups according to the median ΔRVSWI (RVSWI change from rest to peak exercise) of 1.45 (interquartile range [IQR] −0.31 to 8.25) g/m2.

Results

Patients were predominantly male (75%) and the median age was 47 (IQR 38–60) years. Patients with lower ΔRVSWI had significantly higher change on RAP (P=0.019), but significantly lower change on mPAP (P&lt;0.001) compared to those with higher ΔRVSWI. There were no significant differences in age, gender, primary aetiology of heart failure, type of LVAD devices, or echocardiographic parameters including tricuspid annular plane systolic excursion, and RVSWI at rest between the groups. ΔRVSWI during exercise were positively correlated with 6MWD (R=0.69, P&lt;0.01) and peak VO2 (R=0.66, P&lt;0.01) (Figure A). In addition, ΔRVSWI during exercise were positively correlated with the EQ-VAS (R=0.48, P=0.031). On the other hand, there was no significant correlation between RVSWI at rest and 6MWD (R=−0.11, P=0.63) and peak VO2 (R=0.13, P=0.95), and the EQ-VAS (R=0.11, P=0.61). During a median follow-up period of 312 (IQR 176–369) days, adverse events occurred in 3 patients (15%), including 1 death and 2 hospitalisations for major bleeding and right heart failure. Kaplan-Meier analysis revealed that the adverse events more frequently occurred in patients with lower ΔRVSWI compared to those with higher ΔRVSWI (Figure B).

Conclusions

ΔRVSWI was positively correlated with 6MWD, peak VO2 and EQ-VAS irrespective of RV function at rest. Our findings suggest that the assessment of RV reserve function using ΔRVSWI would be useful for risk stratification in patients with LVAD.

Funding Acknowledgement

Type of funding sources: None.

Premature atrial contraction on Holter electrocardiogram predicts the recurrence of atrial fibrillation after catheter ablation

Introduction

It is important to detect the recurrence of atrial fibrillation (AF) after catheter ablation (CA) early, but the method of detection has not been established. The purpose of this study is to determine whether 24-h Holter electrocardiogram (ECG) can predict the recurrence of AF after CA.

Methods

We studied 336 patients of 497 patients enrolled in EARNEST-PVI trial to investigate whether the total number of premature atrial contraction (PAC) and the maximum number of PAC run by 24-h Holter ECG at 6 months after CA predicted AF recurrence after 6 months. We excluded 86 patients with recurrence by 6 months after CA and 75 patients without Holter ECG at 6 months after CA.

Results

Median age was 66 years, male were 77% and median follow-up period was 1138 days. Receiver operating characteristic curve analysis identified the total number of PAC ≥270 beats and the maximum number of PAC run ≥8 beats as the optimal cutoff for prediction of AF recurrence. Kaplan-Meier analysis showed patients with the total number of PAC ≥270 beats had more frequent AF recurrence than those without (Kaplan-Meier estimated 3-year AF recurrence rate 34% vs. 17%, Log-rank P=0.001) and patients with the maximum number of PAC run ≥8 beats had more frequent AF recurrence than those without (Kaplan-Meier estimated 3-year AF recurrence rate 33% vs. 20%, Log-rank P=0.006). Multivariate analysis revealed that the total number of PAC ≥270 beats and the maximum number of PAC run were significantly associated with AF recurrence (hazard ratio [95% confidence interval] 1.83 [1.16–2.91], P=0.01 and 1.01 [1.01–1.02], P=0.001, respectively)

Conclusion

The total number of PAC and the maximum number of PAC run on the Holter ECG may be useful in predicting AF recurrence after CA.

Funding Acknowledgement

Type of funding sources: None.

Evaluation of the direct protective effects of Canagliflozin on the Isoproterenol-induced cell injury in rat cardiomyocytes

Background

Sodium-glucose cotransporter-2 (SGLT2) inhibitors are agents that act by inhibiting glucose and sodium reabsorption in the proximal renal tubule which promotes urinary glucose excretion. More recently, significant benefit data of SGLT2 inhibitors in patients with heart failure, independent of the presence of type 2 diabetes has been reported. We have previously demonstrated that Canagliflozin (Cana), a SGLT2 inhibitor, reduced the ventricular effective refractory period in isoproterenol (ISP)-induced myocardial injury rat model accompanied with the suppression of reactive oxygen species and the elevation of ketone bodies, suggesting the effect of Cana on electrical cardiac remodeling. The direct effect of Cana to the cardiomyocytes and its underlying molecular mechanism was remained to be clarified. We therefore established an ISP-induced neonatal rat ventricular cardiomyocyte (NRVCM) in vitro model, pretreated with Cana and/or ketone bodies.

Methods

Primary NRVCM were isolated from Wistar rats, were pretreated by Cana with or without βOHB (the most abundant ketone body in circulation), followed by a stimulation of ISP (10μM). Cells without drug or ketone body pretreatment were used as control. We then analyzed its effect on cell viability, apoptosis, and mitochondrial membrane potential using MTT assay, TUNEL assay, and mitochondrial membrane potential assay, respectively. MTT assay was also performed with or without PI3k inhibitor, LY294002. The end-labeling of DNA fragmentation were labelled with FITC, followed by the nuclei counterstain with DAPI and were observed with confocal microscope. The apoptotic index was defined as the percentage of TUNEL positive cells / total nuclei.

Results

Cana rescued the reduction of NRVCM cell viability induced by ISP stimulation for 24 hours which was inhibited by LY294002 compared to cells without pretreatment. Interestingly, pretreatment of βOHB with or without Cana improved also the NRCVM cell viability whereas there was no significant difference between these two conditions or with cells treated with Cana only, suggesting the direct protective effect of Cana. In 48 hours of ISP stimulation, the apoptotic index intends to decrease in Cana and/or βOHB compared to cells without pretreatment (Figure 1). Although the mitochondrial function was maintained in Cana-pretreated cells compared to cells without pretreatment, there was no significant difference in βOHB-pretreated cells.

Conclusions

Cana has a direct protective effect on cardiomyocytes cell viability, apoptosis as well as the mitochondrial function impaired by ISP through the cell survival signaling PI3K/Akt pathway. This brings a new insight to the therapeutic target of cardiovascular disease.

Funding Acknowledgement

Type of funding sources: None.

Applying patient characteristics, stent-graft selection, and pre-operative computed tomographic angiography data to a machine learning algorithm: Is endoleak prediction possible?

INTRODUCTION

This study aims to predict endoleak after endovascular aneurysm repair (EVAR) using machine learning (ML) integration of patient characteristics, stent-graft configuration, and a selection of vessel lengths, diameters and angles measured using pre-operative computed tomography angiography (CTA).

METHODS

We evaluated 1-year follow-up CT scans (arterial and delayed phases) in patients who underwent EVAR for the presence or absence of an endoleak. We also obtained data on the patient characteristics, stent-graft selection, and preoperative CT vessel morphology (diameter, length, and angle). The extreme gradient boosting (XGBoost) for the ML system was trained on 30 patients with endoleaks and 81 patients without. We evaluated 5217 items in 111 patients with abdominal aortic aneurysms, including the patient characteristics, stent-graft configuration and vascular morphology acquired using pre-EVAR abdominal CTA. We calculated the area under the curve (AUC) of our receiver operating characteristic analysis using the ML method.

RESULTS

The AUC, accuracy, 95% confidence interval (CI), sensitivity, and specificity were 0.88, 0.88, 0.79-0.97, 0.85, and 0.91 for ML applying XGBoost, respectively.

CONCLUSIONS

The diagnostic performance of the ML method was useful when factors such as the patient characteristics, stent-graft configuration and vessel length, diameter and angle of the vessels were considered from pre-EVAR CTA.

IMPLICATIONS FOR PRACTICE

Based on our findings, we suggest that this is a potential application of ML for the interpretation of abdominal CTA scans in patients with abdominal aortic aneurysms scheduled for EVAR.

Data-driven control for multi-rate multi-input/single-output systems

For the next generation of manufacturing, represented by Industrie 4.0, a multi-input controller is designed directly from controlled data, without using the mathematical plant model, where the ratio between the D/A conversion of multiple inputs and the A/D conversion of a single output is non-uniquely. With the proposed method, the fixed-structured controller is optimally designed by solving a model reference problem using one-shot data. Furthermore, to eliminate inter-sample ripples emerged by input oscillation, the deviation of the control inputs is also evaluated using the proposed method. As a result, a non-ripple data-driven controller is achieved. Numerical examples show that the proposed multi-rate data-driven method is superior than the conventional single-rate method.

Na+/K+ ATPase α1 and β3 subunits are localized to the basolateral membrane of trophectoderm cells in human blastocysts

STUDY QUESTION

Is there a relation between specific Na+/K+ ATPase isoform expression and localization in human blastocysts and the developmental behavior of the embryo?

SUMMARY ANSWER

Na+/K+ ATPase α1, β1 and β3 are the main isoforms expressed in human blastocysts and no association was found between the expression level of their respective mRNAs and the rate of blastocyst expansion.

WHAT IS KNOWN ALREADY

In mouse embryos, Na+/K+ ATPase α1 and β1 are expressed in the basolateral membrane of trophectoderm (TE) cells and are believed to be involved in blastocoel formation (cavitation).

STUDY DESIGN, SIZE, DURATION

A total of 20 surplus embryos from 11 patients who underwent IVF and embryo transfer at a university hospital between 2009 and 2018 were analyzed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

After freezing and thawing Day 5 human blastocysts, their developmental behavior was observed for 24 h using time-lapse imaging, and the expression of Na+/K+ ATPase isoforms was examined using quantitative RT-PCR (RT-qPCR). The expressed isoforms were then localized in blastocysts using fluorescent immunostaining.

MAIN RESULTS AND THE ROLE OF CHANCE

RT-qPCR results demonstrated the expression of Na+/K+ ATPase α1, β1 and β3 isoforms in human blastocysts. Isoforms α1 and β3 were localized to the basolateral membrane of TE cells, and β1 was localized between TE cells. A high level of β3 mRNA expression correlated with easier hatching (P = 0.0261).

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

The expression of mRNA and the localization of proteins of interest were verified, but we have not been able to perform functional analysis.

WIDER IMPLICATIONS OF THE FINDINGS

Of the various Na+/K+ ATPase isoforms, expression levels of the α1, β1 and β3 mRNAs were clearly higher than other isoforms in human blastocysts. Since α1 and β3 were localized to the basolateral membrane via fluorescent immunostaining, we believe that these subunits contribute to the dilation of the blastocoel. The β1 isoform is localized between TE cells and may be involved in tight junction formation, as previously reported in mouse embryos.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the JSPS KAKENHI (https://www.jsps.go.jp/english/index.html), grant number 17K11215. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors have no conflicts of interest.

Optimizing Calibration for a Capacitance-Based Void Fraction Sensor with Asymmetric Electrodes under Horizontal Flow in a Smoothed Circular Macro-Tube

In this study, a technique that uses a capacitance sensor with an asymmetric electrode to measure the void fraction of a refrigerant was developed. It is known that the void fraction and flow pattern affect the measured capacitance. Therefore, the relationship between the void fraction and capacitance is not linear; hence, a calibration method for obtaining accurate measurements is necessary. A calibration method was designed in this study based on repeated capacitance measurements and the bimodal temporal distribution to calibrate the atypical and repetitive flow patterns of slug flow and its transition to the intermittent flow regime. The calibration method also considers the weighted-average relation for the gradual transition of the intermittent to annular flow pattern according to the change from low to high quality. The proposed method was experimentally analyzed under the conditions of R32 refrigerant, a tube inner diameter of 7.1 mm, saturation temperature of 25 °C, mass flux of 100-400 kg m^-2 s^-1, and vapor quality of 0.025-0.900, and it was validated using a quick-closing valve (QCV) system under identical conditions. A relative error of 2.99% was obtained for the entire system, indicating good agreement between the proposed and QCV-based methods.

Radiation dose reduction method combining the ECG-Edit function and high helical pitch in retrospectively-gated CT angiography

INTRODUCTION

The purpose of this study was to demonstrate that dose reduction does not compromise image quality when combining high helical pitch (HP) and the ECG-Edit function during low HP retrospectively gated computed tomography angiography (CTA).

METHODS

This study made use of a pulsating cardiac phantom (ALPHA 1 VTPC). The heart rate (HR) of the cardiac phantom was changed in five intervals, every 5 beats per minute (bpm), from 40 to 60 bpm. Evaluation of a range of HR was important because data loss might occur when combining a low HR and high HP. We performed retrospectively gated CTA scans five times using a low HP (0.16) and high HP (0.24), for each of the five HR intervals, using a 64-detector row CT scanner. The CT volume dose index (CTDI_vol) was recorded from the CT console of each scan. For the images with data loss, data were repaired using the ECG-Edit function. We compared the CTDI_vol, estimated cardiac phantom volume, and the visualization of the coronary ladder phantom between HP 0.16, with or without repaired HP 0.24, using the ECG-Edit function.

RESULTS

Data loss occurred with a HR of 40 bpm and 45 bpm when using HP 0.24. The CTDI_vol was reduced by approximately 33% with HP 0.24 when compared with HP 0.16. There were no significant differences in the mean cardiac motion phantom volume and visualization scores between HP 0.16 and with and without repaired HP 0.24 using the ECG-Edit function (p < 0.05).

CONCLUSION

The ECG-Edit function is potential useful for repairing the lost data in patients with a low HR, and when combined with a high HP, it is possible to reduce the radiation dose by approximately 33%.

IMPLICATIONS FOR PRACTICE

The ECG-Edit function and high HP may be a viable option in pediatric CTA studies.

Observation of photo-induced plasmon-phonon coupling in PbTe via ultrafast x-ray scattering

We report the observation of photo-induced plasmon-phonon coupled modes in the group IV-VI semiconductor PbTe using ultrafast x-ray diffuse scattering at the Linac Coherent Light Source. We measure the near-zone-center excited-state dispersion of the heavily screened longitudinal optical (LO) phonon branch as extracted from differential changes in x-ray diffuse scattering intensity following above bandgap photoexcitation. We suggest that upon photoexcitation, the LO phonon-plasmon coupled (LOPC) modes themselves become coupled to longitudinal acoustic modes that drive electron band shifts via acoustic deformation potentials and possibly to low-energy single-particle excitations within the plasma and that these couplings give rise to displacement-correlations that oscillate in time with a period given effectively by the heavily screened LOPC frequency.