A VS ultrasound diagnostic system with kidney image evaluation functions.

PURPOSE: An inevitable feature of ultrasound-based diagnoses is that the quality of the ultrasound images produced depends directly on the skill of the physician operating the probe. This is because physicians have to constantly adjust the probe position to obtain a cross section of the target organ, which is constantly shifting due to patient respiratory motions. Therefore, we developed an ultrasound diagnostic robot that works in cooperation with a visual servo system based on deep learning that will help alleviate the burdens imposed on physicians. METHODS: Our newly developed robotic ultrasound diagnostic system consists of three robots: an organ tracking robot (OTR), a robotic bed, and a robotic supporting arm. Additionally, we used different image processing methods (YOLOv5s and BiSeNet V2) to detect the target kidney location, as well as to evaluate the appropriateness of the obtained ultrasound images (ResNet 50). Ultimately, the image processing results are transmitted to the OTR for use as motion commands. RESULTS: In our experiments, the highest effective tracking rate (0.749) was obtained by YOLOv5s with Kalman filtering, while the effective tracking rate was improved by about 37% in comparison with cases without such filtering. Additionally, the appropriateness probability of the ultrasound images obtained during the tracking process was also the highest and most stable. The second highest tracking efficiency value (0.694) was obtained by BiSeNet V2 with Kalman filtering and was a 75% improvement over the case without such filtering. CONCLUSION: While the most efficient tracking achieved is based on the combination of YOLOv5s and Kalman filtering, the combination of BiSeNet V2 and Kalman filtering was capable of detecting the kidney center of gravity closer to the kidney's actual motion state. Furthermore, this model could also measure the cross-sectional area, maximum diameter, and other detailed information of the target kidney, which meant it is more practical for use in actual diagnoses.

Methanofullerene Synthesis via Photogenerated Fullerene Radical Anion Intermediates.

This work describes the synthesis of PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) derivatives and other methanofullerene derivatives via generation of fullerene radical anions under photoirradiation and controlled by photoswitching, without preparation, a strong reducing agent, or precise control of the reaction conditions.

Regioselectivity enhancement in synthesis of [70]fullerene derivatives by introduction of a branched structure.

Regio-purity in [70]fullerene derivatives is of great importance to improve the power conversion efficiencies of organic photovoltaics. We found that the introduction of a branched structure to [70]PCBM enhanced the yield of α-isomers. The effect of the steric group in the reaction mechanism was theoretically investigated and a difference in the activation energies within specific pathways was revealed.

Controlling the Polarity of Fullerene Derivatives to Optimize Nanomorphology in Blend Films.

Developing a design strategy to establish the compatibility of acceptor materials with donor materials is important for the rational development of organic solar cells. We synthesized 2,6-dimethoxyphenyl methanofullerene derivatives to realize an enhanced open-circuit voltage, and we investigated polarities and their effects on the film morphology of the active layer. The polarities of the synthesized fullerene derivatives were affected significantly by the presence of functional groups, such as methoxy, ether, and ester groups. Macro/nanoscopic morphological investigation and spectroscopic analysis of the blend films of the poly(3-hexylthiophene)(P3HT)/fullerene derivatives showed that a balanced polarity between materials results in the formation of optimized nanomorphology without grains and robust phase separation. Measurements of the device performance of the photovoltaic cells composed of P3HT and the fullerene derivatives confirmed the same tendency as that shown in the morphological analysis. This finding enables us to obtain an improved power conversion efficiency because of the enhanced open circuit voltage derived from the fullerene derivatives.

Intracoronary electrocardiogram ST-segment elevation in patients with non-ST-segment elevation myocardial infarction and its association with culprit lesion location and myocardial injury.

AIMS: An intracoronary electrocardiogram (IC-ECG) is a sensitive method to detect local myocardial ischaemia. We investigated the prevalence of IC-ECG ST-segment elevation (STE) with respect to culprit lesion location in patients with non-ST-segment elevation myocardial infarction (NSTEMI) and its relationship with elevated levels of cardiac biomarkers. METHODS AND RESULTS: We examined 87 NSTEMI patients who underwent IC-ECG recording by locating the insulated polymer-coated guidewire distal to the culprit lesion before percutaneous coronary intervention (PCI). Cardiac biomarkers were serially examined. IC-ECG STE was observed in 24 patients (27.6%) before PCI, and was significantly more frequent in patients with LCx culprit lesions (LAD vs. LCx vs. RCA, 12.1% vs. 53.3% vs. 16.7%; p<0.001). Peak cardiac troponin I (cTnI) values were associated with IC-ECG STE, ejection fraction (EF), cTnI values on admission, and type B2/C lesions. In multivariate analysis, IC-ECG STE (odds ratio [OR], 5.04; 95% confidence intervals [CI]: 1.51-16.85; p=0.009), and EF (OR, 0.95; 95% CI: 0.90-1.00; p=0.043) were predictors of greater peak cTnI values. CONCLUSIONS: IC-ECG STE was not uncommon in NSTEMI patients, particularly those with LCx culprit lesions. IC-ECG monitoring before PCI may help identify NSTEMI patients with high risk of greater myocardial injury.

Variability of microcirculatory resistance index and its relationship with fractional flow reserve in patients with intermediate coronary artery lesions.

BACKGROUND: The relationship between the functional significance of epicardial coronary artery stenosis and microvascular resistance remains to be determined. Furthermore, little is known regarding the determinants of microvascular resistance in patients with intermediate coronary lesions. METHODS AND RESULTS: Using a pressure-temperature sensor-tipped guidewire, thermodilution-derived index of microcirculatory resistance (IMR) was measured, along with fractional flow reserve (FFR), in 131 coronary arteries of 104 patients with intermediate stenosis, in order to determine the relationship between IMR and clinical data. IMR varied widely (median, 20.8; range, 6.3-65.2), and no significant relationship was observed between IMR and FFR after IMR was corrected for coronary wedge pressure in the territories with functionally significant stenoses. There was no significant relationship between IMR and Framingham risk score, systematic coronary risk evaluation (SCORE), ACC/AHA lesion classification, or SYNTAX score. Right coronary artery (RCA) lesion location and history of hypertension were significantly associated with increased IMR. Multivariate analysis showed that RCA lesion location (odds ratio [OR], 4.52; 95% confidence interval [CI]: 1.84-11.11, P=0.001) and hypertension (OR, 3.03; 95% CI: 1.15-7.96, P=0.025) were independent predictors of increased IMR. CONCLUSIONS: Functional significance of intermediate coronary stenosis was not correlated with microvascular resistance of the perfusion territory. Intermediate coronary lesions may result in increased microcirculatory resistance irrespective of functional significance of the stenosis, with significant regional difference in microvascular resistance.

Design of fullerene derivatives for stabilizing LUMO energy using donor groups placed in spatial proximity to the C60 cage.

A series of arylated dihydrofullerene derivatives were synthesized to elucidate the effective design of fullerene derivatives for enhancing the performance of organic photovoltaics. The LUMO energy of the fullerenes was estimated by the first reduction potential and theoretical calculations. The results showed that the methoxy groups substituted at spatial proximity to the fullerene core offered significant stabilization of the LUMO level. The stabilizing effect of the directly arylated fullerenes is more significant than that of conventional methanofullerenes. The theoretical investigation was performed with regard to the electronic interaction between the methoxy and fullerene moieties.

Impact of coronary plaque morphology assessed by optical coherence tomography on cardiac troponin elevation in patients with elective stent implantation.

BACKGROUND: Mild elevations of cardiac troponin frequently occur after percutaneous coronary intervention (PCI), and patients with elevated post-PCI biomarkers have a worse prognosis. We used optical coherence tomography (OCT) to study the relationship between pre-PCI plaque morphology and post-PCI cardiac troponin I elevations. METHODS AND RESULTS: One hundred thirty-one patients with normal pre-PCI cardiac troponin I levels underwent OCT before nonemergency stent implantation. Clinical and OCT findings were compared between patients with (n=31, 23.7%) and without (n=100, 76.3%) post-PCI cardiac troponin I of >3 × upper reference limit (post-PCI myocardial infarction [MI]). After PCI, long-term follow-up data were collected. Post-PCI MI was associated with angiographic lesion length, type B2/C lesions, presence of thin-cap fibroatheroma, and fibrous cap thickness. In multivariable analysis, presence of thin-cap fibroatheroma (odds ratio, 10.47; 95% confidence interval, 3.74 to 29.28; P<0.001) and type B2/C lesions (odds ratio, 3.74; 95% confidence interval, 1.41 to 9.92; P=0.008) were predictors of post-PCI MI. At a median follow-up of 12 months, cardiac event-free survival was significantly worse in patients with post-PCI MI (log-rank test χ(2)=8.9; P=0.003). Cox proportional hazards analysis showed that post-PCI MI (hazard ratio, 3.67; 95% confidence interval, 1.39 to 9.65; P=0.009) and ejection fraction (hazard ratio, 0.96; 95% confidence interval, 0.92 to 0.99; P=0.029) were independent predictors of adverse cardiovascular events during follow-up. CONCLUSIONS: Type B2/C lesions and the presence of OCT-defined thin-cap fibroatheroma can predict post-PCI MI in patients treated with elective stent implantation, who may require adjunctive therapy after otherwise successful PCI.

Asymmetric total synthesis of highly symmetric squalene-derived cytotoxic polyethers.

The efficient total synthesis of the cytotoxic meso polyether teurilene (1), rarely occurring in nature, was achieved through the effective combination of the concept of two-directional synthesis and rhenium(VII) chemistry. In the key rhenium(VII)-promoted syn oxidative cyclization reaction of the two-directional substrate 16, trans-syn diastereoselectivity (steric control) has been observed in contrast to our early observation of cis-syn diastereoselectivities (chelation control) for bishomoallylic tertiary alcohols 24-27 possessing the neighboring tetrahydrofuran (THF) ring. This synthesis in only 10 steps from commercially available methyl tiglate is significantly shorter than the previous one requiring 25 steps. The total syntheses of four possible C(s) symmetric (3 and 47-49) and one C2 symmetric (4) compounds for biogenetically squalene-derived pentaTHF polyether, glabrescol, was also achieved in relatively few steps by taking advantage of its intrinsic symmetry and one- and two-directional modes of double THF ring formations with vanadium catalyst, tert-butyl hydroperoxide (TBHP), and trifluoroacetic acid (TFA). Thus, the meso structure 3 originally proposed by Jacobs et al. has been revised to the optically pure C2 symmetric structure 4 through its enantioselective total synthesis.