Intravascular ultrasound (IVUS) is a valuable imaging modality for the diagnosis of atherosclerosis. It provides useful clinical information, such as lumen size, vessel wall thickness, and plaque ...composition, by providing a cross-sectional vascular image. For several decades, IVUS has made remarkable progress in improving the accuracy of diagnosing cardiovascular disease that remains the leading cause of death globally. As the quality of IVUS images mainly depends on the performance of the IVUS transducer, various IVUS transducers have been developed. Therefore, in this review, recently developed mechanically rotating IVUS transducers, especially ones exploiting piezoelectric ceramics or single crystals, are discussed. In addition, this review addresses the history and technical challenges in the development of IVUS transducers and the prospects of next-generation IVUS transducers.
Deep‐blue triplet emitters remain far inferior to standard red and green triplet emitters in terms of exhibiting high‐color‐purity Commission International de l'Éclairage (CIE) y values of ≤0.1, ...external quantum efficiencies (EQEs), and high electroluminescent brightnesses in phosphorescent organic light‐emitting diodes. In fact, no deep‐blue triplet emitter with color purity and high device performance has previously been reported. In this study, a deep‐blue triplet emitter, mer‐tris(N‐phenyl, N‐benzyl‐pyridoimidazol‐2‐yl)iridium(III) (mer‐Ir1) is developed, which meets the requirements of the National Television System Committee (NTSC) CIE(x, y) coordinates of (0.149, 0.085) with an extremely high EQE of 24.8% and maximum brightness (Lmax) of 6453 cd m−2, by a device with a 40 vol% doping ratio. Moreover, another device demonstrates an EQEmax of 21.3%, an Lmax of 5247 cd m−2, and CIE(x, y) coordinates of (0.151, 0.086) at a 30 vol% doping ratio. This is the first report of a high‐performance, deep‐blue phosphor, carbene‐based Ir(III) complex device with outstanding CIE(x, y) color coordinates and a high EQE. The results of this study indicate that the novel dopant mer‐Ir1 is a promising candidate for reducing power consumption in display applications.
A high external quantum efficiency for deep‐blue‐emitting organic light‐emitting diodes is developed using a novel carbene‐based Ir(III) complex, which enhances the carrier balance in the emission layer. A high quantum efficiency of 24% with a deep‐blue CIE(x, y) coordinate of (0.149, 0.085) is achieved, which satisfies the stringent National Television System Committee (NTSC) requirements with high efficiency.
The authors investigated the utility of noninvasive hemodynamic assessment in the identification of high-risk plaques that caused subsequent acute coronary syndrome (ACS).
ACS is a critical event ...that impacts the prognosis of patients with coronary artery disease. However, the role of hemodynamic factors in the development of ACS is not well-known.
Seventy-two patients with clearly documented ACS and available coronary computed tomographic angiography (CTA) acquired between 1 month and 2 years before the development of ACS were included. In 66 culprit and 150 nonculprit lesions as a case-control design, the presence of adverse plaque characteristics (APC) was assessed and hemodynamic parameters (fractional flow reserve derived by coronary computed tomographic angiography FFRCT, change in FFRCT across the lesion △FFRCT, wall shear stress WSS, and axial plaque stress) were analyzed using computational fluid dynamics. The best cut-off values for FFRCT, △FFRCT, WSS, and axial plaque stress were used to define the presence of adverse hemodynamic characteristics (AHC). The incremental discriminant and reclassification abilities for ACS prediction were compared among 3 models (model 1: percent diameter stenosis %DS and lesion length, model 2: model 1 + APC, and model 3: model 2 + AHC).
The culprit lesions showed higher %DS (55.5 ± 15.4% vs. 43.1 ± 15.0%; p < 0.001) and higher prevalence of APC (80.3% vs. 42.0%; p < 0.001) than nonculprit lesions. Regarding hemodynamic parameters, culprit lesions showed lower FFRCT and higher △FFRCT, WSS, and axial plaque stress than nonculprit lesions (all p values <0.01). Among the 3 models, model 3, which included hemodynamic parameters, showed the highest c-index, and better discrimination (concordance statistic c-index 0.789 vs. 0.747; p = 0.014) and reclassification abilities (category-free net reclassification index 0.287; p = 0.047; relative integrated discrimination improvement 0.368; p < 0.001) than model 2. Lesions with both APC and AHC showed significantly higher risk of the culprit for subsequent ACS than those with no APC/AHC (hazard ratio: 11.75; 95% confidence interval: 2.85 to 48.51; p = 0.001) and with either APC or AHC (hazard ratio: 3.22; 95% confidence interval: 1.86 to 5.55; p < 0.001).
Noninvasive hemodynamic assessment enhanced the identification of high-risk plaques that subsequently caused ACS. The integration of noninvasive hemodynamic assessments may improve the identification of culprit lesions for future ACS. (Exploring the Mechanism of Plaque Rupture in Acute Coronary Syndrome Using Coronary CT Angiography and Computational Fluid Dynamic EMERALD; NCT02374775)
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Small molecules based on N‐atom‐linked phenylcarbazole‐fluorene as the main scaffold, end‐capped with spirobifluorene derivatives, are developed as organic hole‐transporting materials for highly ...efficient perovskite solar cells (PSCs) and bulk heterojunction (BHJ) inverted organic solar cells (IOSCs). The CzPAF‐SBF‐based devices show remarkable device performance with excellent long‐term stability in PSCs and BHJ IOSCs with a maximum PCE of 17.21% and 7.93%, respectively.
We report a strongly amplified photoacoustic (PA) performance of the new functional hybrid material composed of reduced graphene oxide and gold nanorods. Due to the excellent NIR light absorption ...properties of the reduced graphene oxide coated gold nanorods (r-GO-AuNRs) and highly efficient heat transfer process through the reduced graphene oxide layer, r-GO-AuNRs exhibit excellent photothermal stability and significantly higher photoacoustic amplitudes than those of bare-AuNRs, nonreduced graphene oxide coated AuNRs (GO-AuNRs), or silica-coated AuNR, as demonstrated in both in vitro and in vivo systems. The linear response of PA amplitude from reduced state controlled GO on AuNR indicates the critical role of GO for a strong photothermal effect of r-GO-AuNRs. Theoretical studies with finite-element-method lab-based simulation reveal that a 4 times higher magnitude of the enhanced electromagnetic field around r-GO-AuNRs can be generated compared with bare AuNRs or GO-AuNRs. Furthermore, the r-GO-AuNRs are expected to be a promising deep-tissue imaging probe because of extraordinarily high PA amplitudes in the 4–11 MHz operating frequency of an ultrasound transducer. Therefore, the r-GO-AuNRs can be a useful imaging probe for highly sensitive photoacoustic images and NIR sensitive therapeutics based on a strong photothermal effect.
Objective: For accurate diagnosis of atherosclerosis, the high spatial and contrast resolutions of intravascular ultrasound (IVUS) images are a key requirement. Increasing the center frequency of ...IVUS is a simple solution to meet this requirement. However, this leads to a reduction in imaging depth due to the frequency-dependent attenuation of ultrasound. Here, we report a recently developed dual-element IVUS transducer for tissue harmonic imaging (THI) and frequency compounding to increase the spatial and contrast resolutions of IVUS images, while maintaining the imaging depth to assess the overall morphological change of blood vessels. Methods: One 35-MHz element is used for producing general IVUS images and the other 70-MHz element is for receiving the second harmonic signals induced by the 35-MHz ultrasound. The fundamental and second harmonic signals can also be used for frequency compound imaging to further improve contrast resolution. The spatial and contrast resolutions achieved by the developed transducer were evaluated through wire and tissue-mimicking phantom imaging tests. Additionally, the images of a stent deployed in a tissue-mimicking phantom and an excised pig artery were acquired to assess clinical usefulness of the transducer. Results: The results demonstrated that the developed IVUS transducer enables us to simultaneously examine the overall morphological change of blood vessels by the 35-MHz ultrasound images and the near vessel layers such as the intima, the media, and the adventitia by either THI or compound images with high spatial and contrast resolutions. In addition, the developed transducer facilitates the simultaneous acquisition of 35- and 70-MHz fundamental images when needed. Conclusion: The developed dual-element IVUS transducer makes it possible to fully realize the potential benefits of IVUS in the diagnosis of atherosclerosis.
Large hydrogen‐storage capacity at liquid‐nitrogen temperature is exhibited by the metal–organic framework MIL‐101. In the zeotype architecture of this porous solid (see picture) each intersection of ...the cages is occupied by a supertetrahedron formed by trimers of chromium octahedra assembled with benzene‐1,4‐dicarboxylate ligands.
High efficiency and flexible inverted organic solar cells have been fabricated using solution-processed silver nanowire/zinc oxide composite transparent electrodes. The transparent electrodes showed ...a low sheet resistance of -13 ff）.sq-1 and high transmittance of -93% as well as superior mechanical flexibility. Power conversion efficiencies of -7.57% and -7.21% were achieved for devices fabricated on glass and plastic substrate, respectively. Moreover, the flexible devices did not show any degradation in their performance even after being folded with a radius of-480 μm.
Background
Although several prospective studies have reported the efficacy of stereotactic body radiotherapy (SBRT) for hepatocellular carcinoma (HCC), treatment‐related toxicity varies and has not ...been determined. Therefore, the authors evaluated the safety and efficacy of SBRT for patients with HCC in a hepatitis B virus‐endemic area.
Methods
This multicenter phase 2 trial enrolled patients with unresectable HCC. Patients received SBRT with 45 to 60 Gy in 3 fractions. To evaluate gastroduodenal toxicity, esophagogastroduodenoscopy (EGD) was performed before and 2 months after SBRT. The primary endpoint was treatment‐related severe toxicity at 1 year after SBRT. The secondary endpoints were the 2‐year local control, progression‐free survival, and overall survival rates.
Results
In total, 74 patients were enrolled between January 2012 and April 2015, and 65 eligible patients were analyzed. One patient experienced radiation‐induced liver disease with acute grade ≥3 toxicity 1 month after SBRT. In addition, 1 patient had a grade 3 esophageal ulcer with stenosis 5 months after SBRT. The actuarial rate of treatment‐related severe toxicity at 1 year was 3%. The pre‐SBRT and post‐SBRT EGD findings were not significantly different among the 57 evaluable patients who underwent EGD. The 2‐year and 3‐year local control rates were 97% and 95%, respectively. The progression‐free and overall survival rates were 48% and 84% at 2 years, respectively, and 36% and 76% at 3 years, respectively.
Conclusions
With a median follow‐up of 41 months, this prospective multicenter study demonstrated that SBRT for patients with HCC is well tolerated and is an effective treatment modality.
This multicenter phase 2 trial is focused on hepatic toxicity and esophagogastroendoscopy‐based gastroduodenal toxicity after stereotactic body radiotherapy in patients with hepatocellular carcinoma. On the basis of a low severe toxicity rate of 3% at 1 year, stereotactic body radiotherapy can be safely applied for the treatment of unresectable hepatocellular carcinoma in a hepatitis B virus‐endemic area.
Thyroid cancer (TC) includes tumors of follicular cells; it ranges from well differentiated TC (WDTC) with generally favorable prognosis to clinically aggressive poorly differentiated TC (PDTC) and ...undifferentiated TC (UTC). Papillary thyroid cancer (PTC) is a WDTC and the most common type of thyroid cancer that comprises almost 70-80% of all TC. PTC can present as a solid, cystic, or uneven mass that originates from normal thyroid tissue. Prognosis of PTC is excellent, with an overall 10-year survival rate >90%. However, more than 30% of patients with PTC advance to recurrence or metastasis despite anti-cancer therapy; consequently, systemic therapy is limited, which necessitates expansion of improved clinical approaches. We strived to elucidate genetic distinctions due to patient-derived anti-cancer drug-sensitive or -resistant PTC, which can support in progress novel therapies. Patients with histologically proven PTC were evaluated. PTC cells were gained from drug-sensitive and -resistant patients and were compared using mRNA-Seq. We aimed to assess the in vitro and in vivo synergistic anti-cancer effects of a novel combination therapy in patient-derived refractory PTC. This combination therapy acts synergistically to promote tumor suppression compared with either agent alone. Therefore, genetically altered combination therapy might be a novel therapeutic approach for refractory PTC.
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