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Objectives: To evaluate the added value of MR dynamic susceptibility contrast (DSC)-perfusion-weighted imaging (PWI)-derived tumour microvascular and oxygenation information with cerebral blood volume (CBV) to distinguish pseudoprogression from true progression (TP) in post-treatment glioblastoma. Methods: This retrospective single-institution study included patients with isocitrate dehydrogenase (IDH) wild-type glioblastoma and a newly developed or enlarging measurable contrast-enhancing mass within 12 weeks after concurrent chemoradiotherapy. CBV, capillary transit time heterogeneity (CTH), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO2) were obtained from DSC-PWI. Predictors were selected using univariable logistic regression, and performance was measured with adjusted diagnostic odds with tumour volume and area under the curve (AUC) of receiver operating characteristics analysis. Results: A total of 103 patients were included (mean age, 59.6 years; 59 women), with 67 cases of TP and 36 cases of pseudoprogression. Pseudoprogression exhibited higher CTH (4.0 vs. 3.4, p =.019) and higher OEF (12.7 vs. 10.7, p =.014) than TP, but a similar CBV (1.48 vs. 1.53, p =.13) and CMRO2 (7.7 vs. 7.3s, p =.598). Independent of tumour volume, both high CTH (adjusted odds ratio [OR] 1.52; 95% confidence interval [CI]: 1.11–2.09, p =.009) and high OEF (adjusted OR 1.17; 95% CI:1.03–1.33, p =.016) were predictors of pseudoprogression. The combination of CTH, OEF, and CBV yielded higher diagnostic performance (AUC 0.71) than CBV alone (AUC 0.65). Conclusion: High intratumoural capillary transit heterogeneity and high oxygen extraction fraction derived from DSC-PWI have enhanced the diagnostic value of CBV in pseudoprogression of post-treatment IDH-wild type glioblastoma. Clinical relevance statement: In the early post-treatment stage of glioblastoma, pseudoprogression exhibited both high oxygen extraction fraction and high capillary transit heterogeneity and these dynamic susceptibility contrast-perfusion weighted imaging derived parameters have added value in cerebral blood volume-based noninvasive differentiation of pseudoprogression from true progression. Key Points: • Capillary transit time heterogeneity and oxygen extraction fraction can be measured noninvasively through processing of dynamic susceptibility contrast imaging. • Pseudoprogression exhibited higher capillary transit time heterogeneity and higher oxygen extraction fraction than true progression. • A combination of cerebral blood volume, capillary transit time heterogeneity, and oxygen extraction fraction yielded the highest diagnostic performance (area under the curve 0.71). [ABSTRACT FROM AUTHOR]

This study reveals the trajectories of Korean companies that employ technologies related to 4IR. The data were based on the 2017 and 2018 corporate surveys conducted by Korea Statistics' Microdata Integrated Service. The network analysis methodology was applied, with a focus on visualizing the relationships between nine technologies. The results are as follows; First, there were differences between the corporate technology absorption trajectories from the integrated perspective and from the perspective of the detailed application fields. Second, the Internet of Things occupied a greater proportion, compared to other technologies, in several technology absorption trajectories. This seems to reflect the hyper-connectivity of the Fourth Industrial Revolution. Third, hyper-intelligence appears to be at a nascent stage, in terms of utilization with other technologies. This paper primarily contributes empirical evidence to existing research on technological trajectories with unique data and results, which is generally depending on patents data, creating a foundation for further theoretical and practical applications by scholars and managers. [ABSTRACT FROM AUTHOR]

The application of nanoscale energetic materials (nEMs) composed of metal and oxidizer nanoparticles (NPs) in thermal engineering systems is limited by their relatively high sensitivity and complex three-dimensional (3D) formability. Polymers can be added to nEMs to lower the sensitivity and improve the formability of 3D structures. In this study, the effect of the addition of polyethylene oxide (PEO; polymer) on the combustion characteristics of aluminum (Al; fuel)/copper oxide (CuO; oxidizer)-based nEMs is investigated. With an increase in the PEO content, the resulting PEO/nEM composites are desensitized to relatively high electrical spark discharges. However, the maximum explosion-induced pressure decreases significantly, and the combustion flame fails to propagate when the PEO content exceeds 15 wt.%. Therefore, the optimal PEO content in a nEM matrix must be accurately determined to achieve a compromise between sensitivity and reactivity. To demonstrate their potential application as composite solid propellants (CSPs), 3D-printed disks composed of PEO/nEM composites were assembled using additive manufacturing. They were cross-stacked with conventional potassium nitrate (KNO3)/sucrose (C12H22O11)-based disk-shaped CSPs in a combustion chamber of small rocket motors. Propulsion tests indicated that the specific impulse of KNSU/PEO/nEM (nEMs: 3.4 wt.%)-based CSPs was at a maximum value, which is approximately three times higher than that of KNSU CSPs without nEMs. This suggests that the addition of an optimized amount of polymer to nEMs is beneficial for various CSPs with compromised sensitivity and reactivity and excellent 3D formability, which can significantly enhance the propulsion of small projectiles. [ABSTRACT FROM AUTHOR]

Objectives: To determine whether imaging-based risk stratification enables prognostication in diffuse glioma, NOS (not otherwise specified). Methods: Data from 220 patients classified as diffuse glioma, NOS, between January 2011 and December 2020 were retrospectively included. Two neuroradiologists analyzed pre-surgical CT and MRI to assign gliomas to the three imaging-based risk types considering well-known imaging phenotypes (e.g., T2/FLAIR mismatch). According to the 2021 World Health Organization classification, the three risk types included (1) low-risk, expecting oligodendroglioma, isocitrate dehydrogenase (IDH)-mutant, and 1p/19q-codeleted; (2) intermediate-risk, expecting astrocytoma, IDH-mutant; and (3) high-risk, expecting glioblastoma, IDH-wildtype. Progression-free survival (PFS) and overall survival (OS) were estimated for each risk type. Time-dependent receiver operating characteristic analysis using 10-fold cross-validation with 100-fold bootstrapping was used to compare the performance of an imaging-based survival model with that of a historical molecular-based survival model published in 2015, created using The Cancer Genome Archive data. Results: Prognostication according to the three imaging-based risk types was achieved for both PFS and OS (log-rank test, p < 0.001). The imaging-based survival model showed high prognostic value, with areas under the curves (AUCs) of 0.772 and 0.650 for 1-year PFS and OS, respectively, similar to the historical molecular-based survival model (AUC = 0.74 for PFS and 0.87 for OS). The imaging-based survival model achieved high long-term performance in both 3-year PFS (AUC = 0.806) and 5-year OS (AUC = 0.812). Conclusion: Imaging-based risk stratification achieved histomolecular-level prognostication in diffuse glioma, NOS, and could aid in guiding patient referral for insufficient or unsuccessful molecular diagnosis. Key Points: • Three imaging-based risk types enable distinct prognostication in diffuse glioma, NOS (not otherwise specified). • The imaging-based survival model achieved similar prognostic performance as a historical molecular-based survival model. • For long-term prognostication of 3 and 5 years, the imaging-based survival model showed high performance. [ABSTRACT FROM AUTHOR]

The expanded perlite-based building material for drywall application consisting of sodium silicate solution as a binder was manufactured by varying the degree of compaction and sodium silicate content to investigate moisture diffusion behavior and the effect of moisture treatment on flexural properties of the composites. Moisture treatment was conducted on specimens in a climatic chamber at a temperature of 37°C and a relative humidity of 90% until saturation. Results show that moisture absorption decreased with increasing compaction ratio for a constant sodium silicate content in binder and increased with increasing sodium silicate content in binder for a constant compaction ratio. A range of volume fractions of solid sodium silicate in the foam is identified, in which the fully Fickian diffusion gradually transformed to non-Fickian diffusion as sodium silicate content in foam increased. The concentration-dependent diffusion method was found to be suitable to explain this behavior. The moisture diffusion below this transition range showed an entirely Fickian diffusion and changed to concentration-dependent diffusion above the range. As a result of moisture treatment, the flexural strength of medium density foams was decreased but the lowest- and highest-density foams were not affected while the flexural modulus was increased only for the highest density foam and no significant effects were seen in other cases. The bending failure mechanism of the composite was not affected by the moisture treatment. [ABSTRACT FROM AUTHOR]

Objectives: Tissue conductivity measurements made with electrical properties tomography (EPT) can be used to define temporal changes in tissue habitats on longitudinal multiparametric MRI. We aimed to demonstrate the added insights for identifying tumor habitats obtained by including EPT with diffusion- and perfusion-weighted MRI, and to evaluate the use of these tumor habitats for determining tumor treatment response in post-treatment glioblastoma. Methods: Tumor habitats were developed from EPT, diffusion-weighted, and perfusion-weighted MRI in 60 patients with glioblastoma who underwent concurrent chemoradiotherapy. Voxels from EPT, apparent diffusion coefficient (ADC), and cerebral blood volume (CBV) maps were clustered into habitats, and each habitat was serially examined to assess its temporal change. The usefulness of temporal changes in tumor habitats for diagnosing tumor progression and treatment-related change was investigated using logistic regression. The performance of significant predictors was measured using the area under the curve (AUC) from receiver-operating-characteristics analysis with 1000-fold bootstrapping. Results: Five tumor habitats were identified, and of these, the hypervascular cellular habitat (odds ratio [OR] 5.45; 95% CI, 1.75–31.42; p =.02), hypovascular low conductivity habitat (OR 2.00; 95% CI, 1.45–3.05; p <.001), and hypovascular intermediate habitat (OR 1.57; 95% CI, 1.18–2.30; p =.006) were predictive of tumor progression. Low EPT and low CBV reflected a unique hypovascular low conductivity habitat that showed the highest diagnostic performance (AUC 0.86; 95% CI, 0.76–0.96). The combined habitats showed high performance (AUC 0.90; 95% CI, 0.82–0.98) in the differentiation of tumor progression from treatment-related change. Conclusion: EPT reveals low conductivity habitats that can improve the diagnosis of tumor progression in post-treatment glioblastoma. Key Points: • Electrical properties tomography (EPT) demonstrated lower conductivity in tumor progression than in treatment-related change. • EPT allowed identification of a unique hypovascular low conductivity habitat when combined with cerebral blood volume mapping. • Tumor habitats with a hypovascular low conductivity habitat, hypervascular cellular habitat, and hypovascular intermediate habitat yielded high diagnostic performance for diagnosing tumor progression. [ABSTRACT FROM AUTHOR]

Background: Updated response assessment in neuro-oncology (RANO) does not consider peritumoral non-enhancing lesion (NEL) and baseline (residual) contrast enhancement (CE) volume. The objective of this study is to explore helpful imaging characteristics to refine RANO for assessing early treatment response (pseudoprogression and time-to-progression [TTP]) in patients with IDH wild-type glioblastoma.Methods: This retrospective study enrolled 86 patients with IDH wild-type glioblastoma who underwent consecutive MRI examinations before and after concurrent chemoradiotherapy (CCRT). NEL was classified as edema- or tumor-dominant type on pre-CCRT MRI. CE evolution was categorized into 4 patterns based on post-operative residual CE (measurable vs. non-measurable) and CE volume change (same criteria with RANO) during CCRT. Multivariable logistic regression, including clinical parameters, NEL type, and CE evolution pattern, was used to analyze pseudoprogression rate. TTP and OS according to NEL type and CE evolution pattern was analyzed by the Kaplan-Meier method.Results: Pseudoprogression rate was significantly lower (chi-square test, P = .047) and TTP was significantly shorter (hazard ratio [HR] = 2.03, P = .005) for tumor-dominant type than edema-dominant type of NEL. NEL type was the only predictive marker of pseudoprogression on multivariate analysis (odds ratio = 0.26, P = .046). Among CE evolution patterns, TTP and OS was shortest in patients with residual CE compared with those exhibiting new CE (HR = 4.33, P < 0.001 and HR = 3.71, P = .009, respectively). In edema-dominant NEL type, both TTP and OS was stratified by CE evolution pattern (log-rank, P = .001), whereas it was not in tumor-dominant NEL.Conclusions: NEL type improves prediction of pseudoprogression and, together with CE evolution pattern, further stratifies TTP and OS in patients with IDH wild-type glioblastoma and may become a helpful biomarker for refining RANO. [ABSTRACT FROM AUTHOR]

Colloidal suspensions incorporating particles are pivotal in diverse industries because of their distinct properties. However, challenges such as particle aggregation and sedimentation have impeded their widespread application. Existing techniques for assessing dispersion stability have limitations with respect to the particle type, concentration, and suspension properties. This study focuses on an innovative approach for assessing the dispersion stability and presents a streamlined method for analyzing the particle size and distribution. A theoretical model considering gravity, buoyancy, and viscous forces acting on the particles was developed to calculate the time-varying thickness of the sediment layer at the bottom of the sample colloid. The 3ω method is employed to measure thermal resistance changes at the sample droplet's bottom due to sedimentation. An empirical comparison utilizing Al 2 O 3 particles in deionized water validates the efficacy of the method in understanding sedimentation mechanisms. In addition, a stability constant was proposed to quantitatively compare sedimentation phenomena, factoring in mixing methods, time, particle concentration, and shelf time. This study enhanced the quantification of the dispersion stability of colloids by enabling swift and precise assessment of particle concentration, size, and distribution inside a sample droplet. [Display omitted] • A novel approach to evaluate dispersion stability of a droplet of alumina colloids. • Particle concentration, size, and dispersion stability analyzed using sediment layer's transient thickness. • Dispersion stability depending on mixing parameters are quantified by a stability constant. [ABSTRACT FROM AUTHOR]

Current image processing methods for dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) do not capture complex dynamic information of time-signal intensity curves. We investigated whether an autoencoder-based pattern analysis of DSC MRI captured representative temporal features that improves tissue characterization and tumor diagnosis in a multicenter setting. The autoencoder was applied to the time-signal intensity curves to obtain representative temporal patterns, which were subsequently learned by a convolutional neural network. This network was trained with 216 preoperative DSC MRI acquisitions and validated using external data (n = 43) collected with different DSC acquisition protocols. The autoencoder applied to time-signal intensity curves and clustering obtained nine representative clusters of temporal patterns, which accurately identified tumor and non-tumoral tissues. The dominant clusters of temporal patterns distinguished primary central nervous system lymphoma (PCNSL) from glioblastoma (AUC 0.89) and metastasis from glioblastoma (AUC 0.95). The autoencoder captured DSC time-signal intensity patterns that improved identification of tumoral tissues and differentiation of tumor type and was generalizable across centers. [ABSTRACT FROM AUTHOR]

Conventional dual-active-bridge (DAB) dc–dc converters have a limited structure to balance the bipolar voltage level of the bipolar dc distribution system. Therefore, to regulate the bipolar voltage level, additional voltage balancers are needed for the DAB converters, which eventually requires more devices resulting in low power conversion efficiency and low power density. This article proposes an enhanced DAB dc–dc converter that can balance the bipolar voltage level without the additional voltage balancers. The bipolar voltage level can be tightly regulated under entire unbalanced load condition and even when there is no-load at one side of the dc poles. Besides, its zero-voltage-switching capability can be extended to cover the entire load range, including the no-load condition. Furthermore, the proposed converter can be operated by using a simple single phase-shift modulation. Therefore, its control algorithm can be easily implemented in digital controllers. Finally, the theoretical analysis and the effectiveness of the proposed DAB converter are validated by a 3-kW prototype converter. [ABSTRACT FROM AUTHOR]

In this report, we propose an easy and viable fabrication method for growing multilayer graphene (MLG)-encapsulated nickel nanoparticles (Ni NPs) via a one-step continuous aerosol process comprising combined spray pyrolysis (SP) and thermal chemical vapor deposition (CVD). A bimodal size distribution was observed for the Ni NPs owing to droplet-to-particle and gas-to-particle conversions undergone in the SP at ~1000 °C. The number of graphene layers grown on the surface of Ni NPs in the thermal CVD was controlled by varying the reaction temperature of 300–700 °C, which perturbed the solubility and diffusion rates of carbon in Ni NPs. Finally, we demonstrated that the MLG-encapsulated Ni NP-added nanoenergetic materials were stably ignited by flash irradiation in a short ignition delay time (~267 μs) with fast burn rate (~200 m·s−1). This suggests that the MLG-encapsulated Ni NPs could play an important role as potential optical igniters for practical thermal engineering applications. Unlabelled Image • Multilayer graphene (MLG) is grown on the surface of Ni nanoparticles (NPs) in the gas phase. • The number of graphene layer is controlled by varying the reaction temperature. • MLG-encapsulated Ni NPs are ignited by flash irradiation due to photothermal effect. [ABSTRACT FROM AUTHOR]

• NaN 3 MP/Al NP/metal oxide NP composite powders are ignited using a MHP heater. • The composite powders with CuO and KIO 4 have high burn and pressurization rates. • The addition of CuO and KIO 4 NPs fully inflates the small airbags within ~20 ms. • The addition of Fe 2 O 3 NPs partially inflates the airbags due to incomplete reaction. We investigated the effects of different metal oxide (MO) nanoparticles (e.g., CuO, KIO 4 , Fe 2 O 3) on the combustion and gas-generating characteristics of sodium azide microparticle (NaN 3 MP; gas-generating agent) and aluminum nanoparticle (Al NP; heat source) composite powders. The NaN 3 MP/Al NP/MO NP composite powders were stably ignited using a microhotplate (MHP) heater. The addition of CuO and KIO 4 to the NaN 3 MP/Al NP composite powders resulted in relatively high burn rates and high pressurization rates upon MHP-assisted ignition. This suggests that the highly reactive CuO and KIO 4 NPs significantly increased the combustion of the Al NPs; as a result, sufficient heat energy was generated via the active aluminothermic reaction to thermally decompose the NaN 3 MPs. Finally, the gas generating properties of NaN 3 MP/Al NP composite powders mixed with various MO NPs were tested using homemade inflatable small airbags. The airbags were fully inflated within ~20 ms when CuO and KIO 4 NPs were added to the NaN 3 MP/Al NP composite powders. However, the addition of Fe 2 O 3 NPs to the NaN 3 MP/Al NP composite powder resulted in a slow and only partial inflation of the airbag due to an incomplete aluminothermic reaction, which was due to a slow combustion reaction between the Al NPs and relatively weak oxidizer of the Fe 2 O 3 NPs. This suggests that the rapid, stable, and complete thermal decomposition of NaN 3 MP/Al NP composites can be effectively achieved by employing highly reactive nanoscale oxidizers. [ABSTRACT FROM AUTHOR]

Background: To evaluate radiomics analysis in neuro-oncologic studies according to a radiomics quality score (RQS) system to find room for improvement in clinical use.Methods: Pubmed and Embase were searched up the terms radiomics or radiogenomics and gliomas or glioblastomas until February 2019. From 189 articles, 51 original research articles reporting the diagnostic, prognostic, or predictive utility were selected. The quality of the methodology was evaluated according to the RQS. The adherence rates for the six key domains were evaluated: image protocol and reproducibility, feature reduction and validation, biologic/clinical utility, performance index, a high level of evidence, and open science. Subgroup analyses for journal type (imaging vs. clinical) and biomarker (diagnostic vs. prognostic/predictive) were performed.Results: The median RQS was 11 out of 36 and adherence rate was 37.1%. Only 29.4% performed external validation. The adherence rate was high for reporting imaging protocol (100%), feature reduction (94.1%), and discrimination statistics (96.1%), but low for conducting test-retest analysis (2%), prospective study (3.9%), demonstrating potential clinical utility (2%), and open science (5.9%). None of the studies conducted a phantom study or cost-effectiveness analysis. Prognostic/predictive studies received higher score than diagnostic studies in comparison to gold standard (P < .001), use of calibration (P = .02), and cut-off analysis (P = .001).Conclusions: The quality of reporting of radiomics studies in neuro-oncology is currently insufficient. Validation is necessary using external dataset, and improvements need to be made to feature reproducibility, demonstrating clinical utility, pursuits of a higher level of evidence, and open science. [ABSTRACT FROM AUTHOR]

A whole network consists of the relationships that exist among members of a population. However, prior studies treated the whole network as a metaphor, and consequently, existing empirical research is limited. As such, this paper investigates the effects of a whole network on firm innovation performance among firms engaged in the Korean semiconductor industry using three variables, namely main component, eigenvector centrality, and closeness centrality. The effects are then analysed using two-step generalised method of moments estimates. The results show a firm is included among the main component in a whole network, and the more centralised it is in terms of connectivity and distance, the more advantageous it is for firm innovation. The significance of this paper is two-fold; First, unlike previous studies that use variables reflecting collective characteristics, this study uses variables reflecting the characteristics of individual firms in a whole network. Second, it is a rare empirical study of a whole network. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the imaging features of isocitrate dehydrogenase (IDH) mutant glioma and to assess the diagnostic performance of magnetic resonance imaging (MRI) for prediction of IDH mutation in patients with glioma.Methods: A systematic search of Ovid-MEDLINE and EMBASE up to 10 October 2017 was conducted to find relevant studies. The search terms combined synonyms for 'glioma', 'IDH mutation' and 'MRI'. Studies evaluating the imaging features of IDH mutant glioma and the diagnostic performance of MRI for prediction of IDH mutation in patients with glioma were selected. The pooled summary estimates of sensitivity and specificity and their 95% confidence intervals (CIs) were calculated using a bivariate random-effects model. The results of multiple subgroup analyses are reported.Results: Twenty-eight original articles in a total of 2,146 patients with glioma were included. IDH mutant glioma showed frontal lobe predominance, less contrast enhancement, well-defined border, high apparent diffusion coefficient (ADC) value and low relative cerebral blood volume (rCBV) value. For the meta-analysis that included 18 original articles, the summary sensitivity was 86% (95% CI, 79%-91%) and the summary specificity was 87% (95% CI, 78-92%). In a subgroup analysis, the summary sensitivity of 2-hydroxyglutarate magnetic resonance spectroscopy (MRS) [96% (95% CI, 91-100%)] was higher than the summary sensitivities of other imaging modalities.Conclusions: IDH mutant glioma consistently demonstrated less aggressive imaging features than IDH wild-type glioma. Despite the variety of different MRI techniques used, MRI showed the potential to non-invasively predict IDH mutation in patients with glioma. 2-Hydroxyglutarate MRS shows higher pooled sensitivity than other imaging modalities.Key Points: • IDH mutant glioma showed frontal lobe predominance, less contrast enhancement, well-defined border, high ADC value, and low rCBV value. • The diagnostic performance of MRI for prediction of IDH mutation in patients with glioma is within a clinically acceptable range, the summary sensitivity was 86% (95% CI, 79-91%) and the summary specificity was 87% (95% CI, 78-92%). • In a subgroup analysis, the summary sensitivity of 2-hydroxyglutarate MRS [96% (95% CI, 91-100%)] was higher than the summary sensitivities of other imaging modalities. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • TiO 2 nanoparticles (NPs) with intra-particle porosity are fabricated using surfactant-tempted aerosol process. • Surfactant plays the role as a templating medium to support pore structures inside TiO 2 matrix. • TiO 2 NPs with highly porous structures enhance the photodegradation of methylene blue. Abstract In this work, we fabricated crystallite solid and porous TiO 2 nanoparticles (NPs) using a surfactant-templated aerosol process. Specifically, Brij-58 surfactant was employed as a template in TiO 2 matrix. The porosity of TiO 2 NPs was controlled by varying the amount of Brij-58. The effect of TiO 2 porosity on the photocatalytic reactivity was systematically examined. As a result, the highly porous TiO 2 NPs exhibited much better photocatalytic reactivity than the low porosity TiO 2 NPs. This suggests that the particle size, crystallite structure, and specific surface area play an important role in enhancing the photocatalytic reactivity of the TiO 2 NPs. [ABSTRACT FROM AUTHOR]

Although advanced magnetic resonance imaging (MRI) techniques provide useful information for the differential diagnosis of intra-axial mass-like lesions, the specific diagnostic role of multimodal MRI over conventional magnetic resonance imaging (CMRI) alone in the differential diagnosis of mass-like lesions from a large heterogeneous cohort has not been studied. In this study, we aimed to determine the added value of a joint approach of diffusion-weighted imaging (DWI) and dynamic-susceptibility-contrast perfusion imaging (DSC-PWI) for diagnosis of intra-axial mass-like lesions, comparing them with CMRI alone. Furthermore, we performed these evaluations in a manner simulating clinical practice. Our institutional review board approved this retrospective study and waived the requirement for informed consent. A total of 1038 patients with intra-axial mass-like lesions were retrospectively recruited according to their histological and clinico-radiological diagnoses made between January 2005 and December 2014. All patients underwent CMRI, DWI and DSC-PWI. The diagnostic accuracy and confidence in diagnosing each type of intra-axial mass-like lesions, and for differentiating the intra-axial brain tumors from non-neoplastic lesions, were compared according to the MRI protocols. The disease-specific sensitivity of joint approach differed according to specific disease entities in diagnosing each disease category. Joint approach provided the best diagnostic accuracy for discriminating intra-axial brain tumors from non-neoplastic lesions, with high diagnostic accuracy (95.3–96.7%), specificity (82–84.0%), positive-predictive-value (97.0–97.3%), and negative-predictive-value (84.8–92.7%), with the reader’s confidence values being significantly improved over those on CMRI alone (all p-values < 0.001). In conclusion, joint approach of DWI, DSC-PWI to CMRI helps to differentiate non-neoplastic lesions from intra-axial brain tumors, and improves diagnostic confidence compared with CMRI alone. The benefit from the combined imaging differs for each disease category; thus joint approach needs to be customized according to clinical suspicion. [ABSTRACT FROM AUTHOR]

Objectives: Differentiation of glioma from brain metastasis is clinically crucial because it affects the clinical outcome of patients and alters patient management. Here, we present a systematic review and meta-analysis of the currently available data on perfusion magnetic resonance imaging (MRI) for differentiating glioma from brain metastasis, assessing MRI protocols and parameters.Methods: A computerised search of Ovid-MEDLINE and EMBASE databases was performed up to 3 October 2017, to find studies on the diagnostic performance of perfusion MRI for differentiating glioma from brain metastasis. Pooled summary estimates of sensitivity and specificity were obtained using hierarchical logistic regression modelling. We conducted meta-regression and subgroup analyses to explain the effects of the study heterogeneity.Results: Eighteen studies with 900 patients were included. The pooled sensitivity and specificity were 90% (95% CI, 84-94%) and 91% (95% CI, 84-95%), respectively. The area under the hierarchical summary receiver operating characteristic curve was 0.96 (95% CI, 0.94-0.98). The meta-regression showed that the percentage of glioma in the study population and the study design were significant factors affecting study heterogeneity. In a subgroup analysis including patients with glioblastoma only, the pooled sensitivity was 92% (95% CI, 84-97%) and the pooled specificity was 94% (95% CI, 85-98%).Conclusions: Although various perfusion MRI techniques were used, the current evidence supports the use of perfusion MRI to differentiate glioma from brain metastasis. In particular, perfusion MRI showed excellent diagnostic performance for differentiating glioblastoma from brain metastasis.Key Points: • Perfusion MRI shows high diagnostic performance for differentiating glioma from brain metastasis. • The pooled sensitivity was 90% and pooled specificity was 91%. • Peritumoral rCBV derived from DSC is a relatively well-validated. [ABSTRACT FROM AUTHOR]

In this study, the effect of carbon black nanoparticle (CB NP) additives on the ignition and combustion properties of Al/CuO NP-based nanoscale energetic materials (nEMs) has been systematically investigated. When an excessive amount of CB NPs (> 1 wt.%) was added to these nEMs, their pressurization and burn rates were considerably suppressed by a magnitude of about 50% due to the heat dissipation and thermochemical intervention in the self-propagating reactions of Al/CuO NPs. The ignition delay time of the studied energetic materials was monotonically reduced with increasing amount of added CB NPs because of the enhancement of their heat transfer properties. The total heat energy generated by the Al/CuO NP-based nEMs gradually decreased with increasing amount of CB NPs because of their thermochemical intervention in the exothermic reaction. Finally, the results of soil explosion testing revealed that the diameter of the produced crater could be controlled by varying the content of CB NPs in the nEM matrix. Therefore, the CB NP additives can be potentially used as a control medium, which affects the heat transfer process and thermochemical interactions between nEM components and is thus capable of precisely tuning their ignition, combustion, and explosion properties for various thermal engineering applications. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the value of multiparametric MRI for determination of early treatment response following concurrent chemoradiotherapy in patients with newly diagnosed glioblastoma.Methods: A computerized search of Ovid-MEDLINE and EMBASE up to 1 October 2017 was performed to find studies on the diagnostic performance of multiparametric MRI for differentiating true progression from pseudoprogression. The beginning search date was not specified. Pooled estimates of sensitivity and specificity were obtained using hierarchical logistic regression modeling. We performed meta-regression and sensitivity analyses to explain the effects of the study heterogeneity.Results: Nine studies including 456 patients were included. Pooled sensitivity and specificity were 84 % (95 % CI 74-91) and 95 % (95 % CI 83-99), respectively. Area under the hierarchical summary receiver operating characteristic curve was 0.95 (95 % CI 0.92-0.96). Meta-regression showed true progression in the study population, the mean age and the reference standard were significant factors affecting heterogeneity.Conclusion: Multiparametric MRI may be used as a potential surrogate endpoint for assessment of early treatment response, especially in the differentiation of true progression from pseudoprogression. However, based on the current evidence, monoparametric and multiparametric MRI perform equally in the clinical context. Further evaluation will be needed.Key Points: • Multiparametric MRI shows high diagnostic performance for early treatment response in glioblastoma. • Multiparametric MRI could differentiate true progression from pseudoprogression in newly diagnosed glioblastoma. • The normalized rCBV derived from DSC was the most commonly used parameter. [ABSTRACT FROM AUTHOR]

A sandwich structure consisting of perlite composite foam as core and Brown paper as skin is developed and its flexural behaviour is studied in relation with properties of constituents and manufacturing variables of perlite composite foam core consolidated with sodium silicate binder by compaction. Tensile properties of Brown paper coated with binder were affected by sodium silicate content in diluted binder. The best performance of the Brown paper was found for strength and energy absorption when coated with undiluted binder. The sandwich structure was fabricated with the best performed Brown paper and perlite composite foam cores with various binder contents and compaction ratios. The performance of the sandwich structure for core shear strength, skin normal strength, and stiffness was similarly affected by manufacturing variables to those of perlite foam core. Load carrying capacity of perlite foam core reinforced with Brown paper for the sandwich structure was increased about 3–7 times the unreinforced one depending on how binder and compaction ratio are combined for manufacturing perlite foam core. The flexural failure of perlite composite foam core was initiated from the tension side of the flexural specimen. However, when the foam core was sandwiched with the Brown paper, the failure initiation site was shifted to the mid-plane of flexural specimen. [ABSTRACT FROM AUTHOR]

Mechanism of internal structure formation of perlite composite foams due to compaction is identified. Foam and particle envelope densities, and volume fractions are theoretically modelled for prediction and practical evaluation. The volume fractions, as functions of manufacturing variables, include those affected by topological change of internal structure of foam after compaction process, consisting of binder, perlite material, porous zone of original particles, debris zone, and inter-particle voids. Predictions were validated against directly measured values for foam and particle envelope densities. A problem with the conventional method for obtaining volume fraction of binder is analytically addressed in terms of error sensitivity. Values for volume fraction of binder obtained from the conventional method were found to have errors up to about 300% (or about three times validated one). An example is given to show how the predictive models can be used for optimisation of manufacturing and properties. Applicability of formulas based on the new evaluative method is also shown for syntactic foams. Experimental results were obtained from a foam density range of 0.16–0.50 g/cm 3 and a porosity range of 0.79–0.93 for expanded perlite particle sizes between 3 and 4 mm, a compaction ratio range of 1–3.56, and a pure sodium silicate content range of 0.05–0.35 g/ml in dilution of water for binder. [ABSTRACT FROM AUTHOR]

Background and Purpose: Quantitative measurements, as well as qualitative characterizations, of the vessel walls of the small intracranial arteries became clinically available and reliable beyond the resolution limit of 1.5 T high-resolution magnetic resonance imaging (HR-MRI) with the development of 3 T HR-MRI. We present the quantitative dissection findings of spontaneous and unruptured acute intracranial artery dissection (SID) using 3 T HR-MRI and investigate the differences between each cerebral artery.Methods: Twenty-eight lesions (anterior cerebral artery = 6; middle cerebral artery = 4; vertebral artery = 18) from 26 patients (17 male and 9 female patients; mean age = 47 years; age range = 32-74 years) with presumptive diagnoses of SID were included. The diagnosis was determined based on the clinical features, findings on luminal angiography (such as digital subtraction angiography, computed tomography, or magnetic resonance angiography), and HR-MRI. HR-MRI was performed within one month from onset. The neuroimaging indices (maximal outer diameter and area, remodeling index and modified remodeling index, and wall thickness and wall area index) of aneurysmal dilatation and the signal intensities of the intramural hematomas were rated using HR-MRI. The results were compared between each cerebral artery.Results: The maximal outer diameter and area, remodeling index and modified remodeling index, and wall thickness index and length were significantly different between anterior and posterior circulation (P < .05). The mean relative signal intensities of the intramural hematoma showed consistent values, regardless of the cerebral arteries, without significant difference.Conclusions: Neuroimaging indices of aneurysmal dilatation may be adjunctive indicators in the evaluation of SID. [ABSTRACT FROM AUTHOR]

[Display omitted] • Energetic polymer encapsulation method developed to manage sensitive composites. • Method protects against external stimuli and maintains high explosive reactivity. • Nitrocellulose encapsulation effects on Al/KIO 4 energetic composites examined. • Energetic composites manufactured using spray drying for uniform nanoparticle mixing. • Optimized polymer encapsulation enhances propulsion of small projectiles. Energetic composites composed of metal and oxidizer are limitedly employed in thermal engineering systems due to their sensitivity. Therefore, energetic polymer encapsulation can be suggested as a method of protecting energetic composites from unexpected external stimuli, as well as maintaining relatively high explosive reactivity. In this study, the effect of nitrocellulose (NC; polymer) encapsulation on the ignition and combustion characteristics of aluminum (Al; fuel)/potassium periodate (KIO 4 ; oxidizer) energetic composites is systematically examined. NC-encapsulated Al/KIO 4 energetic composites are manufactured using a spray drying method, which enables uniform mixing of Al nanoparticles (NPs) with KIO 4 NPs in the NC matrix. As the more NC encapsulation is made on Al/KIO 4 energetic composites, the ignition delay time and ignition threshold spark energy increase, suggesting a reduction in the sensitivity of the energetic composites. However, the maximum pressure and pressurization rates of NC-encapsulated Al/KIO 4 energetic composites ignited in a closed cell are higher when the NC content is below 10 wt%, and then they considerably decrease with excessive NC content (>10 wt%). On the basis of propulsion tests, the kinetic energy of bullet-type projectiles and specific impulses of small rocket-type projectiles charged with NC content of 5–10 wt% in the Al/KIO 4 energetic composites are two times higher than the values for Al/KIO 4 energetic composites with no NC content. These results prove that the optimized polymer encapsulation is highly beneficial for developing various functional energetic composites and composite solid propellants, with compromised sensitivity and explosive reactivity, for enhancing the propulsion of small projectiles. [ABSTRACT FROM AUTHOR]

We report the electrical and optical characteristics of indium-tin-oxide (ITO)/GaAs Schottky barrier solar cells (SBSCs) with embedded InAs quantum dots (QDs). Twenty layers of self-assembled InAs QDs are inserted into the SBSCs so as to increase the potential barrier height at the ITO/GaAs junctions and to create additional photo-generated electrons in the quantum confined states of the QDs. After analyzing the current density–voltage characteristics, the photoluminescence, and the external quantum efficiency of the fabricated SBSCs, it was found that the incorporation of InAs QDs into the ITO/GaAs SBSCs results in an increase of both of the open-circuit voltage and the short-circuit current density compared to SBSCs without InAs QDs. [ABSTRACT FROM AUTHOR]

A novel mechanical behaviour of perlite/sodium silicate composites is studied with the benefits of a new manufacturing method based on the perlite particle buoyancy. The objective was to develop perlite composites and to understand their quantitative relations between manufacturing parameters, volume fractions of constituents, and properties. For the composites development, sodium silicate dehydration behaviour was characterised with phases formed during dehydration i.e. liquid, gel, and solid phases. The water loss–time curve for dehydration was found to have three distinctive parts – linear part at an early stage for liquid phase, followed by non-linear part during a period between commencements of gel and hydrated solid phase formations, and then another linear part for hydrated solid phase. Foams as composites were manufactured with diluted sodium silicate binder for a density range of 0.2–0.5 g/cm 3 . One of practical milestones achieved for composite properties without reinforcement was a density of 0.3 g/cm 3 at a compressive strength of 1 MPa. Manufactured perlite/sodium silicate composites are analysed/discussed for understanding from three different perspectives i.e. manufacturing parameters (i.e. binder content, compaction pressure, and compaction ratio), properties (i.e. particle size, density, compressive strength, and modulus), and volume fractions of constituents. A rule of mixtures applicable for perlite composites for a constant compaction ratio was developed in comparison with that for particulate composites with non-compaction. It may be a basis for further development for variable compaction ratio in the future. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the accuracy of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) perfusion MR imaging for distinguishing tumor recurrence from post-treatment effect as alternatives to dynamic-susceptibility contrast-enhanced (DSC) perfusion MR imaging when the DSC image is uninterpretable. Materials and Methods: This retrospective study was approved by our institutional review board. Seventy one post-treatment glioblastoma patients who showed enlarged contrast-enhancing lesions on follow-up MR images after concurrent chemoradiotherapy and uninterpretable DSC images for corresponding enhancing lesions, underwent additional DWI and DCE MR imaging. The primary outcome was the frequency of interpretable DWI and DCE MR cases in these 71 patients. The secondary outcome was the area under the receiver operating characteristic curve (AUC) of DWI and DCE imaging parameters for distinguishing tumor recurrence from post-treatment effect in selected patients with interpretable DWI and DCE images. The imaging parameters were quantified as 10% cumulative histogram cutoff of apparent diffusion coefficient (ADC10) and 90% cumulative histogram cutoff of initial area under the time signal intensity curve (IAUC90). The AUCs were cross-validated by using leave-one-out method. Results: Of the 71 patients, the uninterpretable DSC images were associated with treatment-related hemorrhage within the corresponding enhancing lesions (n = 54, 76.1%) and a near skull base location (n = 17, 23.9%). The frequencies of interpretable DWI and DCE image were 51 (71.8%) and 59 (83.1%) of the 71 cases with uninterpretable DSC images, respectively. Of the 45 selected patients with interpretable DWI and DCE images, the combination of DWI with DCE imaging showed a superior diagnostic performance than DWI or DCE imaging alone for differentiating tumor recurrence from post-treatment effect (cross-validated AUC: 0.78 versus 0.55 and 0.73 for reader 1; cross-validated AUC: 0.78 versus 0.53 and 0.75 for reader 2, respectively). Cross-validated accuracy of the single and combined imaging parameters also showed the highest for the combination of DWI with DCE MR imaging (72.9% for reader 1; 72.5% for reader 2) and the lowest for DWI alone (54.0% for reader 1; 56.4% for reader 2). Inter-reader agreement for DCE imaging was higher than that for DWI (intraclass correlation coefficient: 0.95 versus 0.87). Conclusion: DCE MR imaging could be a superior and more reproducible imaging biomarker than DWI for differentiating tumor recurrence from post-treatment effect in patients with post-treatment glioblastoma when DSC MR images are not interpretable. [ABSTRACT FROM AUTHOR]

Background and Purpose: Brain tumor cellularity has been assessed by using apparent diffusion coefficient (ADC). However, the ADC value might be influenced by both perfusion and true molecular diffusion, and the perfusion effect on ADC can limit the reliability of ADC in the characterization of tumor cellularity, especially, in hypervascular brain tumors. In contrast, the IVIM technique estimates parameter values for diffusion and perfusion effects separately. The purpose of our study was to compare ADC and IVIM for differentiating among glioblastoma, metastatic tumor, and primary CNS lymphoma (PCNSL) focusing on diffusion-related parameter. Materials and Methods: We retrospectively reviewed the data of 128 patients with pathologically confirmed glioblastoma (n = 55), metastasis (n = 31), and PCNSL (n = 42) prior to any treatment. Two neuroradiologists independently calculated the maximum IVIM-f (fmax) and minimum IVIM-D (Dmin) by using 16 different b-values with a bi-exponential fitting of diffusion signal decay, minimum ADC (ADCmin) by using 0 and 1000 b-values with a mono-exponential fitting and maximum normalized cerebral blood volume (nCBVmax). The differences in fmax, Dmin, nCBVmax, and ADCmin among the three tumor pathologies were determined by one-way ANOVA with multiple comparisons. The fmax and Dmin were correlated to the corresponding nCBV and ADC using partial correlation analysis, respectively. Results: Using a mono-exponential fitting of diffusion signal decay, the mean ADCmin was significantly lower in PCNSL than in glioblastoma and metastasis. However, using a bi-exponential fitting, the mean Dmin did not significantly differ in the three groups. The mean fmax significantly increased in the glioblastomas (reader 1, 0.103; reader 2, 0.109) and the metastasis (reader 1, 0.105; reader 2, 0.107), compared to the primary CNS lymphomas (reader 1, 0.025; reader 2, 0.023) (P < .001 for each). The correlation between fmax and the corresponding nCBV was highest in glioblastoma group, and the correlation between Dmin and the corresponding ADC was highest in primary CNS lymphomas group. Conclusion: Unlike ADC value derived from a mono-exponential fitting of diffusion signal, diffusion-related parametric value derived from a bi-exponential fitting with separation of perfusion effect doesn’t differ among glioblastoma, metastasis, and PCNSL. [ABSTRACT FROM AUTHOR]

This paper proposes an effective test bed for a 380-V dc distribution system using isolated power converters. The proposed test-bed system is composed of a grid-interactive ac–dc converter for regulating the dc-bus voltage, a bidirectional converter for the battery power interface, a renewable energy simulator, dc home appliances modified from conventional ac components, a dc distribution panel board, and its monitoring system. This paper discusses three isolated power converters, i.e., a bidirectional ac–dc converter, a bidirectional dc–dc converter, and a unidirectional dc–dc converter for the effective power interface of a dc bus. These isolated power converters are designed using a dual-active-bridge converter and the resonant topologies of $CLLC$ and $LLC$. The proposed test-bed system was implemented using a 5-kW bidirectional ac–dc prototype converter, a 3-kW bidirectional dc–dc prototype converter, and a 3-kW unidirectional dc–dc prototype converter. Finally, the performance of the test-bed system has been verified using practical experiments of load variations and bidirectional power flow, employing the prototype converters. [ABSTRACT FROM PUBLISHER]

The aim of this study was to overcome the shortcomings of technetium-99m red blood cell labeling, such as the requirement of additional time, and to maintain a stable labeling efficiency by reducing the mixing time for technetium-99m red blood cell labeling in the Asan Medical Center red blood cell labeling method developed by this hospital. Thirty patients, who underwent an examination using technetium-99m red blood cell labeling in the nuclear medicine department from April to September 2012, were selected randomly. Blood samples (5 mL per patient) were mixed with acid citrate dextrose, and 1-mL aliquots were taken to make four blood samples. The Asan Medical Center red blood cell labeling method was used for labeling. In this case, the mixing time was set to 5, 10, 15, and 20 min before calculating the efficiency of each labeling. The difference depending on the mixing time was compared. According to the technetium-99m red blood cell labeling efficiency depending on the mixing time in the Asan Medical Center red blood cell labeling method, the efficiency of each labeling was 92 ± 5%, 96 ± 5%, 97 ± 5%, and 98 ± 5% for 5, 10, 15, and 20 min, respectively. Overall, the labeling efficiency was relatively low when the mixing time was 5 min, whereas there was no significant difference in labeling efficiency when the mixing time was longer than 5 min. In conclusion, the Asan Medical Center red blood cell labeling method can provide an environment that is more conducive to the combination of red blood cell with technetium-99m pertechnetate than the previous modified labeling method because the Asan Medical Center red blood cell labeling method removes blood plasma in an additional centrifugation process. [ABSTRACT FROM PUBLISHER]

Highlights: [•] A new process for expanded perlite particle consolidation with starch binder is developed for building materials. [•] Compressive modulus and strength of perlite foams were characterized for a range of foam densities (0.1–0.4g/cm3). [•] Compressive strength of perlite foam with a density of 0.3g/cm3 was found to be compatible with a heavy gypsum. [•] Failure modes of perlite foam are identified as those characterized with longitudinal splitting and shear planes. [•] Damage occurred during compaction is quantified using image analysis. [ABSTRACT FROM AUTHOR]

Peer assessment plays an important role in engineering education for an active involvement in the assessment process, developing autonomy, enhancing reflection, and understanding of how to achieve the learning outcomes. Peer assessment uncertainty for oral presentation skills as part of the FYP assessment is studied. Validity and reliability for complex assessments were conceptualised in the context of quantification, hierarchical system of uncertainties, aleatory uncertainty, and epistemic uncertainty. Systems as assessment methods were also conceptualised to define elements (i.e. examiner, examinee, and difficulty) as variables or/and constants, and to study the uncertainty behaviour of the peer assessment within the framework of the parametric uncertainty model. As a result, a singularity, at which the hierarchical structure of uncertainties breaks down, and its related behaviour were theoretically predicted and experimentally verified. Also, a validity paradox, when the ‘difficulty’ level is sufficiently lowered, was found to be possible and verified for oral presentation skills. It may be useful for understanding fundamental characteristics of the peer assessment in which epistemic uncertainties are dependent on how the assessment is close to the singularity point. [ABSTRACT FROM PUBLISHER]

A quantitative method for estimating an expected uncertainty (reliability and validity) in assessment results arising from the relativity between four variables, viz examiner's expertise, examinee's expertise achieved, assessment task difficulty and examinee's performance, was developed for the complex assessment applicable to final year project thesis assessment including peer assessment. A guide map can be generated by the method for finding expected uncertainties prior to the assessment implementation with a given set of variables. It employs a scale for visualisation of expertise levels, derivation of which is based on quantified clarities of mental images for levels of the examiner's expertise and the examinee's expertise achieved. To identify the relevant expertise areas that depend on the complexity in assessment format, a graphical continuum model was developed. The continuum model consists of assessment task, assessment standards and criterion for the transition towards the complex assessment owing to the relativity between implicitness and explicitness and is capable of identifying areas of expertise required for scale development. [ABSTRACT FROM AUTHOR]

A Correction to this paper has been published: https://doi.org/10.1007/s00330-021-08065-8 [ABSTRACT FROM AUTHOR]

This paper presents a multioutput converter using an asymmetrical pulsewidth modulation half-bridge flyback topology employing a parallel–series-connected transformer. Compared to conventional multioutput topologies, the proposed converter operates using a single-output controller without the need for additional control loops and devices. In order to solve the cross-regulation problem, the output stages of the proposed converter are stacked in series. In addition, the voltage regulation of the proposed multioutput converter is improved through the analysis of its resonant characteristics under load variations and minimizing the secondary conduction loss. The proposed multioutput converter shows excellent performance in terms of its output regulation from no-load to full-load conditions and good cross regulation under high output currents. The design methodology and performance of the proposed converter have been verified through experimentation employing a 110-W (3.3 V/16 A, 5 V/12 A) prototype converter. [ABSTRACT FROM PUBLISHER]

A bidirectional full-bridge CLLC resonant converter using a new symmetric LLC-type resonant network is proposed for a low-voltage direct current power distribution system. This converter can operate under high power conversion efficiency because the symmetric LLC resonant network has zero-voltage switching capability for primary power switches and soft commutation capability for output rectifiers. In addition, the proposed topology does not require any snubber circuits to reduce the voltage stress of the switching devices because the switch voltage of the primary and secondary power stage is confined by the input and output voltage, respectively. In addition, the power conversion efficiency of any directions is exactly same as each other. Using digital control schemes, a 5-kW prototype converter designed for a high-frequency galvanic isolation of 380-V dc buses was developed with a commercial digital signal processor. Intelligent digital control algorithms are also proposed to regulate output voltage and to control bidirectional power conversions. Using the prototype converter, experimental results were obtained to verify the performance of the proposed topology and control algorithms. The converter could softly change the power flow directions and its maximum power conversion efficiency was 97.8% during the bidirectional operation. [ABSTRACT FROM AUTHOR]

A high-efficiency isolated bidirectional ac–dc converter is proposed for a 380-V dc power distribution system to control bidirectional power flows and to improve its power conversion efficiency. To reduce the switches’ losses of the proposed nonisolated full-bridge ac–dc rectifier using an unipolar switching method, switching devices employ insulated-gate bipolar transistors, MOSFETs, and silicon carbide diodes. Using the analysis of the rectifier’s operating modes, each switching device can be selected by considering switch stresses. A simple and intuitive frequency detection method for a single-phase synchronous reference frame-phase-locked loop (SRF-PLL) is also proposed using a filter compensator, a fast period detector, and a finite impulse response filter to improve the robustness and accuracy of PLL performance under fundamental frequency variations. In addition, design and control methodology of the bidirectional full-bridge CLLC resonant converter is suggested for the galvanic isolation of the dc distribution system. A dead-band control algorithm for the bidirectional dc–dc converter is developed to smoothly change power conversion directions only using output voltage information. Experimental results will verify the performance of the proposed methods using a 5-kW prototype converter. [ABSTRACT FROM AUTHOR]

Novel sandwich composites made of syntactic foam core and paper skin were developed as potential building materials. Interface bonding between core and skin was controlled by varying starch content. Two different microsphere size groups were employed for syntactic foam core manufacturing based on the pre-mold processing method. Properties of skin paper with starch adhesive on were found to be affected by drying time of starch adhesive. Mechanical behavior of manufactured sandwich composites in relation with properties of constituent materials was studied. Skin paper contributed to increase up to 40% in estimated flexural strength over syntactic foams, depending on starch content in adhesive between syntactic foam core and paper skin. Small microsphere size group for syntactic foam core was found to be advantageous in strengthening of sandwich composites for a given starch content in adhesive. This finding was in agreement with calculated values of estimated shear stress at interface between skin and core. Failure process of the sandwich composites was discussed in relation with load–deflection curves. Cracking of syntactic foam core was detected to be the first event in sandwich composite failure sequence. Hygroscopic behavior of syntactic foam panels was investigated. Moisture content in the foam was measured to be high for high starch content in the foam panels. No significant moisture effect on flexural strength of syntactic foam panels after being subjected to moisture about 2 months was found for both microsphere size groups. However, substantial decrease (28%) in flexural modulus was found for the foam panels made of large microspheres although not much moisture effect was found on that of small microspheres. [ABSTRACT FROM PUBLISHER]

Abstract: Pre-mould processing for syntactic foams made of starch and ceramic hollow microspheres was studied. A statistical model to relate various parameters such as volume expansion rate (VER) of initial bulk volume of microspheres (IBVMS), microsphere size, microsphere volume fractions, minimum inter-microsphere distance (MID), and mixing ratio of microspheres was developed for theoretical relations. The statistical model consists of cubic cells which can optionally be simple cubic (SC) or face centered cubic (FCC) or body centered cubic (BCC) cells. The theoretical relations were verified with experimental/numerical data for various mixtures of microspheres and found to be capable of predicting effects of microsphere size and mixture ratio of microsphere size groups on VER under various conditions arising from starch content in binder and IBVMS. Volume shrinkage for mixture of microspheres and binder after moulding but before forming syntactic foam was found to be high for high contents of small microspheres in mixture. [Copyright &y& Elsevier]

In subacute sclerosing panencephalitis (SSPE), conventional MRI findings have been reported. However, in the early clinical stages, imaging studies can appear normal. Moreover, with no history of infant measles infection, the diagnosis of SSPE can only be arrived at after extensive investigation that must eliminate a number of neurodegenerative diseases. We report here on F-fluorodeoxyglucose positron emission tomography (F-FDG PET) and magnetic resonance spectroscopy (MRS) findings in a 14-year-old girl with a normal initial MRI who had not contracted measles. Although F-FDG PET and MRS are not specific or diagnostic for SSPE, these techniques can demonstrate substantial metabolic impairments when MRI findings show no obvious abnormalities, as is often the case in the early stages of this disease. [ABSTRACT FROM AUTHOR]

Abstract: A photovoltaic (PV) power conditioning system (PCS) must have high conversion efficiency and low cost. Generally, a PV PCS uses either a single string converter or a multilevel module integrated converter (MIC). Each of these approaches has both advantages and disadvantages. For a high conversion efficiency and low cost PV module, a series connection of a module integrated DC–DC converter output with a photovoltaic panel was proposed. The output voltage of the PV panel is connected to the output capacitor of the fly-back converter. Thus, the converter output voltage is added to the output voltage of the PV panel. The isolated DC–DC converter generates only the difference voltage between the PV panel voltage and the required total output voltage. This method reduces the power level of the DC–DC converter and enhances energy conversion efficiency compared with a conventional DC–DC converter. [Copyright &y& Elsevier]

Abstract: A new method for measuring two-dimensional inter-particle/void distances was developed. The method was successfully applied to computer-generated 2D models representing polished surfaces of particle/void modified plastics ranging from relatively non-flocculated to flocculated particles/voids dispersions. [Copyright &y& Elsevier]

A three-zone model consisting of initial, evolutionary and stabilised plastic zones for tearing resistance was proposed for polymer sheets. An analysis with the model, based on the essential work of fracture (EWF) approach, was demonstrated to be capable for predicting specific total work of fracture along the tear path across all the plastic zones although accuracy of specific essential work of fracture is subject to improvement. Photo-elastic images were used for identification of plastic deformation sizes and profiles. Fracture mode change during loading was described in relation with the three zones. Tearing fracture behaviour of extruded mono- and bi-layer sheets of different types of amorphous co-polyesters and different thicknesses was investigated. Thick material exhibited higher specific total work of tear fracture than thin mono-layer sheet in the case of amorphous polyethylene terephthalate (PET). This finding was explained in terms of plastic zone size formed along the tear path, i.e., thick material underwent larger plastic deformation than thin material. When PET and polyethylene terephthalate glycol (PETG) were laminated with each other, specific total work of fracture of the bi-layer sheets was not noticeably improved over that of the constituent materials. [Copyright &y& Elsevier]

Electrochemical studies of spherical nickel hydroxide Ni(OH)2 with high density were carried out by using a microelectrode technique. A carbon fiber microelectrode was contacted with a single particle of nickel hydroxide in 5 M KOH aqueous solution. In this way, cyclic voltammetry and galvanostatic charge/discharge experiments were carried out. The Ni(OH)2/NiOOH redox reaction, oxygen evolution reaction and charge/discharge capacity were examined without any dilution with a binder and a conductive additive. Data were compared with those of the composite electrode consisting of the nickel hydroxide particle and a polymer binder, which is the practical form in the Ni-MH batteries. The potential-step technique was also performed to evaluate the apparent chemical diffusion coefficient of the proton (Dapp) in the nickel hydroxide. Since the nickel hydroxide particle was a dense, conductive sphere, the spherical diffusion model was employed for the analysis. The Dapp was found to be around 10−9 cm2 s−1. [Copyright &y& Elsevier]

Objectives: To develop a deep learning (DL) for detection of brain metastasis (BM) that incorporates both gradient- and turbo spin-echo contrast-enhanced MRI (dual-enhanced DL) and evaluate it in a clinical cohort in comparison with human readers and DL using gradient-echo-based imaging only (GRE DL). Materials and methods: DL detection was developed using data from 200 patients with BM (training set) and tested in 62 (internal) and 48 (external) consecutive patients who underwent stereotactic radiosurgery and diagnostic dual-enhanced imaging (dual-enhanced DL) and later guide GRE imaging (GRE DL). The detection sensitivity and positive predictive value (PPV) were compared between two DLs. Two neuroradiologists independently analyzed BM and reference standards for BM were separately drawn by another neuroradiologist. The relative differences (RDs) from the reference standard BM numbers were compared between the DLs and neuroradiologists. Results: Sensitivity was similar between GRE DL (93%, 95% confidence interval [CI]: 90–96%) and dual-enhanced DL (92% [89–94%]). The PPV of the dual-enhanced DL was higher (89% [86–92%], p <.001) than that of GRE DL (76%, [72–80%]). GRE DL significantly overestimated the number of metastases (false positives; RD: 0.05, 95% CI: 0.00–0.58) compared with neuroradiologists (RD: 0.00, 95% CI: − 0.28, 0.15, p <.001), whereas dual-enhanced DL (RD: 0.00, 95% CI: 0.00–0.15) did not show a statistically significant difference from neuroradiologists (RD: 0.00, 95% CI: − 0.20–0.10, p =.913). Conclusion: The dual-enhanced DL showed improved detection of BM and reduced overestimation compared with GRE DL, achieving similar performance to neuroradiologists. Clinical relevance statement: The use of deep learning–based brain metastasis detection with turbo spin-echo imaging reduces false positive detections, aiding in the guidance of stereotactic radiosurgery when gradient-echo imaging alone is employed. Key Points: •Deep learning for brain metastasis detection improved by using both gradient- and turbo spin-echo contrast-enhanced MRI (dual-enhanced deep learning). •Dual-enhanced deep learning increased true positive detections and reduced overestimation. •Dual-enhanced deep learning achieved similar performance to neuroradiologists for brain metastasis counts. [ABSTRACT FROM AUTHOR]

Background: Wagstaffe fracture constitutes an indirect injury to the AITFL and can precipitate syndesmotic instability. The prevailing fixation methods often involve the use of mini-screws or K-wires, with absorbable suture repair reserved for cases with small or comminuted fragments exhibiting instability. In this study, we devised a mini-plate fixation method capable of securing the fracture fragment irrespective of its size or condition. Methods: A retrospective chart review was conducted on patients who underwent surgery for ankle fractures between May 2022 and October 2023. The surgical technique involved direct fixation of the Wagstaffe fracture using mini-plate fixation. Radiologic evaluation was performed using postoperative CT images, and clinical outcomes were assessed using the OMAS and VAS. Results: Fourteen patients with an average age of 62.5 years were included. Most fractures were associated with the supination-external rotation type. The average preoperative OMAS significantly improved from 5.95 to 83.57 postoperatively. The average VAS score decreased from 7.95 preoperatively to 0.19 postoperatively. Conclusions: The mini-plate technique for Wagstaffe fractures exhibited dependable fixation strength, effective fracture reduction, a minimal complication rate, and judicious surgical procedure duration. [ABSTRACT FROM AUTHOR]

Objectives: The Image Biomarker Standardization Initiative has helped improve the computational reproducibility of MRI radiomics features. Nonetheless, the MRI sequences and features with high imaging reproducibility are yet to be established. To determine reproducible multiparametric MRI radiomics features across test–retest, multi-scanner, and computational reproducibility comparisons, and to evaluate their clinical value in brain tumor diagnosis. Methods: To assess reproducibility, T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), and diffusion-weighted imaging (DWI) were acquired from three 3-T MRI scanners using standardized phantom, and radiomics features were extracted using two computational algorithms. Reproducible radiomics features were selected when the concordance correlation coefficient value above 0.9 across multiple sessions, scanners, and computational algorithms. Random forest classifiers were trained with reproducible features (n = 117) and validated in a clinical cohort (n = 50) to evaluate whether features with high reproducibility improved the differentiation of glioblastoma from primary central nervous system lymphomas (PCNSLs). Results: Radiomics features from T2WI demonstrated higher repeatability (65–94%) than those from DWI (38–48%) or T1WI (2–92%). Across test–retest, multi-scanner, and computational comparisons, T2WI provided 41 reproducible features, DWI provided six, and T1WI provided two. The performance of the classification model with reproducible features was higher than that using non-reproducible features in both training set (AUC, 0.916 vs. 0.877) and validation set (AUC, 0.957 vs. 0.869). Conclusion: Radiomics features with high reproducibility across multiple sessions, scanners, and computational algorithms were identified, and they showed higher diagnostic performance than non-reproducible radiomics features in the differentiation of glioblastoma from PCNSL. Clinical relevance statement: By identifying the radiomics features showing higher multi-machine reproducibility, our results also demonstrated higher radiomics diagnostic performance in the differentiation of glioblastoma from PCNSL, paving the way for further research designs and clinical application in neuro-oncology. Key Points: • Highly reproducible radiomics features across multiple sessions, scanners, and computational algorithms were identified using phantom and applied to clinical diagnosis. • Radiomics features from T2-weighted imaging were more reproducible than those from T1-weighted and diffusion-weighted imaging. • Radiomics features with good reproducibility had better diagnostic performance for brain tumors than features with poor reproducibility. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to evaluate whether deep learning–based detection and quantification of brain metastasis (BM) may suggest treatment options for patients with BMs. Methods: The deep learning system (DLS) for detection and quantification of BM was developed in 193 patients and applied to 112 patients that were newly detected on black-blood contrast-enhanced T1-weighted imaging. Patients were assigned to one of 3 treatment suggestion groups according to the European Association of Neuro-Oncology (EANO)-European Society for Medical Oncology (ESMO) recommendations using number and volume of the BMs detected by the DLS: short-term imaging follow-up without treatment (group A), surgery or stereotactic radiosurgery (limited BM, group B), or whole-brain radiotherapy or systemic chemotherapy (extensive BM, group C). The concordance between the DLS-based groups and clinical decisions was analyzed with or without consideration of targeted agents. The performance of distinguishing high-risk (B + C) was calculated. Results: Among 112 patients (mean age 64.3 years, 63 men), group C had the largest number and volume of BM, followed by group B (4.4 and 851.6 mm3) and A (1.5 and 15.5 mm3). The DLS-based groups were concordant with the actual clinical decisions, with an accuracy of 76.8% (86 of 112). Modified accuracy considering targeted agents was 81.3% (91 of 112). The DLS showed 95% (82/86) sensitivity and 81% (21/26) specificity for distinguishing the high risk. Conclusion: DLS-based detection and quantification of BM have the potential to be helpful in the determination of treatment options for both low- and high-risk groups of limited and extensive BMs. Clinical relevance statement: For patients with newly diagnosed brain metastasis, deep learning–based detection and quantification may be used in clinical settings where prompt and accurate treatment decisions are required, which can lead to better patient outcomes. Key Points: • Deep learning–based brain metastasis detection and quantification showed excellent agreement with ground-truth classifications. • By setting an algorithm to suggest treatment based on the number and volume of brain metastases detected by the deep learning system, the concordance was 81.3%. • When dividing patients into low- and high-risk groups, the sensitivity for detecting the latter was 95%. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to develop multiparametric physiologic MRI-based spatial habitats and to evaluate whether temporal changes in these habitats help to distinguish tumor progression from treatment-related change in post-treatment glioblastoma. Methods: This retrospective, single-institution study included patients with glioblastoma treated by concurrent chemoradiotherapy who had newly developed or enlarging, measurable contrast-enhancing mass. Contrast-enhancing mass was divided into three spatial habitats by K-means clustering of voxel-wise ADC and CBV values. Temporal changes of these habitats between two consecutive examinations prior to the diagnosis of tumor progression or treatment-related change were assessed. Predictors were selected using logistic regression and the performance was measured with an area under the receiver operating characteristics curve (AUC). Spatiotemporal habitats were further analyzed for correlation with the site of tumor progression. Results: There were 75 patients (mean, 58 years; range, 26−81 years; 43 men) with 48 cases of tumor progression and 39 cases of treatment-related change including 12 patient overlaps at different time points. Three spatial habitats of hypervascular cellular, hypovascular cellular, and nonviable tissue were identified. Increase in the hypervascular cellular (OR 4.55, p =.002) and hypovascular cellular habitat (OR 1.22, p <.001) was predictive of tumor progression. Combination of spatiotemporal habitats yielded a high diagnostic performance with an AUC of 0.89 (95% CI, 0.87–0.92). An increase in hypovascular cellular habitat predicted the site of tumor progression in 84% [21/25] of cases with tumor progression. Conclusions: Temporal changes in spatial habitats derived from multiparametric physiologic MRI provided diagnostic value in distinguishing tumor progression from treatment-related change and predicted site of tumor progression in post-treatment glioblastoma. Key Points: • In post-treatment glioblastoma, three spatial habitats of hypervascular cellular, hypovascular cellular, and nonviable tissue were identified, and an increase in the hypervascular cellular (OR 4.55, p =.002) and hypovascular cellular habitat (OR 1.22, p <.001) was predictive of tumor progression. • Combination of spatiotemporal habitats yielded a high diagnostic performance with an AUC of 0.89 (95% CI, 0.87–0.92). • An increase in hypovascular cellular habitat predicted the site of tumor progression in 84% (21/25) of cases with tumor progression. [ABSTRACT FROM AUTHOR]