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Objective: To investigate the effect of various frequencies of bolus use on the superficial dose of volumetric modulated arc therapy after modified radical mastectomy for breast cancer. Methods: Based on the computed tomography images of a female anthropomorphic breast phantom, a 0.5 cm silicone-based 3D-printed bolus was created. Nine points evenly distributed on the breast skin were selected for assessing the skin dose, and a volume of subcutaneous lymphatic drainage of the breast (noted as ROI2-3) was delineated for assessing the chest wall dose. The treatment plans with and without bolus (plan_wb and plan_nb) were separately designed using the prescription of 50 Gy in 25 fractions following the standard dose constraints of the adjacent organ at risk. To characterize the accuracy of treatment planning system (TPS) dose calculations, the doses of the nine points were measured five times by thermoluminescence dosimeters (TLDs) and then were compared with the TPS calculated dose. Results: Compared with Plan_nb (144.46 ± 10.32 cGy), the breast skin dose for plan_wb (208.75 ± 4.55 cGy) was significantly increased (t = −18.56, P < 0.001). The deviation of skin dose was smaller for Plan_wb, and the uniformity was significantly improved. The calculated value of TPS was in good agreement with the measured value of TLD, and the maximum deviation was within 5%. Skin and ROI2-3 doses were significantly increased with increasing frequencies of bolus applications. The mean dose of the breast skin and ROI2-3 for 15 and 23 times bolus applications were 45.33 Gy, 50.88 Gy and 50.36 Gy, 52.39 Gy, respectively. Conclusion: 3D printing bolus can improve the radiation dose and the accuracy of the planned dose. Setting Plan_wb to 15 times for T1-3N+ breast cancer patients and 23 times for T4N+ breast cancer patients can meet the clinical need. Quantitative analysis of the bolus application frequency for different tumor stages can provide a reference for clinical practice. [ABSTRACT FROM AUTHOR]

Simple Summary: Acute radiation pneumonitis (ARP) is one of the common radiation toxicities in patients with non-small-cell lung cancer (NSCLC) treated by radiotherapy. The prediction for ARP can benefit clinical management and thereby improve the quality of life of patients. Markers derived from radiomics and dosiomics features can be adopted to predict ARP. Moreover, the features from lung subregions can improve the prediction for ARP compared to the whole lung region. The previous studies using lung subregion features for predicting ARP ignored the low-dose covered lung region. In this manuscript, we proposed an incremental-dose-interval-based lung subregion segmentation method by covering the low-dose lung region for ARP modeling and evaluated its effectiveness in improving ARP predictions using pre-treatment CT radiomics features and planning dose features for patients with NSCLC treated by radiotherapy. The performance among ARP models using features from our proposed lung subregion and the whole lung were compared for both multi-omics and single-omics. The results could provide insight into the subregion's ability to predict the ARP and could be useful in predicting the risk of radiation-induced toxicity. This manuscript and its results were neither published in any conferences nor journals. Purpose: To evaluate the effectiveness of features obtained from our proposed incremental-dose-interval-based lung subregion segmentation (IDLSS) for predicting grade ≥ 2 acute radiation pneumonitis (ARP) in lung cancer patients upon intensity-modulated radiotherapy (IMRT). (1) Materials and Methods: A total of 126 non-small-cell lung cancer patients treated with IMRT were retrospectively analyzed. Five lung subregions (SRs) were generated by the intersection of the whole lung (WL) and five sub-regions receiving incremental dose intervals. A total of 4610 radiomics features (RF) from pre-treatment planning computed tomographic (CT) and 213 dosiomics features (DF) were extracted. Six feature groups, including WL-RF, WL-DF, SR-RF, SR-DF, and the combined feature sets of WL-RDF and SR-RDF, were generated. Features were selected by using a variance threshold, followed by a Student t-test. Pearson's correlation test was applied to remove redundant features. Subsequently, Ridge regression was adopted to develop six models for ARP using the six feature groups. Thirty iterations of resampling were implemented to assess overall model performance by using the area under the Receiver-Operating-Characteristic curve (AUC), accuracy, precision, recall, and F1-score. (2) Results: The SR-RDF model achieved the best classification performance and provided significantly better predictability than the WL-RDF model in training cohort (Average AUC: 0.98 ± 0.01 vs. 0.90 ± 0.02, p < 0.001) and testing cohort (Average AUC: 0.88 ± 0.05 vs. 0.80 ± 0.04, p < 0.001). Similarly, predictability of the SR-DF model was significantly stronger than that of the WL-DF model in training cohort (Average AUC: 0.88 ± 0.03 vs. 0.70 ± 0.030, p < 0.001) and in testing cohort (Average AUC: 0.74 ± 0.08 vs. 0.65 ± 0.06, p < 0.001). By contrast, the SR-RF model significantly outperformed the WL-RF model only in the training set (Average AUC: 0.93 ± 0.02 vs. 0.85 ± 0.03, p < 0.001), but not in the testing set (Average AUC: 0.79 ± 0.05 vs. 0.77 ± 0.07, p = 0.13). (3) Conclusions: Our results demonstrated that the IDLSS method improved model performance for classifying ARP with grade ≥ 2 when using dosiomics or combined radiomics-dosiomics features. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to evaluate the utility of a new plan feature (planomics feature) for predicting the results of patient-specific quality assurance using the head and neck (H&N) volumetric modulated arc therapy (VMAT) plan. Methods: One hundred and thirty-one H&N VMAT plans in our institution from 2019 to 2021 were retrospectively collected. Dosimetric verification for all plans was carried out using the portal dosimetry system integrated into the Eclipse treatment planning system based on the electronic portal imaging devices. Gamma passing rates (GPR) were analyzed using three gamma indices of 3%/3 mm, 3%/2 mm, and 2%/2 mm with a 10% dose threshold. Forty-eight conventional features affecting the dose delivery accuracy were used in the study, and 2,476 planomics features were extracted based on the radiotherapy plan file. Three prediction and classification models using conventional features (CF), planomics features (PF), and hybrid features (HF) combining two sets of features were constructed by the gradient boosting regressor (GBR) and Ridge classifier for each GPR of 3%/3 mm, 3%/2 mm, and 2%/2 mm, respectively. The absolute prediction error (APE) and the area under the curve (AUC) were adopted for assessing the performance of prediction and classification models. Results: In the GPR prediction, the average APE of the models using CF, PF, and HF was 1.3 ± 1.2%/3.6 ± 3.0%, 1.7 ± 1.5%/3.8 ± 3.5%, and 1.1 ± 1.0%/4.1 ± 3.1% for 2%/2 mm; 0.7 ± 0.6%/2.0 ± 2.0%, 1.0±1.1%/2.2 ± 1.8%, and 0.6 ± 0.6%/2.2 ± 1.9% for 3%/2 mm; and 0.4 ± 0.3%/1.2 ± 1.2%, 0.4±0.5%/1.3 ± 1.0%, and 0.3±0.3%/1.2 ± 1.1% for 3%/3 mm, respectively. In the regression prediction, three models give a similar modeling performance for predicting the GPR. The classification results were 0.67 ± 0.03/0.66 ± 0.07, 0.77 ± 0.03/0.73 ± 0.06, and 0.78 ± 0.02/0.75 ± 0.04 for 3%/3 mm, respectively. For 3%/2 mm, the AUCs of the training and testing cohorts were 0.64 ± 0.03/0.62 ± 0.07, 0.70 ± 0.03/0.67 ± 0.06, and 0.75 ± 0.03/0.71 ± 0.07, respectively, and for 2%/2 mm, the average AUCs of the training and testing cohorts were 0.72 ± 0.03/0.72 ± 0.06, 0.78 ± 0.04/0.73 ± 0.07, and 0.81 ± 0.03/0.75 ± 0.06, respectively. In the classification, the PF model has a better classification performance than the CF model. Moreover, the HF model provides the best result among the three classifications models. Conclusions: The planomics features can be used for predicting and classifying the GPR results and for improving the model performance after combining the conventional features for the GPR classification. [ABSTRACT FROM AUTHOR]

Abstract We describe a case of cerebral schistosomiasis, caused by Asian (oriental) Schistosoma japonicum trematode blood flukes, in a young Chinese patient and its management. We also provide a brief update for physicians on the clinical features, diagnosis and treatment of schistosomiasis, with particular emphasis on neuroschistosomiasis, the most severe clinical outcome associated with this parasitic infection.

The introduction of multiple carbon rings is one of the common ways for graphene modification. Starting from warped C80H30 nanographene, which consists of a number of six- and seven-membered carbon rings (C6 and C7) centering at a five-membered carbon ring (C5), we explored the structure and property variations of its derivatives in which their C7 rings were gradually replaced with C6 rings. With reducing number of C7 rings, their curved boundary with the C6 rings becomes flat until a bowl-like structure is formed when all the C7 rings disappear. The optical absorption spectra vary accordingly. Both the α-bands and the maximum absorption bands in the visible region are related to the number and location of the C7 rings. Further analysis of the excited states of the C80H30 derivatives, as well as on the designed model systems, revealed that the C7 rings affect the electron excitations in two ways. In addition to their participation in electronic transitions, they control the composition of molecular orbitals that are involved in the excitations. The highest occupied molecular orbitals are mainly contributed by atoms on the C6 and C7 rings, while the lowest unoccupied molecular orbitals by atoms on the C5 and C6 rings. Our study sheds some light on how the multiple carbon rings affect the optical absorption of nanographenes and provides information for the preparation of nanographenes with tunable structural and optical properties. [ABSTRACT FROM AUTHOR]

Understanding the size-dependent structures and properties of ligand-capped nanoclusters in solvent is of particular interest for the design, synthesis and application of II–VI colloidal QDs. Using DFT and TDDFT calculations, we studied the structure and optical property evolution of the cysteine-capped (CdSe)N clusters of N = 1–10, 13, 16 and 19 in gas, toluene, water and alkaline aqueous solution, and made a comparison with their corresponding bare clusters. The cysteine binds with (CdSe)Nvia several patterns depending on the medium they exist in, affecting the cluster structures and in consequence their optical absorption. In general, the absorption bands of (CdSe)N blueshift when cysteine is added, and the shift varies with the interaction strength between the cluster and the ligand, and the dielectric constant of the solvent. However, bare clusters retain their size sensitivity, in particular the redshift trend with increasing cluster size, and some similarity was noted for the optical absorption of the bare and ligated clusters regardless of the gas or solvent media. Population analysis reveals that the excitations are mainly from orbitals distributing on the (CdSe)N part, while the ligand is negligibly involved in the excitations. This is an important feature for the II–VI QDs as biosensors with which the information of biomolecules is detected from the size dependent optical absorption or emission of the QDs other than the biomolecules. [ABSTRACT FROM AUTHOR]

From density functional theory calculations on dry and hydrated MMT, Na-MMT, NH 4 + -MMT, and formamide-MMT structures at various interlayer spacings, we proposed an interlayer expansion model for the counterion-intercalated MMT systems. Complex interactions exist among the counterions, lower and upper MMT surfaces, including ionic bonding, hydrogen bonding, electrostatic attraction/repulsion, and van der Waals forces. These interactions vary with different counterions and different interlayer spacings, playing a crucial role in the energy landscape of interlayer expansion. The equilibrium spacings are related to counterion volume, and the competition between interlayer electrostatic attraction and repulsion. The expansion energy potential near the equilibrium spacings can be approximately described with a quadratic function of spacing increase. At large spacings, however, the counterions have a tendency to form relatively strong interaction with either surface, making their energy potential in MMT approach to constant values. [ABSTRACT FROM AUTHOR]

Abstract: Density functional theory calculations were performed to study the intercalating behaviors of positively charged counterions in montmorillonites (MMTs) with Si4+/Al3+ substitution in their first internal layer. The substitution has great influence on the interaction between the counterions and the internal surface as well as on the MMT lattice structures. The intercalated counterions are characterized by their strong bonding with the six-oxygen-ring (SOR) on the substituted layer and with the O atoms on the opposite surface. The cations with smaller radii or higher charge have stronger interaction with the surface atoms. The inclusion of dispersion correction in the calculations leads to small changes to the lattice structures. [Copyright &y& Elsevier]

Poly(N-vinyl-2-pyrrolidone) (PVP) is often used to protect active Au clusters from coalescence. The influences of PVP on the O2 adsorption on Au32 clusters were investigated using density functional theory calculations. Various low-lying structures of O2:Au32 and O2:Au32:PVP complexes, in which the Au32 is either neutral or anionic and the O2 is either molecular or dissociative, were identified. The PVP influences were evaluated in terms of the changes in geometry, adsorption energy, charge redistribution, spin density, and density of states upon PVP pre-adsorption. Our calculations reveal that PVP weakly adsorbs on the cluster surface, with rather small changes in the structural, geometrical and electronic properties that are relevant to the O2 activation. The activity of neutral or anionic Au32 towards O2 is kept or slightly enhanced by PVP because of the cooperative adsorption of PVP and O2. This is the structural basis of choosing PVP as the protective ligand for Au clusters.

We describe a case of cerebral schistosomiasis, caused by Asian (oriental) Schistosoma japonicum trematode blood flukes, in a young Chinese patient and its management. We also provide a brief update for physicians on the clinical features, diagnosis and treatment of schistosomiasis, with particular emphasis on neuroschistosomiasis, the most severe clinical outcome associated with this parasitic infection.