Development and validation of a MRI-based radiomics signature for prediction of KRAS mutation in rectal cancer.

OBJECTIVE: To develop a T2-weighted (T2W) image-based radiomics signature for the individual prediction of KRAS mutation status in patients with rectal cancer. METHODS: Three hundred four consecutive patients from center I with pathologically diagnosed rectal adenocarcinoma (training dataset, n = 213; internal validation dataset, n = 91) were enrolled in our retrospective study. The patients from center II (n = 86) were selected as an external validation dataset. A total of 960 imaging features were extracted from high-resolution T2W images for each patient. Five steps, mainly univariate statistical tests, were applied for feature selection. Subsequently, three classification methods, i.e., logistic regression (LR), decision tree (DT), and support vector machine (SVM) algorithm, were applied to develop the radiomics signature for KRAS prediction in the training dataset. The predictive performance was evaluated by receiver operating characteristics curve (ROC) analysis, calibration curve, and decision curve analysis (DCA). RESULTS: Seven radiomics features were screened as a KRAS-associated radiomics signature of rectal cancer. Our best prediction model was obtained with SVM classifiers with AUC of 0.722 (95%CI, 0.654-0.790) in the training dataset. This was validated in the internal and external validation datasets with good calibration, and the corresponding AUCs were 0.682 (95% CI, 0.569-0.794) and 0.714 (95% CI, 0.602-0.827), respectively. DCA confirmed its clinical usefulness. CONCLUSIONS: The proposed T2WI-based radiomics signature has a moderate performance to predict KRAS status, and may be useful for supplementing genomic analysis to determine KRAS expression in rectal cancer patients. KEY POINTS: • T2WI-based radiomics showed a moderate diagnostic significance for KRAS status. • The best prediction model was obtained with SVM classifier. • The baseline clinical and histopathological characteristics were not associated with KRAS mutation.

Diffusion kurtosis imaging-derived histogram metrics for prediction of KRAS mutation in rectal adenocarcinoma: Preliminary findings.

BACKGROUND: Although histological examination is the standard method for assessing genetic status, the development of a noninvasive method, which can display the heterogeneity of the whole tumor to supplement genotype analysis, might be important for personalized treatment strategies. PURPOSE: To evaluate the potential role of diffusion kurtosis imaging (DKI)-derived parameters using histogram analysis derived from whole-tumor volumes for prediction of the status of KRAS mutations in patients with rectal adenocarcinoma. STUDY TYPE: Retrospective. SUBJECTS: In all, 148 consecutive patients with histologically confirmed rectal adenocarcinoma who were treated at our institution. SEQUENCE: DKI was performed with a 3.0 T MRI system using a single-shot echo-planar imaging sequence with b values of 0, 700, 1400, and 2100 sec/mm2 . ASSESSMENT: D, K, and apparent diffusion coefficient (ADC) values were measured using whole-tumor volume histogram analysis and were compared between different KRAS mutations status. STATISTICAL TESTS: Student's t-test or Mann-Whitney U-test, and receiver operating characteristic (ROC) curves were used for statistical analysis. RESULTS: All the percentile metrics of ADC and D values were significantly lower in the mutated group than those in the wildtype group (all P < 0.05), except for the minimum value of ADC and D (both P > 0.05), while K-related percentile metrics were higher in the mutated group compared with those in the wildtype group (all P < 0.05). Regarding the comparison of the diagnostic performance of all the histogram metrics, K75th showed the highest AUC value of 0.871, and the corresponding values for sensitivity, specificity, positive predictive value, and negative predictive value were 81.43%, 78.21%, 77.03%, and 82.43%, respectively. DATA CONCLUSION: DKI metrics with whole-tumor volume histogram analysis is associated with KRAS mutations, and thus may be useful for predicting the KRAS status of rectal cancers for guiding targeted therapy. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:930-939.

Radiomics analysis of multiparametric MRI for prediction of pathological complete response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer.

OBJECTIVES: To develop and validate a radiomics predictive model based on pre-treatment multiparameter magnetic resonance imaging (MRI) features and clinical features to predict a pathological complete response (pCR) in patients with locally advanced rectal cancer (LARC) after receiving neoadjuvant chemoradiotherapy (CRT). METHODS: One hundred and eighty-six consecutive patients with LARC (training dataset, n = 131; validation dataset, n = 55) were enrolled in our retrospective study. A total of 1,188 imaging features were extracted from pre-CRT T2-weighted (T2-w), contrast-enhanced T1-weighted (cT1-w) and ADC images for each patient. Three steps including least absolute shrinkage and selection operator (LASSO) regression were performed to select key features and build a radiomics signature. Combining clinical risk factors, a radiomics nomogram was constructed. The predictive performance was evaluated by receiver operator characteristic (ROC) curve analysis, and then assessed with respect to its calibration, discrimination and clinical usefulness. RESULTS: Thirty-one of 186 patients (16.7%) achieved pCR. The radiomics signature derived from joint T2-w, ADC, and cT1-w images, comprising 12 selected features, was significantly associated with pCR status and showed better predictive performance than signatures derived from either of them alone in both datasets. The radiomics nomogram, incorporating the radiomics signature and MR-reported T-stages, also showed good discrimination, with areas under the ROC curves (AUCs) of 0.948 (95% CI, 0.907-0.989) and 0.966 (95% CI, 0.924-1.000), as well as good calibration in both datasets. Decision curve analysis confirmed its clinical usefulness. CONCLUSIONS: This study demonstrated that the pre-treatment radiomics nomogram can predict pCR in patients with LARC and potentially guide treatments to select patients for a "wait-and-see" policy. KEY POINTS: • Radiomics analysis of pre-CRT multiparameter MR images could predict pCR in patients with LARC. • Proposed radiomics signature from joint T2-w, ADC and cT1-w images showed better predictive performance than individual signatures. • Most of the clinical characteristics were unable to predict pCR.

A New Model and Its Application for the Dynamic Response of RGO Resistive Gas Sensor.

An reduced graphene oxide (RGO) resistive gas sensor was prepared to detect ammonia at room temperature, the result indicated that the desorption of gas (NH 3 ) molecules from a graphene-based sensor was difficult, which lead to a baseline drift. The responses of different concentrations were compared and studied. It was found that both the response rate and its acceleration were affected by the gas concentration. An Intermolecular Forces Based Model was established to explain the adsorption and desorption dynamic response curves. A new method was proposed based on this model. The first and second derivative extrema (FSDE) of the response curve can be attained quickly to calibrate the gas concentrations. The experiment results demonstrated that this new method could eliminate the baseline drift and was capable of increasing the efficiency of gas calibration significantly.

Whole-tumour diffusion kurtosis MR imaging histogram analysis of rectal adenocarcinoma: Correlation with clinical pathologic prognostic factors.

OBJECTIVE: To investigate potential relationships between diffusion kurtosis imaging (DKI)-derived parameters using whole-tumour volume histogram analysis and clinicopathological prognostic factors in patients with rectal adenocarcinoma. MATERIAL AND METHODS: 79 consecutive patients who underwent MRI examination with rectal adenocarcinoma were retrospectively evaluated. Parameters D, K and conventional ADC were measured using whole-tumour volume histogram analysis. Student's t-test or Mann-Whitney U-test, receiver operating characteristic curves and Spearman's correlation were used for statistical analysis. RESULTS: Almost all the percentile metrics of K were correlated positively with nodal involvement, higher histological grades, the presence of lymphangiovascular invasion (LVI) and circumferential margin (CRM) (p<0.05), with the exception of between K10th, K90th and histological grades. In contrast, significant negative correlations were observed between 25th, 50th percentiles and mean values of ADC and D, as well as ADC10th, with tumour T stages (p< 0.05). Meanwhile, lower 75th and 90th percentiles of ADC and D values were also correlated inversely with nodal involvement (p< 0.05). Kmean showed a relatively higher area under the curve (AUC) and higher specificity than other percentiles for differentiation of lesions with nodal involvement. CONCLUSION: DKI metrics with whole-tumour volume histogram analysis, especially K parameters, were associated with important prognostic factors of rectal cancer. KEY POINTS: • K correlated positively with some important prognostic factors of rectal cancer. • K mean showed higher AUC and specificity for differentiation of nodal involvement. • DKI metrics with whole-tumour volume histogram analysis depicted tumour heterogeneity.

Temperature-programmed multicapillary gas chromatograph microcolumn for the analysis of odorous sulfur pollutants.

We report the fabrication and performance of a silicon-on-glass micro gas chromatography eight-capillary column based on microelectromechanical systems technology that is 50 cm long, 30 µm wide, and 300 µm deep. According to the theory of a gas chromatography column, an even gas flow among different capillaries play a vital role in the peak broadening. Thus, a flow splitter structure is designed by the finite element method through the comparison of the velocity distributions of the eight-capillary columns with and without splitter as well as an open tubular column. The simulation results reveal that eight-capillary column with flow splitters can receive more uniform flow velocity in different capillaries, hence decreases the peak broadening and in turn increases the separation efficiency. The separation experiment results show that the separation efficiency of about 22 000 plates/m is achieved with the chip column temperature programmed for analysis of odorous sulfur pollutants. This figure is nearly two times higher than that of the commercial capillary column coated the similar stationary phase. And the separation time of all the components in the microcolumn is less than 3.8 min, which is faster than the commercial capillary column.

Chromatographic separation of simulants of nerve and blister agents by combining one- and two-channel columns with different stationary phases.

A two-channel gas chromatography column and a single-channel column were made by deep reactive-ion etching technology. The two short columns were coated with different stationary phases, and then linked without a modulator. This is to aim at increasing the sample capacity and achieving a higher separation efficiency in complex environments. The results show that the capacity of the connected column is approximately 4 and 1.5 times larger than that of the single- and two-channel columns, respectively. The linked column was utilized to separate a six-component mixture, composed of three simulants of nerve and blister agents and three interfering vapors. The results demonstrate that the combined column has a remarkably higher separation efficiency than the individual columns, and an acceptable resolution is achieved although the total length of the linked column is only 1.5 m.

Spectral CT imaging in cervical computed tomography angiography: comparison of spectral CT monochromatic imaging and conventional CT polychromatic imaging.

OBJECTIVE: To compare the image quality of spectral CT monochromatic imaging and conventional CT polychromatic imaging for analysing CTAs in patients with cervical cancer. METHODS: In this IRB approved prospective study, 60 patients who had been diagnosed with cervical cancer underwent pelvic arterial CTA between May 2013 and July 2013. They were randomly divided into two groups; one group (30 patients) received 120 kVp polychromatic imaging (conventional CT group) and the other group (30 patients) received spectral CT imaging (spectral CT group), while all patients in both the groups received injections of 1 ml/kg of contrast agent. A total of 101 sets of monochromatic images (40-140 keV) were obtained via data reconstruction in the spectral CT group, and the monochromatic images with the best contrast-to-noise ratio (CNR) between the common iliac artery and pelvic fat (i.e. the best monochromatic energy) were selected. The best monochromatic images for the spectral CT group and the polychromatic images for the conventional CT group were postprocessed and visualised in MIP, VR and CPR mode. The CT attenuation value, noise and CNR of bilateral common iliac arteries were measured with the best monochromatic energy, as well as with 70 keV, in the spectral CT group and in the conventional CT group. The quality of the CT images was evaluated with a 5-point scale. The CTDIvol and the dose-length product (DLP) of the two groups were measured, and the results were statistically analysed. RESULTS: When images were at 50±1 keV, the common iliac artery and pelvic fat had the highest CNR, which was 72.00% higher than the images at 70 keV (P=.001) in the spectral group, and thus, the images at 50±1 keV were considered to have the best monochromatic energy. The average CT value of the internal iliac artery, which had the best monochromatic energy from the spectral CT group, was higher than that of the images from the conventional CT group (603.96±62.68 vs 251.24±28.77; P<.001), and the differences in the CNR (73.97±11.83 vs 45.21±16.63) and the subjective score (3.10±1.73 vs 2.80±1.63) were statistically significant (both P<.05). There were no significant differences in the CTDIvol (10.48±2.86 vs 12.38±1.88 mGy) or the DLP (317.76±95.50 vs 332.25±21.25 mGy cm) between the spectral and the conventional CT groups. CONCLUSION: Monochromatic spectral CT imaging has excellent soft tissue contrast and good spatial resolution and can visualise the arteries and branches supplying the tumours more clearly in patients with cervical cancer. Compared with polychromatic images, monochromatic spectral CT images are higher quality, which helps the treatment of patients with cervical cancer.

Nonfreezing Water Structuration in Heteroprotein Coacervates.

Surface-bound water in protein solutions has been identified with a reduction in its freezing point. We studied the presence of such nonfreezing water (NFW) in various protein-polyelectrolyte, micelle-polyelectrolyte, and protein-protein (heteroprotein) coacervates, along with appropriate concentrated solutions of macromolecules alone, finding up to 15% w/w NFW for the heteroprotein coacervate of lactoferrin (LF) and ß-lactoglobulin (BLG). The level of NFW is always higher in coacervates than in the control (single macromolecule) systems, particularly for protein-containing coacervates: a coacervate of bovine serum albumin (BSA) and poly(dimethyldiallylammonium chloride) (PDADMAC) showed a ratio of NFW/protein twice that of BSA alone (0.6 vs 0.3), with a similarly high ratio for LF-BLG coacervate. These results are attributed to the maximization of water-protein contacts, structural features that reflect the mode of sample assembly, as they are not seen in a noncoacervated LF-BLG solution with identical concentrations of all species.

Selectively splitting a droplet using superhydrophobic stripes on hydrophilic surfaces.

Superhydrophobic patterns were fabricated on hydrophilic surfaces by selective painting. The impinging process of water droplets on these hybrid surfaces was investigated. The droplet can be split by impinging on the hydrophilic surface with a single stripe at a high velocity. The time to split the droplet is independent of the impact velocity and it is smaller than the contact time of a droplet impinging on the fully superhydrophobic surface. The volume ratios of the split mini-droplets could be precisely controlled by adjusting the landing position of the original droplet. The droplet could be split uniformly into more mini-marbles by increasing the stripe numbers.

The initial experience of the upper abdominal CT angiography using low-concentration contrast medium on dual energy spectral CT.

OBJECTIVE: To investigate the feasibility of using Spectral CT imaging with low contrast medium in abdominal CT angiography (CTA). SUBJECTS AND METHODS: 70 consecutive patients (40 men, 42.6 ± 20.4 years; 30 women, 46.7 ± 18.8 years) with suspected abdominal focal lesions were referred to CTA exam. They were randomly assigned into two groups. Group A: 35 patients underwent conventional CT scan of Tube voltage 120 kVp, automatic current modulation with a Noise Index of 12, ASIR 30%, and injected with Iohexol (350 mgI/ml). Group B: 35 patients underwent Spectral CT Imaging, with Tube current of 600 mA, injected with Iodixanol (270 mgI/ml). The optimal mono-energy keV was achieved using the optimal contrast noise ratio in abdominal aorta at the renal artery level relative to the erector spine muscle. Both groups were injected with an injection rate of 3.5 ml/s, and a contrast volume of 1.5 ml/kg body weight. The Hounsfield units (HU) and noise of the bilateral renal arteries and muscle of both groups, as well as the optimal monochromatic image set of Group B were measured. Two radiologists assessed all images with a 5-points scale. CTDIvol and DLP were recorded. Data were analyzed using student t test. RESULTS: The total iodine intake of Group B was 28% lower than that of Group A. The CNR of abdomen artery, celiac trunk, superior mesenteric artery, and renal artery in spectral group (at the best mono-energy of 53.0 keV) were higher than those in conventional CTA group (p < 0.001). The subjective image quality score of spectral CTA group was also rated higher than conventional CTA group (p < 0.001). CTDIvol, DLP, and effective dose of spectral group were all lower than conventional group, but there were no significant differences (p > 0.05). CONCLUSION: With 28% contrast medium reduction and reduced radiation dose, CT angiography using spectral imaging and lower concentration contrast agent provided better image quality than conventional CTA.

The enhanced formaldehyde-sensing properties of P3HT-ZnO hybrid thin film OTFT sensor and further insight into its stability.

A thin-film transistor (TFT) having an organic-inorganic hybrid thin film combines the advantage of TFT sensors and the enhanced sensing performance of hybrid materials. In this work, poly(3-hexylthiophene) (P3HT)-zinc oxide (ZnO) nanoparticles' hybrid thin film was fabricated by a spraying process as the active layer of TFT for the employment of a room temperature operated formaldehyde (HCHO) gas sensor. The effects of ZnO nanoparticles on morphological and compositional features, electronic and HCHO-sensing properties of P3HT-ZnO thin film were systematically investigated. The results showed that P3HT-ZnO hybrid thin film sensor exhibited considerable improvement of sensing response (more than two times) and reversibility compared to the pristine P3HT film sensor. An accumulation p-n heterojunction mechanism model was developed to understand the mechanism of enhanced sensing properties by incorporation of ZnO nanoparticles. X-ray photoelectron spectroscope (XPS) and atomic force microscopy (AFM) characterizations were used to investigate the stability of the sensor in-depth, which reveals the performance deterioration was due to the changes of element composition and the chemical state of hybrid thin film surface induced by light and oxygen. Our study demonstrated that P3HT-ZnO hybrid thin film TFT sensor is beneficial in the advancement of novel room temperature HCHO sensing technology.

The Different Sensitive Behaviors of a Hydrogen-Bond Acidic Polymer-Coated SAW Sensor for Chemical Warfare Agents and Their Simulants.

A linear hydrogen-bond acidic (HBA) linear functionalized polymer (PLF), was deposited onto a bare surface acoustic wave (SAW) device to fabricate a chemical sensor. Real-time responses of the sensor to a series of compounds including sarin (GB), dimethyl methylphosphonate (DMMP), mustard gas (HD), chloroethyl ethyl sulphide (2-CEES), 1,5-dichloropentane (DCP) and some organic solvents were studied. The results show that the sensor is highly sensitive to GB and DMMP, and has low sensitivity to HD and DCP, as expected. However, the sensor possesses an unexpected high sensitivity toward 2-CEES. This good sensing performance can't be solely or mainly attributed to the dipole-dipole interaction since the sensor is not sensitive to some high polarity solvents. We believe the lone pair electrons around the sulphur atom of 2-CEES provide an electron-rich site, which facilitates the formation of hydrogen bonding between PLF and 2-CEES. On the contrary, the electron cloud on the sulphur atom of the HD molecule is offset or depleted by its two neighbouring strong electron-withdrawing groups, hence, hydrogen bonding can hardly be formed.

Protein-selective coacervation with hyaluronic acid.

Selective coacervation with hyaluronic acid (HA), a biocompatible and injectable anionic polysaccharide, was used to isolate a target protein, bovine serum albumin (BSA), with 90% purity from a 1:1 mixture with a second protein of similar pI, ß-lactoglobulin (BLG). This separation was attributed to the higher HA-affinity of BSA, arising from its more concentrated positive domain. The values of pH corresponding respectively to the onset of complex formation, coacervation, precipitation, and redissolution (pH(c), pHϕ, pH(p), and pH(d)) were determined as a function of ionic strength I. These pH values were related to critical values of protein charge, Z, and their dependence on I provided some insights into the mechanisms of these transitions. The higher polyanion binding affinity of BSA, deduced from its higher values of pH(c), was confirmed by isothermal titration calorimetry (ITC). Confocal laser microscopy clearly showed time-dependent coalescence of vesicular droplets into a continuous film. Comparisons with prior results for the polycation poly(diallyldimethylammonium chloride) (PDADMAC) show reversal of protein selectivity due to reversal of the polyelectrolyte charge. Stronger binding of both proteins to PDADMAC established by ITC may be related to the higher chain flexibility and effective linear charge density of this polycation.

Structure of bovine ß-lactoglobulin-lactoferrin coacervates.

Lactoferrin (LF) and ß-lactoglobulin (BLG) are among the protein pairs that exhibit heteroprotein coacervation, a unique and relatively unexamined type of liquid-liquid phase separation (LLPS). In prior work we found that LF and BLG undergo coacervation at highly constrained conditions of pH, ionic strength and protein stoichiometry. The molar stoichiometry in coacervate and supernatant is LF : BLG2 1 : 2 (where BLG2 represents the 38 kDa BLG dimer), suggesting that this is the primary unit of the coacervate. The precise balance of repulsive and attractive forces among these units, thought to stabilize the coacervate, is achieved only at limited conditions of pH and I. Our purpose here is to define the process by which such structural units form, and to elucidate the forces among them that lead to the long-range order found in equilibrium coacervates. We use confocal laser scanning microscopy (CLSM), small angle neutron scattering (SANS), and rheology to (1) define the uniformity of interprotein spacing within the coacervate phase, (2) verify structural unit dimensions and spacing, and (3) rationalize bulk fluid properties in terms of inter-unit forces. Electrostatic modeling is used in concert with SANS to develop a molecular model for the primary unit of the coacervate that accounts for bulk viscoelastic properties. Modeling suggests that the charge anisotropies of the two proteins stabilize the dipole-like LF(BLG2)2 primary unit, while assembly of these dipoles into higher order equilibrium structures governs the macroscopic properties of the coacervate.

Advanced Textile-Based Wearable Biosensors for Healthcare Monitoring.

With the innovation of wearable technology and the rapid development of biosensors, wearable biosensors based on flexible textile materials have become a hot topic. Such textile-based wearable biosensors promote the development of health monitoring, motion detection and medical management, and they have become an important support tool for human healthcare monitoring. Textile-based wearable biosensors not only non-invasively monitor various physiological indicators of the human body in real time, but they also provide accurate feedback of individual health information. This review examines the recent research progress of fabric-based wearable biosensors. Moreover, materials, detection principles and fabrication methods for textile-based wearable biosensors are introduced. In addition, the applications of biosensors in monitoring vital signs and detecting body fluids are also presented. Finally, we also discuss several challenges faced by textile-based wearable biosensors and the direction of future development.

Assembled Reduced Graphene Oxide/Tungsten Diselenide/Pd Heterojunction with Matching Energy Bands for Quick Banana Ripeness Detection.

The monitoring of ethylene is of great importance to fruit and vegetable quality, yet routine techniques rely on manual and complex operation. Herein, a chemiresistive ethylene sensor based on reduced graphene oxide (rGO)/tungsten diselenide (WSe2)/Pd heterojunctions was designed for room-temperature (RT) ethylene detection. The sensor exhibited high sensitivity and quick p-type response/recovery (33/13 s) to 10-100 ppm ethylene at RT, and full reversibility and excellent selectivity to ethylene were also achieved. Such excellent ethylene sensing behaviors could be attributed to the synergistic effects of ethylene adsorption abilities derived from the negative adsorption energy and the promoted electron transfer across the WSe2/Pd and rGO/WSe2 interfaces through band energy alignment. Furthermore, its application feasibility to banana ripeness detection was verified by comparison with routine technique through simulation experiments. This work provides a feasible methodology toward designing and fabricating RT ethylene sensors, and may greatly push forward the development of modernized intelligent agriculture.

Equilibrium water contents of cellulose films determined via solvent exchange and quartz crystal microbalance with dissipation monitoring.

Model cellulose surfaces have attracted increasing attention for studying interactions with cell wall matrix polymers and as substrates for enzymatic degradation studies. Quartz crystal microbalance with dissipation monitoring (QCM-D) solvent exchange studies showed that the water content of regenerated cellulose (RC) films was proportional to the film thickness (d) and was consistent with about five water molecules per anhydroglucose unit. Sulfated nanocrystalline cellulose (SNC) and desulfated nanocrystalline cellulose (DNC) films had comparable water contents and contained about five times more water than RC films. A cellulase mixture served as a probe for studies of substrate accessibility and degradation. Cellulase adsorption onto RC films was independent of d, whereas degradation times increased with d. However, adsorption onto SNC and DNC films increased with d, whereas cellulase degradation times for DNC films were independent of studied d. Enhanced access to guest molecules for SNC and DNC films revealed they are more porous than RC films.

Enhancing electrochemical performance of electrode material via combining defect and heterojunction engineering for supercapacitors.

The poor conductivity and deficient active sites of transition metal oxides lead to low energy density of supercapacitors, which limits their wide application. In this work, double transition metal oxide heterojunctions with oxygen vacancy (Vo-ZnO/CoO) nanowires are prepared by effective hydrothermal and thermal treatments. The formation of the heterojunction results in the redistribution of interface charge between ZnO and CoO, generating an internal electric field to accelerate the electron transport. Meanwhile, oxygen vacancies can enhance the redox reaction activity to further improve the electrochemical kinetics of the electrode material. Therefore, the prepared Vo-ZnO/CoO can provide a superior specific capacity of 845 C g-1 (1 A g-1). An asymmetric supercapacitor with the Vo-ZnO/CoO as positive electrode shows a higher energy density of 51.6 Wh kg-1 when the power density reaches 799.9 W kg-1. This work proposes a synergistic combination of defect and heterojunction engineering to improve the electrochemical properties of materials, providing an important guidance for material design in energy-storage field.

Prognostic value of multiparametric MRI-based radiomics model: Potential role for chemotherapeutic benefits in locally advanced rectal cancer.

BACKGROUND AND PURPOSE: We aimed to develop a radiomics model for the prediction of survival and chemotherapeutic benefits using pretreatment multiparameter MR images and clinicopathological features in patients with locally advanced rectal cancer (LARC). MATERIALS AND METHODS: 186 consecutive patients with LARC underwent feature extraction from the whole tumor on T2-weighted, contrast enhanced T1-weighted, and ADC images. Feature selection was based on feature stability and the Boruta algorithm. Radiomics signatures for predicting DFS (disease-free survival) were then generated using the selected features. Combining clinical risk factors, a radiomics nomogram was constructed using Cox proportional hazards regression model. The predictive performance was evaluated by Harrell's concordance indices (C-index) and time-independent receiver operating characteristic (ROC) analysis. RESULTS: Four features were selected to construct the radiomics signature, significantly associated with DFS (P < 0.001). The radiomics nomogram, incorporating radiomics signature and two clinicopathological variables (pN and tumor differentiation), exhibited better prediction performance for DFS than the clinicopathological model, with C-index of 0.780 (95%CI, 0.718-0.843) and 0.803 (95%CI, 0.717-0.889) in the training and validation cohorts, respectively. The radiomics nomogram-defined high-risk group had a shorter DFS, DMFS, and OS than those in the low-risk group (all P < 0.05). Further analysis showed that patients with higher nomogram-defined score exhibited a favorable response to adjuvant chemotherapy (AC) while the low-risk could not. CONCLUSION: This study demonstrated that the newly developed pretreatment multiparameter MRI-based radiomics model could serve as a powerful predictor of prognosis, and may act as a potential indicator for guiding AC in patients with LARC.