Background
Deep learning‐based reconstruction (DLR) can potentially improve image quality by reduction of noise, thereby enabling fast acquisition of magnetic resonance imaging (MRI). However, a ...systematic evaluation of image quality and diagnostic performance of MRI using short acquisition time with DLR has rarely been investigated in men with prostate cancer.
Purpose
To assess the image quality and diagnostic performance of MRI using short acquisition time with DLR for the evaluation of extraprostatic extension (EPE).
Study Type
Retrospective.
Population
One hundred and nine men.
Field Strength/Sequence
3 T; turbo spin echo T2‐weighted images (T2WI), echo‐planar diffusion‐weighted, and spoiled gradient echo dynamic contrast‐enhanced images.
Assessment
To compare image quality, signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR) and subjective analysis using Likert scales on three T2WIs (MRI using conventional acquisition time, MRI using short acquisition time fast MRI, and fast MRI with DLR) were performed. The diagnostic performance for EPE was evaluated by three independent readers.
Statistical Tests
SNR, CNR, and image quality scores across the three imaging protocols were compared using Friedman tests. The diagnostic performance for EPE was assessed using the area under receiver operating characteristic curves (AUCs). P < 0.05 was considered statistically significant.
Results
Fast MRI with DLR demonstrated significantly higher SNR (mean ± SD, 14.7 ± 6.8 vs. 8.8 ± 4.9) and CNR (mean ± SD, 6.5 ± 6.3 vs. 3.4 ± 3.6) values and higher image quality scores (median, 4.0 vs. 3.0 for three readers) than fast MRI. The AUCs for EPE were significantly higher with the use of DLR (0.86 vs. 0.75 for reader 2 and 0.82 vs. 0.73 for reader 3) compared with fast MRI, whereas differences were not significant for reader 1 (0.81 vs. 0.74; P = 0.09).
Data Conclusion
DLR may be useful in reducing the acquisition time of prostate MRI without compromising image quality or diagnostic performance.
Level of Evidence
4
Technical Efficacy
Stage 3
Background
There appears to be less agreement in the identification of cancers in the transition zone (TZ), which is not as reliable as those in peripheral zone when using the Prostate Imaging ...Reporting and Data System (PI‐RADS) version 2 (v2). In response to such shortcomings, the updated version 2.1 was introduced, which incorporated diffusion‐weighted imaging (DWI) into category 2 and clarified lexicons.
Purpose
To compare the diagnostic performance for the detection of clinically significant TZ prostate cancers (csPCa) and interreader agreement between PI‐RADS v2.1 and v2.
Study Type
Retrospective study.
Population
In all, 142 patients, 201 TZ lesions.
Field Strength/Sequence
3.0T; T2‐weighted image and DWI.
Assessment
Lesions were scored by three independent readers using PI‐RADS v2 and v2.1.
Statistical Tests
The sensitivity and specificity at category ≥3 were compared between v2 and v2.1 using the generalized estimating equation model. Detection rates for csPCa of upgraded and downgraded lesions in the use of PI‐RADS v2.1 from v2 were assessed. Interreader agreement was assessed using κ statistics.
Results
PI‐RADS v2.1 showed a higher sensitivity and specificity (94.5% and 60.9%) than v2 (91.8% and 56.3%) for category ≥3 lesions in the detection of csPCa, although not significantly. Of eight upgraded lesions from category 2 to 3 (2 + 1) with an incorporated DWI, 50% (4/8) were csPCa. This was significantly higher than category 2 lesions (4.4%; P = 0.003). No csPCa was detected among the 22.8% (46/201) downgraded lesions. There was a moderate interreader agreement for scores ≥3 (κ = 0.565) in v2.1, which was slightly higher than that for v2 (κ = 0.534), although not significantly.
Data Conclusion
PI‐RADS v2.1 provides moderate and comparable interreader agreement at category ≥3 than v2 in the TZ lesions. Upgraded lesions from category 2 to 3 demonstrated a higher detection rate of csPCa than category 2 lesions in v2.1.
Level of Evidence
4
Technical Efficacy Stage
2 J. Magn. Reson. Imaging 2020;52:577–586.
Background
The Prostate Imaging Reporting and Data System (PI‐RADS) was introduced in 2012 and updated to version 2.1 (v2.1) in early 2019 to improve diagnostic performance and interreader ...reliability.
Purpose
To evaluate the diagnostic performance of PI‐RADS v2.1 in comparison with v2.
Methods
A systematic review and meta‐analysis of the literature was performed using MEDLINE, EMBASE, and Cochrane databases to identify studies evaluating the diagnostic performance of PI‐RADS v2.1 for diagnosing clinically significant prostate cancer (csPCa).
Study Type
Systematic review and meta‐analysis.
Subject
One thousand two hundred forty‐eight patients with 1406 lesions from 10 eligible articles.
Field Strength/sequence
Conventional MR sequences at 1.5 T and 3 T.
Assessment
Two reviewers independently identified and reviewed the original articles reporting diagnostic performance of PI‐RADS v2.1.
Statistical Tests
Meta‐analytic summary sensitivity and specificity were calculated using a bivariate random effects model. Meta‐analytic sensitivity and specificity between PI‐RADS v2 and v2.1 were compared.
Results
The pooled sensitivity and specificity of PI‐RADS v2.1 were 87% (95% confidence intervals, 82–91%) and 74% (63–82%), respectively. In five studies available for a head‐to‐head comparison between PI‐RADS v2.1 and v2, there were no significant differences in either sensitivity (90% 86–94% vs. 88% 83–93%, respectively) or specificity (76% 59–93% vs. 61% 39–83%, respectively; P = 0.37). The sensitivity and specificity were 81% (73–87%) and 82% (68–91%), respectively, for a PI‐RADS score cutoff of ≥4, and 94% (88–97%) and 56% (35–97%) for ≥3. Regarding the zonal location, the sensitivity and specificity for the transitional zone only were 90% (84–96%) and 76% (62–90%) respectively, whereas for the whole gland they were 85% (79–91%) and 71% (57–85%).
Data Conclusion
PI‐RADS v2.1 demonstrated good overall performance for the diagnosis of csPCa. PI‐RADS v2.1 tended to show higher specificity than v2, but the difference lacked statistical significance.
Level of Evidence
3
Technical Efficacy Stage
3
Korean government has selected and stocked five type antigens of two clades as Korean national antigen bank having high possibility of introduction to Korea. We aimed to evaluate the efficacy of the ...clade 2.3.2.1c and 2.3.4.4c H5Nx vaccines from the Korean avian influenza (AI) national antigen bank for emergency preparedness for their potency and protective efficacy against lethal homologous and heterologous viruses in layer and breeder chickens practically. The PD
(dose of vaccine that protects 50% of chickens from viral challenge) of all vaccinated groups was >50, which was satisfied with minimum antigen requirement of OIE, and the PD
levels of the two vaccines differed depending on strain and chicken breed. In homologous challenge, all vaccinated groups exhibited 100% survival with no clinical symptoms and high levels of pre-challenge protective immunity (7.2-8.5 log
), although they did not completely prevent virus shedding. On the other hand, against heterologous virus challenge, vaccinated animals exhibited 62.5-80% survival with lower antibody titers (2.3-3.4 log
) and a longer period of virus shedding (14 days post infection dpi). Our results suggest that the clade 2.3.2.1c and 2.3.4.4c H5Nx vaccines are good candidates for emergency vaccination of commercial chickens and support the idea that close genetic matching between vaccine and challenge virus provides the best protection.
The present study was conducted to monitor sales activity and immunogenicity of commercial H9N2 vaccines produced in Korea from 2007 to 2017. Recorded sales of H9N2 vaccine were around 671 million ...doses, with 10 million doses sold in 2007, rising to a peak of 93 million doses in 2016, with a slight fall in 2017. Multivalent combined vaccines made up around 90% of all vaccine sales, and around 30% of all vaccines were distributed by regional governments for free. The regional vaccination rate was the highest in Gyeonggi and Chungnam, respectively with proportional to the population of layer and breeder chickens. There have been no cases of field infection since 2009. The mean antibody titer was 5.82 log2 across the study period. Our results suggest that continuous genetic monitoring of H9N2 viruses circulating in the field and updating the vaccine seed strain periodically are necessary in order to control H9N2 outbreaks.
In drug discovery, rapid and accurate prediction of protein–ligand binding affinities is a pivotal task for lead optimization with acceptable on-target potency as well as pharmacological efficacy. ...Furthermore, researchers hope for a high correlation between docking score and pose with key interactive residues, although scoring functions as free energy surrogates of protein–ligand complexes have failed to provide collinearity. Recently, various machine learning or deep learning methods have been proposed to overcome the drawbacks of scoring functions. Despite being highly accurate, their featurization process is complex and the meaning of the embedded features cannot directly be interpreted by human recognition without an additional feature analysis. Here, we propose SMPLIP-Score (Substructural Molecular and Protein–Ligand Interaction Pattern Score), a direct interpretable predictor of absolute binding affinity. Our simple featurization embeds the interaction fingerprint pattern on the ligand-binding site environment and molecular fragments of ligands into an input vectorized matrix for learning layers (random forest or deep neural network). Despite their less complex features than other state-of-the-art models, SMPLIP-Score achieved comparable performance, a Pearson’s correlation coefficient up to 0.80, and a root mean square error up to 1.18 in p
K
units with several benchmark datasets (PDBbind v.2015, Astex Diverse Set, CSAR NRC HiQ, FEP, PDBbind NMR, and CASF-2016). For this model, generality, predictive power, ranking power, and robustness were examined using direct interpretation of feature matrices for specific targets.
In recent years, pharmacophore modeling and molecular docking approaches have been extensively used to characterize the structural requirements and explore the conformational space of a ligand in the ...binding pocket of the selected target protein. Herein, we report a pharmacophore modeling and molecular docking of 45 compounds comprising of the indole scaffold as vitamin D receptor (VDR) inhibitors. Based on the selected best hypothesis (DRRRR.61), an atom‐based three‐dimensional quantitative structure‐activity relationships model was developed to rationalize the structural requirement of biological activity modulating components. The developed model predicted the binding affinity for the training set and test set with R2(training) = 0.8869 and R2(test) = 0.8139, respectively. Furthermore, molecular docking and dynamics simulation were performed to understand the underpinning of binding interaction and stability of selected VDR inhibitors in the binding pocket. In conclusion, the results presented here, in the form of functional and structural data, agreed well with the proposed pharmacophores and provide further insights into the development of novel VDR inhibitors with better activity.
Under the best hypothesis (DRRRR), an atom‐based three‐dimensional quantitative structure‐activity relationships model was developed to rationalize the structural requirement for modulation of biological activity with the statistical values, R2(training) = 0.8869 and R2(test) = 0.8139.
The solid‐state nanopore has attracted much attention as a next‐generation DNA sequencing tool or a single‐molecule biosensor platform with its high sensitivity of biomolecule detection. The platform ...has advantages of processability, robustness of the device, and flexibility in the nanopore dimensions as compared with the protein nanopore, but with the limitation of insufficient spatial and temporal resolution to be utilized in DNA sequencing. Here, the fundamental principles of the solid‐state nanopore are summarized to illustrate the novelty of the device, and improvements in the performance of the platform in terms of device fabrication are explained. The efforts to reduce the electrical noise of solid‐state nanopore devices, and thus to enhance the sensitivity of detection, are presented along with detailed descriptions of the noise properties of the solid‐state nanopore. Applications of 2D materials including graphene, h‐BN, and MoS2 as a nanopore membrane to enhance the spatial resolution of nanopore detection, and organic coatings on the nanopore membranes for the addition of chemical functionality to the nanopore are summarized. Finally, the recently reported applications of the solid‐state nanopore are categorized and described according to the target biomolecules: DNA‐bound proteins, modified DNA structures, proteins, and protein oligomers.
The solid‐state nanopore has attracted much attention as a next‐generation DNA sequencing tool or a single‐molecule biosensor platform with its high sensitivity of biomolecule detection. The history, fundamental principles, improvements in the performance, and the recently reported applications of the solid‐state nanopore are highlighted, with a focus on devices, materials, and fabrication methods.
Isotropic InP/ZnSe/ZnS quantum dots (QDs) are prepared at a high reaction temperature, which facilitates ZnSe shell growth on random facets of the InP core. Fast crystal growth enables stacking ...faults elimination, which induces anisotropic growth, and as a result, improves the photoluminescence (PL) quantum yield by nearly 20%. Herein, the effect of the QD morphology on photophysical properties is investigated by observing the PL blinking and ultrafast charge carrier dynamics. It is found that hot hole trapping is considerably suppressed in isotropic InP QDs, indicating that the stacking faults in the anisotropic InP/ZnSe structures act as defects for luminescence. These results highlight the importance of understanding the correlation between QD shapes and hot carrier dynamics, and present a way to design highly luminescent QDs for further promising display applications.
Kinetically fast ZnSe shell growth by controlling reaction temperature produces InP/ZnSe/ZnS quantum dots (QDs) with uniform shape. The isotropic InP/ZnSe/ZnS QDs show a significant improvement of photoluminescence quantum yield by 20% compared to pristine InP/ZnSe/ZnS QDs. Hot carrier trapping is especially suppressed in InP QDs with uniform shells by eliminating the structural defects induced by stacking faults.
The immunogenicity and protective efficacy of inactivated clade 2.3.2.1c (rgKA435) and clade 2.3.4.4c (rgES2) H5Nx vaccines, which are representatives of an avian influenza antigen bank in Korea, ...were examined in mice. Mice were vaccinated twice and then challenged with homologous virus. Hemagglutinin inhibition and serum neutralizing antibody titers in the rgES2-vaccinated group were higher (4.4 ± 1.7 and 10.8 ± 2.3 log2, respectively) than those in the rgKA435-vaccinated group (2.8 ± 1.1 and 2.5 ± 0.9 log2, respectively). rgES2 conferred 100% protection, with no morbidity, no severe body weight loss, and no virus replication in any of the tissues tested. By contrast, 80% of mice in the rgKA435 group survived. One mouse in this group died at 10 dpi. Virus titers in the lung and turbinate were 102.5–3.5 TCID50/0.1 ml at 3–7 dpi and 101.5 TCID50/0.1 ml at 3–5 dpi, respectively. In particular, the viral titer in the turbinate from the rgKA435 group at 3 dpi was significantly lower than that in the equivalent control group (p < 0.05). The data suggest that both of these antigen bank vaccines are promising candidates for further evaluation in humans.
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