This large international radiation dose survey demonstrates considerable reduction of radiation exposure in coronary CTA during the last decade. However, the large inter-site variability in radiation exposure underlines the need for further site-specific training and adaptation of contemporary cardiac scan protocols.

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To date, the molecular mechanism underlying constitutive signal transducer and activator of transcription 3 (STAT3) activation in gliomas is largely unclear. In this study, we report that Smad6 is overexpressed in nuclei of glioma cells, which correlates with poor patient survival and regulates STAT3 activity via negatively regulating the Protein Inhibitors of Activated STAT3 (PIAS3). Mechanically, Smad6 interacts directly with PIAS3, and this interaction is mediated through the Mad homology 2 (MH2) domain of Smad6 and the Ring domain of PIAS3. Smad6 recruits Smurf1 to facilitate PIAS3 ubiquitination and degradation, which also depends on the MH2 domain and the PY motif of Smad6. Consequently, Smad6 reduces PIAS3-mediated STAT3 inhibition and promotes glioma cell growth and stem-like cell initiation. Moreover, the Smad6 MH2 transducible protein restores PIAS3 expression and subsequently reduces gliomagenesis. Collectively, we conclude that nuclear-Smad6 enhances glioma development by inducing PIAS3 degradation and subsequent STAT3 activity upregulation.

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Dual-modal imaging techniques have gained intense attention for their potential role in the dawning era of tumor early accurate diagnosis. Chelate-free robust dual-modal imaging nanoprobes with high efficiency and low toxicity are of essential importance for tumor targeted dual-modal in vivo imaging. It is still a crucial issue to endow Cd-free dual-modal nanoprobes with bright fluorescence as well as high relaxivity. Herein, a facile synthetic strategy was developed to prepare Gd-doped CuInS/ZnS bimodal quantum dots (GCIS/ZnS, BQDs) with optimized properties. The fluorescent properties of the GCIS/ZnS BQDs can be thoroughly optimized by varying reaction temperature, aging time, and ZnS coating. The amount of Gd precursor can be well-controlled to realize the optimized balance between the MR relaxivity and optical properties. The obtained hydrophobic GCIS/ZnS BQDs were surface engineered into aqueous phase with PEGylated dextran-stearyl acid polymeric lipid vesicles (PEG-DS PLVs). Upon the phase transfer, the hydrophilic GCIS/ZnS@PLVs exhibited pronounced near-infrared fluorescence as well as high longitudinal relaxivity (r1 = 9.45 mM(-1) S(-1)) in water with good colloidal stability. In vivo tumor-bearing animal experiments further verified GCIS/ZnS@PLVs could achieve tumor-targeted MR/fluorescence dual-modal imaging. No toxicity was observed in the in vivo and ex vivo experiments. The GCIS/ZnS@PLVs present great potential as bimodal imaging contrast agents for tumor diagnosis.

Background Gleason score (GS) is a histologic prognostic factor and the basis of treatment decision‐making for prostate cancer (PCa). Treatment regimens between lower‐grade (GS ≤7) and high‐grade (GS >7) PCa differ largely and have great effects on cancer progression. Purpose To investigate the use of different sequences in biparametric MRI (bpMRI) of the prostate gland for noninvasively distinguishing high‐grade PCa. Study Type Retrospective. Population In all, 489 patients (training cohort: N = 326; test cohort: N = 163) with PCa between June 2008 and January 2018. Field Strength/Sequence 3.0T, pelvic phased‐array coils, bpMRI including T2‐weighted imaging (T2WI) and diffusion‐weighted imaging (DWI); apparent diffusion coefficient map extracted from DWI. Assessment The whole prostate gland was delineated. Radiomic features were extracted and selected using the Kruskal–Wallis test, the minimum redundancy‐maximum relevance, and the sequential backward elimination algorithm. Two single‐sequence radiomic (T2WI, DWI) and two combined (T2WI‐DWI, T2WI‐DWI‐Clinic) models were respectively constructed and validated via logistic regression. Statistical Tests The Kruskal–Wallis test and chi‐squared test were utilized to evaluate the differences among variable groups. P < 0.05 determined statistical significance. The area under the receiver operating characteristic curve (AUC), specificity, sensitivity, and accuracy were used to evaluate model performance. The Delong test was conducted to compare the differences between the AUCs of all models. Result All radiomic models showed significant (P < 0.001) predictive performances. Between the single‐sequence radiomic models, the DWI model achieved the most encouraging results, with AUCs of 0.801 and 0.787 in the training and test cohorts, respectively. For the combined models, the T2WI‐DWI models acquired an AUC of 0.788, which was almost the same with DWI in the test cohort, and no significant difference was found between them (training cohort: P = 0.199; test cohort: P = 0.924). Data Conclusion Radiomics based on bpMRI can noninvasively identify high‐grade PCa before the operation, which is helpful for individualized diagnosis of PCa. Level of Evidence 4 Technical Efficacy Stage 2 J. Magn. Reson. Imaging 2020;52:1102–1109.

A new catalytic enantioselective approach for the formation of allyl alpha-amino acid derivatives by reaction of N-tosyl alpha-imino esters with allyl stannanes and silanes catalyzed by chiral copper(I) complexes has been developed. A series of different BINAP and phosphine-oxazoline (P,N) ligands have, in combination with various Lewis acids, been tested as chiral catalysts for allylation of N-tosyl alpha-imino esters. It has been found that both type of ligands, in combination with copper(I) salts, give highly valuable unsaturated alpha-amino acid derivatives. The reaction has been investigated for different allyl stannanes and silanes, and it has been found that tri-n-butyl allyl stannane gives the best results of the simple allyl compounds tested, leading to gamma,delta-unsaturated alpha-amino acid derivatives in up to 94% yield and with up to 83% ee, which can be improved to be >95% ee by recrystallization. The reaction has also been investigated using different acyclic and cyclic allyl stannanes leading to various types of unsaturated alpha-amino acid derivatives in very high yield (up to 95%) and with up to 98% ee. The stereochemistry and absolute configurations of the allyl alpha-amino acid derivatives have been determined by X-ray analysis, and it is suggested that the reaction takes place as an ene-like reaction.

A highly enantioselective ene reaction of readily available tosyl a-imino esters with alkenes catalysed by only 0.1 mol% of chiral CuPF 6 -BINAP complexes is presented.The development of asymmetric catalytic reactions has in recent years added a new and very important aspect to chemistry as it allows one to use a small amount of chiral catalysts to form directly optically active compounds. 1 The ene reaction of alkenes 1 with a-imino esters 2 can give a-amino acids 3 which are among the most fundamental compounds in nature (Scheme 1).