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Background: Diffuse myocardial interstitial fibrosis (DMIF) is a key factor for heart failure (HF) in diabetic cardiomyopathy. MRI T1‐mapping technique can quantitatively evaluate DMIF. Purpose: To evaluate of early DMIF in a type 1 diabetes mellitus (T1DM) mouse model through 7.0 T MRI T1 mapping. Study Type: Prospective. Animal Model: A total of 50 8‐week‐old C57Bl/6J male mice were divided into control (n = 20) and T1DM (n = 30) groups. Field Strength/Sequence: A 7.0 T small animal MRI; gradient echo Look–Locker inversion recovery T1‐mapping sequence; cine MRI. Scans were acquired in control and T1DM mice every 4 weeks until 24 weeks. Assessment: End‐diastolic volume (EDV), end‐systolic volume (ESV), ejection fraction (EF), left ventricle (LV) mass, fractional shortening (FS), and E/A ratio. They were evaluated through echocardiography and cine MRI. The extracellular volume fraction (ECV) was calculated. Sirius Red staining was performed and calculated collagen volume fraction (CVF). Statistical Tests: Differences in ECV and CVF between two groups were analyzed using one‐way analysis of variance. The correlation between ECV and CVF was assessed using Pearson's correlations. Results: Compared with the control group, a progressive decrease in FS, EF, and E/A ratio was observed in the T1DM group. Both ECV and CVF values gradually increased during diabetes progression. A significant increase in ECV and CVF values was observed at 12 weeks (ECV: 32.5% ± 1.6% vs. 28.1% ± 1.8%; CVF: 6.9% ± 1.8% vs. 3.3% ± 1.1%). ECV showed a strong correlation with CVF (r = 0.856). Data Conclusion: ECV is an accurate and feasible imaging marker that can be used to quantitatively assess DMIF changes over time in T1DM mice. ECV has potential to accurately detect DMIF in the early stage and may be a useful imaging tool to assess the need for early intervention in T1DM mice. Evidence Level: 1 Technical Efficacy: Stage 3. [ABSTRACT FROM AUTHOR]

Background: Late gadolinium enhancement (LGE) is absent in many patients with suspected myocarditis and preserved left ventricular ejection fraction (LV‐EF), which poses difficulties in diagnosis and risk stratification. Purpose To investigate the diagnostic and prognostic value of ventricular myocardial strain in patients with suspected myocarditis, preserved LV‐EF, and negative Lake Louis Criteria (LLC) by comparing the findings in LGE negative and LGE positive patients. Study Type: Retrospective. Population A total of 108 patients with clinically suspected myocarditis who did not satisfy LLC were divided into LGE negative (N = 65) and LGE positive (N = 43) groups. A control group consisted of 50 healthy volunteers. Field Strength/Sequence: Steady‐state free precession cine and phase‐sensitive inversion recovery segmented gradient echo LGE sequences at 3.0 T. Assessment Myocardial strain of the ventricles was evaluated by feature tracking, major adverse cardiovascular events (MACE) were assessed during follow‐up since the date of magnetic resonance examination. Statistical Tests: Independent‐samples t test, Mann–Whitney U test, receiver operating characteristic curve analysis, and Cox proportional hazard regression were performed. A P‐value <0.05 was considered statistically significant. Results: Cardiac function and myocardial deformability were impaired in all patients relative to controls. Left ventricular‐global radial (LV‐GRS), circumferential (LV‐GCS), and longitudinal (LV‐GLS) strain had diagnostic value, even in LGE negative patients (sensitivity = 0.446, 0.523, and 0.662; specificity = 0.92, 0.80, and 0.64; AUC = 0.685, 0.675, and 0.648, respectively). After a median follow‐up of 530.5 (interquartile range: 168.5–969.25) days, MACE occurred in 18 (16.67%) patients. Right ventricular GLS showed prognostic value in all patients and in LGE negative patients, both in univariable analysis (hazard ratio [HR] 1.049, 95% confidence interval [CI] 1.001–1.099 and HR 1.068, 95% CI 1.011–1.127, respectively) and in multivariable Cox survival analysis. LV‐GLS was associated with MACE in LGE positive patients in multivariable Cox survival analysis. Data Conclusion: Myocardial strain provides diagnostic and prognostic value in suspected myocarditis with preserved LV‐EF, even in the absence of LGE. Level of Evidence: 3 Technical Efficacy: 2 [ABSTRACT FROM AUTHOR]

Retinoid X receptors (RXRs) function as ligand-activated transcription factors and are obligatory components of a large number of nuclear receptor heterodimers. RXRs help regulate diverse physiological responses including the cancer prevention responses of cell proliferation, inflammation, cell differentiation, and apoptosis. Since RXRs represent important targets for cancer chemoprevention, an ultrafiltration mass spectrometry-based assay was developed to facilitate the discovery of potential chemoprevention agents that bind to human RXR[alpha]. Natural and synthetic ligands for RXR[alpha] including 9-cis-retinoic acid, docosahexaenoic acid, and LG100268 could be detected and identified in DMSO (dimethyl sulfoxide) or even complex matrixes such as extracts of marine bacteria. Specific binding of ligands to RXR[alpha] was demonstrated through competitive binding using ultrafiltration LC-MS/ MS (liquid chromatography-tandem mass spectrometry), and ligands could be ranked in order of affinity for RXR[alpha]. Therefore, ultrafiltration LC-MS/MS is suitable for the screening of complex mixtures such as natural product extracts for the discovery of new ligands to RXR[alpha].

Highlights: [•] Mechanism of cycloaddition between Me2Si Si: and formaldehyde has been investigated. [•] π Orbital and 3p unoccupied orbital of Si: in Me2Si Si: are object in cycloaddition. [•] [2+2] Cycloaddition to form a four-membered Si-heterocyclic ring silylene. [•] It further reacts with formaldehyde form a spiro-Si-heterocyclic ring compound. [ABSTRACT FROM AUTHOR]

The mechanism of the cycloaddition reaction between singlet state silylene germylidene (H2Si = Ge:) and ethene has been investigated with the CCSD(T)//MP2/6-31G* method; from the potential energy profile, we predict that the reaction has one dominant reaction pathway. This dominant pathway has the two reactants firstly forming a Si-heterocyclic four-membered ring germylene (INT1) through a [2 + 2] cycloaddition reaction. Due to the sp3 hybridisation of the Ge: atom in INT1, the latter further combines with ethene to form a bis-heterocyclic product containing Si and Ge (P2). [ABSTRACT FROM AUTHOR]

The mechanism of the cycloaddition reaction between singlet dichlorosilylene germylidene (Cl2SiGe:) and formaldehyde has been investigated with the CCSD(T)//MP2/6-31G* method. From the potential energy profile, it could be predicted that the reaction has one dominant reaction pathway. The reaction rule presented is that the two reactants first form a four-membered Si-heterocyclic ring germylene through the [2 + 2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge atom in the four-membered Si-heterocyclic ring germylene and the π orbital of formaldehyde forming a π→p donor-acceptor bond, the four-membered Si-heterocyclic ring germylene further combines with formaldehyde to form an intermediate. Because the Ge atom in intermediate undergoes sp3 hybridization after transition state, then, the intermediate isomerizes to a spiro-heterocyclic ring compound involving Si and Ge via a transition state. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Abstract: The mechanism of the cycloaddition reaction between singlet H2Geormaldehyde has been investigated with the CCSD(T)//MP2/6-31G* method. From the potential energy profile, it could be predicted that the reaction has one dominant reaction pathway. The reaction rule presented is that the [2+2] cycloaddition reaction between two reactants firstly generates a four-membered Ge-heterocyclic ring germylene. Because the 4p unoccupied orbital of Ge: atom in the four-membered Ge-heterocyclic ring germylene and the π orbital of formaldehyde form a π→p donor–acceptor bond, the four-membered Ge-heterocyclic ring germylene further combines with formaldehyde to form an intermediate. Because the Ge: atom in intermediate happens sp3 hybridization after transition state, then, intermediate isomerizes to a spiro-Ge-heterocyclic ring compound via a transition state. The research result indicates the laws of cycloaddition reaction between H2Gets derivatives(X2Ge:hsp sp="0.25" />=F, Cl, CH3, Ph, Ar…) and the asymmetric π-bonded compounds, which is significant for the synthesis of small-ring and spiro-Ge-heterocyclic compounds. The study extends research area and enriches the research content of germylene chemistry. [Copyright &y& Elsevier]