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A 6-bromo-7-hydroxycoumarin-4-ylmethyl (Bhc) caged compound having a click-modifiable chemical handle was designed and synthesized. This molecule was applied to the synthesis of modular caged paclitaxels (PTXs) in which additional functional units could be easily installed. This system was used to prepare water-soluble caged PTXs with improved photolysis efficiencies.

A convenient method for the preparation of meso,β-dual-functionalized porphyrin was developed. The bromination of zincated β-silylporphyrin with NBS selectively yielded meso-bromo-β-silylporphyrin, whereas, the bromination of free-base β-silylporphyrin selectively yielded β-bromoporphyrin via an ipso-substitution of the silyl group. These meso,β-dual-functionalized porphyrins could be used as multipurpose synthons for fabricating various porphyrin derivatives.

Purpose This study aimed to compare the characteristics of triple-negative breast cancer (TNBC) with non-TNBC on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and synthetic MRI. Method This retrospective study included 79 patients with histopathologically proven breast cancer (TNBC: 16, non-TNBC: 63) who underwent synthetic MRI. Using synthetic MR images, we obtained T1 and T2 relaxation times in breast lesions before (Pre-T1, Pre-T2, Pre-PD) and after (Gd-T1, Gd-T2, Gd-PD) contrast agent injection. Subsequently, we calculated the ΔT1 (Pre-T1 – Gd-T1), ΔT2 (Pre-T2 – Gd-T2), Pre-T1/T2, and Gd-T1/T2. We compared the aforementioned quantitative values, as well as several morphologic features between TNBCs and non-TNBCs that were identified on DCE-MRI. Results The multivariate analyses revealed that the Pre-T2 (P = 0.037) and the presence of rim enhancement (P-RIM) (P = 0.034) were significant and independent predictors of TNBC. The area under the receiver operating characteristics curve for all breast cancers was greater when a combination of Pre-T2 and P-RIM (Pre-T2＋P-RIM; Method 3, AUC (area under the curve) = 0.858) was used to distinguish between TNBCs and non-TNBCs versus the use of either Pre-T2 alone (Method 1, AUC = 0.786) or P-RIM alone (Method 2, AUC = 0.747). Conclusions Pre-T2 obtained using synthetic MRI and P-RIM identified on DCE-MRI allowed the differentiation between TNBCs and non-TNBCs. However, these results are preliminary and need to be verified by further studies.

BACKGROUND The addition of synthetic MRI might improve the diagnostic performance of dynamic contrast-enhanced MRI (DCE-MRI) in patients with breast cancer. PURPOSE To evaluate the diagnostic value of a combination of DCE-MRI and quantitative evaluation using synthetic MRI for differentiation between benign and malignant breast masses. STUDY TYPE Retrospective, observational. POPULATION In all, 121 patients with 131 breast masses who underwent DCE-MRI with additional synthetic MRI were enrolled. FIELD STRENGTH/SEQUENCE 3.0 Tesla, T1 -weighted DCE-MRI and synthetic MRI acquired by a multiple-dynamic, multiple-echo sequence. ASSESSMENT All lesions were differentiated as benign or malignant using the following three diagnostic methods: DCE-MRI type based on the Breast Imaging-Reporting and Data System; synthetic MRI type using quantitative evaluation values calculated by synthetic MRI; and a combination of the DCE-MRI + Synthetic MRI types. The diagnostic performance of the three methods were compared. STATISTICAL TESTS Univariate (Mann-Whitney U-test) and multivariate (binomial logistic regression) analyses were performed, followed by receiver-operating characteristic curve (AUC) analysis. RESULTS Univariate and multivariate analyses showed that the mean T1 relaxation time in a breast mass obtained by synthetic MRI prior to injection of contrast agent (pre-T1 ) was the only significant quantitative value acquired by synthetic MRI that could independently differentiate between malignant and benign breast masses. The AUC for all enrolled breast masses assessed by DCE-MRI + Synthetic MRI type (0.83) was significantly greater than that for the DCE-MRI type (0.70, P

Total synthesis of (+)-gliocladin C has been achieved on the basis of one-pot construction of the 3a-(3-indolyl)pyrroloindoline core structure by the cross-coupling of a tryptophan derivative and an indole promoted by a sulfonium species generated from dialkylsulfoxide and triflic anhydride.

The absolute configurations of simple alkyl-substituted chiral epoxides not bearing other ligating groups are readily determined via the exciton-coupled circular dichroism (ECCD) protocol using bidentate bis(zinc porphyrin) host system BP1 as a CD-sensitive chirality probe. In this situation, chiral epoxides can successfully be incorporated into the cleft of V-shaped host BP1 by double coordination of both oxygen lone pairs of the guest to the two central zinc ions of the host. We also propose a working model based on an MM2 optimized structure of the substrates that enables nonempirical prediction of the chirality of the bound epoxide.

In this study, we examined the rheology of polyurethane foam (PUF) as an analogue system of magma undergoing vesiculation, deformation, and solidification. Solid PUF was formed by mixing two polymeric liquids, followed by chemical reactions of foaming and curing. The transient rheology during the processes was investigated using an instrument based on a stress-controlled rheometer. First, the oscillatory rheology was measured applying small-amplitude oscillations with cyclic frequency sweeps. In the foaming stage, the frequency-dependence of the rheology depends on the dynamic capillary number in a similar way to the existing bubbly flow model. In the curing stage, the viscoelasticity of the liquid becomes dominant, and the rheology of PUF shows Maxwell-type viscoelasticity with relaxation time exponentially increasing with time. When the reaction is rapid because of high temperature, the viscoelasticity during curing is not scaled by the single relaxation time. Instead, PUF passes through a condition called gelation, which is characterized by a power-law relaxation spectrum. Next, we examined the relationship between the dynamic viscosity measured by the small-strain oscillation and the shear viscosity measured with a fixed shear rate at a large strain. We found that PUF obeys the Cox-Merz rule, which states that the two viscosities are equivalent when the shear rate and the angular frequency are equal. Specifically, the shear viscosity tends to be smaller than the dynamic viscosity by a few tens of percent. The difference was shown to be in the range expected for bubbly fluid in the foaming stage, while it went beyond what can be explained by the bubbly fluid model when the viscoelasticity of the liquid becomes significant. X-ray computed tomography analyses revealed that samples in these cases contained large bubbles, indicating bubble coalescence. We infer that the difference is caused by bubble coalescence as well as non-Newtonian rheology during solidification, including gelation. All these processes might occur in actual magma during eruptions. We show that the ranges of the capillary number comparing the deformation time and the bubble shape relaxation time and Deborah number comparing the deformation time and the viscoelastic relaxation time in our experiments are comparable with their ranges expected for magma ascending in an eruptive conduit. The characteristic time of viscosity increase of PUF was also shown to be realizable for magma in natural volcanoes. We conclude that PUF is useful for simulating magma processes in eruptive conduits.

Tube pumice, the bubbles of which are highly elongated in one direction, is a common product of explosive silicic eruptions, especially caldera-forming eruptions. To understand the conditions necessary to generate tube-like bubbles, we performed extensional experiments on polyurethane foam, which experiences vesiculation, deformation, and solidification at room temperature. The strain and strain rate of pure shear deformation were controlled by the pull length and pull rate of the extension, respectively. The shapes of bubbles in the solidified polyurethane foam were analyzed in three dimensions by X-ray computed tomography. The experimental results demonstrate that strain and capillary number control the degree of bubble deformation. Highly deformed (tube-like) bubbles were found in the experiments with large strain and large capillary number. In each experimental sample, there is scatter in the relation between the degrees of bubble deformation and expected capillary numbers, which we interpret to be the result of the inhomogeneous shear field around individual bubbles and bubble coalescence. Despite the large scatter, the average deformation degree is predicted well by the dynamics of a single bubble, where the viscous stress acting on the bubble surface is taken as the product of bulk strain rate and effective viscosity. Using this approach, the average deformation degree of experimental bubbles in each sample was approximately calculated from the deformation model of a single bubble at least in the range of pure shear strain smaller than 1.5. Small bubbles in the samples extended at low viscosities tend to be less elongated than those calculated from the deformation model, due to shape relaxation. The effect of shape relaxation is quantified by a new dimensionless number, i.e., the quench number, which represents the ratio of the timescale of increasing viscosity and shape relaxation. Our experiment suggests that bubble shapes in highly vesicular pumice can be used to analyze their viscosity and strain rate during the elongation process. An analysis of the published data was presented as a test case.