Topotactic Conversion of β‐Helix‐Layered Silicate into AST‐Type Zeolite through Successive Interlayer Modifications

AST‐type zeolite with a plate morphology can be synthesized by topotactic conversion of a layered silicate (β‐helix‐layered silicate; HLS) by using N,N‐dimethylpropionamide (DPA) to control the layer stacking of silicate layers and the subsequent interlayer condensation. Treatment of HLS twice with 1) hydrochloric acid/ethanol and 2) dimethylsulfoxide (DMSO) are needed to remove interlayer hydrated Na ions and tetramethylammonium (TMA) ions in intralayer cup‐like cavities (intracavity TMA ions), both of which are introduced during the preparation of HLS. The utilization of an amide molecule is effective for the control of the stacking sequence of silicate layers. This method could be applicable to various layered silicates that cannot be topotactically converted into three‐dimensional networks by simple interlayer condensation by judicious choice of amide molecules.     

Chemoselective and Direct Functionalization of Methyl Benzyl Ethers and Unsymmetrical Dibenzyl Ethers by Using Iron Trichloride

Methyl and benzyl ethers are widely utilized as protected alcohols due to their chemical stability, such as the low reactivity of the methoxy and benzyloxy groups as leaving groups under nucleophilic conditions. We have established the direct azidation of chemically stable methyl and benzyl ethers derived from secondary and tertiary benzyl alcohols. The present azidation chemoselectively proceeds at the secondary or tertiary benzylic positions of methyl benzyl ethers or unsymmetrical dibenzyl ethers and is also applicable to direct allylation, alkynylation, and cyanation reactions, as well as the azidation. The present methodologies provide not only a novel chemoselectivity but also the advantage of shortened synthetic steps, due to the direct process without the deprotection of the methyl and benzyl ethers.     

Iron‐Catalyzed Friedel–Crafts Benzylation with Benzyl TMS Ethers at Room Temperature

Friedel–Crafts benzylations between unactivated arenes and benzyl alcohol derivatives are clean and straightforward processes to construct biologically useful di‐ and tri‐arylmethanes. We have established an efficient iron‐catalyzed Friedel–Crafts benzylation method at room temperature that uses benzyl TMS ethers as substrates, which are poorly reactive under common nucleophilic substitution conditions. The reaction seems to progress through iron‐catalyzed self‐condensation of the benzyl TMS ether to the corresponding dibenzylic ether. The use of excess arene relative to benzyl TMS ether produced mono‐benzylated arene (di‐ and tri‐arylmethane products), whereas the use of excess benzyl TMS ether versus arene provided bis‐benzylated arene (polyarylated products) in high yields and regioselectivities. In previous methods, the latter double Friedel–Crafts benzylations hardly proceed.     

Isolation and quantification of messenger RNA from tissue models by using a double-barrel carbon probe

In this study, we introduce the double-barrel carbon probe (DBCP)—a simple, affordable microring electrode—which enables the collection and analysis of single cells independent of cellular positioning. The target cells were punctured by utilizing an electric pulse between the two electrodes in DBCP, and the cellular lysates were collected by manual aspiration using the DBCP. The mRNA in the collected lysate was evaluated quantitatively using real-time PCR. The histograms of single-cell relative gene expression normalized to GAPDH were fit to a theoretical lognormal distribution. In the tissue culture model, we focused on angiogenesis to prove that multiple gene expression analysis was available. Finally, we applied DBCP for the embryonic stem (ES) cell-derived cardiomyocytes to substantiate the capability of the probe to collect cells, even from high-volume samples such as spheroids. This method achieves high sensitivity for mRNA at the single-cell level and is applicable in the analysis of various biological samples independent of cellular positioning.

Relationship between Echo Intensity of Vastus Lateralis and Knee Extension Strength in Patients with Type 2 Diabetes Mellitus

Objective: This study aimed to determine the association between echo intensity (EI) of vastus lateralis and knee extension strength (KES) in patients with type 2 diabetes mellitus (T2DM). Methods: This retrospective study included a total of 304 patients (189 males and 115 females) with T2DM who were hospitalized for treatment or care. EI and muscle thickness (MT) of the right vastus lateralis were assessed from transverse ultrasound images. Maximal isometric KES was evaluated using a dynamometer and normalized for body weight (%KES). Results: %KES was significantly positively correlated with MT and stages of change for exercise behavior, and significantly negatively correlated with age, T2DM duration, and EI. %KES was significantly higher in male than in female. %KES was significantly higher in non-diabetic peripheral neuropathy (DPN) than in DPN. Stepwise multiple regression analysis showed that sex, age, T2DM duration, EI, and stages of change for exercise behavior were significant determinants of %KES. Conclusion: The study results suggest that EI is associated with %KES in patients with T2DM.     

Utilization of Sodium Nitroprusside as an Intestinal Permeation Enhancer for Lipophilic Drug Absorption Improvement in the Rat Proximal Intestine

As advanced synthetic technology has enabled drug candidate development with complex structure, resulting in low solubility and membrane permeability, the strategies to improve poorly absorbed drug bioavailability have attracted the attention of pharmaceutical companies. It has been demonstrated that nitric oxide (NO), a vital signaling molecule that plays an important role in various physiological systems, affects intestinal drug absorption. However, NO and its oxidants are directly toxic to the gastrointestinal tract, thereby limiting their potential clinical application as absorption enhancers. In this study, we show that sodium nitroprusside (SNP), an FDA-approved vasodilator, enhances the intestinal absorption of lipophilic drugs in the proximal parts of the small intestine in rats. The SNP pretreatment of the rat gastrointestinal sacs significantly increased griseofulvin and flurbiprofen permeation in the duodenum and jejunum but not in the ileum and colon. These SNP-related enhancement effects were attenuated by the co-pretreatment with dithiothreitol or c-PTIO, an NO scavenger. The permeation-enhancing effects were not observed in the case of antipyrine, theophylline, and propranolol in the duodenum and jejunum. Furthermore, the SNP treatment significantly increased acidic glycoprotein release from the mucosal layers specifically in the duodenum and jejunum but not in the ileum and colon. These results suggest that SNP increases lipophilic drug membrane permeability specifically in the proximal region of the small intestine through disruption of the mucosal layer.     

Thermal degradation of partly complexed poly(vinylpyridines) with transition metal chloride

The thermal degradation of poly(vinylpyridines), partly complexed with transition metal chlorides containing Co(II), Ni(II), Cu(II) and Zn(II) ions, was investigated using thermogravimetry, infrared spectrometry and gc/mass spectrometry. When poly(2-vinylpyridine) and poly(4-vinylpyridine) were partly complexed with transition metal ions, thermal degradation was initiated at low temperature. The complexes were decomposed even near the threshold temperature for weight loss. Degradations were modified by the complexation, particularly for poly(2-vinylpyridine). Yields of dimers, ethylpyridine, etc., increased linearly with degree of complexation, but that of monomer decreased linearly. The increase of the yield of dimer could be explained from the concept that polymer radicals reacted with metal chlorides, then dehydrochlorinated and underwent β-scission.     

Reduction‐Induced Highly Selective Uptake of Cesium Ions by an Ionic Crystal Based on Silicododecamolybdate

Cation adsorption and exchange has been an important topic in both basic and applied chemistry relevant to materials synthesis and chemical conversion, as well as purification and separation. Selective Cs⁺ uptake from aqueous solutions is especially important because Cs⁺ is expensive and is contained in radioactive wastes. However, the reported adsorbents incorporate Rb⁺ as well as Cs⁺, and an adsorbent with high selectivity toward Cs⁺ has not yet been reported. Highly selective uptake of Cs⁺ by an ionic crystal (etpyH)₂[Cr₃O(OOCH)₆(etpy)₃]₂[α‐SiMo₁₂O₄₀]?3 H₂O (etpy =4‐ethylpyridine) is described. The compound incorporated up to 3.8 mol(Cs⁺) mol(s)^?1 (where s=solid) by cation‐exchange with etpyH⁺ and reduction of silicododecamolybdate with ascorbic acid. The amount of Cs⁺ uptake was comparable to that of Prussian blue, which is widely recognized as a good Cs⁺ adsorbent. Moreover, other alkali‐metal and alkaline‐earth‐metal cations were almost completely excluded (<0.2 mol mol(s)^?1).     

Cellulose alkyl ester/poly(<Emphasis Type="Italic">ε</Emphasis>-caprolactone) blends: characterization of miscibility and crystallization behaviour

Cellulose valerate (CV)/poly(ε-caprolactone) (PCL) blends were investigated to clarify the effect of the degree of substitution (DS) of the cellulose ester component on the miscibility. CVs of DS > 2.15 were miscible with PCL in their amorphous states, as judged from the detection of a single T _g by differential scanning calorimetry (DSC). This result and other complementary data for cellulose acetate (CA), propionate (CP), and butyrate (CB) blends with PCL made up a miscibility map as a function of the number N of carbons in the normal acyl substituent as well as of DS. CB of N = 4 and CV of N = 5, the ester side-chains of which make a higher similarity in chemical structure with a repeating unit of PCL, were found to be miscible with the aliphatic polyester at a comparatively lower DS; the critical butyryl DS of ∼1.85 being still lower than 2.15. For PCL-rich compositions of CB(DS > 2.0)/PCL and CV(DS > 2.2)/PCL blends, isothermal melt-crystallization behaviour was characterized by calorimetry and polarized optical microscopy. The CB and CV components gave rise to a marked diminution of the crystallization rate of PCL, as a result of the diluent action of the cellulose esters in the respective miscible, molten mixtures. Through a quantitative analysis of the kinetics, it is suggested regarding the supramolecular morphology that the bulky cellulose esters would be trapped not only on the fold surfaces but also on the growth faces of PCL lamellar crystals, to form a non-crystalline mixed polymer phase in the crystal boundary regions.