Imaging mass spectrometry distinguished the cancer and stromal regions of oral squamous cell carcinoma by visualizing phosphatidylcholine (16:0/16:1) and phosphatidylcholine (18:1/20:4)

Most oral cancers are oral squamous cell carcinoma (OSCC). The anatomical features of OSCC have been histochemically evaluated with hematoxylin and eosin. However, the border between the cancer and stromal regions is unclear and large portions of the cancer and stromal regions are resected in surgery. To reduce the resected area and maintain oral function, a new method of diagnosis is needed. In this study, we tried to clearly distinguish the border on the basis of biomolecule distributions visualized by imaging mass spectrometry (IMS). In the IMS dataset, eleven signals were significantly different in intensity (p?<?0.01) between the cancer and stromal regions. Two signals at m/z 770.5 and m/z 846.6 were distributed in each region, and a clear border was revealed. Tandem mass spectrometric (MS/MS) analysis identified these signals as phosphatidylcholine (PC) (16:0/16:1) at m/z 770.5 in the cancer region and PC (18:1/20:4) at m/z 846.6 in the stromal region. Moreover, the distribution of PC species containing arachidonic acid in the stromal region suggests that lymphocytes accumulated in response to the inflammation caused by cancer invasion. In conclusion, the cancer and stromal regions of OSCCs were clearly distinguished by use of these PC species and IMS analysis, and this molecular identification can provide important information to elucidate the mechanism of cancer invasion.     

Hydrothermal formation of tobermorite studied by in situ X‐ray diffraction under autoclave condition

Hydrothermal formation of tobermorite from a pre‐cured cake has been investigated by transmission X‐ray diffraction (XRD) using high‐energy X‐rays from a synchrotron radiation source in combination with a newly designed autoclave cell. The autoclave cell has a large and thin beryllium window for wide‐angle X‐ray diffraction; nevertheless, it withstands a steam pressure of more than 1.2 MPa, which enables in situ XRD measurements in a temperature range of 373 to 463 K under a saturated steam pressure. Formation and/or decomposition of several components has been successfully observed during 7.5 h of reaction time. From the intensity changes of the intermediate materials, namely non‐crystalline C–S–H and hydroxylellestadite, two pathways for tobermorite formation have been confirmed. Thus, the newly developed autoclave cell can be used for the analyses of reaction mechanisms under specific atmospheres and temperatures.     

Cycloaddition reaction of pyrimidine-dienols with dienophiles. A new approach to quinazolines

A new synthetic approach to quinazolines bearing a carboxy group is described. Reaction of 5-carbonyl substituted 1,3,6-tri-methyluracils (I) with dimethyl acetylenedicarboxylate or electron-deficient olefines affords quinazoline derivatives (III-VI) $\text{via}$ pyrimidine(Z)-dienols (II) formed by base-catalyzed isomerization.     

Preparation of sterically congested di(4-pyridyl)diazomethanes and characterization of triplet carbenes from them

Di(4-pyridyl)diazomethanes having two and four ortho chlorine groups were prepared, and the triplet carbenes generated from them were characterized by ESR and UV/vis at low temperature and time-resolved UV/vis at room temperature. An appreciable increase in the stability of triplet carbenes is achieved by introducing ortho chlorine groups. [structure: see text]     

High Refractive-Index Microspheres as Optical Cavity Structure

Microspheres of refractive index of n_D > 2.0 have been investigated. The organic-inorganic hybrid microspheres of n_D = 1.72 were prepared by the vibrating orifice technique using titanium-tetra-n-butoxide (TTBu) and diphenyldimethoxysilane (DPhDMS). For lasing demonstration, Eu³⁺-doped microspheres were prepared using europium (III) thenoyltrifluoroacetonate [Eu(TTFA)₃] as the dopant. The particles have good spherical shape, smooth surface and high optical transparency. The diameters of the particles could be controlled to within 0.1 m. Subsequent heating of the microspheres at 550°C under oxygen atmosphere resulted in an increase in the refractive index up to n_D = 2.6 with retention of the spherical shape. Resonant emission was confirmed from Eu^{3 +}-doped microspheres after heating at 400–550°C, by pumping with the 514.5 nm line of a CW- Ar⁺laser.     

High-pressure elastic properties of solid argon to 70 GPa

The acoustic velocities, adiabatic elastic constants, bulk modulus, elastic anisotropy, Cauchy violation, and density in an ideal solid argon (Ar) have been determined at high pressures up to 70 GPa in a diamond anvil cell by making new approaches of Brillouin spectroscopy. These results place the first complete study for elastic properties of dense Ar and provide an improved basis for making the theoretical calculations of rare-gas solids over a wide range of compression.     

Synthesis of a Hematoside Analog Containing Phytosphingosine and α-Hydroxyfatty Acid

Abstract

The hematoside analog 1 [NeuGcα(2→3)Galβ(1→4)Glcβ(1→1)Cer], which contains a phytosphingosine as a sphingoid base and an α-hydroxyfatty acid, has been synthesized. Coupling of the methyl (methyl 5-benzyloxyacetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-2-thio-D-glycero-α- and -β-D-galacto-2-nonulopyranosid)onate 5, prepared from the corresponding 5-acetamido derivative 2, with a lactose derivative 6 afforded sialolactoside 7, which was converted to the corresponding trichloroacetimidate 10. Glycosylation of 10 with the ceramide tribenzoate 12 gave the protected hematoside analog 13, which was deprotected to the hematoside analog 1.     

Gold electrodes from recordable CDs for mercury quantification by flow injection analysis

The development of a new methodology for the construction of very efficient flow cells for mercury detection by potentiometric stripping analysis, employing the thin gold layer of recordable CDs as working ¶electrode is reported. This new source of electrodes (CDtrodes) show very attractive performance, similar to that obtained with commercial gold electrodes, with superior versatility. The low cost of this new source of “gold electrodes” allows a frequent replacement of the electrode, avoiding cumbersome clean-up treatments. Various experimental parameters have been optimized to yield low detection limits (0.25 ng/mL of mercury for 5 min deposition at 0.3 V) and good precision (standard deviation of 1.9% was obtained for 15 repetitive measurements using 10 ng/mL of mercury). Standard curves were found to be linear over the range of 0.5–100 μg L^–1 of mercury. The flow cells developed were used for the quantification of mercury in oceanic and tap water.