Super strong nuclear force caused by migrating K? mesons - Revival of the Heitler-London-Heisenberg scheme in kaonic nuclear clusters

We have studied the structure of K⁻pp comprehensively by solving this threebody system in a variational method, starting from the Ansatz that the Λ(1405) resonance (≡Λ^*) is a K⁻p bound state. The structure of K⁻pp reveals a molecular feature, namely, the K⁻ in Λ^* as an “atomic center” plays a key role in producing strong covalent bonding with the other proton. We point out that strongly bound $\bar{K}$ nuclear systems are formed by “super strong” nuclear force due to migrating real bosonic particles $\bar{K}$ a la Heitler-London-Heisenberg, whereas the normal nuclear force is caused by mediating virtual mesons. We have shown that the elementary process, p + p → K⁺ + Λ^* + p, which occurs in a short impact parameter and with a large momentum transfer, leads to unusually large self-trapping of Λ^* by the involved proton, since the Λ^*-p system exists as a compact doorway state propagating to K⁻pp.     

Quantitative Detection for Porphyromonas gingivalis in Tooth Pocket and Saliva by Portable Electrochemical DNA Sensor Linked with PCR

Here, a quantitative electrochemical analysis of periodontal bacteria in gingival crevicular fluid (GCF) and saliva by direct polymerase chain reaction (PCR) is presented. The electrochemical measurement was performed by mixing with PCR products and electrochemical indicator (bisbenzimidazole trihydrochloride). The peak current of indicator is reduced due to slower diffusion when the dye intercalates into the amplified DNA, and the degree of reduction in the peak current is correlates with the quantity of amplified DNA. Therefore, a quantitative analysis is possible by using our electrochemical method at the end point of PCR. In the GCF testing, The number of Porphyromonas gingivalis (Pg) detected by our electrochemical method at the end point of PCR were almost same compared with that were calculated by the conventional method of quantitative real? time PCR. In the saliva testing, the relationship between number of Pg in saliva and average pocket depth, and age‐dependence were also clearly observed. Since the saliva sample is obtained in a non‐invasive manner, this method is useful for the primary screening of periodontal disease. Moreover, our detection method is simple and uses a hand‐held potentiostat making it suitable for development of an on‐site periodontal diagnosis system.     

Total Synthesis of the Antibiotic Kendomycin: A Macrocyclization Using the Tsuji–Trost Etherification

A highly stereocontrolled, convergent total synthesis of kendomycin [(?)‐TAN2162], an ansa‐macrocyclic antibiotic, is reported. The key of the strategy is an unprecedented Tsuji–Trost macrocyclic etherification, followed by a transannular Claisen rearrangement to construct the 18‐membered carbocyclic framework. The oxa‐six‐ and five‐membered rings were also stereoselectively constructed respectively by a cascade oxidative cyclization at an unfunctionalized benzylic position and using a one‐pot epoxidation/5‐exo‐tet epoxide opening.     

Essential Oils Derived from Cistus Species Activate Mitochondria by Inducing SIRT1 Expression in Human Keratinocytes,Leading to Senescence Inhibition

Cistus L. is a genus of dicotyledonous perennial herbaceous plants. Cistus species have been commonly used in folk medicine in the Mediterranean region. In the present study, the biological activities of essential oils derived from Cistus species (Cistus laurifolius, C. monspeliensis, C. creticus, and C. salviifolius) were evaluated. Essential oils derived from C. laurifolius and C. monspeliensis were found to augment the expression of SIRT1, an anti-aging gene, in the normal culture of HaCaT cells. Furthermore, these essential oils increased the number and size of mitochondria and augmented their activity. These effects were thought to be caused by the up- and downregulated expression of MITOL and Drp1 in HaCaT cells, respectively, in response to the essential oil treatment. In addition, these essential oils were found to attenuate ultraviolet-B-induced mitochondrial damage and cellular senescence in HaCaT cells. These findings indicate that essential oils derived from C. laurifolius and C. monspeliensis may inhibit skin aging through mitochondrial regulation via SIRT1 activation.     

Static light scattering from poly(ethylene oxide) in methanol

Static light scattering measurements were performed on dilute solutions of monodisperse poly(ethylene oxide) (PEO) in methanol at 25°C. PEOs of five different molecular weights ranging from nominal M_w = 8.6 × 10⁴ to 9.13 × 10⁵ were used. Linear Zimm plots were obtained for all the PEO samples: no downturn was observed at small angles, indicating that no large aggregates of PEO molecules exist in the solution. From the plots, values of the weight-average molecular weight, M_w, the radius gyration, R_G, and the second virial coefficient, A₂, were successfully determined for respective PEOs. Observed relationship between R_G and M_w indicates that methanol is certainly a good solvent for the polymer. © 1996 John Wiley & Sons, Inc.     

Kinetic study of radical polymerization of dialkyl fumarates using electron spin resonance spectroscopy

The radical polymerization of dialkyl fumarates (DRF) bearing various ester alkyl groups was kinetically studied. The propagation and termination rate constants were determined using electron spin resonance (ESR) spectroscopy. The introduction of the bulky ester alkyl groups such as a tert-butyl group decreased the termination rate constant as expected. However, it has also been revealed that the bulky groups promote propagation despite the steric repulsion. The propagation rate and mechanism are discussed in relation to the propagation manner, i.e., tacticity of the polymer. © 1996 John Wiley & Sons, Inc.     

Speciation of Arsenic Compounds in the Urine of Rats Orally Exposed to Dimethylarsinic Acid Ion Chromatography with ICP–MS as an Element-Selective Detector

A combined ion chromatography (IC) with inductively coupled plasma mass spectrometry (ICP—MS) system as an element-selective detector has been used for the determination of arsenic compounds. Seven arsenic compounds were separated by cation-exchange chromatography. Subsequently, the separated arsenic compounds were directly introduced into the ICP—MS and were detected at m/z =75. Detection limits for the seven arsenic compounds ranged from 0.8 to 3.8 μg As/l. The IC–ICP–MS system was applied to the determination of arsenic compounds in the urine of dimethylarsinic acid (DMAA)-exposed rats. DMAA was the most abundant arsenic compound detected. Arsenous acid, monomethylarsonic acid and trimethylarsine oxide were also detected.     

VLS Growth of ITO Whiskers Prepared by the Electron Shower Method

Indium tin oxide (ITO) whiskers were grown by VLS (vapour-liquid-solid) mechanism, using the electron shower method. The whiskers were grown above 200 °C, and the deposition rate was above 0.6 nm/s. The electron shower controlled the size of the whiskers, and the size was 30 nm in diameter and 600 nm in length. The whiskers grew along the substrate at t < 300 s, but grew in a direction perpendicular to the substrate at t > 300 s. When the ITO whiskers grown along the substrate were used as NO₂ gas sensor, the sensitivity was 340, and about 300 times higher than those of the whiskers grown in a direction perpendicular to the substrate and plate-like ITO crystallites.     

Synthesis of cycl[3.2.2]azine and benzo[g]cycl[3.2.2]azine derivatives by use of the [2 + 8] cycloaddition reaction of indolizines and dimethyl acetylenedicarboxylate

The reaction of 1-ethoxycarbonylmethylpyridinium bromides 5a-k with nitro ketene dithioacetal, 1,1-bis-(methylthio)-2-nitroethylene ( 2 ), in the presence of triethylamine in ethanol gave the desired ethyl 2-methyl-thioindolizine-3-carboxylates 3a-k in good yields, along with ethyl 2-methylthio-1-nitroindolizine-3-carboxyl-ates 4a-d . Deesterification of 3 using sodium hydroxide in methanol followed by treatment with polyphosphoric acid gave the corresponding 2-methylthioindolizines 5a-d in good yields. The desulfurization of 5 with Raney-nickel in ethanol occurs smoothly to give the 1,2,3-unsubstituted indolizines 6a-c (a , parent indolizine; b , 8-methylindolzine; c , 6,8-dimethylindolizine). Similarly, pyrrolo[2,1-a]isoquinoline ( 19 ) was also synthesized. These indolizine and pyrrolo[1,2-a]isoquinoline derivatives were allowed to react with dimethyl acetylene to give the corresponding cycl[3.2.2]azine and benzo[g]cycl[3.2.2]azine derivatives in good results.     

Chemical modification of diamond powder using photolysis of perfluoroazooctane

Photolysis of perfluoroazooctane with diamond powders led to chemical modification of the surface with the introduction of perfluorooctyl ester and ether functional groups, the presence of which was confirmed by means of FT-IR, XPS and 19F NMR measurements.