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A combined microscopic, i.e., powder and single crystal x-ray diffraction and inelastic x-ray scattering, and macroscopic, i.e., heat capacity, characterization was carried out on YB 66 between 10 and 400 K. The system crystallizes in a rather large unit cell with a lattice parameter of about 23.4 Å at room temperature. The volume thermal expansion coefficient is found to be 3.9 × 10 − 5 K − 1 at 295 K. A high Debye temperature above 1000 K was determined using several methods, 1043 (25) K , from heat capacity measurements, 1430 (59) K , from elastic constants measurements, and 1690 (198) K , from thermal expansion measurements. The thermal transport is modeled as a collection of Einstein oscillators with an Einstein temperature of 194 (2) K. The C 11 and C 44 elastic constants are above 400 and 150 GPa , respectively. The average speed of sound in YB 66 is estimated to be 9631 (380) m / s , similar to the average speed of sound in corundum, 10 000 m / s. The large volume of the unit cell and the stiffness of the crystal structure make YB 66 a promising candidate for high-resolution x-ray monochromatization applications. Candidate reflections for high-resolution resonant inelastic x-ray scattering are indicated and potential pitfalls relevant to the quality of crystals and multi-beam cases are mentioned. [ABSTRACT FROM AUTHOR]

Two expressions for nuclear-magnetic-shielding tensor components based on analytically differentiating the electronic energy of a system are presented. The first is based on a second-order Douglas-Kroll-Hess approach, in which the off-diagonal block terms of the transformed Dirac Hamiltonian are diminished to second order with respect to both the electrostatic nuclear attraction potential V and the magnetic vector potential A. The second expression is based on the method of Barysz-Sadlej-Snijders, in which the off-diagonal block terms in the transformed Dirac Hamiltonian are completely eliminated with respect to purely V terms, while they are diminished to second order with respect to terms including A. The two approaches are applied to the calculation of nuclear magnetic shieldings of HX (X=F,Cl,Br,I), H2X (X=O,S,Se,Te), and noble gas X (X=He,Ne,Ar,Kr,Xe) systems with common gauge origins. The results show that relativistic corrections of higher than second order are negligibly small, except for the paramagnetic parts of I, Te, and Xe shieldings. The present calculations yield very large positive values for the anisotropy of proton shielding, Δσ(H)=σ∥(H)-σ⊥(H), of HI compared to previous reports. Unfortunately, no experimental values for the anisotropy of proton shielding in HI are available for verification. [ABSTRACT FROM AUTHOR]

An ab initio zeroth-order regular approximation (ZORA) theory for relativistic calculation of the nuclear magnetic shielding tensors is presented at the Hartree-Fock level. The nuclear magnetic shieldings tensors of hydrogen halides, HX (X=F, Cl, Br, and I), are calculated, and the results are compared to experimental values and other calculated results obtained using the Douglas-KrollHess (DKH) transformation, the four-component random phase approximation (RPA), and the Dirac-Fock (DF) approaches. It is shown that the ZORA method underestimates the relativistic effects on the magnetic shieldings as compared to the four-component RPA results. However, as to the proton chemical shifts, the ZORA results are closer to the experimental proton shifts than those of the DKH and 4-RPA approaches. [ABSTRACT FROM AUTHOR]

We have found some typing mistakes on p. 3534 in the original article.[1] At the right-hand side of Eq. (24), HT ht should read HT ht . Erratum: "Calculation of nuclear spin-spin couplings. At the right-hand side of Eq. (25), I F i SB I mn i sb and I F i SB I lm i sb should read HT ht and HT ht , respectively. [Extracted from the article]

Reports that the gauge-origin independent expression for the relativistic nuclear magnetic shieldings was derived from the Douglas-Kroll transformation of the no-pair equation and the use of the gauge including atomic orbitals proposed by F. London. Approximations introduced to simplify the wave equation.

Nuclear magnetic shieldings in first- and second-row hydrides were calculated with electron correlation taken into account through third order. The calculation was performed using London’s gauge-invariant atomic orbitals (GIAOs) and finite-field Mo\ller–Plesset perturbation theory (FF-MPPT). Furthermore, the vibrational motion corrections to the magnetic shieldings were evaluated. It was shown that the calculated isotropic shielding constants at the experimental geometries are higher than the experimental values, but that vibrational corrections are generally negative and improve the calculated shielding constants. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The lowest order relativistic effect theory for nuclear magnetic shieldings was derived from a two-component positive energy Hamiltonian. It was shown that the previous relativistic shielding theory based on the two-component Hamiltonian is not gauge invariant and the new terms have to be added to make a result gauge invariant. The presented theory is gauge invariant to the order of (Z/137)4 where Z is the atomic number of the heaviest atom in the molecule. One of the new contributions to the relativistic magnetic shieldings is a second-order perturbation term due to the combination of the spin-orbit interaction and the Fermi-contact interaction. A numerical estimation for this term was performed for the four hydrogen halides, HF, HCl, HBr, and HI. The computational results showed that the contribution of this term to the hydrogen shieldings is negligibly small, but the contribution to the halogen atoms is considerable. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Ab initio self-consistent-field (SCF) and electron correlation calculations have been carried out for the dihedral angle dependence of the vicinal proton–proton coupling constants, 3JHH, in ethane molecule. The four contributions to 3JHH, (JFC, JSD, JOP, and JOD) have been computed with the three different basis sets, [5s2p1d/2s1p], [5s3p1d/3s1p], and [7s4p2d/5s2p]. The Fermi contact (FC) contribution was largest and the spin–dipole (SD) contribution was smallest. The FC and orbital paramagnetic (OP) contributions showed large basis set dependence, but the SD and orbital diamagnetic (OD) contributions presented little basis set dependence. The calculated total SCF contribution to 3JHH was higher than the experimental coupling. Using the Mo\ller–Plesset perturbation theory we have introduced electron correlation effects on the FC and OP terms. The correlation effects on the OP term was shown to be negligible. The second-order correlation in the FC term was very large and amounted to half of its SCF value in magnitude with opposite sign. However, the third-order correlation in the FC contribution was small. Unfortunately, the calculated 3JHH value including correlation corrections through third order was too small compared to the experimental one. The poor agreement between calculation and experiment is claimed to be due to higher than third-order correlations in the FC term. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Nuclear magnetic shieldings were calculated with electron correlations through third order. The calculation was performed on the use of London’s gauge invariant atomic orbitals (GIAO) and the finite field many-body perturbation theory (FF-MBPT), in which the two kinds of perturbation fields, i.e., the external magnetic field and the field due to the nuclear magnetic moment, were introduced to get the perturbed one-electron states. The Hartree–Fock (HF) values and the second- and third-order Mo\ller–Plesset (MP) correlation corrections of the nuclear magnetic shieldings were calculated in (i) four first-row hydrides HF, H2O, NH3, and CH4; and (ii) three linear molecules with a multiple bond N2, CO, and HCN. The calculations showed that the post-HF correlations are important and much improve the calculated shielding values, and that the second-order corrections are positive, but the third-order ones are negative. Furthermore, the rovibrational corrections to the shielding constants in the HF molecule at 300 K were estimated to be -9.9 ppm for F and -0.66 ppm for H. [ABSTRACT FROM AUTHOR]

Electron correlation effects on the five mechanisms in the indirect nuclear spin–spin coupling tensors are computed for H 19F, H2 17O,14NH3,13CH4, H 35Cl, 33SH2, 31PH3, and 29SiH4. The five coupling mechanisms consist of Fermi-contact (FC), spin-dipole (SD), Fermi-contact and spin-dipole cross term (FC/SD), orbital paramagnetic (OP), and orbital diamagnetic (OD) terms. Electron correlation contributions through the second order are calculated by the finite-field many-body perturbation theory (FF-MBPT). The results show an extremely large contribution of the (FC/SD) cross term to the anisotropic part of the couplings. The FC contribution is dominant in the isotropic part, but the OP term is considerable in HF, HCl, and H2O. Electron correlation effects are large in the FC contribution. They are small, but not negligible, in the other terms except in the OD term. [ABSTRACT FROM AUTHOR]

The calculation of nuclear magnetic shieldings σ was performed for four first-row hydrides, i.e., HF, H2O, NH3, and CH4 using the finite-field many-body perturbation theory through second order in the electron correlation correction with London’s gauge invariant atomic orbitals. The calculated isotropic shieldings σ for the heavy atoms were larger than the experimental values. The rotational and vibrational correction for the σ of the F atom in HF at 300 K was estimated to be -4.0 ppm. [ABSTRACT FROM AUTHOR]

The Fermi-contact contributions to the nuclear spin–spin coupling constants are computed for four first-row hydrides, i.e., HF, H2O, NH3, and CH4 using the finite perturbation many-body perturbation theory (FP-MBPT) through the second order in the electron correlation correction. The calculated values of JXH (X=O,N,C) yield reasonable results, but the calculation for JFH and the geminal JHH (in H2O, NH3, and CH4) presents too large values. [ABSTRACT FROM AUTHOR]

Examines the use of the Schrodinger-Pauli type perturbation theory for nuclear magnetic shieldings. Derivation of nuclear magnetic shieldings from Douglas-Kroll transformation; Calculation of mass correction effect on nuclear magnetic shieldings; Proportionality of the shieldings to the atomic numbers of halogen nuclei.

Configuration interaction calculation for σ- and π-electron contributions to the nuclear spin–spin coupling constants in acetylene and ethylene molecules is presented. The calculation is performed by the sum-over-states configuration interaction (SOS-CI) method with the two kinds of electron correlation approximations, which use the singly and doubly excited configuration interaction (SD-CI) calculation for the ground state and use the S-CI or SD-CI calculation for the excited triplet states. Quantitative agreement between the calculated and experimental coupling constants is not good, but the π-electron contribution Jπ shows the same trends for all the used basis sets and two approximations of electron correlation. Jπ contributes negligibly to the one-bond coupling constants 1JCC and 1JCH, but it makes important contributions to the two-bond coupling constants 2JHH and 2JCH. [ABSTRACT FROM AUTHOR]

Presents a model of overwrite based on anisotropy field distributions of particles for γFe[sub2]O[sub3] and Co-γFe[sub2]O[sub3] high-coercivity particulate media. Magnitude and angle distributions of the anisotropy field; Calculation of the write field of thin-film heads; Way in which to improve the overwrite performance.

Magnetic shielding constants are calculated for the hydrogens and oxygens in the isolated species of H2O, H3O+, and OH- using the coupled Hartree–Fock (CHF) method with gauge invariant atomic orbitals (GIAO). The difference from the H2O shielding is evaluated and compared with the shift relative to water in the gas phase measured experimentally. The calculated relative shift of the H3O+ protons has the same sign as the experimental result, but the shift to low field found experimentally for the OH- proton is not reproduced. [ABSTRACT FROM AUTHOR]

Background: The regenerating gene Iα (REG Iα) is involved in gastric carcinogenesis as an antiapoptotic factor. Therefore, we investigated whether REG Iα confers resistance to chemotherapeutic drugs in gastric cancer (GC) cells and whether REG Iα expression is useful for predicting the response to chemotherapy and outcome in patients with GC.Methods: A total of 70 patients with unresectable stage IV GC received first-line chemotherapy with S-1 and cisplatin (S-1/CDDP). The expression of REG Iα was evaluated immunohistochemically using biopsy samples obtained before chemotherapy, and its relationship to clinicopathological parameters was analysed statistically. The effects of REG Iα gene induction on resistance to 5-FU or CDDP treatment were examined by cell survival assay and flow cytometry.Results: Of the 70 patients with unresectable stage IV GC, 19 (27%) were positive for REG Iα expression. The expression of REG Iα was independently predictive of poorer progression-free and overall survival in such patients (hazard ratio (HR) 2.46; P=0.002 and HR 1.89; P=0.037, respectively). The gene induction of REG Iα conferred resistance to cell death induced by 5-FU or CDDP in GC cells.Conclusion: In patients with stage IV GC, REG Iα, which confers resistance to chemotherapeutic drugs in GC cells, is a potential biomarker for predicting resistance to S-1/CDDP treatment. [ABSTRACT FROM AUTHOR]

We discuss extended X-ray absorption fine structure (EXAFS) measurements on light element compounds under high pressure. An absorption edge in light elements, ≤2 keV in energy, is measured by X-ray Raman scattering using 20 keV X-rays. To enhance the intensity, a large-culet, sintered polycrystalline diamond anvil cell is used, so that a scattering volume is maximized. For a pressure monitor, diffraction lines from NaCl powders compressed together with the sample are measured through an X-ray Raman spectrometer. With this set-up, we have measured EXAFS features at the oxygenK-edge inglass up to 30 GPa. As the pressure increases, the oscillation pattern drastically changes, associated with the densification of the glass. [ABSTRACT FROM PUBLISHER]

We studied the relationship between the lattice constant and magnetism of L 1 0 -ordered FePt under high pressure by means of first-principles calculations and synchrotron x-ray measurements. Based on our calculations, we found that the c/a ratio shows a local maximum at ∼20 GPa and that the Pt magnetic moment first remains almost unchanged and is sharply suppressed at ∼60 GPa. As for the c/a, we experimentally verified the local maximum at ∼20 GPa by powder x-ray diffraction. We also measured the x-ray magnetic circular dichroism at the Pt L edge up to ∼20 GPa. Any significant change in the Pt magnetic moment was not observed in agreement with the calculations. These results, thus, indicate that magnetic states, where the magnetization of Fe decreased and that of Pt did not change, can be created in L 1 0 -ordered FePt by lattice deformation under high pressure. [ABSTRACT FROM AUTHOR]

Background: Interleukin-22 (IL-22) has been recently highlighted owing to its biological significance in the modulation of tissue responses during inflammation. However, the role of IL-22 in carcinogenesis has remained unclear. Here, we investigated the pathophysiological significance of IL-22 expression in gastric cancer tissues and examined the mechanism by which IL-22 promotes gastric cancer cell invasion.Methods: Human gastric cancer specimens were analysed by immunohistochemistry for expression of IL-22 and IL-22 receptor 1 (IL-22R1). The effects of IL-22-induced STAT3 and ERK signalling on invasive ability of gastric cancer cells were examined using a small-interfering RNA system and specific inhibitors. AGS cells were co-cultured with cancer-associated fibroblasts (CAFs) from human gastric cancer tissues and assessed by invasion assay.Results: Interleukin-22 and its receptor were expressed in α-smooth muscle actin-positive stromal cells and tumour cells at the invasive front of gastric cancer tissues, respectively. The expression of IL-22 and IL-22R1 was significantly related to lymphatic invasion. Interleukin-22 treatment promoted the invasive ability of gastric cancer cells through STAT3 and ERK activation. The invasive ability of gastric cancer cells was significantly enhanced by co-culture with IL-22-expressing CAFs.Conclusions: Interleukin-22 produced by CAFs promotes gastric cancer cell invasion via STAT3 and ERK signalling. [ABSTRACT FROM AUTHOR]

Background:Interleukin-22 (IL-22) has been recently highlighted owing to its biological significance in the modulation of tissue responses during inflammation. However, the role of IL-22 in carcinogenesis has remained unclear. Here, we investigated the pathophysiological significance of IL-22 expression in gastric cancer tissues and examined the mechanism by which IL-22 promotes gastric cancer cell invasion.Methods:Human gastric cancer specimens were analysed by immunohistochemistry for expression of IL-22 and IL-22 receptor 1 (IL-22R1). The effects of IL-22-induced STAT3 and ERK signalling on invasive ability of gastric cancer cells were examined using a small-interfering RNA system and specific inhibitors. AGS cells were co-cultured with cancer-associated fibroblasts (CAFs) from human gastric cancer tissues and assessed by invasion assay.Results:Interleukin-22 and its receptor were expressed in α-smooth muscle actin-positive stromal cells and tumour cells at the invasive front of gastric cancer tissues, respectively. The expression of IL-22 and IL-22R1 was significantly related to lymphatic invasion. Interleukin-22 treatment promoted the invasive ability of gastric cancer cells through STAT3 and ERK activation. The invasive ability of gastric cancer cells was significantly enhanced by co-culture with IL-22-expressing CAFs.Conclusions:Interleukin-22 produced by CAFs promotes gastric cancer cell invasion via STAT3 and ERK signalling. [ABSTRACT FROM AUTHOR]

An X-ray Raman spectrometer for studies of local structures in minerals is discussed. Contrary to widely adopted back-scattering spectrometers using ≤10 keV X-rays, a spectrometer utilizing ∼20 keV X-rays and a bent Laue analyzer is proposed. The 20 keV photons penetrate mineral samples much more deeply than 10 keV photons, so that high intensity is obtained owing to an enhancement of the scattering volume. Furthermore, a bent Laue analyzer provides a wide band-pass and a high reflectivity, leading to a much enhanced integrated intensity. A prototype spectrometer has been constructed and performance tests carried out. The oxygen K-edge in SiO2 glass and crystal (α-quartz) has been measured with energy resolutions of 4 eV (EXAFS mode) and 1.3 eV (XANES mode). Unlike methods previously adopted, it is proposed to determine the pre-edge curve based on a theoretical Compton profile and a Monte Carlo multiple-scattering simulation before extracting EXAFS features. It is shown that the obtained EXAFS features are reproduced fairly well by a cluster model with a minimal set of fitting parameters. The spectrometer and the data processing proposed here are readily applicable to high-pressure studies. [ABSTRACT FROM AUTHOR]

Background:The regenerating gene Iα (REG Iα) is involved in gastric carcinogenesis as an antiapoptotic factor. Therefore, we investigated whether REG Iα confers resistance to chemotherapeutic drugs in gastric cancer (GC) cells and whether REG Iα expression is useful for predicting the response to chemotherapy and outcome in patients with GC.Methods:A total of 70 patients with unresectable stage IV GC received first-line chemotherapy with S-1 and cisplatin (S-1/CDDP). The expression of REG Iα was evaluated immunohistochemically using biopsy samples obtained before chemotherapy, and its relationship to clinicopathological parameters was analysed statistically. The effects of REG Iα gene induction on resistance to 5-FU or CDDP treatment were examined by cell survival assay and flow cytometry.Results:Of the 70 patients with unresectable stage IV GC, 19 (27%) were positive for REG Iα expression. The expression of REG Iα was independently predictive of poorer progression-free and overall survival in such patients (hazard ratio (HR) 2.46; P=0.002 and HR 1.89; P=0.037, respectively). The gene induction of REG Iα conferred resistance to cell death induced by 5-FU or CDDP in GC cells.Conclusion:In patients with stage IV GC, REG Iα, which confers resistance to chemotherapeutic drugs in GC cells, is a potential biomarker for predicting resistance to S-1/CDDP treatment. [ABSTRACT FROM AUTHOR]

We report that music therapy is effective in the treatment of Alzheimer's disease. We found that the secretion of 17β-estradiol and testosterone, hormones that are supposed to have preventive effects on Alzheimer's disease, is significantly increased by music therapy. During the sessions, patients with Alzheimer's disease were allowed to listen to music and songs with verbal contact from the therapist. It was found that problematic behaviors such as poriomania (fugue) had decreased. Music therapy has the potential as an alternative treatment for adverse hormone replacement therapy. [ABSTRACT FROM AUTHOR]

The regenerating gene ( Reg) was originally isolated from regenerating rat pancreatic islets and revealed recently to constitute a multi-gene family in humans. REG Iα protein is known to be overexpressed not only in various human inflammatory diseases but also in various experimental models of inflammation in animal tissues. However, its involvement in pathophysiology of the minor salivary gland (MSG) is not clear. We investigated REG Iα expression in the MSG of patients with primary Sjögren's syndrome (SS) and assessed its role in ductal epithelial cell proliferation in such tissues. Lip biopsy specimens were obtained from 40 patients with primary SS and examined using immunohistochemistry for REG Iα protein, Ki67 and single-strand DNA (ssDNA). The relationships among clinicopathological factors and expression of REG Iα protein, Ki67 and ssDNA in the MSG were then analysed. REG Iα protein was expressed rarely in ductal epithelial cells of the normal MSG but was apparently overexpressed in those of patients with SS. The labelling indices for both Ki67 and ssDNA in the ductal cells of the MSGs were significantly higher in SS patients than in controls. Moreover, these labelling indices were significantly higher in REG Iα-positive than in negative SS patients. REG Iα protein may play a role in the regeneration of ductal epithelial cells in the MSGs of patients with SS. [ABSTRACT FROM AUTHOR]

Although stromal cell-derived factor (SDF)-1 alpha and its receptor CXCR4 are experimentally suggested to be involved in tumorigenicity, the clinicopathological significance of their expression in human disease is not fully understood. We examined SDF-1 alpha and CXCR4 expression in colorectal cancers (CRCs) and their related lymph nodes (LNs), and investigated its relationship to clinicopathological features. Specimens of 60 primary CRCs and 27 related LNs were examined immunohistochemically for not only positivity but also immunostaining patterns for SDF-1 alpha and CXCR4. The relationships between clinicopathological features and SDF-1 alpha or CXCR4 expression were then analysed. Stromal cell-derived factor-1 alpha and CXCR4 expression were significantly associated with LN metastasis, tumour stage, and survival of CRC patients. Twenty-nine of 47 CXCR4-positive CRCs (61.7%) showed clear CXCR4 immunoreactivity in the nucleus and a weak signal in the cytoplasm (nuclear type), whereas others showed no nuclear immunoreactivity but a diffuse signal in the cytoplasm and at the plasma membrane (cytomembrane type). Colorectal cancer patients with nuclear CXCR4 expression showed significantly more frequent LN metastasis than did those with cytomembrane expression. Colorectal cancer patients with nuclear CXCR4 expression in the primary lesion frequently had cytomembrane CXCR4-positive tumours in their LNs. In conclusion, expression of SDF-1 alpha and nuclear CXCR4 predicts LN metastasis in CRCs. [ABSTRACT FROM AUTHOR]

Abstract: AVHRR data obtained over land on April 24 and 25, 1997, are analyzed and reported in this paper. At our study site, the aerosol optical thicknesses of visible and near-infrared bands were measured using a sky radiometer. The 0.64 channel data were corrected with our atmospheric correction system and the sky observation data. The surface reflectance at the 3.75 channel was converted from the observed radiance by using the Rojer and Vermote scheme. We found empirical linear relationships of the surface reflectance between the 0.64 and 3.75 channels. By using the linear relationships, the aerosol optical thickness at 0.64μm could be estimated at the study site. [Copyright &y& Elsevier]

Background and aims: Although regenerating gene (REG) lα protein may be involved in the inflammation and carcinogenesis in the gastrointestinal tract, its pathophysiological role in ulcerative colitis (UC) and the resulting colitic cancer remains unclear. We investigated expression of the REG lα gene and its protein in UC and colitic cancer tissues. We examined whether cytokines are responsible for REG lα gene expression and whether REG lot protein has a trophic and/or an antiapoptotic effect on colon cancer cells. Methods: Expression of REG In mRNA and its gene product in UC tissues was analysed by real time reverse transcription-polymerase chain reaction and immunohistochemistry, respectively. The effects of cytokines on REG lα promoter activity were examined in LoVo cells by luciferase reporter assay. The effects of REG lot protein on growth and H2O2 induced apoptosis were examined in LoVo cells by MU and TUNEL assays, respectively. Results: REG lα protein was strongly expressed in inflamed epithelium and in dysplasias and cancerous lesions in UC tissues. The level of REG lα mRNA expression in UC tissues correlated significantly with severity of inflammation and disease duration. REG let promoter activity was enhanced by stimulation with interferon γ or interleukin 6. REG lα protein promoted cell growth and conferred resistance to H2O2 induced apoptosis in LoVo cells. REG lα protein promoted Akt phosphorylation and enhanced Bcl-xL and Bcl-2 expression in LoVo cells. Conclusions: The REG lαgene is inducible by cytokines and its gene product may function as a mitogenic and/or an antiapoptotic factor in the UC-colitic cancer sequence. [ABSTRACT FROM AUTHOR]

Abstract: Surface reflectance ratios between visible and infrared bands are determined for land areas in Japan from Terra MODIS images and from the ground-measured aerosol optical thickness (AOT). For validation, the resulting ratios are used to retrieve the AOT from the Terra ASTER and Landsat ETM+ images, leading to satisfactory agreement between the satellite-retrieved and ground-measured aerosol optical thickness values. [Copyright &y& Elsevier]

The present study was aimed at elucidating how pacemaker activity (plateau potentials) (mean frequency: 15.9 ± 2.8 times min−1) from submucosal interstitial cells of Cajal (ICC-SM) control spontaneous contractions in the mouse proximal colon. Mechanical activities in the circular muscle direction showed high-frequency (mean frequency: 15.6 ± 2.7 times min−1) and low-amplitude (mean amplitude: 0.01 ± 0.005 g) (HFLA) rhythmic contractions. Simultaneous recordings of circular muscle mechanical activity and electrical activity from ICC-SM revealed that HFLA contractions were synchronized with plateau potentials (mean frequency: 15.9 ± 2.8 times min−1). Although low-frequency (3.5 ± 2.1 times min−1) and high-amplitude (0.12 ± 0.03 g) (LFHA) contractions in both longitudinal and circular muscle directions were synchronized with burst of action potentials in both muscle cells, these LFHA contractions were not synchronous with plateau potentials. Intracellular Ca2+ release from the internal stores through IP3 receptors is not a major factor to generate both action potentials differently from plateau potentials. Neither tetrodotoxin nor atropine affected the plateau potentials. The results reveal that the pacemaker activity from ICC-SM drives only the spontaneous HFLA (one-tenth amplitude of the LFHA circular and longitudinal muscle contractions) circular muscle contractions without control by enteric nerves. [ABSTRACT FROM AUTHOR]

A scheme for calculating nuclear magnetic shieldings using the infinite-order Foldy-Wouthuysen (FW) transformation proposed by Barysz and Sadlej (BS) is presented. The nuclear magnetic shieldings of hydrogen halides are calculated by three variant BS schemes; a double finite perturbation method for the external magnetic flux density ( B 0 ) and the nuclear magnetic dipole moment ( μ M ) (BS/FPT-2), a single finite perturbation method for B 0 with analytical differentiation of energy with respect to ( μ M ) (BS/FPT-1), and an approximate analytical differentiation method with respect to both B 0 and μ M (BS/CHF). Although the BS/FPT-2 method is exact theoretically, the actual computation for heavy nuclei includes large error due to reduction of the number of significant figures. The BS/FPT-1 and BS/CHF approaches, on the other hand, yield reasonable values for all of the shieldings. Although several results could not be obtained by the BS/FPT-2 method, no serious contradictions were recognized among these three results. From a comparison of our results with values in the literature, our shieldings for the halogen nuclei are lower than those determined by the four-component relativistic random phase approximation (4-RPA), but the reason for this is not obvious. [ABSTRACT FROM AUTHOR]

Differential isolation of physiologically and ecologically diverse microbial groups facilitates evaluation of their activities in the environment. Here we describe a new method for differential isolation of freely dispersed and particle-associated peat microorganisms. The method is based on sequential elution of peat. Two types of natural peat, “young” sphagnum peat and “old” reed-based peat that have significantly different molecular composition as revealed by solid-state 13C NMR, were used for the method development. Various combinations of elution parameters (pH values, surfactant concentration, and sonication) were tested. Protein yield, CFU counts, 16S rDNA gene sequence, and T-RFLP analyses were used as criteria for evaluating the effectiveness of the elution protocols. The optimal method consisted of sequential elutions with (i) pH 6.2, 0.1 M potassium phosphate buffer, (ii) the same buffer amended with 0.01% of Tween 80, and (iii) treatment (ii) amended with sonication for 2 min. This method allowed differential isolation of freely dispersed and particle-associated microorganisms with (i) highest yield, (ii) highest diversity within the each microbial fraction, and (iii) best discrimination between the freely dispersed and particle-associated microbial communities. The method was applied for characterization of peat microbial communities and revealed different taxonomic composition and similar spatial organization of sphagnum and reed-sage peat microorganisms. [Copyright &y& Elsevier]

An equation of state (EoS) for Ca(OH) 2 portlandite has been obtained through measurements of pressure and temperature dependence of volume by means of in-situ X-ray observation. The bulk modulus and its pressure derivative at zero pressure calculated using third-order Birch-Murnaghan's equation of state is 33.1 GPa and 4.2 at 300 K, respectively. The unit cell parameters and the volumes have been also determined at 573 K and 673 K. Temperature derivatives of the bulk modulus and its pressure derivative have been calculated to be -0.022 GPa/K and 0.0072 K -1 , respectively. Thermal expansion coefficient of portlandite has been calculated from the EoS. The pressure dependence of entropy has been obtained from the present thermo-elastic parameters. [ABSTRACT FROM AUTHOR]

A two-component relativistic SCF perturbation theory, based on the Douglas–Kroll–Hess (DKH) transformation, has been applied to the calculation of nuclear magnetic shielding tensors of hydrogen halides, HX (X = F, Cl, Br, I). Calculations were performed via the unrestricted coupled Hartree–Fock (CHF) scheme using gauge-including atomic orbitals (GIAOs) at four different levels. In the level I calculation, both the scalar relativistic (SR) and spin–orbit (SO) interactions were included in the zero-order Hamiltonian. However, the magnetic pertubation Hamiltonians were treated non-relativistically. The results of these calculations indicated a large interplay between the SR and SO interactions. The level I calculation was found to be insufficient to explain the full relativistic effect on the halogen atom shieldings. In order to reproduce the full relativistic effect, the mass–velocity effect on the magnetic perturbation Hamiltonians was introduced in the levels II–IV calculations. Inclusion of the mass–velocity effects into all of the perturbation Hamiltonians made in levels III and IV improved the results greatly. The cross term between the nuclear attraction potential and the magnetic vector potential was introduced approximately in level IV. The level III calculation agreed most closely with the four-component relativistic random phase approximation (RPA) calculation. [ABSTRACT FROM AUTHOR]

Looks at a study that examined the roles of indigenous bacterial communities on suppression of leaf infection by the anthurium bacterial blight pathogen Xanthomonas campestris pv. dieffencachiae. Survival of Xcd-lux in guttation fluids of anthurium plants; Effects of guttation bacteria on survival of Xcd-lux in the filter-sterilized guttation fluid; Growth and survival of Xcd-lux in guttation fluids from various anthurium cultivars.

Ab initio self-consistent field and Moller-Plesset perturbation calculations have been carried out for the dihedral angle ( phi ) dependence of the vicinal proton-proton coupling constants ( 3 J ) in methanol and methylamine. The four contributions to the 3 J have been computed. HH The Fermi-contact (FC) contribution was largest and the spin-dipolar contribution was smallest. The orbital paramagnetic and diamagnetic contributions provided comparable magnitudes of opposite signs. The second-order correlation was large but the third-order one was very small. The addition of the tight s-type functions increased the FC contribution. The calculated curves for 3 J versus phi reproduced the experimental ones well. HH HH. [ABSTRACT FROM AUTHOR]

We have previously reported that B cell abnormality in NZB/W F1 mice developed independently of thymus, Here we examined further whether B cells from NZB/W Fl mice respond to interlcukin-6 (IL-6), a factor for terminal differentiation of B cells. When freshly isolated splenic B cells were incubated for 5 days in the presence of human IL-6, an increased production of both IgM and IgG, including anti-DNA antibody, was evident in NZB/W Fl mice; there was no increase in BALB/c mice. A magnitude of augmentation in IgG but not IgM production by IL-6 became more apparent in older NZB/W FI mice. The increased immunoglobulin production seen with IL-6 was neutralized by treatment with rabbit anti-recombinant human IL-6 antibody. As B cells from athymic NZB/W Fl nude mice also responded to IL-6, it was suggested that B cells in NZB/W Fl mice differentiated into the IL-6-responding state in a thymus-independent manner. This B cell abnormality may be associated with the pathogenesis of autoimmune disease in NZB/W Fl mice. [ABSTRACT FROM AUTHOR]

Investigates the mating behavior in Drosophila melanogaster selected for either early or late life fitness components. Use of six genetically distinct stock of flies; Experimental procedure; Differences in the probability of mating; Analysis of mating efficiency.

Discusses Japan under new Prime Minister Noboru Takeshita. The workings of the Liberal Democratic Party (LDP); How Japan chooses a prime minister; Formation of the cabinet; Takeshita's policies.

A clear definition for the division of the magnetic shielding tensor (σ) into two terms of the diamagnetic part (σ d) and paramagnetic part (σ p) is proposed based on the gauge invariant coupled-Hartree–Fock (GI–CHF) theory. In this definition, both σ d and σ p are written individually by gauge invariant and Hermitian operators. The present formulas are applied to calculate the magnetic shielding tensors of diatomic molecules, and lead to better results, even with small basis sets, than gauge dependent results obtained with large basis sets. [ABSTRACT FROM AUTHOR]

Abstract: We investigate the longitudinal static second hyperpolarizabilities (γ) of several square planar nickel, palladium and platinum complexes involving two bidentate o-semiquinonato type ligands. It turns out that the diradical character and γ value of this type of complex can be controlled by modifying the donor atoms and the metal core. [Copyright &y& Elsevier]

Abstract: The longitudinal static second hyperpolarizabilities (γ) of one-dimensional open-shell singlet diphenalenyl radical clusters (up to trimer) are investigated using the spin-unrestricted hybrid density functional theory, UBHandHLYP, method. The longitudinal γ values per monomer for these clusters are found to significantly increase with increasing the number of monomers: the increase ratio [γ/n(n-mer)/γ(monomer)] is 2.0 (dimer) and 3.1 (trimer). The significant enhancement is predicted to be caused by the field-induced intermolecular virtual charge transfer between the both-end-phenalenyl rings, originating in the strong covalent interaction between the unpaired electrons of the cofacial phenalenyl rings. [Copyright &y& Elsevier]

In this work, the intercalation of alkyl trimethylammonium ion (C n N+) and dialkyl dimethylammonium ion (2C n N+) were attempted for α‑zirconium phosphate (α-ZrP) and γ-ZrP. And then a pure intercalation compounds were obtained only for γ-ZrP. It was expected that the intercalation of linear quaternary ammonium ion would produce not only a hydrophobic environment in the interlayer space but also form an appropriate void for the adsorption of hydrophobic air pollutants. The basal spacing of 2C n N+-intercalated γ-ZrP was greater than that of C n N+-intercalated γ-ZrP because C n N+ was arranged in a mono-molecular structure in the interlayer space contrary to the bi-molecular structure of 2C n N+. Furthermore, the alkyl chain in the interlayer space of γ-ZrP was in a gauche form for C n N+, for a smaller carbon number (n), and changed to a trans structure for a larger n. γ-ZrP with a modified interlayer space could adsorb gaseous aromatic hydrocarbons contrary to the nonmodified γ-ZrP. Maximum adsorption was attained for C 18 N+-intercalated γ-ZrP with a mono-molecular structure and trans structure alkyl chain, although the basal spacing and uptake of alkyl ammonium reached a maximum for 2C 18 N+-intercalated γ-ZrP. Hence, not only the basal spacing and carbon number but also the void space in the interlayer region affected adsorption. It was interesting to note that the conformation of the long alkyl chain was reversibly changed through adsorption and desorption. Unlabelled Image • Linear quaternary ammonium ion was easily intercalated into γ-zirconium phosphate. • Alkyl chain in the interlayer space converted into an all-trans structure. • Linear quaternary ammonium ion-intercalated γ-zirconium phosphate could adsorb aromatic hydrocarbons. • Maximum adsorption was observed for octadecyl trimethylammonium intercalated γ-zirconium phosphate. • Intercalation compound after adsorption was back to the initial state by drying. [ABSTRACT FROM AUTHOR]

A correction to the article "Calculation of nuclear magnetic shieldings using an analytically differentiated relativistic shielding formula" in a previous issue of the "Journal of Chemical Physics" is presented.

Presents a correction to the article, entitled `Calculation of nuclear spin-spin couplings. X. Analytical derivative method of perturbation energy,' published in the volume 112 of the `Journal of Chemical Physics'.

The expression for the analytical derivatives of the second-order correlation energy was derived for a system under the spin-dependent perturbations, and it was applied to the correlated calculation of the [sup 3]J[sub HH]'s in ethane, methanol, and methylamine. The calculation showed that the addition of tight s-type functions to the basis set considerably affects the Fermi contact (FC) contribution. Furthermore, the third- and fourth-order correlations were also evaluated for the FC contribution with the finite perturbation theory. The three noncontact contributions were computed at the Hartree-Fock (HF) level. The total contribution to the [sup 3]J[sub HH] in ethane was significantly lower than the experimental value. The calculated [sup 3]J[sub HH]'s in methanol and methylamine were nearer to the experimental couplings than in ethane. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents a correction to the article 'Calculation of Nuclear Magnetic Shieldings. VIII. Gauge Invariant Many-Body Perturbation Method.'