Resolving Discrepancy between Theoretical and Experimental Optical Trapping Forces Using Effects of Beam Waist and Trapping Position Displacement due to Gravity

Optical trapping forces of polystyrene microspheres are analyzed both theoretically and experimentally, and comparisons are made between the two. Discrepancies are mainly caused by straight-ray approximation for axial trapping, and by trapping-position vertical displacement due to gravity for transverse trapping.     

Intake of different chemical species of dietary arsenic by the japanese,and their blood and urinary arsenic levels

We calculated the intake of each chemical species of dietary arsenic by typical Japanese, and determined urinary and blood levels of each chemical species of arsenic. The mean total arsenic intake by 35 volunteers was 195±235 (15.8-1039) μg As day^?1, composed of 76% trimethylated arsenic (TMA), 17.3% inorganic arsenic (As_i), 5.8% dimethylated arsenic (DMA), and 0.8% monomethylated arsenic (MA): the intake of TMA was the largest of all the measured species. Intake of As_i characteristically and invariably occurred in each meal. Of the intake of As_i, 45-75% was methylated in vivo to form MA and DMA, and excreted in these forms into urine. The mean measured urinary total arsenic level in 56 healthy volunteers was 129±92.0 μg As dm^?3, composed of 64.6% TMA, 26.7% DMA, 6.7% As_i and 2.2% MA. The mean blood total arsenic level in the 56 volunteers was 0.73±0.57 μg dl^?1, composed of 73% TMA, 14% DMA and 9.6% As_i. The urinary TMA levels proved to be significantly correlated with the whole-blood TMA levels (r = 0.376; P<0.01).     

Influence of Zn Diffusion on Bandwidth and Extinction in MQW Electroabsorption Modulators Buried with Semi-Insulating InP

A comprehensive analysis of multi-quantum-well electroabsorption modulators buried with semi-insulating (SI)-InP is presented. We quantitatively demonstrate that suppression of Zn diffusion into the burying and optical core layers plays a key role in high-speed and high-extinction operation.     

Rotational bands in 181Ta

High-spin states in ¹⁸¹Ta have been studied via the ¹⁷⁶Yb(¹¹B,α2n) reaction at 52 MeV using the PEX array and at 57 MeV using the NORDBALL array, with α-particle detection. The previously known, K^π=(7/2)⁺ ground state band and K^π=(9/2)⁻ band have been extended to spins (29/2)⁺ and (31/2)⁻, respectively. Two new one-quasiparticle bands, the K^π=(5/2)⁺ band built on the known (5/2)⁺ isomer and a K^π=((1/2)⁻) band have been observed. Two other rotational bands with three-quasiparticle structure, K^π=(15/2)⁻ and ((19/2)⁺ with π(7/2)[404]ν²(1/2)[510](9/2)[624] and π(9/2)[514]ν²(1/2)[510](9/2)[624] configurations, respectively, have been newly observed. The half-life of the K^π=((19/2)⁺) bandhead which decays to the head of the (15/2)⁻ band has been measured to be 140(36) ns. However, transitions from the ((19/2)⁺) state to the (15/2)⁻ band have not been observed. Received: 26 August 1998     

Effect of extracts of Zingiberaceae herbs on gastric secretion in rabbits

Some of the Zingiberaceae herbs are known to be useful as stomachics. Water extracts and methanol extracts of eight such herbs were examined in intact unanesthetized rabbits for their effect on gastric secretion. Oral administration of either water extracts or methanol extracts caused a significant decrease in gastric secretion. A significant effect of these extracts appeared at 3 h after administration. The effect of water extracts on gastric secretion was very similar to that of cimetidine, with a significant decrease in acid output. The effect of the methanol extracts was primarily observed as decreased pepsin output.     

Antitumor activity of Hypsizigus marmoreus. I. Antitumor activity of extracts and polysaccharides.

Antitumor activity of Hypsizigus marmoreus, one of the most popular Japanese edible mushrooms, was investigated. The aqueous and methanol extracts were tested against allogeneic tumor, solid sarcoma 180 and syngeneic tumor, Meth A fibrosarcoma. The aqueous extract was highly active in inhibiting growth of solid sarcoma 180, but not as much for Meth A fibrosarcoma. Fractionation of antitumor substances of the aqueous extract isolated four polysaccharides. Chemical analysis revealed one of them to be beta-(1-3)-glucan with a remarkable inhibitory effect against tumor-growth of sarcoma 180.     

Efficient esterification of carboxylic acids and phosphonic acids with trialkyl orthoacetate in ionic liquid

An operationally simple, inexpensive, efficient, and environmentally friendly esterification of various carboxylic acids, phosphonic acids, and phosphinic acids with triethyl orthoacetate or trimethyl orthoacetate under neutral conditions in a typical room temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate, was successfully carried out to provide the corresponding ethyl esters or methyl esters in high yields.     

Halogen derivatives of m-phenylene(carbeno)nitrene: a switch in ground-state multiplicity

m-Phenylene-coupled carbenonitrenes [(3-nitrenophenyl)methylene (2-H), (3-nitrenophenyl)fluoromethylene (2-F), (3-nitrenophenyl)chloromethylene (2-Cl), (3-nitrenophenyl)bromomethylene (2-Br)] have been investigated computationally (with B3LYP, MCSCF, CASPT2, ROMP2, and QCISD(T) methods) and experimentally (with IR, UV, and ESR spectroscopy). For each species, five electronic states were considered. At the highest level of theory explored, the parent compound (2-H) has a quintet ground state, but its halogen derivatives (2-X, X = F, Cl, and Br) have triplet ground states. A linear relationship between the Q[bond]T energy gap of 2-X and the T-S gap of the corresponding phenylcarbenes 8-X is found, which can be helpful in rationalizing and predicting ground-state multiplicities in m-phenylene-linked carbenonitrenes and similar species. Precursors for the photochemical generation of 2-X (X = H, F, Cl, and Br) were synthesized and photolyzed in matrixes (Ar, triacetin) at low temperatures. IR (Ar, 13 K) and ESR (triacetin, 77 K) data are compatible with the generation of triplet halocarbenonitrenes 2-X, (X = F, Cl, and Br). All four compounds upon further irradiation undergo isomerization to substituted cyclopropenes 5-X (X = H, F, Cl, and Br), as suggested by their IR spectra.