Ball lens coupled fiber-optic probe for depth-resolved spectroscopy of epithelial tissue

A ball lens coupled fiber-optic probe design is described for depth-resolved measurements of the fluorescence and reflectance properties of epithelial tissue. A reflectance target, fluorescence targets, and a two-layer tissue phantom consisting of fluorescent microspheres suspended in collagen are used to characterize the performance of the probe. Localization of the signal to within 300 microm of the probe tip is observed by use of reflectance and fluorescence targets in air. Differential enhancement of the fluorescence signal from the top layer of the two-layer tissue phantom is observed.     

Diastereotopy in some 3,4-dihydroisocoumarins--effect of changing the substituents on the chiral centre

Diastereotopy has been investigated in eight different derivatives of 3,4-dihydroisocoumarins by changing the substituent on the pyran ring chiral centre, C-3. A diastereotopic NMR effect is observed for the prochiral methylene protons on the benzopyran ring and the effect is greatly influenced by the pi-electron system of the substituent. The effect is also observed for the substituents, however, the extent of diastereotopy depends upon their nature and the separation of methylene groups from the chiral centre.     

Tetrahedral complexes of 1,2-dimorpholinoethane and 1,3-dimorpholinopropane: Crystal and molecular structure of dichloro(1,2-dimorpholinoethane)cobalt(II)

The ligands 1,2-dimorpholinoethane (DME) and 1,3-dimorpholinopropane (DMP) have been used to prepare Cu(II), Ni(II), Co(II), Hg(II), Zn(II), and Cd(II) complexes having the general formulationMLX ₂ (L=DME and DMP,X=Cl^–). These complexes exhibit spectral properties indicative of a distorted tetrahedral geometry, with DME or DMP coordinating through two nitrogen atoms and two chloride anions making up the coordination sphere of the central metal atom. This is in contrast to six-coordinated, distorted octahedral geometry exhibited by metal complexes of DME when NO ₂ ^– or NO ₃ ^– were used as counter ions. The tetrahedral geometry was confirmed for [Co(DME)Cl₂] by X-ray structure determination. The structure was solved by the heavy-atom method using CAD4 diffractometer data, and refined to a finalR value of 0.028 for 1097 independent reflections. The morpholine moieties of DME in [Co(DME)Cl₂] are in a chair configuration, forbidding any coordination through ethereal oxygen atoms.     

Holographic particle velocimeter using forward scattering with filtering

We propose a new approach, forward-scattering holography with a filter, to holographic particle velocimetry for significant improvement in terms of increased effective aperture, modest laser power requirement, simple geometric setup, improved signal-to-noise ratio, and higher seeding density. We achieve this result by using a smooth (Guassian-like) high-pass filter during recording.     

The structure of 2-phenylperhydro-1,2-oxazolo[3,2-c] [1,4]oxazine

The title compound crystallizes in the monoclinic space group P2₁/n, witha=9.590(6),b=11.574(2),c=9.609(2) Å, =105.72(3)^o andZ=4. The structure was solved by direct methods and refined by full matrix least squares methods toR=0.039 for 1899 observed reflections. The stereochemistry of this 6/5 ring system is found to becis-fused with C(3)–C(4) bond in the axial and N(9)–O(1) bond in equatorial disposition. The six-membered ring in the molecule is in the chair and the five-membered isoxazolidine ring adopts an envelope conformation.     

On heavy baryon decay form factors

An(n?1)/2+1 parameter, solution of the Yang Baxter equation is presented giving rise to the quantum Group \(GL_{X;q_{ij} } (n)\) . Determinant and inverse are constructed. The group acts covariantly on a quantum vector space of non-commutative coordinates. The associated exterior space can be identified with the differentials exhibiting a multiparameter deformed differential calculus following the construction of Wess and Zumino.