bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intracorneal vacuoles in skin diseases with parakeratotic hyperkeratosis in the dog: a retrospective light‐microscopy study of 111 cases (1973–2000)
Authors: Senter David A. , Scott Danny W. , Miller William H. , Erb Hollis N. 
Published: July 2002

AbstractTwo recent case reports described a congenital keratinization defect (congenital follicular parakeratosis; CFP) in Rottweiler and Siberian Husky dogs. Skin biopsy specimens revealed marked parakeratosis targeting the hair follicle and numerous intracorneal vacuoles. A retrospective histopathological study was conducted on skin biopsy specimens from 111 dogs with diseases associated with parakeratotic hyperkeratosis to determine whether intracorneal vacuoles were present. Additional criteria evaluated were the size and location of the vacuoles and the degree of parakeratosis. Cases examined included dogs with primary idiopathic seborrhoea, necrolytic migratory erythema (NME),Malasseziadermatitis, zinc‐responsive dermatosis, hereditary nasal hyperkeratosis of Labrador Retriever dogs, thallotoxicosis and CFP. Thirty‐seven cases (37/111, 33%) had intracorneal vacuoles, including nine cases of primary idiopathic seborrhoea (9/29, 31%), 10 cases of NME (10/18, 56%), five cases ofMalasseziadermatitis (5/19, 26%), five cases of zinc‐responsive dermatosis (5/36, 14%), five cases of hereditary nasal hyperkeratosis (5/5, 100%) and three cases of CFP (3/3, 100%). If present, intracorneal vacuoles were found throughout all layers of the parakeratin. The sizes of intracorneal vacuoles varied among diseases, but large (> 5 µm) vacuoles only were present in CFP. Biopsies with a larger degree of parakeratosis were significantly more likely to have intracorneal vacuoles (P = < 0.001). Based on this study, intracorneal vacuoles are a common finding in many parakeratotic skin diseases of the dog, but large (> 5 µm) vacuoles are found only in CFP.
Cost‐effectiveness of digital cataract assessment
Authors: Dimock J , Robman L D , McCarty C A , Taylor H R 
Published: July 2002

Purpose: The aim of this study was to compare costs of digital photograph grading with that of film‐based, human grading of the lens in epidemiological studies involving cataract assessment. Methods: Cost‐effectiveness was measured by establishing the number of participants with ungradeable images and incorporating these lost data into the overall cost per participant for each study. Results: The digital grading system cost was A$105 000 with operating costs of $2.81 per participant, with 99.4% effectiveness. The film‐based, human grading set‐up costs were $43 000 with operating costs of $18.49 per participant and 90% effectiveness. After examining 3500 people the use of the digital equipment becomes cost‐beneficial. Conclusions: The high costs of setting up a digital cataract grading system are offset by the low running costs, less ungradeable images and greater accuracy over the duration of a large scale ophthalmic epidemiological study.
Postnatal corticosteroids and sensorineural outcome at 5 years of age
Authors: The Victorian Infant Collaborative Study Group  
Published: July 2002

Background: Postnatal corticosteroids reduce ventilator dependence in preterm infants, but possible long‐term benefits for either survival or sensorineural morbidity are not proved. Aim: The aim of this study was to determine the association between corticosteroid therapy given postnatally and sensorineural outcome in childhood. Subjects: The subjects comprised 346 consecutive livebirths either of birthweight < 1000 g or with gestational age < 28 weeks born in the state of Victoria during 1991 and 1992, and who survived the first week after birth; 120 (34.7%) were given corticosteroids postnatally. Results: Of the 120 children who received corticosteroids, 98 (81.7%) survived to 5 years of age, compared with 200 (88.5%) of the 226 children who did not receive corticosteroids. At 5 years of age, survivors treated with corticosteroids postnatally had significantly higher rates of cerebral palsy (corticosteroids 23%, no corticosteroids 4%), blindness (corticosteroids 4%, no corticosteroids 1%) or an intelligence quotient more than one standard deviation below the mean (corticosteroids 54%, no corticosteroids 32%) compared with children not treated with corticosteroids. The rate of sensorineural disabilities imposed by these impairments was significantly higher in children treated with postnatal corticosteroids, and the association between adverse sensorineural outcome and postnatal corticosteroids remained after adjustments for potentially confounding variables. In a separate case‐control analysis of 60 children in each group, the rate of cerebral palsy remained significantly elevated (corticosteroids 22%, no corticosteroids 5%). Conclusion: Postnatal corticosteroid therapy is associated with substantial adverse sensorineural outcomes at 5 years of age.
Diabetes mellitus secondary to glycogen storage disease type III
Authors: Oki Y. , Okubo M. , Tanaka S. , Nakanishi K. , Kobayashi T. , Murase T. 
Published: July 2002

SUMMARY Background  Diabetes mellitus is a rare complication of glycogen storage disease type III (GSD III).Case report  We describe a 47‐year‐old man with GSD III who developed diabetes mellitus. He was diagnosed as having GSD III at the age of 18 years, and his glucose tolerance was normal at that time. Liver dysfunction and muscle atrophy gradually progressed, and the patient developed diabetes mellitus at the age of 45. When the post‐prandial hyperglycaemia worsened, we instituted treatment with an alpha‐glucosidase inhibitor, voglibose, and this improved glycaemic control without any adverse effects.Conclusions  We recommend serial evaluation for complications of GSD III, and propose that an alpha‐glucosidase inhibitor may be a favourable drug in treating diabetes mellitus secondary to GSD III.
FT-IR spectra of vacuum deposited clathrate hydrates of oxirane H2S, THF, and ethane
Authors: Richardson Hugh H. , Wooldridge Paul J. , Devlin J. Paul 
Published: July 2002

An ability to prepare clathrate hydrates using low temperature–high vacuum techniques, originally demonstrated for the hydrate of oxirane (Bertie and Devlin), has been extended to include the structure I hydrate of H2S, the mixed structure I hydrate of oxirane and ethane, as well as the structure II simple hydrate of THF and the double hydrates of THF with oxirane and H2S. The crystalline clathrate films (∼6 μ) have been formed either by annealing amorphous host–guest deposits at ∼130 K, epitaxial growth at 110 K (oxirane and mixed ethane–oxirane), or direct deposition at 150 K (THF and its double clathrates). Use of the epitaxial approach at ∼100 K has permitted the formation of the oxirane clathrate hydrate containing intact isolated D2O molecules. This has permitted the FT–IR observation of the ν3–ν1 doublet in the O–D stretching region (2455 and 2380 cm−1 at 100 K) with the values, after correction for Fermi resonance, suggesting a splitting from intramolecular coupling of ∼56 cm−1 (2455 vs 2399 cm−1), which compares closely with the 52 cm−1 deduced for cubic ice. Spectra for the structure I hydrates of oxirane and H2S contain absorption bands produced by guest molecules confined to both small and large clathrate cages. Use of the structure II double hydrates has permitted the firm identification of the structure I infrared bands with oxirane and H2S molecules in cages of one size or the other. Thus, the weaker ν3 and (ν11,ν14) bands of oxirane at 1281 and 1152 cm−1 have been assigned to molecules in the small cages since only these oxirane features remain in the structure II double hydrate with THF. In this case the smaller oxirane molecules occupy the small cages while the THF molecules enter the larger cages, exclusively. In a similar manner, the H–S stretching vibrations of H2S in the structure I small cages have been assigned to a band complex near 2610 cm−1, some 50 cm−1 above the band system for H2S in the large structure I clathrate cages.
Such a result suggests that the net H2S perturbation, relative to the gas phase, is greater for the large than for the small cages and may be interpreted as evidence for a ‘‘double well’’ large cage potential or as further evidence that the cage model of Pimentel and Charles for guest-molecule stretching modes is valid.
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o SCF calculation on LinHm molecules and cations with four or less atoms
Authors: Cardelino B. H. , Eberhardt W. H. , Borkman R. F. 
Published: July 2002

All possible molecules and monopositive cations containing lithium and hydrogen, up to a total of four atoms, have been studied by ab initio calculations using SCF wave functions built from Gaussian-type orbitals. The triatomic molecules and ions Li2H, Li3, H+3 , LiH+2 , Li2H+, and Li+3 were all found to be stable, i.e., of lower energy than any possible dissociation product. The neutral molecules H3 and LiH2 were found to be unstable relative to H2+H and Li+H2, respectively. The ions H+3 and Li+3 were found to be equilateral triangles, Li2H+ was found to be a linear species, while all of the other stable triatomic species were found to be bent. The binding energies (relative to the most stable dissociation products) for the triatomic molecules and ions ranged from 4.53 eV for H+3 to 0.24 eV for LiH+2 . All of the ten possible tetra-atomic molecules and cations were found to be stable (except H4 neutral, for which no calculations were done). The lowest energy structures for LiH3 and LiH+3 consisted of planar structures with an H2 unit perpendicular to an LiH unit and having the H2 at the Li atom end. The lowest energy for Li2H2 was obtained for a planar rhombic structure, while for the corresponding cation it was obtained for a planar structure with an Li2 unit perpendicular to an H2 unit. Li3H and Li3H+ were found to have lowest energy for planar kite shaped structures with a lithium atom loosely bound to the base of a triangle formed by an Li–H–Li unit. The shapes of Li4 and Li+4 were respectively: a rhombic structure and a triangular Li+3 unit with the fourth lithium atom attached to a vertex to form a planar structure similar to H+4 .
The predicted binding energies for the tetra-atomic molecules and ions ranged from 0.08 eV for LiH3 (least stable) to 1.20 eV for Li2H2 (most stable). The present work predicted for the first time a stable LiH3 neutral molecule, and stable Li2H+2 and Li3H+ cations. It also predicted for the first time that the most stable Li+4 ion corresponded to a C2v structure analogous to that of H+4 .
The rotational spectra of NH3–CO and NH3–N2
Authors: Fraser G. T. , Nelson D. D. , Peterson K. I. , Klemperer W. 
Published: July 2002

The rotational spectra of NH3–CO, ND3–CO, ND2H–CO, NDH2–CO, NH3–13CO, and NH3–N2 have been measured by molecular beam electric resonance. The K=0 ground vibrational state transitions for these species were fit to a linear molecule Hamiltonian and the following constants were obtained for NH3–CO; (B+C)/2 (MHz)=3485.757(2), DJ (kHz)=110.2(2), eQqNaa (MHz)=−1.890(7), μa (D)=1.2477(8). These constants were also determined for
ND3–CO [3078.440(7), 75.7(8), −2.028(15), 1.2845(9)], NHD2–CO [3202.303(4), 86.8(6), −1.972(11), 1.2686(8)], NH2D–CO [3338.235(4), 98.9(6), −1.916(12), 1.2546(8)], NH3–13CO [3451.684(5), 108.7(7), −1.870(15), 1.2452(8)]. For NH3–N2 (B+C)/2=3385.76(21), DJ =117.(10), and μa =1.069(14). For NH3–CO three ‖ΔJ‖=1, K=0 progressions were seen along with two ‖ΔJ‖=1, K=1 progressions, suggesting nonrigidity in the complex. The internal rotation of the NH3 subunit about its C3 axis is expected to be essentially free, but this motion, by itself, is not sufficient to explain
the observed spectra, thus, large amplitude dynamics are occurring in at least two degrees of freedom. The quadrupole coupling constants, eQqNaa indicate that in each of the isotopes of NH3–CO the NH3 subunit has its C3 axis relatively rigidly oriented at an angle of approximately 36° with respect to the line connecting the centers of mass of the two subunits. The structure is not hydrogen bonded; the N atom is closest to the CO subunit. The orientation of the CO subunit is not established. The distance between the N atom and the center of mass of the CO unit (RN–CO) is 3.54(3) Å. The spectroscopic constants suggest that the weak bond stretching force constant is quite small (0.01 mdyn/Å) but compatible with the long bond length.
The exact multicenter multipolar part of a molecular charge distribution and its simplified representations
Authors: Vigné-Maeder Fabienne , Claverie Pierre 
Published: July 2002

We study the problem of representing the molecular charge distribution in a convenient way for practical applications and we propose, instead of a single representation, a flexible procedure for building approximations with an arbitrary level of accuracy as concerns the long-range part of the electrostatic potential. We first discuss the splitting of the total electrostatic potential into a multipolar part (long-range) and a penetration part (shortrange) in connection with the usual one-center multipole expansion: at large enough distances, this expansion precisely converges towards the multipolar part. However, this representation is not practically efficient as soon as the molecule departs from a spherical shape, and we therefore consider a so-called multicenter multipole representation. In the MO-LCAO framework, the use of a basis of Gaussian atomic orbitals {χα} generates such a representation in a natural way: indeed, each elementary distribution χ*αχβ then reduces to a one-center distribution with a finite number of multipoles, hence an exact multipolar representation (corresponding to the approximate MO-LCGO wave function) involving a finite (albeit large, in general) number of centers, each one bearing a finite (small) number of multipoles. From this representation used as a reference, we then generate simplified multicenter multipole representations through a systematic procedure of reduction of the number of centers (having chosen a reduced set of new centers, we represent the multipoles of each suppressed old center through suitable new multipoles located on a few new centers closest to the old one under consideration). The number and locations of the new centers are arbitrary, hence the great flexibility of the method. We checked the accuracy of this procedure for molecules of different polarity (water, benzene, adenine), and we noticeably found that a representation involved as centers, the atoms plus one
point per chemical bond exhibited quite a satisfactory accuracy. In the conclusion, we briefly discuss the possibility of extending the method to other kinds of basis functions (e.g., Slater orbitals), in connection with the problem of representing the charge distribution associated with the exact molecular wave function, we also discuss the choice of the number centers according to the desired accuracy and we briefly describe a way of applying the method to the problem of representing a large molecule in terms of molecular fragments.
Multiphoton excitation, ionization, and dissociation decay dynamics of small clusters of niobium, tantalum, and tungsten: Time-resolved thermionic emission
Authors: Amrein Andreas , Simpson Richard , Hackett Peter 
Published: July 2002

The ionization dynamics of transition metal clusters have been investigated using time-of-flight mass and electron spectroscopy following single-photon (220 nm) and two-photon (351, 308, and 248 nm) excitation by pulsed laser light. At 220 nm, the ionization is direct and only prompt photoelectrons are produced. At 308 nm, delayed photoelectrons are produced. In consequence of this delayed ionization process, the time-of-flight mass spectrum peaks show exponential tails (decay time 0.67, 0.40, and 1.54 μs for Nb+7, Ta+7, and W+7, respectively). The decay time is shown to have an explicit dependence upon the cluster nuclearity and the laser wavelength.
Experiments, in which the acceleration voltage of the time-of-flight spectrometer is pulsed on after the photoionization laser pulse, reveal that the precursor to the delayed ion signals is a neutral molecule, further evidence for a delayed ionization process. Similar effects are also seen for transition metal carbide clusters. Clusters of the same nuclearity have approximately equal decay times independent of the number of carbon atoms in the cluster. Transition metal oxide clusters do not give a two-photon ionization signal. These observations are explained using a model for the two-photon excitation, dissociation, and ionization dynamics. The central feature of this model is that following single photon excitation of an electronic transition below the ionization potential, there is rapid internal conversion among all vibronic states. The absorption of a second photon then creates a vibrationally excited cluster which contains internal energy greater than the ionization potential, but which can only ionize by a nonadiabatic process. This delayed ionization process occurs in competition with dissociation. As clusters of niobium, tantalum, and tungsten and their carbides are very strongly bound, the dissociation rate is slow and the delayed ionization may be observed. Oxidized clusters are expected to be less strongly bound as the diatomic transition metal oxide provides an excellent leaving group; in consequence, no delayed ionization is observed for partially oxidized clusters. The rates for dissociation and ionization of the bare metal clusters have been calculated within the framework of a generalized statistical theory for cluster processes. These rates are in general agreement with the measured decay times. In addition, the rates have been estimated by a procedure which uses tabulated thermodynamic parameters for the bulk elemental materials and makes an explicit correction for the size dependence. Once again, a reasonable agreement is obtained. These results provide the first experimental observation of a delayed ionization process for a neutral polyatomic molecular system. In analogy with materials properties, they also represent the first experimental observation of time-resolved thermionic emission.
Rydberg states of the Ar2 molecule
Authors: Kane D. J. , Kim S. B. , Shannon D. C. , Herring C. M. , Eden J. G. , Ginter M. L. 
Published: July 2002

Extensive spectra attributable to transitions from the 4sσ a 3Σ+ metastable state of Ar2 to excited Rydberg states have been observed by intracavity absorption spectroscopy and by laser excitation spectroscopy in the afterglow of a pulsed corona discharge. Of these the most extensive and best resolved were the laser induced fluorescence spectra. Most of the spectra can be assigned to vibronic transitions in the nfλ (3Πg,3Σ+g) and npλ (3Πg,3Σ+g)←a 3Σ+u series. The 5pπ3Πg←a 3Σ+u and 7pσ 3Σ+g←a 3Σ+u transitions observed near 19 823 and 19 529 cm−1, respectively, exhibit many bands with v′≠0 in their (v′–v″) vibrational band system developments. The higher n value members of these and other observed series are dominated by (0–0) transitions. Rotational structure is partially resolved in a few bands of the 7pσ 3Σ+g–a system, but most of the spectra observed appear to be either rotationally unresolved or made up of blended collections of rotational lines. Above the 7pσ, 5pπ pair, the (n+2)pσ 3Σ+g and npπ 3Πg members of the npλ series rapidly coalesce, indicating a rapid onset of decoupling of the electronic orbital angular momentum, L̂, from the internuclear axis.
Such decoupling leads to np-complex formation at n values much lower than observed in the npλ series of the lighter dimers: He2 and Ne2. From the data for the observed series, the lowest ionization limit of Ar2 (relative to a 3Σ+u,v=0 ) was determined to be 29 373±3 cm−1. Vibrational intervals ΔG(v+1/2) for a 3Σ+u(v≤4) and 7pσ 3Σ+g(v≤2) yield the vibrational constants ωe=296 and 282 cm−1 and xωe=2.5 and 17 cm−1, respectively.
Spectroscopy and nuclear dynamics of tetracene–rare-gas heteroclusters
Authors: Ben-Horin Narda , Even Uzi , Jortner Joshua , Leutwyler Samuel 
Published: July 2002

In this paper we report on the electronic spectroscopy of mass-resolved tetracene⋅Arn (n=1–26) and tetracene⋅Krn (n=1–14) heteroclusters, utilizing two-photon, two-color near-threshold ionization in conjunction with mass-spectrometric detection. The spectra of the S0 → S1 transition and the ionization threshold of these heteroclusters were monitored. The structured spectral features of the S0 → S1 transition of small- and medium-sized (n=1–8) heteroclusters were attributed to the electronic origins of structural isomers and to their intermolecular vibrations. The S0 → S1 spectra of large (n≥9) heteroclusters are broad and were assigned to inhomogeneous broadening due to the coexistence of isomers, with the spectral feature(s) of each distinct isomer being homogeneously broadened. Isomer-specific inhomogeneous line broadening was interrogated by the observation of isomer-specific ionization potentials for medium-sized (n=6–7) heteroclusters and of the dependence of the relative intensities of the spectral features on the conditions of the supersonic expansion.
The ionization thresholds of the tetracene⋅An (A=Ar,Kr) reveal a linear (or superlinear) n dependence, being qualitatively different from the sublinear n dependence of the spectral shifts. These different patterns of the size dependence can be traced to the different intermolecular interactions which govern excitation and ionization and to the difference in the charge distribution in S0 and in the positive ion. The experimental spectroscopic data for the spectral shifts and the spectral linewidths were simulated in terms of the first and second moments of the classical line shape, which were obtained from Monte Carlo (MC) constant temperature simulations, in conjunction with a two-parameter fit of the excited-state tetracene–rare-gas potential. The Monte Carlo simulations of the structural fluctuation parameters identified several isomerization phenomena, i.e., correlated restricted and unrestricted surface motion, adcluster isomerization, surface melting and side crossing, and characterized the size dependence of the temperature onsets of these processes for small and medium sized n=2–20 clusters. These isomerization processes could not be interrogated by the investigation of the size dependence of the spectral shifts and linewidths. The size dependence and the isomer specificity of the spectral shifts are well accounted for by the MC simulations. The homogeneous spectral linewidths of small (n&lt;8) clusters pertain to the spectroscopy of ‘‘static’’ isomers, while the line broadening of large (n≥20) clusters manifests inhomogeneous line broadening due to the coexistence of wetting and nonwetting isomers. The temperature dependence of the spectral shifts and inhomogeneous linewidths of large (n≥20) clusters provides means for internal cluster thermometry.