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1.
Rev Sci Instrum ; 50(6): 708, 1979 Jun.
Article in English | MEDLINE | ID: mdl-18699587

ABSTRACT

A compact cw chemical HF/DF laser is described. The laser system consists of a microwave discharge using a surfatron to dissociate SF6 molecules mixed with He, a reaction chamber engineered to provide a fast mixing of reacting atoms and molecules, and an optical resonator which includes a concave mirror and a blazed grating for line selection, both mounted on a rigid Invar frame. The laser oscillates on a single line single TEM00 mode over many P transitions of HF and DF with a typical intensity fluctuation of 5% and a frequency jitter of about 30 MHz.

2.
J Am Vet Med Assoc ; 209(6): 1114-6, 1996 Sep 15.
Article in English | MEDLINE | ID: mdl-8800259

ABSTRACT

OBJECTIVE: To determine whether cats with inflammatory hepatic disease had concurrent inflammatory bowel disease (IBD), pancreatitis, or chronic interstitial nephritis. DESIGN: Prospective case series. SAMPLE POPULATION: 78 tissue sections of liver, intestine, pancreas, and kidney from cats that had previous necropsy examinations at the teaching hospital. PROCEDURE: We reviewed histologic sections of liver, intestine, pancreas, and kidney from cats that had previous necropsy examinations and determined the prevalence of lymphocytic portal hepatitis, cholangiohepatitis, IBD, pancreatitis, and chronic interstitial nephritis, and the relationship among them. RESULTS: 36 cats had lymphocytic portal hepatitis, 18 had cholangiohepatitis, and 24 did not have inflammatory hepatic disease. The prevalence of IBD (10/36; 28%) and pancreatitis (5/36; 14%) in cats with lymphocytic portal hepatitis was not significantly different from cats without inflammatory hepatic disease. The prevalence of IBD (15/18; 83%) and pancreatitis (9/18; 50%) was greater (P < 0.05) for cats with cholangiohepatitis, compared with cats without inflammatory hepatic disease. Thirty-nine percent of cats (7/18) with cholangiohepatitis had IBD and pancreatitis. Evidence of IBD in association with cholangiohepatitis was characterized by infiltration of lymphocytes and plasma cells into the lamina propria; however, neutrophilic infiltrates also were found in 6 of 15 (40%) cats with cholangiohepatitis. Pancreatitis was mild in all cats. CLINICAL IMPLICATIONS: Cats with a diagnosis of cholangiohepatitis should be evaluated for IBD and pancreatitis.


Subject(s)
Cat Diseases , Hepatitis, Animal/complications , Inflammatory Bowel Diseases/veterinary , Nephritis, Interstitial/veterinary , Pancreatitis/veterinary , Age Distribution , Animals , Cat Diseases/epidemiology , Cat Diseases/pathology , Cats , Chronic Disease , Hepatitis, Animal/epidemiology , Hepatitis, Animal/pathology , Inflammatory Bowel Diseases/complications , Inflammatory Bowel Diseases/pathology , Intestines/pathology , Kidney/pathology , Liver/pathology , Nephritis, Interstitial/complications , Nephritis, Interstitial/pathology , Pancreas/pathology , Pancreatitis/complications , Pancreatitis/pathology , Prevalence , Prospective Studies
3.
J Am Vet Med Assoc ; 214(4): 513-6, 1999 Feb 15.
Article in English | MEDLINE | ID: mdl-10029853

ABSTRACT

OBJECTIVE: To compare the clinical and clinicopathologic findings in and prognosis for cats with lymphocytic portal hepatitis (LPH) versus cats with acute or chronic cholangiohepatitis (CH). DESIGN: Retrospective study. ANIMALS: 25 cats with LPH; 16 cats with CH (7 acute, 9 chronic). PROCEDURE: Cats with LPH and CH were selected by evaluating records from liver biopsy specimens submitted to the University of Minnesota Veterinary Teaching Hospital during a 10-year period. Clinical and clinicopathologic data were retrieved. RESULTS: Cats with CH had higher segmented and band neutrophil counts, alanine aminotransferase activities, and total bilirubin concentrations than did cats with LPH. Cats with acute CH had higher segmented and band neutrophil counts and lower serum alkaline phosphatase activities and total bilirubin concentrations than did cats with chronic CH. Twelve of 14 cats with LPH or CH had coarse or nodular texture to the liver on ultrasonography, with loss of portal vein wall clarity noticed in 4 of 8 cats with LPH. Sixteen of 23 cats with LPH and 8 of 15 cats with CH survived > 1 year. Of those cats living < 1 year, all cats with LPH and 5 of 7 cats with CH had a serious concurrent illness that may have been responsible for their deaths. CLINICAL IMPLICATIONS: LPH and CH can be detected and tentatively differentiated through evaluation of clinical laboratory test results, but histologic evaluation of liver specimens is necessary for definitive differentiation. Survival time was good regardless of the type of inflammatory liver disease.


Subject(s)
Cat Diseases , Cholangitis/veterinary , Hepatitis, Animal , Acute Disease , Animals , Bile Ducts, Intrahepatic/pathology , Biopsy , Cat Diseases/blood , Cat Diseases/mortality , Cat Diseases/pathology , Cats , Cholangitis/blood , Cholangitis/mortality , Cholangitis/pathology , Chronic Disease , Diagnosis, Differential , Female , Hepatitis, Animal/blood , Hepatitis, Animal/mortality , Hepatitis, Animal/pathology , Liver/diagnostic imaging , Liver/pathology , Lymphocytosis/veterinary , Male , Portal System/pathology , Prognosis , Radiography , Retrospective Studies , Ultrasonography
4.
Appl Opt ; 7(4): 581-4, 1968 Apr 01.
Article in French | MEDLINE | ID: mdl-20068641

ABSTRACT

This paper describes a high resolution photoelectric Fabry-Perot spectrometer for measuring optical line shifts, hyperfine structure intensities, and spectral line widths. The measurements reported were made within an accuracy of 1%. Details of the instrument construction are given.

5.
Appl Opt ; 6(10): 1649-54, 1967 Oct 01.
Article in French | MEDLINE | ID: mdl-20062282

ABSTRACT

By means of high resolution optical spectroscopy, we can determine nuclear quadrupole moments of radioactive or stable nuclides with even atomic number in the heavy elements region. We discuss and summarize the main conditions applicable to the method.

6.
Appl Opt ; 29(30): 4489-93, 1990 Oct 20.
Article in English | MEDLINE | ID: mdl-20577414

ABSTRACT

The frequency of a AlGaAs diode laser has been locked to the 8118-cm(-1)(f(3)d(2)s(5)M(0)(7))-20,218-cm(-1) transition of UI at 826.20570 nm using the optogalvanic effect. A hollow cathode vapor generator has been utilized to produce a density of 10(12) atoms/cm(3) of uranium in vapor phase. The absolute frequency stability for a 10-min run was estimated to be better than 500 kHz P-P at an integration time of 1 s. This preliminary result shows that the rich optogalvanic spectrum of uranium can be efficiently used for the frequency-locking of semiconductor lasers.

7.
Opt Lett ; 13(3): 198-200, 1988 Mar 01.
Article in English | MEDLINE | ID: mdl-19742026

ABSTRACT

We have studied by emission spectroscopy the spectral properties of doubly ionized uranium, produced in a vapor generator of hollow-cathode design, as a function of the nature of a pure fill gas (helium, neon, argon, krypton, xenon) and its pressure. The spectral intensity is found to increase with increasing ionization potential of the discharge buffer gas, except in the case of helium. Based on our preliminary results, a simple and practical method for the positive identification of the complex U III spectrum is suggested.

8.
Vet Clin Pathol ; 24(3): 91-95, 1995.
Article in English | MEDLINE | ID: mdl-12664431

ABSTRACT

To better understand the relationship of portal lymphocytic infiltrates to feline inflammatory liver disease, liver sections were semiquantitatively evaluated from healthy cat and liver sections randomly selected at necropsy from clinical cases. Healthy specific pathogen-free kittens and healthy young adult cats had up to 10 lymphocytes and plasma cells per portal area. Neutrophils were infrequently seen in portal areas. Approximately one-third of sections obtained from clinical cases younger than 10 years had increased numbers of lymphocytes and plasma cells in portal areas. Seventy percent of these had a concurrent increase in neutrophils. Eighty-two percent of liver sections obtained from clinical cases older than 10 years had increased numbers of portal lymphocytes and plasma cells. Almost all of these sections had concurrent fibrosis and bile duct proliferation. These data indicate that a progressive lymphocytic portal hepatitis is a common finding in cats older than 10 years.

9.
Appl Opt ; 19(3): 463-8, 1980 Feb 01.
Article in English | MEDLINE | ID: mdl-20216870

ABSTRACT

During the development and study of a hollow cathode pulsed source of uranium vapor, we have observed that the absorption line shape changes considerably with time. This has been shown to be due to oscillatory collective displacement of the vapor in the cavity of the source.

10.
Vet Pathol ; 33(5): 521-6, 1996 Sep.
Article in English | MEDLINE | ID: mdl-8885178

ABSTRACT

To better define the histopathologic features of feline inflammatory liver disease, we studied feline liver biopsies evaluated at the University of Minnesota Veterinary Teaching Hospital over a 10-year period. Of 175 liver sections examined, 45 had portal inflammatory infiltrates. Of these, 60% had infiltrates consisting of lymphocytes and plasma cells, 24% had infiltrates consisting of neutrophils, and 16% had mixed infiltrates consisting of neutrophils, lymphocytes, and plasma cells. Lymphocytic-plasmacytic portal infiltrates were characterized by various degrees of bile duct proliferation and fibrosis without evidence of bile duct infiltration or periportal necrosis. Sections with portal neutrophilic infiltrates were characterized by bile duct infiltration, bile duct epithelial degeneration, periportal necrosis, and infiltration of neutrophils into adjacent lobules. We propose that hepatitis characterized by portal lymphocyte and plasma cell infiltration be termed lymphocytic portal hepatitis and that hepatitis characterized by cholangitis and portal neutrophilic infiltrates with or without lymphocytes and plasma cells be termed cholangiohepatitis.


Subject(s)
Cholangitis/pathology , Cholangitis/veterinary , Hepatitis, Animal/pathology , Animals , Cats
11.
Appl Opt ; 13(12): 2835-9, 1974 Dec 01.
Article in English | MEDLINE | ID: mdl-20134797

ABSTRACT

A small transverse-flow HF chemical laser has been constructed using a large volume microwave plasma generator for the production of F atoms. The F atoms react with hydrogen to form the lasing HF molecules. The active medium is about 5 cm long, and the maximum average laser power was found to be 560mW for all lines. Three laser lines with wavelengths 2.61 microm, 2.64 microm, and 2.73 microm were observed. The time-varying laser transition profile closely resembles the density profile of the excited fluorine atoms in the plasma. Both profiles are greatly affected by changes in flow conditions.

12.
Appl Opt ; 12(3): 522-7, 1973 Mar 01.
Article in English | MEDLINE | ID: mdl-20125338

ABSTRACT

This paper describes the principles, realization, and characteristics of a refractometer used as a reference for measuring the scanning of a high resolution, photoelectric Fabry-Perot spectrometer. The precision of the measurements on this refractometer is approximately one order of magnitude greater than that obtainable with other instruments.

13.
Appl Opt ; 12(8): 1894-6, 1973 Aug 01.
Article in English | MEDLINE | ID: mdl-20125627

ABSTRACT

A new method is described that uses an elegtronic imaging tube to record and explore Fabry-Perot fringes. The light intensity distribution of an interference pattern and the Doppler effect of a line can be observed with an exploration time of the order of 1O(-5) sec. Some important applications in the fields of spectroscopy and education are also considered.

14.
Appl Opt ; 8(5): 931, 1969 May 01.
Article in English | MEDLINE | ID: mdl-20072348

ABSTRACT

Nous décrivons une méthode pour relever le profil d'une raie spectrale à l'aide d'un dispositif de comptage photonique et d'un spectromètre Fabry-Pérot. Cette méthode a été appliqué au cas où l'intensité lumineuse effective au maximum d'une raie spectrale est inférieure à 1'intensité du mouvement proper d'un photomultiplicateur.

15.
Appl Opt ; 28(8): 1533-7, 1989 Apr 15.
Article in English | MEDLINE | ID: mdl-20548695

ABSTRACT

We have investigated the effects of a buffer gas (air) on the vapor plume produced in a laser open atomizer using atomic absorption spectroscopy. The absorption signal is related to the concentration of absorbing species by a modified Beer-Lambert equation in which the buffer gas pressure and temperature and the diameter of the diffusing species appear explicitly. Our experimental results show that the observed maximum of absoprtion as a function of gas pressure is well explained by the classical gas diffusion theory. Furthermore, our measurements indicate that the plume created by the laser has a conical shape.

16.
Appl Opt ; 20(21): 3770-3, 1981 Nov 01.
Article in English | MEDLINE | ID: mdl-20372257

ABSTRACT

The influence of different carrier gases (Ne, Ar, Kr, Xe), their pressure, and discharge current on the excitation and ionization of uranium atoms in a vapor generator of hollow-cathode design has been investigated by monitoring emission line intensities. From our measurements of line intensities as a function of the carrier gas we obtain an indication of the role of Penning collisions on the excitation of radiative levels in U II.

17.
Appl Opt ; 19(8): 1373-9, 1980 Apr 15.
Article in English | MEDLINE | ID: mdl-20221044

ABSTRACT

A self-scanned photodiode array has been used to detect the image from a Fabry-Perot spectrograph, the recording being a cut along a diameter of the interference pattern. A microcomputer plus a 12-bit analogto- digital converter are employed to store numerically the data as a central logic system and to eliminate the fixed pattern noise of the array. From the spatial photosensibility distribution, we can restore the profile of the light distribution at the sampled points. Using the Shannon interpolation method on these ideal samples, we can thus pinpoint precisely the maxima of the fringes and linearize the spectra. Theoretical and experimental comparisons with photographic plates pointed out an improvement in the SNR for the photodiode system and open up interesting and useful applications to Fabry-Perot spectrography.

18.
Appl Opt ; 18(7): 1084-7, 1979 Apr 01.
Article in English | MEDLINE | ID: mdl-20208879

ABSTRACT

The density of U atoms in the (5)L(0)(6) ground state present in a vapor of this element from a hollow cathode lamp has been measured using laser absorption spectroscopy. The influence of the carrier gases (Ar, Kr, Xe) on the density, the absorption coefficient profiles, and on the ratio of U atoms to the dissipated electrical power has been investigated. It has been found that, in our range of operating conditions, the xenon gas is the most efficient. With xenon, a density of 2.2 x 10(12) cm(-3) ground-state U atoms is obtained when the lamp dissipates 40 W of electrical power.

19.
Appl Opt ; 18(13): 2107-11, 1979 Jul 01.
Article in English | MEDLINE | ID: mdl-20212621

ABSTRACT

The production of uranium vapors has been studied in the (5)L(0)(6)ground state using a pulsed hollow cathode lamp. The evolution of the (238)U ((5)L(0)(6)) concentration with time has been studied with Xe and Ar as buffer gases. A density of 2.7 x 10(13) atoms cm(-3) was obtained with Xe as a buffer gas. In addition, those measurements, obtained from the absorption of a laser beam tuned to the 5758.143 A ((5)L(0)(6)-17,361(7)L(6)) transition, allowed the determination of the transition probability A = 2.1 x 10(5) sec(-1) and of the branching ratio BR = 0.08 for this transition.

20.
Appl Opt ; 13(3): 581-8, 1974 Mar 01.
Article in English | MEDLINE | ID: mdl-20126026

ABSTRACT

The sampling theorem for deterministic functions is used to locate the center of gravity of a spectral line obtained by photon counting with a multichannel spectrometer. The sampling step and the width of the channels have been evaluated to locate the line with maximum accuracy. Our analysis and experimental results give the requirements needed of a photon counting multichannel Fabry-Perot spectrometer to improve the accuracy of measurement of the spectral interval between two lines.

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