Chemical exfoliation of vermiculite and the production of colloidal dispersions   总被引：1，自引：0，他引：1  

Walker GF  Garrett WG 《Science (New York, N.Y.)》1967,156(3773):385-387

Chemical treatments involving ion exchange cause gross onedimensional swelling in water of single crystals of vermiculite minerals. A delicate balance of forces holds the individual silicate layers (10 angstroms thick) parallel to one another although separated by several hundred angstroms. Colloidal dispersions produced from the swollen crystals are morphologically unique and show strong filmforming characteristics.  相似文献   

Bright Spots, Structure, and Magmatism in Southern Tibet from INDEPTH Seismic Reflection Profiling   总被引：8，自引：0，他引：8  

LD Brown  W Zhao  KD Nelson  M Hauck  D Alsdorf  A Ross  M Cogan  M Clark  X Liu  J Che 《Science (New York, N.Y.)》1996,274(5293):1688-1690

INDEPTH seismic reflection profiling shows that the decollement beneath which Indian lithosphere underthrusts the Himalaya extends at least 225 kilometers north of the Himalayan deformation front to a depth of approximately 50 kilometers. Prominent reflections appear at depths of 15 to 18 kilometers near where the decollement reflector apparently terminates. These reflections extend north of the Zangbo suture to the Damxung graben of the Tibet Plateau. Some of these reflections have locally anomalous amplitudes (bright spots) and coincident negative polarities implying that they are produced by fluids in the crust. The presence of geothermal activity and high heat flow in the regions of these reflections and the tectonic setting suggest that the bright spots mark granitic magmas derived by partial melting of the tectonically thickened crust.  相似文献   

Kinetic isotope effects for the reactions of muonic helium and muonium with H2     

Fleming DG  Arseneau DJ  Sukhorukov O  Brewer JH  Mielke SL  Schatz GC  Garrett BC  Peterson KA  Truhlar DG 《Science (New York, N.Y.)》2011,331(6016):448-450

The neutral muonic helium atom may be regarded as the heaviest isotope of the hydrogen atom, with a mass of ~4.1 atomic mass units ((4.1)H), because the negative muon almost perfectly screens one proton charge. We report the reaction rate of (4.1)H with (1)H(2) to produce (4.1)H(1)H + (1)H at 295 to 500 kelvin. The experimental rate constants are compared with the predictions of accurate quantum-mechanical dynamics calculations carried out on an accurate Born-Huang potential energy surface and with previously measured rate constants of (0.11)H (where (0.11)H is shorthand for muonium). Kinetic isotope effects can be compared for the unprecedentedly large mass ratio of 36. The agreement with accurate quantum dynamics is quantitative at 500 kelvin, and variational transition-state theory is used to interpret the extremely low (large inverse) kinetic isotope effects in the 10(-4) to 10(-2) range.  相似文献   

Development of a novel diagnostic test for detection of bovine viral diarrhea persistently infected animals using hair   总被引：1，自引：0，他引：1  

Kuldeep Singh  Myrna M. Miller  Laura J. Kohrt  Gail Scherba  Edgar F. Garrett  Richard L. Fredrickson 《Journal of veterinary science (Suw?n-si, Korea)》2011,12(3):295-297

The purpose of this study was to determine whether manually plucked hairs might serve as an alternative sample for a quantitative real time polymerase chain reaction (qRT-PCR) testing. Twenty three, 1~3 week old, non-bovine viral diarrhea virus (BVDV) vaccinated calves, found to be positive for BVDV by immunohistochemical staining, were selected and hairs were manually plucked from the ear. qRT-PCR was performed on samples consisting of more than 30 hairs (30~100) and whole blood. All 23 animals were positive for the virus by qRT-PCR performed on the whole blood and when samples of more than 30 hairs were assayed. Additionally, qRT-PCR was performed on groups of 10 and 20 hairs harvested from 7 out of 23 immunohistochemical staining-positive calves. When groups of 20 and 10 hairs were tested, 6 and 4 animals, respectively, were positive for the virus.  相似文献   

RADIOGRAPHIC IMAGING OF THE CANINE INTERCONDYLAR FOSSA     

R.D. Montgomery  D.V.M.  M.S. R.B. Fitch  D.V.M.  M.S.  J.T. Hathcock  D.V.M.  M.S.  R.F. Laprade  M.D. M.E. Wilson  R.T. P.D. Garrett  D.V.M.  M.S. 《Veterinary radiology & ultrasound》1995,36(4):276-282

The intercondylar fossa is believed to play an important role in the pathology of cranial cruciate ligament rupture and therefore has received considerable attention in the last decade. Accurate radiographic imaging of the intercondylar fossa requires that the central x-ray beam pass through the center of the intercondylar "tunnel". The anatomy of the canine intercondylar fossa is similar to humans, however, the orientations of the intercondylar fossa's differ. Consequently, the positioning techniques described for humans are not appropriate for the dog. To pass through the center of the dog, intercondylar fossa, the central x-ray beam should be 12° (S.D. 1.7°) caudal from the femoral diaphysis in the sagittal plane and obliqued caudolateral to craniomedial 7° (S.D. 0.60°) (caudo78°proximo7° lateralcraniodistomedial oblique). Cross table positioning was used with the hip flexed and the radiograph cassette placed on the cranial surface of the stifle. However, superimposition of the tuber ischii and soft tissues caudal to the femur made 15° to 20° the best angle obtainable. There was not a significant difference (p = 0.17) in the notch width index between a 12° versus 20° angle of the central x-ray beam caudal to the femoral diaphysis, both with 7° of external rotation of the stifle. The notch width index of 0.252 obtained from radiographic measurements was not significantly different from measurements obtained grossly of 0.254 (n = 26; p = 0.69). Failure to oblique the central x-ray beam caused a significant (p = 0.0008) decrease in the apparent fossa width radiographically.  相似文献   

COLOR DOPPLER AND DOPPLER SPECTRAL ANALYSIS IN THE SPINAL CORD OF NORMAL DOGS     

Judith A.  Hudson  DVM  PhD  Susan T.  Finn-Bodner  DVM  MS  Joan R.  Coates  DVM  Donald C.  Sorjonen  DVM  MS  Stephen T.  Simpson  DVM  MS  James C.  Wright  DVM  PhD  Jan E.  Steiss  DVM  PhD  Nancy R.  Cox  DVM  PhD  Dana M.  Vaughn  DVM  PhD  Starr C.  Miller  BS  Scott A.  Brown  DVM  PhD  Phillip D.  Garrett  DVM  MS 《Veterinary radiology & ultrasound》1995,36(6):542-547

Doppler ultrasonography of the spinal cord was performed in 34 normal, anesthetized dogs following hemilaminectomy. This study was part of an investigation to evaluate the efficacy of a 21-aminosteroid compound and high dose methylprednisolone for the treatment of spinal cord trauma. Grey-scale images of the canine spinal cord were similar to those described for the spinal cord of people. Doppler waveforms of intraparenchymal spinal arteries exhibited high end diastolic blood flow velocities, indicating low resistance to flow. Doppler values (mean ± SD) for arteries immediately ventrolateral to the central canal were: Peak Systolic Velocity = 5.78 ± 2.5 cm/sec, Minimum Diastolic Velocity = 3.5 ± 1.62 cm/sec, Mean Velocity = 4.45 ± 1.96 cm/sec, Minimum Diastolic Velocity = 3.5 ± 1.62 cm/sec, Mean Velocity = 4.45 ± 1.96 cm/sec, Systolic/Diastolic ratio = 169 ± 0.19, Pulsatility Index = 0.53 ± 0.09, and Resistance Index = 0.4 ± 0.06.  相似文献   

Surgical technique to cannulate the rete testis of the goat     

B G Brown  E R Kogelschatz  B W Gray  P D Garrett  V K Ganjam 《American journal of veterinary research》1984,45(11):2389-2392

A surgical technique was devised to collect rete testis fluid from 14 mature goats. The tubular portion of the extratesticular rete testis was cannulated where it penetrated the tunica albuginea of the testis under the center of the head of the epididymis. The tip of the cannula was sutured in place in the extratesticular rete testis and the opposite end was passed through the scrotum and into a plastic collection bottle. The bottle was glued to pillow ticking, which was sutured to the scrotum. Continuous flow of rete testis fluid occurred for 0 to 14 days and was usually terminated by a sperm clot in the cannula. The flow rate was 0.59 +/- 0.37 ml/hr.  相似文献   

Techniques for venous blood sampling from the white pekin duck     

P D Garrett  L M Krista  W M Pedersoli  J S Spano  R J Kemppainen 《Avian diseases》1987,31(2):358-364

Common sites for blood sampling in the pekin duck and other avian species include the basilic vein, jugular vein, superficial plantar metatarsal vein, heart, and occipital sinus. The use of each of these sites is described and/or illustrated. In the present study using the pekin duck, the superficial plantar metatarsal vein proved most satisfactory for collecting repeated samples (every 5 minutes for 30 minutes) with minimal trauma to the duck.  相似文献   

Multiple dose pharmacokinetics and acute safety of piroxicam and cimetidine in the cat     

Heeb HL  Chun R  Koch DE  Moore L  Radlinsky M  Corse M  Pellerin MA  Garrett L  Hunter RP 《Journal of veterinary pharmacology and therapeutics》2005,28(5):447-452

The purpose of this study was to evaluate the multiple dose pharmacokinetics and acute safety of piroxicam and cimetidine alone and in combination in cats. Seven healthy cats were included in this randomized-crossover study. The cats were assigned to groups designated to receive cimetidine alone (15 mg/kg, p.o., q12 h), piroxicam alone (0.3 mg/kg, p.o., q24 h), and piroxicam combined with cimetidine (both at aforementioned doses). The cats were dosed for 10 days followed by at least a 2-week washout period between trials. Serial blood samples were collected following the first and last doses and analyzed utilizing a high-performance liquid chromatography with mass spectrometry detection (LC/MS) assay. Pharmacokinetic parameters were determined using noncompartmental analysis. Endoscopic evaluation of the gastric mucosa was performed and serum urea nitrogen (SUN), creatinine, alkaline phosphatase (ALP), and alanine transaminase (ALT) activities were evaluated. There were not a clinically relevant difference between the pharmacokinetic parameters of piroxicam administered alone or in combination with cimetidine after either the first or last dose. Gastric ulcers were not observed in any cats although gastric erosions were. The SUN, creatinine, ALP, and ALT activities remained within reference ranges for all cats. It appears that once daily, short-term use of piroxicam alone and in combination with cimetidine in cats is relatively safe based on the parameters evaluated in this study. However, further studies are necessary to determine the long-term gastrointestinal safety of piroxicam.  相似文献   

Cultivar mixtures for the simultaneous management of multiple diseases: tan spot and leaf rust of wheat     

Cox CM  Garrett KA  Bowden RL  Fritz AK  Dendy SP  Heer WF 《Phytopathology》2004,94(9):961-969

ABSTRACT Because of differences in life histories between Puccinia triticina, a highly specialized, polycyclic, windborne pathogen with a shallow dispersal gradient, and Pyrenophora tritici-repentis, a residue-borne pathogen with a steep dispersal gradient, wheat mixtures are expected to be more effective at controlling leaf rust than tan spot. The objectives of this research were to determine the effect of two-cultivar mixtures with varying proportions and different pathogen resistance profiles on the severity of tan spot and leaf rust, to evaluate yield of the mixtures in the presence or absence of disease, and to directly compare the relative effectiveness of cultivar mixing for tan spot versus leaf rust. In a field experiment at two sites in Kansas over two growing seasons, winter wheat cvs. Jagger and 2145, which have differential resistance reactions to leaf rust and tan spot, each were planted in proportions of 0.25, 0.50, 0.75, and 1.00. Plots were inoculated with each pathogen alone, both pathogens, treated with a fungicide, or exposed to ambient conditions. For both diseases for all siteyears, severity decreased substantially on the susceptible cultivar as the proportion of that cultivar decreased in mixture. Mixtures were significantly more effective at reducing leaf rust than tan spot in three of four site-years. Mixtures generally yielded the same as the weighted mean of components in monoculture although, in two of three site-years, at least one fungicide-treated and one diseased mixture each yielded higher than expected values. Although this particular mixture produced only modest yield benefits, the potential for simultaneous reductions in tan spot and leaf rust was demonstrated.  相似文献