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1.
The effects of fine suture materials on corneal wound healing in the dog were studied. In 20 dogs, standardized perforating perilimbal clear corneal wounds were made and closed with either monofilament Polyglactin 910 or nylon. Five dogs each were euthanized 8,12,16, and 21 days postoperatively. Results of gross, biomicroscopic, and histologic examinations at 8,12,16, and 21 days showed nylon and Polyglactin 910 to cause similar inflammatory responses. Epithelialization and suppuration around the suture tracts were observed more frequently when Polyglactin 910 was used. Both materials were associated with a foreign body (granulomatous) response. There was no loss of wound integrity with either material. Strengths of the incised corneal tissues with and without the sutures intact were determined. At day 16 postsurgery, there was a statistically significant difference in tissue strengths between cases in which sutures were and were not intact. This difference was not apparent at 21 days postsurgery, which suggested that the suture dependent phase ends between the 16th and 21st postsurgical days. In addition, at day 16 there was no statistical difference between the tissue strength of wounds sutured with nylon or Polyglactin 910. Corneal suture materials studied should remain in place for at least 16 days, and absorbable material is only appropriate if it retains tensile strength for 16 days.  相似文献   
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An interlaboratory study was conducted to compare pesticide recovery from Empore C(18) and Speedisks C(18)XF solid phase extraction disks after shipping. Four pesticides were used for the comparison of the two disk extraction materials: atrazine, diazinon, metolachlor, and tebuconazole. These pesticides were chosen to provide a range of physiochemical properties. Water samples were extracted onto the disk types and shipped to a cooperating laboratory for elution and analysis. The mean recoveries from Empore disks were atrazine, 95%; diazinon, 91%; metolachlor, 92%; and tebuconazole, 83%. The recoveries from Speedisks C(18)XF were atrazine, 89%; diazinon, 87%; metolachlor, 86%; and tebuconazole, 79%. Means for each of the pesticides using the different disk types were not statistically different (alpha = 0.05), but results were more variable when using Speedisks C(18)XF as compared to Empore disks. Reasons for the increased variability are discussed, but overall results indicate that Speedisks C(18)XF could be used as an alternative to Empore disks. Speedisks C(18)XF are enclosed in a plastic housing, so they can be used more easily in remote sampling sites without the possibility of glassware breakage, no prefiltration of samples is needed, and there are realignment problems that can be associated with the Empore disks.  相似文献   
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Holstein bull calves were blocked by birth order and randomly assigned to one of three treatments in trial I: stall (N = 7), pen (N = 7) and hutch (N = 7), and to one of four treatments in trial II: stall (N = 6), pen (N = 5), hutch (N = 6) and yard (N = 8). Stalls were elevated, .56 X 1.2 m, with wooden slatted floors. Stalled calves were tethered from the front with a collar and .5-m chain. Pens were elevated, 1.2 X 1.5 m, with wooden slatted floors and were located in the same open-front building as the stalls. Hutches were 1.2 X 1.2 X 2.4 m long and open on one end. Hutch calves were restrained with a dog collar and 2.4-m chain. Yard calves were housed as a group in a 3.6 X 7.9 m, outdoor enclosure, of which one-half was a covered, three-sided structure. Calves were placed on treatment between 12 to 24 h of age, bottle-fed 1.9 liters colostrum twice daily for 2 d and then bucket-fed 1.9 liters milk replacer twice daily, with continuous access to hay and grain. Jugular blood samples taken at 6 wk were analyzed for blood cell counts, blood chemistry profile (13 items), triiodothyronine (T3), thyroxine (T4), basal cortisol and adrenal response (cortisol) to exogenous adrenocorticotrophic hormone (ACTH). Average daily gain from 0 to 42 d was highly variable and was not significantly different for different treatments.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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Comparison of four methods of calf confinement. II. Behavior   总被引:1,自引:0,他引:1  
Holstein bull calves (N = 46) were blocked by birth order and randomly assigned to be individually reared in stalls, pens or hutches (trials I and II) or as a group in a 3.6 X 7.9 m yard (trial II only). Treatments differed by the degree of restraint and social isolation imposed, with stalls the most restrictive and yard the least. Stalls and pens had wooden slatted floors; hutches and yard were on ground. Calves were placed on treatment within 24 h of birth and remained on treatment 6.5 wk. Total time standing or lying per 24 h in situ at 5 wk was not affected by treatment (P greater than .05), but hutch calves changed position between standing and lying more often than others (P less than .05), in order to remain in sun or shade. At 6.5 wk, calves (N = 24) in trial II were individually open-field tested for 20 min in the presence of alien calves. Stall and pen calves performed more actions utilized in locomotion and defense and engaged in more social behavior than hutch or yard calves (P less than .05). Only stall and pen calves stumbled and fell, but observations were insufficient to allow statistical analysis of these incidents. Treatment effects were found with respect to vocalizations: stall and pen calves emitted more "baaocks," while yard calves emitted more "moos." Results of this study and of a companion physiological study of the calves suggest that the intensification of drives induced by chronic suppression of their release may be accompanied by physiological responses associated with chronic stress.  相似文献   
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ObjectivesTo investigate the modulation of the nociceptive withdrawal reflex (NWR) and temporal summation (TS) by low‐dose acepromazine (ACP) in conscious dogs. To assess the short‐ and long‐term stability of the reflex thresholds.Study designRandomized, blinded, placebo‐controlled cross‐over experimental study.AnimalsEight adult male Beagles.MethodsThe NWR was elicited using single transcutaneous electrical stimulation of the ulnar nerve. Repeated stimuli (10 pulses, 5 Hz) were applied to evoke TS. The responses of the deltoideus muscle were recorded and quantified by surface electromyography and the behavioural reactions were scored. Each dog received 0.01 mg kg?1 ACP or an equal volume saline intravenously (IV) at 1 week intervals. Measurements were performed before (baseline) and 20, 60 and 100 minutes after drug administration. Sedation was scored before drug administration and then at 10 minutes intervals. Data were analyzed with Friedman repeated measures analysis of variance on ranks and Wilcoxon signed rank tests.ResultsAcepromazine resulted in a mild tranquilization becoming obvious at 20 minutes and peaking 30 minutes after injection. Single (It) and repeated stimuli (TSt) threshold intensities, NWR and TS characteristics and behavioural responses were not affected by the ACP at any time point. Both It and TSt were stable over time.Conclusions and clinical relevanceIn dogs, 0.01 mg kg?1 ACP IV had no modulatory action on the NWR evoked by single or repeated stimuli, suggesting no antinociceptive activity on phasic nociceptive stimuli. The evidence of the stability of the NWR thresholds supports the use of the model as an objective tool to investigate nociception in conscious dogs. A low dose of ACP administered as the sole drug, can be used to facilitate the recordings in anxious subjects without altering the validity of this model.  相似文献   
8.
High-power and highly directional semiconductor microcylinder lasers based on an optical resonator with deformed cross section are reported. In the favorable directions of the far-field, a power increase of up to three orders of magnitude over the conventional circularly symmetric lasers was obtained. A "bow-tie"-shaped resonance is responsible for the improved performance of the lasers in the higher range of deformations, in contrast to "whispering-gallery"-type modes of circular and weakly deformed lasers. This resonator design, although demonstrated here in midinfrared quantum-cascade lasers, should be applicable to any laser based on semiconductors or other high-refractive index materials.  相似文献   
9.
Local control of the domain orientation in diblock copolymer thin films can be obtained by the application of electric fields on micrometer-length scales. Thin films of an asymmetric polystyrene-polymethylmethacrylate diblock copolymer, with cylindrical polymethylmethacrylate microdomains, were spin-coated onto substrates previously patterned with planar electrodes. The substrates, 100-nanometer-thick silicon nitride membranes, allow direct observation of the electrodes and the copolymer domain structure by transmission electron microscopy. The cylinders aligned parallel to the electric field lines for fields exceeding 30 kilovolts per centimeter, after annealing at 250°C in an inert atmosphere for 24 hours. This technique could find application in nanostructure fabrication.  相似文献   
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AIM: To identify and purify secretory immunoglobulin A (sIgA), a key effecter molecule in mucosal immune responses, from milk of the brushtail possum (Trichosurus vulpecula).

METHODS: Milk samples were collected from female possums with pouch young, and clarified by centrifugation and precipitation methods. The clarified fraction was purified by gel filtration and affinity chromatography to yield sIgA. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting techniques were used to assess the purity of the final product, and to identify the heavy (H) chain, light (L) chain and secretory component (SC) of possum sIgA.

RESULTS: Immunoblotting, using antibodies raised against cloned possum sIgA SC and H-chain, and a synthetic peptide fragment of the H-chain, confirmed the identity of the purified protein. The N-terminal amino acid sequence of purified possum sIgA showed strong homology to reported sequences of H-chain variable regions of marsupial immunoglobulins.

CONCLUSIONS: Milk was shown to be a convenient source of mucosal secretion containing sIgA, and a process involving 2 precipitation and 2 chromatography steps produced purified sIgA. This IgA preparation will prove useful for the generation of sIgA-specific immunological reagents for measurement of immune responses in the development of mucosal-based vaccines for biological control of possums.  相似文献   
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