Measurements of the equation of state of deuterium at the fluid insulator-metal transition   总被引：1，自引：0，他引：1  

GW Collins  Da Silva LB  P Celliers  DM Gold  ME Foord  RJ Wallace  A Ng  SV Weber  KS Budil  R Cauble 《Science (New York, N.Y.)》1998,281(5380):1178-1181

A high-intensity laser was used to shock-compress liquid deuterium to pressures from 22 to 340 gigapascals. In this regime deuterium is predicted to transform from an insulating molecular fluid to an atomic metallic fluid. Shock densities and pressures, determined by radiography, revealed an increase in compressibility near 100 gigapascals indicative of such a transition. Velocity interferometry measurements, obtained by reflecting a laser probe directly off the shock front in flight, demonstrated that deuterium shocked above 55 gigapascals has an electrical conductivity characteristic of a liquid metal and independently confirmed the radiography.  相似文献   

Localization of metastable atom beams with optical standing waves: nanolithography at the heisenberg limit     

KS Johnson  JH Thywissen  NH Dekker  KK Berggren  AP Chu  R Younkin  M Prentiss 《Science (New York, N.Y.)》1998,280(5369):1583-1586

The spatially dependent de-excitation of a beam of metastable argon atoms, traveling through an optical standing wave, produced a periodic array of localized metastable atoms with position and momentum spreads approaching the limit stated by the Heisenberg uncertainty principle. Silicon and silicon dioxide substrates placed in the path of the atom beam were patterned by the metastable atoms. The de-excitation of metastable atoms upon collision with the surface promoted the deposition of a carbonaceous film from a vapor-phase hydrocarbon precursor. The resulting patterns were imaged both directly and after chemical etching. Thus, quantum-mechanical steady-state atom distributions can be used for sub-0.1-micrometer lithography.  相似文献   

Effect of prenatal stress on subsequent response to mixing stress and a lipopolysaccharide challenge in pigs     

Lay DC  Kattesh HG  Cunnick JE  Daniels MJ  Kranendonk G  McMunn KA  Toscano MJ  Roberts MP 《Journal of animal science》2011,89(6):1787-1794

Sows subjected to prenatal stress have been found to produce offspring that have altered responses to stress. Our objective was to determine if exposing a sow to stress would alter the response of the offspring to lipopolysaccharide (LPS) at 2 mo of age or their response to mixing stress at 4 mo of age. Sow treatments consisted of intravenous injections of ACTH (1 IU/kg of BW), exposure to rough handling for a 10-min duration (rough), or no treatment (control) once per week from d 42 to 77 of gestation. At 2 mo of age, pigs from each treatment, 1 per litter (n = 21, 17, and 15 for the ACTH, rough, and control treatments, respectively), were challenged with 2 μg of LPS/kg of BW or saline, or served as a noninjected control. Their behavioral response to a human approach test and salivary cortisol were measured. At 4 mo of age, 1 pig from each treatment (n = 14, 14, and 15 for the ACTH, rough, and control treatments, respectively) was taken from its home pen and placed in a pen of unfamiliar pigs. At this time, a punch biopsy wound (6 × 6 mm) was created to measure the ability of the pig to heal the wound. At this same time, each pig received a 1-mL intramuscular injection of 20% ovine red blood cells (oRBC), and then a second injection of oRBC at 21 d postmixing. Blood samples were collected 3 times per week for 2 wk and then once a week for 4 more weeks. Blood samples were analyzed for cortisol, porcine corticosteroid-binding globulin, antibody response to oRBC, and nitric oxide production by macrophages. Behavior was recorded during the first 5 d after mixing. All pigs in the LPS challenge responded with characteristic sickness behavior; however, pigs in the rough treatment showed less sickness behavior than those in the other 2 treatments (P < 0.05). Maternal stress treatment did not affect (P < 0.43) salivary cortisol. Pigs from all treatments responded similarly to mixing stress with regard to cortisol, porcine corticosteroid-binding globulin, antibody titers, nitric oxide production, and hematology measures, and all pigs experienced the same amount of aggression in response to mixing. Without altering peripheral measures of stress responsivity, prenatal stress enhanced the ability of pigs to cope with a simulated immune challenge, which could prove to be an adaptation to challenging environments.  相似文献   

Nitrous oxide by itself is insufficient to relieve pain due to castration in piglets     

Rault JL  Lay DC 《Journal of animal science》2011,89(10):3318-3325

Surgical castration is performed on most male piglets in the United States. However, castration is painful and analgesics have been considered to relieve pain. Inhalant gases with analgesic properties allow for a fast induction, have short-term and reversible effects, and are a needle-free option. Nitrous oxide (N(2)O; "laughing gas") has been widely used in human surgery and dental offices as an analgesic, sedative, and anxiolytic drug, yet N(2)O has not been thoroughly investigated for use in farm animals. We hypothesized that the analgesic effect of N(2)O could reduce the pain experienced by piglets during or immediately after castration. Twenty-four male piglets, from 12 litters, were castrated at 3 d of age. One piglet received N(2)O and a littermate received air as a control. After 150 s of exposure to the gas, castration was performed while the piglet remained exposed to the gas. Agitation scores and total vocalization length were recorded during castration. Behavioral observations were continued for 3 d postcastration by using a 5-min scan-sampling method for 4 h the first morning and for 2-h periods in the morning and afternoon of each day thereafter. Body weight gain was measured on the day before castration, at 3 d postcastration, and at weaning. Data were analyzed using a mixed model in SAS (Cary, NC). Nitrous oxide successfully induced anesthesia in all N(2)O piglets, as validated by a skin pinch test and the loss of the palpebral reflex. Total vocalization length was shorter in piglets receiving N(2)O during the induction phase (P = 0.003) but was not different during castration itself because piglets receiving N(2)O awoke and vocalized as much as control piglets (P = 0.87). Agitation scores during the whole procedure were reduced in piglets receiving N(2)O in both frequency (P = 0.005) and intensity (P = 0.026). For 2 h after castration, piglets receiving N(2)O displayed less huddling behavior than did control piglets (P = 0.01). Over the 3 d, piglets receiving N(2)O performed more tail wagging (P = 0.02) and tended to show fewer sleep spasms (P = 0.06) than did control piglets. Piglets given N(2)O tended to have a reduced growth rate compared with control piglets at 3 d postcastration and at weaning (P = 0.05 and P = 0.06, respectively). Nitrous oxide was effective in inducing anesthesia in neonatal piglets during handling. Nonetheless, its analgesic effects appeared insufficient in preventing castration-induced pain.  相似文献   

Induction, collection, and partial characterization of induced respiratory macrophages of the turkey   总被引：1，自引：0，他引：1  

M D Ficken  J F Edwards  J C Lay 《Avian diseases》1986,30(4):766-771

Respiratory macrophages (RM) of the turkey were elicited with a 1:4 (v/v) suspension of incomplete Freund's adjuvant in sterile phosphate-buffered saline injected directly into the abdominal air sacs. RM were purified by passage through a Ficoll-Hypaque gradient resulting in 95.7 +/- 5.9% purity and 94.8 +/- 12.3% viability. On days 7 and 9 postinjection, adequate numbers (7.15 +/- 5.47 X 10(6) macrophages per turkey) of RM for in vitro experiments were obtained. RM of the turkey demonstrated the ability to adhere to glass, phagocytize Zymosan A, and kill Escherichia coli in vitro.  相似文献   

Biochemical response of inbred and hybrid corn (Zea mays L.) to R-25788 and its distribution with EPTC in corn seedlings     

Ming-muh Lay  Ann M. Niland 《Pesticide biochemistry and physiology》1985,23(1):131-140

The average endogenous GSH content of eight lines of inbred corn was almost twofold greater than ten varieties of hybrid corn. When inbred and hybrid corn lines were treated with R-25788, the average GSH content increased by 56 and 95%, respectively. R-25788 protected two special inbred corn lines, GT 112 (atrazine susceptible) and GT 112 RfRf (atrazine resistant) from EPTC injury by increasing the GSH content and GSH S-transferase activity in roots. Most of the radiolabel from [¹⁴C]R-25788-treated plants remained in the root tissues whereas the radiolabel in [¹⁴C]EPTC-treated plants was evenly distributed between foliar and root tissues. From radiolabel experiments, hybrid corn seedlings were found to absorb more R-25788 from soil than EPTC. There was no difference between inbred and hybrid corn in the amounts of R-25788 or EPTC taken up or in the enhancement of GSH S-transferase activity caused by R-25788.  相似文献   

A comparative physiological and behavioral study of freeze and hot-iron branding using dairy cows.     

D C Lay  T H Friend  C L Bowers  K K Grissom  O C Jenkins 《Journal of animal science》1992,70(4):1121-1125

A public debate has recently arisen, largely surrounding the issue of pain, over whether freeze or hot-iron branding should be the preferred method of permanently identifying cattle. This study addressed that question by quantifying the following accepted measures of distress and pain over a 25-min sampling period: elevated heart rate, concentrations of cortisol, epinephrine, and norepinephrine, and escape-avoidance reactions and vocalizations. Twenty-four dairy cows (15 Holsteins and 9 Jerseys) were assigned to one of three treatments: freeze-branded (F), hot-iron-branded (H), or sham-branded (S), in which a room-temperature brander was applied. Plasma epinephrine and norepinephrine concentrations showed no discernible trends. Plasma cortisol concentrations were elevated in the F and H cows from 5.5 min to 25.5 min postbranding (P = .04). Heart rate, analyzed as a proportion of the prebranding mean, showed that H cows had a greater, more acute, response than did F cows (P = .04), which exhibited a more prolonged response (P = .07). No cows vocalized during branding; however, H cows had a greater escape-avoidance reaction toward branding than did the F and S cows. Both methods of branding produced elevated heart rates and cortisol concentrations indicative of pain sensations. Because the cows exhibited a greater escape-avoidance reaction and heart rate proportions to hot-iron branding, freeze banding would be preferable to hot-iron branding when feasible.  相似文献   

Replacing dietary antibiotics with 0.20% l-glutamine in swine nursery diets: impact on intestinal physiology and the microbiome following weaning and transport     

Alan W Duttlinger  Ruth E Centeno Martinez  Betty R McConn  Kouassi R Kpodo  Donald C Lay  Jr  Brian T Richert  Timothy A Johnson  Jay S Johnson 《Journal of animal science》2021,99(6)

Previous research demonstrates that supplementing 0.20% l-glutamine (GLN) in the diets of newly weaned and transported pigs improves growth rate to a similar extent as providing dietary antibiotics (AB). However, research comparing the effects of GLN vs. AB on intestinal physiology and the microbiome is limited. Therefore, the study objective was to compare the effects of supplementing nursery diets with GLN, AB, or no dietary antibiotics (NA) on intestinal physiology and the microbiome of pigs in a production environment following weaning and transport. Mixed-sex piglets (N = 480; 5.62 ± 0.06 kg body weight [BW]) were weaned (18.4 ± 0.2 d of age) and transported for 12 h in central Indiana, for two replicates, during the summer of 2016 and the spring of 2017. Pens were blocked by BW and allotted to one of the three dietary treatments (n = 10 pens/dietary treatment/replicate [8 pigs/pen]): AB (chlortetracycline [441 ppm] + tiamulin [38.6 ppm]), GLN (0.20% as-fed), or NA fed for 14 d. From day 14 to 34, pigs were fed common AB-free diets in two phases. On day 33, villus height:crypt depth tended to be increased (P = 0.07; 7.0%) in GLN and AB pigs vs. NA pigs. On day 33, glucagon-like peptide 2 (GLP-2) mRNA abundance was decreased (P = 0.01; 50.3%) in GLN and NA pigs vs. AB pigs. Crypt depth was increased overall on day 33 (P = 0.01; 16.2%) during the spring replicate compared with the summer replicate. Villus height:crypt depth was reduced (P = 0.01; 9.6%) during the spring replicate compared with the summer replicate on day 33. On day 13, tumor necrosis factor-alpha and occludin mRNA abundance was increased (P ≤ 0.04; 45.9% and 106.5%, respectively) and zonula occludens-1 mRNA abundance tended to be greater (P = 0.10; 19.2%) in the spring replicate compared with the summer replicate. In addition, AB pigs had increased (P = 0.01; 101.3%) GLP-2 mRNA abundance compared with GLN and NA pigs. Microbiome analysis indicated that on day 13, dietary treatment altered the microbiota community structure (P = 0.03). Specifically, the AB pigs tended to be distinct from both the NA and GLN pigs (P = 0.08), and Lactobacillus was increased nearly 2-fold in AB compared with NA pigs (q = 0.04) and GLN pigs (q = 0.22). In conclusion, GLN supplementation tended to improve some morphological markers of intestinal health similarly to AB pigs, while the microbiome composition in GLN pigs was more similar to NA pigs than AB pigs.  相似文献   

Postnatal piglet husbandry practices and well-being: the effects of alternative techniques delivered separately     

Marchant-Forde JN  Lay DC  McMunn KA  Cheng HW  Pajor EA  Marchant-Forde RM 《Journal of animal science》2009,87(4):1479-1492

The aim of this study was to evaluate stress responses evoked by 2 alternative methods for performing the following processing procedures: 1) teeth resection-clipping vs. grinding; 2) tail docking-cold vs. hot clipping; 3) identification-ear notch vs. tag; 4) iron administration-injection vs. oral; 5) castration-cords cut vs. torn. Eight to 10 litters of 8-, 2-, and 3-d-old piglets were assigned to each procedure. Within each litter, 2 piglets were assigned to 1 of 4 possible procedures: the 2 alternative methods, a sham procedure, and a sham procedure plus blood sampling. Blood was sampled before processing and at 45 min, 4 h, 48 h, 1 wk, and 2 wk postprocedure and assayed for cortisol and beta-endorphin. Procedures were videotaped and analyzed to evaluate the time taken to perform the procedure and the number of squeals, grunts, and escape attempts. Vocalizations were analyzed to determine mean and peak frequencies and duration. Piglets were weighed before the procedure and at 24 h, 48 h, 1 wk, and 2 wk afterward. Lesions were scored on a scale of 0 to 5 on pigs in the identification, tail docking, and castration treatments at 24 h, 1 wk, and 2 wk postprocedure. For teeth resection, grinding took longer than clipping and resulted in greater cortisol concentration overall, poorer growth rates, and longer vocalizations compared with pigs in the control treatment (P<0.05). For tail docking, hot clipping took longer, and hot-clipped piglets grew slower than cold-clipped piglets (P<0.05). Hot clipping also resulted in longer and higher frequency squealing compared with pigs in the control treatment (P<0.01). For identification, ear notching took longer than tagging, and ear-notched piglets had worse wound scores than tagged piglets (P<0.05). Cortisol concentrations at 4 h also tended to be greater for ear-notched piglets (P<0.10). Ear notching evoked calls with higher peak frequencies than the control treatments. For iron administration, oral delivery took numerically longer than injecting, but there were no significant differences between injecting and oral delivery for any of the measures. For castration, tearing took longer than cutting the cords (P<0.05), but beta-endorphin concentrations at 45 min postprocedure were greater for cut piglets. When measures of behavior, physiology, and productivity were used, the responses to teeth resection, tail docking, and identification were shown to be altered by the procedural method, whereas responses to iron administration and castration did not differ. The time taken to carry out the procedure would appear to be an important factor in the strength of the stress response.  相似文献   

THE SUCCESSIVE STIMULATION OF THE ARC LINES OF HELIUM BELOW THE IONIZATION POTENTIAL     

Bazzoni CB  Lay JT 《Science (New York, N.Y.)》1925,61(1585):518

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