Creep-resistant, Al2O3-forming austenitic stainless steels   总被引：1，自引：0，他引：1  

Yamamoto Y  Brady MP  Lu ZP  Maziasz PJ  Liu CT  Pint BA  More KL  Meyer HM  Payzant EA 《Science (New York, N.Y.)》2007,316(5823):433-436

A family of inexpensive, Al2O3-forming, high-creep strength austenitic stainless steels has been developed. The alloys are based on Fe-20Ni-14Cr-2.5Al weight percent, with strengthening achieved through nanodispersions of NbC. These alloys offer the potential to substantially increase the operating temperatures of structural components and can be used under the aggressive oxidizing conditions encountered in energy-conversion systems. Protective Al2O3 scale formation was achieved with smaller amounts of aluminum in austenitic alloys than previously used, provided that the titanium and vanadium alloying additions frequently used for strengthening were eliminated. The smaller amounts of aluminum permitted stabilization of the austenitic matrix structure and made it possible to obtain excellent creep resistance. Creep-rupture lifetime exceeding 2000 hours at 750 degrees C and 100 megapascals in air, and resistance to oxidation in air with 10% water vapor at 650 degrees and 800 degrees C, were demonstrated.  相似文献   

Practices of place‐making: Globalisation and locality in the Philippines     

Deirdre McKay  Carol Brady 《Asia Pacific viewpoint》2005,46(2):89-103

Abstract: Global flows of people and information in the Asia–Pacific region are creating new forms of place that stretch across national boundaries and rural–urban distinctions. These new mobile forms of place link long‐inhabited rural areas to cities, national centres, and to rural frontiers within the nation. Here, we describe new forms of place that are being produced by contemporary migration and economic change, using data from the Philippines and applying Appadurai's theorisation of translocality. Our analysis links these flows of overseas migrants to concomitant processes of economic change, migration and new rural livelihoods. We outline changing practices of place within the Philippines, exploring ways that transnational migration can articulate with apparently ‘local’ development and the flow‐on effects from migration on the spatial patterns of rural livelihoods.  相似文献   

DNA typing of hops (Humulus lupulus) through application of RAPD and microsatellite marker sequences converted to sequence tagged sites (STS)     

Jamie L. Brady  Nigel S. Scott  Mark R. Thomas 《Euphytica》1996,91(3):277-284

Summary Both random amplified polymorphic DNA and microsatellite repeat sequences were investigated as DNA markers for distinguishing hop cultivars. Microsatellite sequences converted to STS markers proved to be most successful. The relative abundance of microsatellite repeat sequences in the hop genome varied depending on the sequence class. Of the repeat types investigated the dinucleotide repeats (GA)_n and (GT)_n are the most highly represented in the hop genome. Microsatellite repeat sequences in hops have been shown to be highly polymorphic and are very informatives as STS molecular markers. A DNA typing system using sequence-tagged microsatellite site markers has been developed which will not only be useful for hop cultivar identification but also marker assisted breeding and quality control purposes.  相似文献   

Effect of Three pFSH Doses on Superovulation and Embryo Quality in Goats During Two Breeding Seasons in North‐eastern Mexico     

F Sánchez‐Dávila  RA Ledezma‐Torres  G Padilla‐Rivas  AS del Bosque‐González  A González Gómez  H Bernal‐Barragán 《Reproduction in domestic animals》2014,49(4):e40-e43

The aim of this research was to evaluate the effectiveness of three pFSH doses (80 mg; 145 mg and 215 mg) on ovarian response and on quantity and quality of transferable embryos of goats during the breeding and the non‐breeding seasons. Ovary structures were exposed (laparatomy under general anaesthesia) and numbers of follicles and corpora lutea were registered. Surgical embryo flushing was conducted to count and classify embryos. There were more follicles (3.4 ± 1.1) in does administered 80 mg of pFSH (p < 0.05) than in goats administered 145 mg of pFSH (2.2 ± 1.1) and 215 mg of pFSH (0.9 ± 0.6). Numbers of corpora lutea, blastocysts, and recovered and transferable embryos of goats administered 145 mg pFSH (13.4 ± 3.7, 2.42 ± 1.0, 3.4 ± 1.2 and 3.2 ± 1.1, respectively) and those of goats administered 215 mg pFSH (11.6 ± 2.6, 3.2 ± 0.9, 5.7 ± 1.5, and 5.6 ± 1.5) were greater (p < 0.05) than values obtained from goats administered 80 mg pFSH (4.0 ± 1.5, 0.5 ± 0.3, 1.0 ± 0.5, and 0.8 ± 0.5). Numbers of morula of does administered 80 and 145 mg pFSH (0.4 ± 0.4 and 0.8 ± 0.3) were lower (p < 0.05) than those obtained from animals treated with 215 mg pFSH (2.4 ± 0.9). There was no effect of season upon the analyzed variables. In conclusion, under the prevalent conditions in north‐eastern Mexico, administration of 145 or 215 mg pFSH in a decreasing dose schedule over 3.5 days to bred goats provided a satisfactory superovulatory result.  相似文献   

Inhibition of Angiotensin‐Converting Enzyme Increases Oestradiol Production in Ewes Submitted to Oestrous Synchronization Protocol     

AS Costa  AS Junior  GEN Viana  MCS Muratori  AM Reis  APR Costa 《Reproduction in domestic animals》2014,49(5):E53-E55

This study aimed at evaluating the effects of angiotensin‐converting enzyme inhibitor (enalapril) and angiotensin II antagonist (valsartan) on the oestradiol and progesterone production in ewes submitted to oestrous synchronization protocol. The animals were weighed and randomly divided into three groups (n = 7). A pre‐experiment conducted to verify the effectiveness and toxicity of enalapril (0.5 mg/kg LW) and valsartan (2.2 mg/kg LW) showed that, in the doses used, these drugs were effective in reducing blood pressure without producing toxic effects. In the experiment, all animals were subjected to oestrous synchronization protocol during 12 days. On D10, D11 and D12, animals received saline, enalapril or valsartan (same doses of the pre‐experiment), according to the group randomly divided. The hormonal analysis showed an increase in oestradiol on the last day of the protocol (D12) in animals that received enalapril (p < 0.05), but not in other groups, without changing the concentration of progesterone in any of the treatments. It is concluded that valsartan and enalapril are safe and effective subcutaneously for use in sheep and that the angiotensin‐converting enzyme (ACE) inhibition with enalapril leads to an increase in oestradiol production near ovulation without changing the concentration of progesterone. This shows that ACE inhibition may be a useful tool in reproductive biotechnologies involving induction and synchronization of oestrus and ovulation in sheep.  相似文献   

Effects of continuously infusing glucose or casein into the terminal ileum on biomarkers of metabolism,inflammation, and intestinal morphology in growing pigs     

Edith J Mayorga  Erin A Horst  Mohmmad Al-Qaisi  Brady M Goetz  Megan A Abeyta  Sonia Rodríguez-Jimnez  Samantha Lei  Jesus A Acosta  John F Patience  Mariana C Rossoni Serao  Lance H Baumgard 《Journal of animal science》2021,99(7)

Study objectives were to determine the effects of continuously infusing glucose (GLC) or casein (CAS) into the terminal ileum on biomarkers of metabolism, inflammation, and intestinal morphology in growing pigs. Crossbred gilts (n = 19; 81 ± 3 kg body weight [BW]) previously fitted with T-cannulas at terminal ileum were used in the current experiment. Following 4 d of acclimation, pigs were enrolled in 2 experimental 4-d periods (P). During P1, pigs were housed in individual pens and fed ad libitum for collection of baseline parameters. At the beginning of P2, pigs were assigned to 1 of 3 infusion treatments: 1) control (CON; water; 3 liters/d; n = 7), 2) GLC (dextrose 50%; 500 g/d; n = 6;), or 3) CAS (casein sodium salt; 300 g/d; n = 6). Water, GLC, and CAS solutions were continuously infused at a rate of 125 mL/h for the entirety of P2. Animals were euthanized at the end of P2, and intestinal tissue was collected. During P2, average daily feed intake differed across treatments and was reduced in GLC compared with CON pigs (14%), while CAS pigs consumed an intermediate amount (P = 0.05). Average daily gain and final BW were similar across treatments. A treatment by time interaction was observed for blood urea nitrogen (BUN; P < 0.01), as it decreased in GLC (21%) while it gradually increased in CAS (76%) pigs relative to CON pigs. Mild hyperthermia occurred with both GLC and CAS infusions relative to CON (+0.3 and 0.2 °C, respectively; P < 0.01). Blood neutrophils increased in CAS relative to CON pigs (26%) but remained similar between CON and GLC treatments (P < 0.01). Blood monocytes decreased in GLC relative to CON pigs (24%) while CAS pigs had an intermediate value (P = 0.03). Circulating lipopolysaccharide binding protein tended to decrease in GLC (29%) relative to CON pigs but remained similar between CON and CAS pigs (P = 0.10). Plasma tumor necrosis factor-alpha was similar across treatments. Ileum villus height:crypt depth was increased in CAS compared with CON pigs (33%; P = 0.05) while GLC pigs had an intermediate value. Colon myeloperoxidase-stained area increased in CAS compared with CON pigs (45%; P = 0.03) but remained similar between GLC and CON pigs. In summary, continuously infusing GLC or CAS into the terminal ileum appeared to stimulate a mild immune response and differently altered BUN patterns but had little or no effects on blood inflammatory markers, intestinal morphology, or key production parameters.  相似文献   

Evaluating the use of plasma hematocrit samples to detect ketones utilizing urine dipstick colorimetric methodology in diabetic dogs and cats     

Mark A. Brady  Jeffrey S. Dennis  Colette Wagner‐Mann 《Journal of Veterinary Emergency and Critical Care》2003,13(1):1-6

Objective: To determine whether plasma from a heparinized hematocrit tube placed on a urine dipstick would accurately reflect (positive or negative) urine ketone results in diabetic dogs and cats. Design: Prospective study, 37 dogs and 43 cats, with a known history of diabetes or hyperglycemia, glucosuria, and symptoms of undiagnosed diabetes mellitus were tested. Setting: Veterinary Referral Hospital. Animals: Client owned dogs and cats. Interventions: None. Measurement and main results: Heparinized plasma and urine ketone results were recorded using urine reagent strips. Plasma dipstick results were compared to urine dipstick results as the standard. Results were recorded based on the color chart provided by the manufacturer. Two individuals were responsible for verifying the results of the colorimetric test. Test efficiency was 97% (sensitivity = 96%, specificity = 100%) for the canine population, 93% (sensitivity = 100%, specificity = 83%) for the feline population, and 95% (sensitivity = 98%, specificity = 91%) for the total population. Four of 80 animals were found to have discordant results (1 dog and 3 cats). Conclusion: Plasma from heparinized hematocrit tubes is clinically useful for detecting the presence or absence of ketonuria, and therefore ketosis, in diabetic dogs and cats using urine dipstick colorimetric methodology.  相似文献   

Rapamycin administration during an acute heat stress challenge in growing pigs     

Edith J Mayorga  Erin A Horst  Brady M Goetz  Sonia Rodríguez-Jimnez  Megan A Abeyta  Mohmmad Al-Qaisi  Samantha Lei  Robert P Rhoads  Joshua T Selsby  Lance H Baumgard 《Journal of animal science》2021,99(5)

Study objectives were to determine the effects of rapamycin (Rapa) on biomarkers of metabolism and inflammation during acute heat stress (HS) in growing pigs. Crossbred barrows (n = 32; 63.5 ± 7.2 kg body weight [BW]) were blocked by initial BW and randomly assigned to 1 of 4 environmental-therapeutic treatments: 1) thermoneutral (TN) control (n = 8; TNCon), 2) TN and Rapa (n = 8; TNRapa), 3) HS control (n = 8; HSCon), or 4) HS and Rapa (n = 8; HSRapa). Following 6 d of acclimation to individual pens, pigs were enrolled in two experimental periods (P). During P1 (10 d), pigs were fed ad libitum and housed in TN conditions (21.3 ± 0.2°C). During P2 (24 h), HSCon and HSRapa pigs were exposed to constant HS (35.5 ± 0.4°C), while TNCon and TNRapa pigs remained in TN conditions. Rapamycin (0.15 mg/kg BW) was orally administered twice daily (0700 and 1800 hours) during both P1 and P2. HS increased rectal temperature and respiration rate compared to TN treatments (1.3°C and 87 breaths/min, respectively; P < 0.01). Feed intake (FI) markedly decreased in HS relative to TN treatments (64%; P < 0.01). Additionally, pigs exposed to HS lost BW (4 kg; P < 0.01), while TN pigs gained BW (0.7 kg; P < 0.01). Despite marked changes in phenotypic parameters caused by HS, circulating glucose and blood urea nitrogen did not differ among treatments (P > 0.10). However, the insulin:FI increased in HS relative to TN treatments (P = 0.04). Plasma nonesterified fatty acids (NEFA) increased in HS relative to TN treatments; although this difference was driven by increased NEFA in HSCon compared to TN and HSRapa pigs (P < 0.01). Overall, circulating white blood cells, lymphocytes, and monocytes decreased in HS compared to TN pigs (19%, 23%, and 33%, respectively; P ≤ 0.05). However, circulating neutrophils were similar across treatments (P > 0.31). The neutrophil-to-lymphocyte ratio (NLR) was increased in HS relative to TN pigs (P = 0.02); however, a tendency for reduced NLR was observed in HSRapa compared to HSCon pigs (21%; P = 0.06). Plasma C-reactive protein tended to differ across treatments (P = 0.06) and was increased in HSRapa relative to HSCon pigs (46%; P = 0.03). Circulating haptoglobin was similar between groups. In summary, pigs exposed to HS had altered phenotypic, metabolic, and leukocyte responses; however, Rapa administration had limited impact on outcomes measured herein.  相似文献   

Factors influencing optimization of diffusion assays for antibiotics     

M S Brady  S E Katz 《Journal of the Association of Official Analytical Chemists》1990,73(2):202-205

Agar nutrient content, cylinder charge volume, thickness (volume) of the agar layer, and incubation temperature were 4 factors varied to determine their effect(s) on the optimization of the cylinder-plate diffusion assay. Chlortetracycline was the pilot antibiotic and Bacillus cereus was used as the assay organism. Zones of inhibition were larger when the incubation temperature was lower than that which was commonly used and/or when the nutrient level was decreased; the zones were smaller when the incubation temperature was raised and/or when an increased nutrient level was used. The thickness (volume) of the assay layer played the most important role; the thinner the layer the less the effect the cylinder charge volume had on the zone diameter. The slopes of the response lines were minimally affected by cylinder charge volume. For a 7 mL assay layer per standard Petri plate, cylinder charge volumes ranging from 150 to 250 microL had little effect on zone diameter. The linearity of the response line was unaffected by assay layer thickness (volume), nutrient level, temperature of incubation, or cylinder charge volume. As long as the conditions for the assay were standardized, there were no discernible effects on recoveries or potencies.  相似文献   

Simplified plate diffusion system for microbial assays of antibiotics   总被引：1，自引：0，他引：1  

M S Brady  S E Katz 《Journal of the Association of Official Analytical Chemists》1987,70(4):641-646

A protocol for microbial assays of antibiotics, using the plate diffusion system, is presented. The system is based on the concept that a complete standard curve and assay unknowns can be placed on an assay plate and that 2 plates can be a complete assay with an accuracy and precision essentially equivalent to the official AOAC diffusion procedure. Four antibiotics, bacitracin, chlortetracycline, oxytetracycline, and streptomycin, were used in the design and comparison studies with the AOAC protocol. The coefficients of variation (CVs) for the AOAC design, using 10 replicates, ranged from 1.4 to 10.3% with a mean of 4.5%. The CVs for the single-plate option of the simplified design ranged from 4.3 to 9.6% with a mean of 6.6%; the CVs for the 2-plate option ranged from 2.5 to 6.8% with a mean of 4.3%; the CVs for the 3-plate option ranged from 1.2 to 5.0% with a mean of 3.0%.  相似文献