Local Control of Microdomain Orientation in Diblock Copolymer Thin Films with Electric Fields     

TL Morkved  M Lu  AM Urbas  EE Ehrichs  HM Jaeger  P Mansky  TP Russell 《Science (New York, N.Y.)》1996,273(5277):931-933

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   

Amplification of acidic protease virulence gene (aprV2) in samples from footrot lesions did not help in diagnosis of clinical virulent footrot in affected sheep flocks in New South Wales     

AM Collins  BG Bowring 《Australian veterinary journal》2020,98(7):298-304

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Last occurrence and survival during winter of the arbovirus vector Culicoides brevitarsis at the southern limits of its distribution     

AL BISHOP  IM BARCHIA  AM HARRIS 《Australian veterinary journal》1995,72(2):53-55

SUMMARY: Linear regression analysis was used to describe the decline in numbers of Culicoides brevitarsis Kieffer into winter with monthly maximum, average and minimum temperatures at the southern limits to its distribution in New South Wales. From this, low temperature thresholds were derived when C brevitarsis would be absent from the field. The low minimum threshold ± 2 SE (95% Confidence Interval) of 8.1 ± 0.3°C was used with historical temperature data to estimate the last month that the species should occur (March to June) and the mean number of months (2 to 6.5) below the threshold at 17 selected sites. Probability for survival during winter at these sites was estimated from years when the number of consecutive months below the threshold was ≤ 2 months. This varied from zero to 51% depending on the location of the site. Last occurrence was 0.7 months later on average and absolute probabilities for survival ranged from zero to 100% when the temperatures were increased by an arbitrary 2°C.  相似文献   

Use of magnetic particles to improve the diagnosis of sheep-associated malignant catarrhal fever by polymerase chain reaction     

TM ELLIS  AM MASTERS 《Australian veterinary journal》1997,75(7):520-521

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Isolation of Nocardia mexicana from focal proliferative tenosynovitis and arthritis in a steer          下载免费PDF全文

H Owen  K Buckle  J Olm  M Leitner  S Pandey  JB Gaughan  ML Sullivan  AM Lees  JS Gibson 《Australian veterinary journal》2015,93(5):170-173

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Fermented liquid feed for pigs: an ancient technique for the future     

Joris AM Missotten  Joris Michiels  Jeroen Degroote  Stefaan De Smet 《畜牧与生物技术杂志(英文版)》2015,6(1)

Fermented liquid feed is feed that has been mixed with water at a ratio ranging from 1:1.5 to 1:4. By mixing with water, lactic acid bacteria and yeasts naturally occurring in the feed proliferate and produce lactic acid, acetic acid and ethanol which reduces the pH of the mixture. This reduction in pH inhibits pathogenic organisms from developing in the feed. In addition, when this low pH mixture is fed, it reduces the pH in the stomach of pigs and prevents the proliferation of pathogens such as coliforms and Salmonella in the gastrointestinal tract. For piglets, the use of fermented liquid feed offers the possibility of simultaneously providing feed and water, which may facilitate an easier transition from sow’s milk to solid feed. Secondly, offering properly produced fermented liquid feed may strengthen the role of the stomach as the first line of defense against possible pathogenic infections by lowering the pH in the gastrointestinal tract thereby helping to exclude enteropathogens. Finally, feeding fermented liquid feed to pigs has been shown to improve the performance of suckling pigs, weaner pigs and growing-finishing pigs. In this review, current knowledge about the use of fermented liquid feed in pig diets will be discussed. This will include a discussion of the desirable properties of fermented liquid feed and factors affecting fermentation. In addition, advantages and disadvantages of fermented liquid feed will be discussed including its effects on gastrointestinal health, intestinal pH and the types of bacteria found in the gastrointestinal tract as well as the effects of fermented liquid feeds on pig performance.  相似文献   

Planet Within a Planet: Rotation of the Inner Core of Earth     

W Su  AM Dziewonski  R Jeanloz 《Science (New York, N.Y.)》1996,274(5294):1883-1887

The time dependence of the orientation of Earth's inner core relative to the mantle was determined using a recently discovered 10-degree tilt in the axis of symmetry of the inner core's seismic-velocity anisotropy. Two methods of analyzing travel-time variations for rays traversing the inner core, on the basis of 29 years of data from the International Seismological Centre (1964-1992), reveal that the inner core appears to rotate about 3 degrees per year faster than the mantle. An anomalous variation in inner-core orientation from 1969 to 1973 coincides in time with a sudden change ("jerk") in the geomagnetic field.  相似文献   

Toll‐like receptor and related cytokine mRNA expression in bovine corpora lutea during the oestrous cycle and pregnancy          下载免费PDF全文

JE Gadsby  AM Tyson Nipper  HA Faircloth  M D'Annibale‐Tolhurst  J Chang  PW Farin  IM Sheldon  DH Poole 《Reproduction in domestic animals》2017,52(3):495-504

Improving our understanding of the mechanisms controlling the corpus luteum (CL) and its role in regulating the reproductive cycle should lead to improvements in the sustainability of today's global animal industry. The corpus luteum (CL) is a transient endocrine organ composed of a heterogeneous mixture steroidogenic, endothelial and immune cells, and it is becoming clear that immune mechanisms play a key role in CL regulation especially in luteolysis. Toll‐like receptors (TLR) mediate innate immune mechanisms via the production of pro‐inflammatory cytokines, especially within various tissues, although the role of TLR within CL remains unknown. Thus, the objectives of this study were to characterize TLR mRNA expression in the CL during the oestrous cycle and in pregnancy (day 30–50), and to examine the role of TLR signalling in luteal cells. Corpora lutea were collected at various stages of the cycle and pregnancy and analysed for TLR and cytokine mRNA expression. In addition, luteal cells were cultured with the TLR4 ligand (lipopolysaccharide, LPS) for 24 h to evaluate the role of TLR4 in regulating luteal function. Toll‐like receptors 1, 2, 4, 6, tumour necrosis factor alpha (TNF), interferon gamma (IFN‐G), and interleukin (IL)‐12, mRNA expressions were greatest in regressing CL compared with earlier stages (p < .05), whereas no change was observed for IL‐6 mRNA expression. Cytokine mRNA expression in cultured luteal cells was not altered by LPS. Based on these data, one or more of the TLRs found within the CL may play a role in luteolysis, perhaps via pro‐inflammatory cytokine mRNA expression.  相似文献   

Solution properties of single-walled carbon nanotubes   总被引：3，自引：0，他引：3  

J Chen  MA Hamon  H Hu  Y Chen  AM Rao  PC Eklund  RC Haddon 《Science (New York, N.Y.)》1998,282(5386):95-98

Naked metallic and semiconducting single-walled carbon nanotubes (SWNTs) were dissolved in organic solutions by derivatization with thionychloride and octadecylamine. Both ionic (charge transfer) and covalent solution-phase chemistry with concomitant modulation of the SWNT band structure were demonstrated. Solution-phase near-infrared spectroscopy was used to study the effects of chemical modifications on the band gaps of the SWNTs. Reaction of soluble SWNTs with dichlorocarbene led to functionalization of the nanotube walls.  相似文献   

Design of a surface alloy catalyst for steam reforming   总被引：1，自引：0，他引：1  

F Besenbacher  I Chorkendorff  BS Clausen  B Hammer  AM Molenbroek  JK Norskov  I Stensgaard 《Science (New York, N.Y.)》1998,279(5358):1913-1915

Detailed studies of elementary chemical processes on well-characterized single crystal surfaces have contributed substantially to the understanding of heterogeneous catalysis. Insight into the structure of surface alloys combined with an understanding of the relation between the surface composition and reactivity is shown to lead directly to new ideas for catalyst design. The feasibility of such an approach is illustrated by the synthesis, characterization, and tests of a high-surface area gold-nickel catalyst for steam reforming.  相似文献