Characterization of the antibody isotype response in serum and milk of heifers vaccinated with a Staphylococcus aureus bacterin (Lysigin)

The objective was to characterize the antibody isotype responses to vaccination with a commercial Staphylococcus aureus bacterin in dairy heifers. Twenty-five Holstein-Friesian dairy heifers were assigned at random to one of two groups, vaccinates (n=14) or controls (n=11). Vaccinates received two 5-ml doses of Lysigin 28 d apart in late gestation. Both groups were challenged with a heterologous serotype 5 strain of Staph. aureus by aseptic intramammary infusion on days 6, 7 and 8 of lactation. Samples for serum antibody isotype (IgG, IgG1, IgG2 and IgM) determinations were taken before each vaccination, immediately prior to challenge (6 d post-calving) and at the end of the study (28 d post-calving). Samples for milk antibody isotype determinations were taken immediately prior to challenge and at the end of the study. Antibody isotype sample-to-positive ratios (S:P ratio=(mean test sample OD-mean within-plate negative control OD)/(mean within-plate positive control OD-mean within-plate negative control OD)) were determined in milk and serum using a series of ELISAs coated with different strains of Staph. aureus belonging to capsular polysaccharide (CP) serotype 5 or 8 or surface polysaccharide (SP) serotype 336. Vaccinates had higher mean serum IgG1 and IgG2 S:P ratios than controls against all three strains of Staph. aureus (P < or = 0.023). Vaccinates had higher mean milk IgG S:P ratios than controls against CP8 and SP336 strains of Staph. aureus (P< or = 0.030). Hence, a humoural immune response to the vaccine was detected in serum and milk, but responses varied according to strain and antibody isotype tested.     

Bead-based DNA diagnostic assay for chlamydia using nanoparticle-mediated surface-enhanced resonance Raman scattering detection within a lab-on-a-chip format

There is a continued interest in the development of new on-chip protocols for the determination of the causes of infectious disease. In this paper, we demonstrate the use of surface-enhanced resonance Raman scattering (SERRS) for detecting the clinically relevant nucleic acid sequences of Chlamydia trachomatis in a bead-based lab-on-a-chip format, incorporating a solid-phase sample clean-up on-chip. The assay uses streptavidinated polymer microspheres to capture a biotinylated PCR product of the oligonucleotide sequence, which was subsequently hybridized against a complementary rhodamine-labeled, Raman active probe. Central to the assay is an in-channel integrated microfilter, which was used to retain the microspheres, enabling the bound target to be separated from the rest of the sample as part of a solid-phase clean-up (thereby removing any contributions from the background). After washing, the bound Rhodamine labeled detection probe was released thermally from the microspheres by heating and was subsequently mixed on-chip with a stream of silver nanoparticles. The signal was detected downstream using a Raman spectrometer to collect the SERRS response. The assay offers several advantages over traditional laboratory methods, including: the speed of the assay on-chip, the potential for sample clean-up; and the low volume of sample required.     

NMR spectroscopic studies on the in vitro acyl glucuronide migration kinetics of Ibuprofen ((+/-)-(R,S)-2-(4-isobutylphenyl) propanoic acid), its metabolites, and analogues

Carboxylic acid-containing drugs are often metabolized to 1-beta-O-acyl glucuronides (AGs). These can undergo an internal chemical rearrangement, and the resulting reactive positional isomers can bind to endogenous proteins, with clear potential for adverse effects. Additionally any 1-beta-O-acyl-glucuronidated phase I metabolite of the drug can also show this propensity, and investigation of the adverse effect potential of a drug also needs to consider such metabolites. Here the transacylation of the common drug ibuprofen and two of its metabolites is investigated in vitro. 1-beta-O-Acyl (S)-ibuprofen glucuronide was isolated from human urine and also synthesized by selective acylation. Urine was also used as a source of the (R)-ibuprofen, (S)-2-hydroxyibuprofen, and (S,S)-carboxyibuprofen AGs. The degradation rates (a combination of transacylation and hydrolysis) were measured using 1H NMR spectroscopy, and the measured decrease in the 1-beta anomer over time was used to derive half-lives for the glucuronides. The biosynthetic and chemically synthesized (S)-ibuprofen AGs had half-lives of 3.68 and 3.76 h, respectively. (R)-Ibuprofen AG had a half-life of 1.79 h, a value approximately half that of the (S)-diastereoisomer, consistent with results from other 2-aryl propionic acid drug AGs. The 2-hydroxyibuprofen and carboxyibuprofen AGs gave half-lives of 5.03 and 4.80 h, considerably longer than that of either of the parent drug glucuronides. In addition, two (S)-ibuprofen glucuronides were synthesized with the glucuronide carboxyl function esterified with either ethyl or allyl groups. The (S)-ibuprofen AG ethyl ester and (S)-ibuprofen AG allyl esters were determined to have half-lives of 7.24 and 9.35 h, respectively. In order to construct useful structure-reactivity relationships, it is necessary to evaluate transacylation and hydrolysis separately, and here it is shown that the (R)- and (S)-ibuprofen AGs have different transacylation properties. The implications of these findings are discussed in terms of structure-activity relationships.     

The ACE-MAESTRO instrument on SCISAT: description, performance, and preliminary results

The Measurement of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation (MAESTRO) instrument on the SCISAT satellite is a simple, compact spectrophotometer for the measurement of atmospheric extinction, ozone, nitrogen dioxide, and other trace gases in the stratosphere and upper troposphere as part of the Atmospheric Chemistry Experiment (ACE) mission. We provide an overview of the instrument from requirements to realization, including optical design, prelaunch and on-orbit performance, and a preliminary examination of retrievals of ozone and NO(2).     

Incorporation of cellulose nanocrystals and reactive surfactants for improved pressure-sensitive adhesive performance

Pressure-sensitive adhesives (PSAs), which achieve instantaneous adhesion with the application of light pressure, are used in a large range of commodity applications. In this work, PSAs enriched with cellulose nanocrystals (CNCs) and stabilized with a reactive surfactant (Hitenol AR-1025, AR) were synthesized via in situ emulsion polymerization. Incorporation of CNCs into AR-stabilized PSAs lead to improvements of peel strength, shear strength, and loop tack with significant increases observed at a CNC concentration of 0.75 parts per hundred monomer (phm). A comparative investigation of PSAs stabilized with reactive (AR) and non-reactive (sodium dodecyl sulfate) surfactant revealed that the enhanced performance can be attributed to the synergistic combination of CNCs and reactive surfactant, as only modest improvements can be attributed to surfactant type. In contrast to previous studies that report a trade-off in adhesive properties, we present a well-rounded PSA with exceptional peel strength, shear strength, and loop tack.     

采访彼德·埃森曼

采访主要包括5个方面话题：对建筑教育的态度和对在美国普林斯顿大学40年教学经历的终止的回顾；如何理解埃森曼的批判性写作、批判性阅读和批判性实践之间的关系，以及在不断发展中所呈现出的多样变化甚至矛盾关系；对建筑学的一些基本问题的认识，以及这些认识与当代语境之间的联系；作为一个重要的文化角色，埃氏本人如何理解他的同事和学生所提出的“后批判”和“投射理论”，以及他本人如何进行回应；关于中国的话题。     

Cobalt Nanoparticle Arrays made by Templated Solid‐State Dewetting

Self‐assembled cobalt particle arrays are formed by annealing, which cause agglomeration (dewetting) of thin Co films on oxidized silicon substrates that are topographically prepatterned with an array of 200‐nm‐period pits. The Co nanoparticle size and uniformity are related to the initial film thickness, annealing temperature, and template geometry. One particle per 200‐nm‐period pit is formed from a 15‐nm film annealed at 850 °C; on a smooth substrate, the same annealing process forms particles with an average interparticle distance of 200 nm. Laser annealing enables templated dewetting of 5‐nm‐thick films to give one particle per pit. Although the as‐deposited films exhibit a mixture of hexagonal close‐packed and face‐centered cubic (fcc) phases, the ordered cobalt particles are predominantly twinned fcc crystals with weak magnetic anisotropy. Templated dewetting is shown to provide a method for forming arrays of nanoparticles with well‐controlled sizes and positions.     

Is the United States losing ground in science? A global perspective on the world science system

Based on the Science Citation Index-Expanded web-version, the USA is still by far the strongest nation in terms of scientific performance. Its relative decline in percentage share of publications is largely due to the emergence of China and other Asian nations. In 2006, China has become the second largest nation in terms of the number of publications within this database. In terms of citations, the competitive advantage of the American “domestic market” is diminished, while the European Union (EU) is profiting more from the enlargement of the database over time than the USA. However, the USA is still outperforming all other countries in terms of highly cited papers and citation/publication ratios, and it is more successful than the EU in coordinating its research efforts in strategic priority areas like nanotechnology. In this field, the People’s Republic of China (PRC) has become second largest nation in both numbers of papers published and citations behind the USA.