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41.
The action of a psychotropic substance, N-ethyl-2(2-methoxy-5--sulfamido-benzamidomethyl)-pyrrolidine (sulpiride, Dobren), on cellular metabolism has been studied by means of the in vitro lymphocyte activation technique. The effect of the continuous presence of the compound in the culture, at a concentration permitting cellular vitality was evaluated. Furthermore the effect of the drug on the culture during the lymphocyte stimulating phase and during the incorporation phase of 3H-thymidine was separately evaluated. The results indicate that the sample population can be divided into two different groups depending on the modality of the response to the drug in vitro taken as activity index (A.I.). Whether our conclusion has any practical significance remains to be elucidated. 相似文献
42.
AJ Karter JM Gazzaniga RD Cohen ML Casper BD Davis GA Kaplan 《Canadian Metallurgical Quarterly》1998,169(3):139-145
Electrochemiluminescence (ECL) of 200 ppm 2,3-diaminonaphthalene (2,3-DAN) was studied alone and in conjunction with 100 ppm of 34 different metal and non-metal ions and revealed three relatively intense ECL responses from interactions of 2,3-DAN with Au+, Fe+3 and V+5. ECL responses from Cr+6 or Ru+3 with 2,3-DAN were less intense, but noteworthy, as was the coloured fluorescent product of the non-metal ion Se+4 interaction with 2,3-DAN. Several intense 2,3-DAN-metal ion ECL reactions were studied in greater detail and revealed various titration curves with ionic detection limits in the low ppm range, using a fixed level (200 ppm) of 2,3-DAN. 相似文献
43.
The reaction of fibrinogen with thrombin to produce fibrin goes through a multistep sequence in which up to four peptides are cleaved off. When this reaction takes place at pH 6.3 in a shear flow field, the formation of fibrous product is retarded as compared with stagnant conditions. The retardation is greater at 50 s?1 than at 135 s?1. The morphology of the coagulated product appears to be different when produced at 50 s?1 than at either stagnant or 135 s?1, with the material at 50 s?1 having a sheetlike appearance in contrast to a fibrous appearance for the material at 135 s?1 and stagnant conditions: The explanation of the retardation may lie in the separation of thrombin from fibrinogen during the sheared reactions. Shear rate varies more in the vascular bed than does pH or ionic strength and probably is a more important factor in controlling physiological coagulation than these more frequently studied variables. 相似文献
44.
Andreasen Casper Schousboe Elingaard Martin Ohrt Aage Niels 《Structural and Multidisciplinary Optimization》2020,62(2):685-707
Structural and Multidisciplinary Optimization - The level set and density methods for topology optimization are often perceived as two very different approaches. This has to some extent led to two... 相似文献
45.
46.
Matthew E. Altenritter Stephen M. Pescitelli Andrya L. Whitten Andrew F. Casper 《河流研究与利用》2019,35(7):1044-1052
Barriers to fish movement have been used to prevent the spread of invasive fishes but may also limit the movements of native fishes. We evaluated the potential consequences of a proposed barrier on the Illinois River Waterway, meant to inhibit the spread of silver and bighead carps, to the continued recovery of native fishes in the Des Plaines River following water quality improvements. We compared changes in upstream cumulative species richness and community structure from 1983 to 2013 in the DuPage River, an adjacent tributary with an impassable dam, to the area upstream of a newly proposed barrier on the Des Plaines River where fish can currently pass through a navigational lock. Fewer species displayed truncated distributions upstream of the passable lock and dam (n = 18) compared with the impassable dam (n = 23). Due to water quality improvements in the Illinois River as a whole, cumulative species richness downstream of both dams steadily increased over time. Richness also increased upstream of the passable dam but plateaued upstream of the impassable dam. Fifteen to 18 species accounted for differences in community structure between areas downstream and upstream of either dam. Most species (78–100%) were found in greater relative abundance downstream of the impassable dam, and only 53% were found in greater relative abundance downstream of the passable dam. The truncation in species richness and abundance at the impassable dam foreshadows the potential consequences of an indiscriminate barrier on native fishes and the continued recovery of native assemblages. 相似文献
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48.
J.A.D.R.N. Appuhamy L.E. Moraes C. Wagner-Riddle D.P. Casper E. Kebreab 《Journal of dairy science》2018,101(1):820-829
Organic matter (OM) in livestock manure consisting of biodegradable and nonbiodegradable fractions is known as volatile solids (VS). According to the Intergovernmental Panel on Climate Change (IPCC) Tier 2 guidelines, methane produced by stored manure is determined based on VS. However, only biodegradable OM generates methane production. Therefore, estimates of biodegradable VS (dVS; dVS = VS ? lignin) would yield better estimates of methane emissions from manure. The objective of the study was to develop mathematical models for estimating VS and dVS outputs of lactating dairy cows. Dry matter intake, dietary nutrient contents, milk yield and composition, body weight, and days in milk were used as potential predictor variables. Multicollinearity, model simplicity, and random study effects were taken into account during model development that used 857 VS and dVS measurements made on individual cows (kg/cow per day) from 43 metabolic trials conducted at the USDA Energy and Metabolism laboratory in Beltsville, Maryland. The new models and the IPCC Tier 2 model were evaluated with an independent data set including 209 VS and dVS measurements (kg/cow per day) from 2 metabolic trials conducted at the University of California, Davis. Organic matter intake (kg/d) and dietary crude protein and neutral detergent fiber contents (% of dry matter) were significantly associated with VS. A new model including these variables fitted best to data. When evaluated with independent data, the new model had a root mean squared prediction error as a percentage of average observed value (RMSPE) of 12.5%. Mean and slope biases were negligible at <1% of total prediction bias. When energy digestibility of the diet was assumed to be 67%, the IPCC Tier 2 model had a RMSPE of 13.7% and a notable mean bias for VS to be overpredicted by 0.4 kg/cow per day. A separate model including OM intake as well as dietary crude protein and neutral detergent fiber contents as predictor variables fitted best to dVS data and performed well on independent data (RMSPE = 12.7%). The Cornell Net Carbohydrate and Protein System model relying on fat-corrected milk yield and body weight more successfully predicted dry matter intake (DMI; RMSPE = 14.1%) than the simplified (RMSPE = 16.9%) and comprehensive (RMSPE = 23.4%) models to predict DMI in IPCC Tier 2 methodology. New models and the IPCC Tier 2 model using DMI from the Cornell Net Carbohydrate and Protein System model predicted VS (RMSPE = 17.7–19.4%) and dVS (RMSPE = 20%) well with small systematic bias (<10% of total bias). The present study offers empirical models that can accurately predict VS and dVS of dairy cows using routinely available data in dairy farms and thereby assist in efficiently determining methane emissions from stored manure. 相似文献
49.
Polycrystalline bismuth ferrite (BiFeO3 or BFO) thin films were prepared by chemical solution deposition to explore the impact of processing conditions including annealing temperature, percent excess bismuth, and gel drying temperature on film microstructure and properties. Incorporating 0–5 % excess Bi and annealing at 550 °C in air produced stoichiometric single-phase BiFeO3 films. Deviation from this temperature yielded the bismuth-rich Bi36Fe2O57 phase at temperatures below 550 °C or the bismuth-deficient Bi2Fe4O9 phase at temperatures above 550 °C, both of which contributed to higher DC leakage. However, even single-phase BiFeO3 films produced at 550 °C show high DC leakage (~1.2 × 10?1 A/cm2 at 140 kV/cm) due to a porous microstructure. We have thus investigated unconventional thermal treatments that significantly increase film densification while maintaining phase purity. Under these revised thermal treatment conditions, room temperature leakage current values are reduced by three orders of magnitude to ~1.0 × 10?4 A/cm2 at 140 kV/cm. 相似文献
50.
Lu Z Zhang X Leung C Esfandiari N Casper RF Sun Y 《IEEE transactions on bio-medical engineering》2011,58(7):2102-2108
This paper is the first report of robotic intracytoplasmic sperm injection (ICSI). ICSI is a clinical procedure performed worldwide in fertility clinics, requiring pick-up of a single sperm and insertion of it into an oocyte (i.e., egg cell). Since its invention 20 years ago, ICSI has been conducted manually by a handful of highly skilled embryologists; however, success rates vary significantly among clinics due to poor reproducibility and inconsistency across operators. We leverage our work in robotic cell injection to realize robotic ICSI and aim ultimately, to standardize how clinical ICSI is performed. This paper presents some of the technical aspects of our robotic ICSI system, including a cell holding device, motion control, and computer vision algorithms. The system performs visual tracking of single sperm, robotic immobilization of sperm, aspiration of sperm with picoliter volume, and insertion of sperm into an oocyte with a high degree of reproducibility. The system requires minimal human involvement (requiring only a few computer mouse clicks), and is human operator skill independent. Using the hamster oocyte-human sperm model in preliminary trials, the robotic system demonstrated a high success rate of 90.0% and survival rate of 90.7% (n=120). 相似文献