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S Ramcharan PL Meenhorst JM Otten CH Koks D de Boer RA Maes JH Beijnen 《Canadian Metallurgical Quarterly》1998,36(7):727-731
This study was designed to evaluate the potential advantages of combined epidural and light general anesthesia over the commonly employed general anesthesia during open heart surgery. Twenty-four patients undergoing mitral valve replacement were thus studied. General anesthesia was maintained with an isoflurane-nitrous oxide-oxygen was mixture and morphine sulfate (0.4 mg/kg i.v. initially) followed by postoperative pain control with morphine in 12 patients (group GA). The remaining 12 patients (group EAA) received continuous epidural bupivacaine (0.125%)-morphine (50 micrograms/ml) supplemented with the same gas mixture as group GA. Epidural infusion was continued until the third postoperative day. Changes in the serum cortisol and beta-endorphin levels together with postoperative pain relief defined as good (scale 0-2), fair (3-4), or poor (5-10) were observed serially. Lower cortisol levels were observed in group EAA than in group GA (P < 0.05) just before skin closure, on the second and the third postoperative day. The beta-endorphin levels were substantially lower in group EAA than in group GA throughout the observation. The pain scores were good in 2 patients (17%), fair in 6 (50%), and poor in 4 (33%) for group GA, and good in 8 (67%), fair in 3 (25%), and poor in 1 (8%) for group EAA. We thus conclude that a combined epidural and light general anesthesia is considered to attenuate the stress response and thereby provides a better quality of postoperative pain control. 相似文献
3.
Sencer Yeralan Rolf Arrestam Jan Holmlund David J. Ramcharan 《Computers & Industrial Engineering》1992,23(1-4):331-334
Microcontrollers are being used in many commercial and consumer products to introduce a higher level of intelligence. There exist an opportunity and need to develop high-level languages to be used specifically in industrial product development. A recent trend in such embedded applications is the use of fuzzy-logic control. An ongoing project in the Industrial Research Laboratory at the University of Florida investigates the various aspects of microcontroller architectures, operating systems and languages. This report summarizes our progress in developing a fuzzy-logic control language for microcontrollers. 相似文献
4.
High density lipoprotein (HDL) levels are known to be higher in women than in men, and to increase with estrogen use. To assess
the effects of estrogens on HDL subspecies, analytic ultracentrifuge measurements of HDL were compared in 11 menopausal estrogen
users and 16 controls. The difference in mean schlieren patterns between the groups showed a significantly higher level of
HDL with flotation rate (F
1.20
o
)>1.5 (predominantly HDL2) in the users. This was similar to the difference in HDL seen between nonusers of hormones and age-matched males. A previous
study had shown that users of combination oral contraceptives had increased levels of HDL with F
1.20
o
≤3.5 (primarily HDL3) suggesting that the estrogen effect on HDL is altered by the presence of added progestin. The progrestin effect was studied
here in more detail in two women with type V hyperlipoproteinemia treated with norethindrone acetate. Reduction in serum triglyceride
was accompanied by a reduction in HDL, predominantly in the less dense species (HDL2). Among groups of oral contraceptive and noncontraceptive estrogen and progestin users whose HDL-cholesterol levels have
been reported recently, there was a direct correlation (r=0.86, p<.001) between mean HDL-cholesterol and triglyceride levels.
Endogenous hormonal influences on HDL were assessed by serum hormone and lipoprotein measurements at weekly intervals during
two consecutive menstrual cycles in four healthy females. An increase in HDL of highest flotation rate (F
1.20
o
5–9) was seen, which corresponded with the time of ovulation raising the possibility of pituitary as well as gonadal hormone
effects on HDL. 相似文献
5.
Deficiencies in small quantities of micronutrients, especially iodine and iron, severely affect more than a third of the world's population, resulting in serious public health consequences, especially for women and young children. Salt is an ideal carrier of micronutrients. The double fortification of salt with both iodine and iron is an attractive approach to the reduction of both anemia and iodine-deficiency disorders. Because iodine is unstable under the storage conditions found during the manufacturing, distribution, and sale of salt in most developing countries, the effects of packaging materials and environmental conditions on the stability of salt double-fortified with iron and iodine were investigated. Salt was double-fortified with potassium iodide or potassium iodate and with ferrous sulfate or ferrous fumarate. The effects of stabilizers on the stability of iodine and iron were followed by storing the salt under three conditions that represent the extremes of normal distribution and sale for salt in developing countries: room temperature (25 degrees C) with 50%-70% relative humidity, 40 degrees C with 60% relative humidity, and 40 degrees C with 100% relative humidity. The effects of stabilizers, such as sodium hexametaphosphate (SHMP), calcium carbonate, calcium silicate, and dextrose were investigated. None of the combinations of iron and iodine compounds was stable at elevated temperatures. Essentially all of the iodine was lost over a period of six months. SHMP effectively slowed down the iodine loss, whereas magnesium chloride, a typical hygroscopic impurity, greatly accelerated this process. Calcium carbonate did not have a sparing effect on iodine, despite contrary indications in the literature. Ferrous sulfate-fortified salts generally turned yellow and developed an unpleasant rusty flavor. Salt fortified with ferrous fumarate and potassium, iodide was reasonably stable and maintained its organoleptic properties, making it more likely to be acceptable to consumers. We confirmed that application of the iodine compounds as solutions resulted in a more even distribution of the iodine throughout the sample. The effect of the packaging materials was overshadowed by the other variables. None of the packaging materials was clearly better than any other. This may have been due to the fact that the polymer bags were not heat sealed, and thus some moisture penetration was possible. The results indicate that with careful control of processing, packaging, and storage conditions, a double-fortified salt could be stabilized for the six-month period required for distribution and consumption. Unfortunately, the processing and storage required are difficult to attain under typical conditions in developing countries. 相似文献
6.
DL Boger NE Haynes PA Kitos MS Warren J Ramcharan AE Marolewski SJ Benkovic 《Canadian Metallurgical Quarterly》1997,5(9):1817-1830
The synthesis of 10-formyl-5,8,10-trideazafolic acid (3) as a potential inhibitor of glycinamide ribonucleotide transformylase (GAR Tfase) is reported. The target compound was prepared by a convergent synthesis utilizing the alkylation of hydrazone 5 with benzylic bromide 6 to construct the core heterocycle 7. The aldehyde 3 and related agents were evaluated as inhibitors of purN GAR Tfase and avian AICAR Tfase. Compound 3 exhibited potent inhibition of GAR Tfase with a Ki of 0.26 +/- 0.05 microM. In contrast, 3 exhibited more moderate inhibition of aminoimidazole carboxamide ribonucleotide transformylase (AICAR Tfase), with Ki of 7.6 +/- 1.5 microM. 相似文献
7.
Analysis of Linear Alkylbenzene Sulfonate in Laundry Wastewater by HPLC–UV and UV–Vis Spectrophotometry
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A lack of natural water resources and an increase in the demand for fresh potable water has shifted focus to the possible reuse of recycled laundry wastewater water that is considered to be relatively clean. Organic components such as linear alkylbenzene sulfonates (LAS) are the major and most abundant contributing anionic surfactant constituents found in laundry detergents. The development and reliability of treatment methods targeted at purification of laundry wastewater necessitates a fast and accurate method for quantification of LAS. This paper focuses on a comparative study for the quantification of LAS based on traditional liquid–liquid extraction (LLE) and HPLC–UV methods. In the case of LLE, the anionic surfactant LAS complexes via ion association to a methylene blue (MB) cationic dye resulting in the formation of an anionic surfactant–methylene blue (AS–MB) complex. The AS–MB complex extracted with chloroform absorbs at a λ max of 653 nm. Optimized conditions for quantification of a single eluted LAS peak using HPLC–UV were obtained by isocratic elution on a C18 column with a 95 % acetonitrile and 5 % 0.7 M acetic acid mobile phase. Both methods displayed percentage recoveries >90 % and statistically showed reproducibility and precision in the quantitation of LAS. HPLC–UV prevailed over UV–Vis as the method of choice for LAS determinations given the ease of sample preparation and applicability to a wider range of samples. Typical levels of LAS in laundry samples assessed in this study ranged between 116 and 454 mg L?1. 相似文献
8.
Dudu V Ramcharan M Gilchrist ML Holland EC Vazquez M 《Journal of nanoscience and nanotechnology》2008,8(5):2293-2300
An increasing number of studies have demonstrated the multiple advantages of using nanocrystals, such as Quantum dots, for biological imaging. Quantum dots functionalized with biomolecules on their surfaces were shown to be able to bind to specific extracellular targets via specific recognition and to be internalized inside the cells, thereby allowing the imaging of intracellular pathways. However, the use of Quantum dots for live tracking of intracellular molecules is relatively limited because of the difficulties encountered during the induction of Quantum dots across living cell membranes. In this study we show that cationic liposomes can deliver low concentrations of non-targeted Quantum dots into the cytosol of living cells via a lipid-mediated fusion with the cell membrane. The intracellular Quantum dots exhibit aggregation that appears dependent upon their concentration, but does not visibly affect cell viability. Our results point towards the use of cationic liposomes as an effective delivery system for targeted Quantum dots within the cell cytosol, which would facilitate live cell imaging of the labeled molecules. 相似文献
9.
An ectopic recombination system using ura3 heteroalleles varying in size from 80 to 960 bp has been used to examine the effect of substrate length on spontaneous mitotic recombination. The ura3 heteroalleles were positioned either on nonhomologous chromosomes (heterochromosomal repeats) or as direct or inverted repeats on the same chromosome (intrachromosomal repeats). While the intrachromosomal events occur at rates at least 2 orders of magnitude greater than the corresponding heterochromosomal events, the recombination rate for each type of repeat considered separately exhibits a linear dependence on substrate length. The linear relationships allow estimation of the corresponding minimal efficient processing segments, which are approximately 250 bp regardless of the relative positions of the repeats in the yeast genome. An examination of the distribution of recombination events into simple gene conversion versus crossover events indicates that reciprocal exchange is more sensitive to substrate size than is gene conversion. 相似文献
10.
Jacob H. Jordahl Luis Solorio Hongli Sun Stacy Ramcharan Clark B. Teeple Henry R. Haley Kyung Jin Lee Thomas W. Eyster Gary D. Luker Paul H. Krebsbach Joerg Lahann 《Advanced materials (Deerfield Beach, Fla.)》2018,30(14)
The advent of adaptive manufacturing techniques supports the vision of cell‐instructive materials that mimic biological tissues. 3D jet writing, a modified electrospinning process reported herein, yields 3D structures with unprecedented precision and resolution offering customizable pore geometries and scalability to over tens of centimeters. These scaffolds support the 3D expansion and differentiation of human mesenchymal stem cells in vitro. Implantation of these constructs leads to the healing of critical bone defects in vivo without exogenous growth factors. When applied as a metastatic target site in mice, circulating cancer cells home in to the osteogenic environment simulated on 3D jet writing scaffolds, despite implantation in an anatomically abnormal site. Through 3D jet writing, the formation of tessellated microtissues is demonstrated, which serve as a versatile 3D cell culture platform in a range of biomedical applications including regenerative medicine, cancer biology, and stem cell biotechnology. 相似文献