Transported snapshot model order reduction approach for parametric,steady-state fluid flows containing parameter-dependent shocks

A new model order reduction approach is proposed for parametric steady-state nonlinear fluid flows characterized by shocks and discontinuities whose spatial locations and orientations are strongly parameter dependent. In this method, solutions in the predictive regime are approximated using a linear superposition of parameter-dependent basis. The sought-after parametric reduced bases are obtained by transporting the snapshots in a spatially and parametrically dependent transport field. Key to the proposed approach is the observation that the transport fields are typically smooth and continuous, despite the solution themselves not being so. As a result, the transport fields can be accurately expressed using a low-order polynomial expansion. Similar to traditional projection-based model order reduction approaches, the proposed method is formulated mathematically as a residual minimization problem for the generalized coordinates. The proposed approach is also integrated with well-known hyper-reduction strategies to obtain significant computational speedups. The method is successfully applied to the reduction of a parametric one-dimensional flow in a converging-diverging nozzle, a parametric two-dimensional supersonic flow over a forward-facing step, and a parametric two-dimensional jet diffusion flame in a combustor.     

A reliability test-plan for series systems with components havingstochastic failure rates

This paper proposes a reliability test plan for a series system, by considering the parameter λ_j of the exponential distribution to be a random variable having uniform distribution over [0, &thetas;_j], j = 1, 2,..., n. Explicit expressions are obtained for the optimal values of the t_j, when the number of components in the system is 2. The general solution, albeit implicit, has also been obtained when the number of components in a given system is ⩾3. Mathematical programming is used to find the optimal solution and to illustrate it with numerical results     

Terpenoids from Stinking toe (Hymneae courbaril) fruits with cyclooxygenase and lipid peroxidation inhibitory activities

Stinking toe (Hymenaea courbaril), also called Jatoba and Kerosene tree, is a medicinal plant commonly found in the central and South American countries. In the Caribbean, Mexico and Brazil, the powdery sweet dust of its fruit is consumed for energy. The chemical examination of the yellowish sweet powder of the fruit yielded sucrose and linolenic acid as major compounds. The pods yielded the labdane diterpenoids crotomachlin (1), labd-13E-en-8-ol-15-oic acid (2), labdanolic acid (4), (13E)-labda 7, 13 dien-15-oic acid (5) and labd-8 (17), 13E- dien-15-oic acid (6), along with the sesquiterpene, spathulenol (7), as confirmed by ¹H and ¹³C NMR spectral studies. The methyl ester of labd-13E-en-8-ol-15-oic acid (3) was also characterized during the purification of compound 5. The total amount of these terpenoids in the fruit was about 0.1% (w/w) of the dried fruit. Compounds 1–5 and 7 were assayed for anti-inflammatory activity using cyclooxygenase-1 (COX-1) and -2 (COX-2) enzymes. At 100 ppm, compounds 3 and 4 showed selective COX-2 enzyme inhibition. Also, compounds 1, 2 and 5 inhibited lipid peroxidation by 46%, 48% and 75%, respectively, at 100 ppm. These compounds were isolated from this fruit and their COX and lipid peroxidation inhibitory activities are reported for the first time in this paper.     

Sugar Ester Surfactants: Enzymatic Synthesis and Applications in Food Industry

Sugar esters are non-ionic surfactants that can be synthesized in a single enzymatic reaction step using lipases. The stability and efficiency of lipases under unusual conditions and using non-conventional media can be significantly improved through immobilization and protein engineering. Also, the development of de novo enzymes has seen a significant increase lately under the scope of the new field of synthetic biology. Depending on the esterification degree and the nature of fatty acid and/or sugar, a range of sugar esters can be synthesized. Due to their surface activity and emulsifying capacity, sugar esters are promising for applications in food industry.     

Mineralocorticoid hormone receptor and the epithelial sodium channel in a human leukemic cell line

A Cell extract from the HEL (human erythroblastic leukemia) cell line was positive for both the epithelial sodium channel (ENaC) and the mineralocorticoid receptor (MCR) as glycosylated 82-84 kDa bands, and a single 102 kDa band, respectively, in Western blots using polyclonal antibodies raised against these proteins. The immunofluorescent labeling of the MCR in all cell lines showed a nucleocytoplasmic localization of the receptor whereas the ENaC was exclusively membrane-bound. These results were confirmed by confocal microscopy. The expression of the MCR in HEL cells was evident as a predicted band of 843 bp (234 amino acids) after total RNA from HEL cells had been reverse transcribed and then amplified by PCR; the ENaC was similarly evident as a predicted band of 520 bp. In both cases, near 100% identity was observed between the deduced amino acid sequences of the PCR products and those from known human sources. The multiplication of HEL cells was influenced by antagonists (RU 26752, ZK 91587) targeted for specificity to the MCR and this was reversed by the natural hormone aldosterone. These steroids also provoked chromatin condensation in the HEL population.     

Serial cytological assay of micronucleus induction: a new tool to predict human cancer radiosensitivity

The role of the propeptide sequence and a disulfide bridge between sites 1 and 122 in chymotrypsin has been examined by comparing enzyme activities of wild-type and mutant enzymes. The kinetic constants of mutants devoid of the Cys1-Cys122 disulfide-linked propeptide show that this linkage is not important either for activity or substrate specificity. However this linkage appears to be the major factor in keeping the zymogen stable against non-specific activation. A comparison of zymogen stabilities showed that the trypsinogen propeptide is ten times more effective than the chymotrypsinogen propeptide in preventing non-specific zymogen activation during heterologous expression and secretion from yeast. This feature can also be transferred in trans to chymotrypsinogen; i.e. the chymotrypsin trypsin propeptide chimera forms a stable zymogen.     

Analysis of the association of a heat shock protein70-1 gene promoter polymorphism with myocardial infarction and coronary risk traits

In 12 depressed inpatients referred for bilateral electroconvulsive therapy (ECT), each patient was titrated at the first treatment session by using an ascending method-of-limits procedure with a step-wise increase in pulse frequency (frequency titration) or train duration (duration titration). At the second treatment session, seizure threshold was redetermined by using the method (frequency or duration titration) not used at the first treatment. Frequency or duration was maintained at the lowest level when the other parameter was titrated. Seizure threshold was significantly lower with duration titration (mean, 90 mC; SD, 27.3) than frequency titration (mean, 114 mC; SD, 35.6; p = 0.03). On average, patients in the duration-titration group required 1.2 (SD, 0.6) subconvulsive stimulations before a seizure was elicited, and patients in the frequency-titration group required 1.7 (SD, 0.9) subconvulsive stimulations before a seizure was elicited, a nonsignificant difference. These findings suggest that to elicit a seizure during ECT, increasing train duration may be slightly more efficient than increasing frequency. Basic and other clinical research findings indicate that increasing pulse width may be an inefficient way to elicit a seizure. Therefore the following sequence in the determination of seizure threshold is worth considering when using dose-titration or related techniques: the train duration should be increased first before increasing pulse frequency, and the decision to increase pulse width should be reserved for patients who do not seize at the maximal duration and frequency settings. Further empiric research is needed to establish the utility of this approach.     

CD4-CD8-C.B-17 SCID thymocytes enter the CD4+CD8+ stage in the presence of neonatally grafted T cells

Our previous studies in iron-loaded rat heart cells showed that in vitro iron loading results in peroxidative injury, manifested in a marked decrease in rate and amplitude of heart cell contractility and rhythmicity, which is correctable by treatment with deferoxamine (DF). In the present studies we explored the role of mitochondrial damage in myocardial iron toxicity. Iron loading by 24-hour incubation with 0.36 mmol/L ferric ammonium citrate resulted in a decrease in the activity of nicotinamide adenine dinucleotide (NADH)-cytochrome c oxidoreductase (complex I+III) to 35.3%+/-11.2% of the value in untreated controls; of succinate-cytochrome c oxidoreductase (complex II+III) to 57.4%+/-3.1%; and of succinate dehydrogenase to 63.5%+/-12.6% (p < 0.001 in all cases). The decrease in activity of other mitochondrial enzymes, including NADH-ferricyanide reductase, succinate ubiquinone oxidoreductase (complex II), cytochrome c oxidase (complex IV), and ubiquinol cytochrome c oxidoreductase (complex III), was less impressive and ranged from 71.5%+/-15.8% to 91.5%+/-14.6% of controls. That the observed loss of respiratory enzyme activity was a specific effect of iron toxicity was clearly demonstrated by the complete restoration of enzyme activities by in vitro iron chelation therapy. Sequential treatment with iron and doxorubicin caused a loss of complex I+III and complex II+III activity that was greater than that seen with either agent alone but was only partially correctable by DF treatment. Alterations in cellular adenosine triphosphate measurements paralleled very closely the changes observed in respiratory complex activity. These findings demonstrate for the first time the impairment of cardiac mitochondrial respiratory enzyme activity caused by iron loading at conditions formerly shown to produce severe abnormalities in contractility and rhythmicity.     

The control of protein release from poly(DL-lactide co-glycolide) microparticles by variation of the external aqueous phase surfactant in the water-in oil-in water method

A unique feature of p21 that distinguishes it from the other cyclin-dependent kinase (CDK) inhibitors is its ability to associate with the proliferating cell nuclear antigen (PCNA), an auxiliary factor for DNA polymerases delta and epsilon. While it is now well established that inhibition of cyclin/CDK complexes by p21 can result in G1 cell cycle arrest, the consequences of p21/PCNA interaction on cell cycle progression have not yet been determined. Here, we show, using a tetracycline-regulated system, that expression of wild-type p21 in p53-deficient DLD1 human colon cancer cells inhibits DNA synthesis and causes G1 and G2 cell cycle arrest. Similar effects are observed in cells expressing p21CDK-, a mutant impaired in the interaction with CDKs, but not in cells expressing p21PCNA-, a mutant deficient for the interaction with PCNA. Analysis of cells treated with a p21-derived PCNA-binding peptide provides additional evidence that the growth inhibitory effects of p21 and p21CDK result from their ability to bind to PCNA. Our results suggest that p21 might inhibit cell cycle progression by two independent mechanisms, inhibition of cyclin/CDK complexes, and inhibition of PCNA function resulting in both G1 and G2 arrest.     

Baculovirus expression of the fusion protein gene of bovine respiratory syncytial virus and utility of the recombinant protein in a diagnostic enzyme immunoassay

The fusion (F) protein of bovine respiratory syncytial virus (BRSV) was expressed by using a baculovirus vector. Antigenicity was tested by immunofluorescence analysis with F-specific monoclonal and polyclonal antibodies. Antibodies to recombinant F protein raised in a rabbit neutralized BRSV and human respiratory syncytial virus infectivity when tested in a plaque reduction assay. The recombinant F protein was evaluated as a source of antigen in an enzyme-linked immunosorbent assay (ELISA), and this ELISA was compared with the virus neutralization (VN) test for detecting BRSV antibodies in 10 consecutive serum samples from four calves vaccinated with a live modified BRSV vaccine and from two nonvaccinated control calves. The ELISA with the baculovirus-expressed F protein as an antigen compared favorably with the VN test and is a rapid, sensitive, and specific method for detecting serum antibodies to BRSV.