A path planning method based on the particle swarm optimization trained fuzzy neural network algorithm

Cluster Computing - The basic fuzzy neural network algorithm has slow convergence and large amount of calculation, so this paper designed a particle swarm optimization trained fuzzy neural network...     

Real time imaging of single fluorophores on moving actin with an epifluorescence microscope.

Relatively simple modifications of an ordinary epifluorescence microscope have greatly reduced its background luminescence, allowing continuous and real time imaging of single fluorophores in an aqueous medium. Main modifications were changing the excitation light path and setting an aperture stop so that stray light does not scatter inside the microscope. A simple and accurate method using actin filaments is presented to establish the singularity of the observed fluorophores. It was possible, at the video rate of 30 frames/s, to image individual tetramethylrhodamine fluorophores bound to actin filaments sliding over heavy meromyosin. The successful imaging of moving fluorophores demonstrates that conventional microscopes may become a routine tool for studying dynamic interactions among individual biomolecules in physiological environments.     

Estimation of the lipophilicity of anti-HIV nucleoside analogues by determination of the partition coefficient and retention time on a Lichrospher 60 RP-8 HPLC column

There is a close linear correlation between the log partition coefficient (Pa) of a series of 2'-deoxyriboside (dR), 2',3'-didehydro-3'-dideoxyriboside (ddeR), 2',3'-dideoxyriboside (ddR), 3'-fluoro-2',3'-dideoxyriboside (FddR) and 3'-azido-2',3'-dideoxyriboside (AzddR) derivatives of uracil, cytosine, thymine, guanine, adenine and 2,6-diaminopurine and their retention times (Rt) on a Lichrospher 60 RP-8 HPLC column (correlation coefficient r greater than 0.970). Within each class of compounds the following order of increasing lipophilicity was noted: dR less than ddeR less than ddR less than FddR less than AzddR. A straight-forward structure-lipophilicity relationship for both base and sugar modified purine and pyrimidine 2',3'-dideoxynucleosides could be delineated.     

First phase release coefficient of insulin in subjects with normal glucose tolerance on glucose infusion analyzed by computer simulation

We report here a mathematical model using computer simulation to solve the phase fractionation coefficient (f) of instantaneous insulin release on glucose infusion. By extensive model testing with the cited parameters obtained from the literature, the values of the factor f were shown to lie in range of 0.93+/-0.02 (mean+/-2S.D., n=15), indicating that the high pulsatile bolus of glucose by i.v. infusion may trigger acute insulin release (AIR) corresponding to a fraction of more than 90% of the stored insulin release in the first phase from the secretory granules of pancreatic beta cells. In addition, the value of the factor f was shown to be independent of both the glucose infusion method and the non-insulin-dependent uptake of glucose.     

Real time expression of ACC oxidase and PR-protein genes mediated by Methylobacterium spp. in tomato plants challenged with Xanthomonas campestris pv. vesicatoria

Biotic stress like pathogenic infection increases ethylene biosynthesis in plants and ethylene inhibitors are known to alleviate the severity of plant disease incidence. This study aimed to reduce the bacterial spot disease incidence in tomato plants caused by Xanthomonas campestris pv. vesicatoria (XCV) by modulating stress ethylene with 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity of Methylobacterium strains. Under greenhouse condition, Methylobacterium strains inoculated and pathogen challenged tomato plants had low ethylene emission compared to pathogen infected ones. ACC accumulation and ACC oxidase (ACO) activity with ACO related gene expression increased in XCV infected tomato plants over Methylobacterium strains inoculated plants. Among the Methylobacterium spp., CBMB12 resulted lowest ACO related gene expression (1.46 Normalized Fold Expression), whereas CBMB20 had high gene expression (3.42 Normalized Fold Expression) in pathogen challenged tomato. But a significant increase in ACO gene expression (7.09 Normalized Fold Expression) was observed in the bacterial pathogen infected plants. In contrast, Methylobacterium strains enhanced β-1,3-glucanase and phenylalanine ammonia-lyase (PAL) enzyme activities in pathogen challenged tomato plants. The respective increase in β-1,3-glucanase related gene expressions due to CBMB12, CBMB15, and CBMB20 strains were 66.3, 25.5 and 10.4% higher over pathogen infected plants. Similarly, PAL gene expression was high with 0.67 and 0.30 Normalized Fold Expression, in pathogen challenged tomato plants inoculated with CBMB12 and CBMB15 strains. The results suggest that ethylene is a crucial factor in bacterial spot disease incidence and that methylobacteria with ACC deaminase activity can reduce the disease severity with ultimate pathogenesis-related protein increase in tomato.     

A customized fixation plate with novel structure designed by topological optimization for mandibular angle fracture based on finite element analysis

Background

The purpose of this study was to design a customized fixation plate for mandibular angle fracture using topological optimization based on the biomechanical properties of the two conventional fixation systems, and compare the results of stress, strain and displacement distributions calculated by finite element analysis (FEA).

Methods

A three-dimensional (3D) virtual mandible was reconstructed from CT images with a mimic angle fracture and a 1 mm gap between two bone segments, and then a FEA model, including volume mesh with inhomogeneous bone material properties, three loading conditions and constraints (muscles and condyles), was created to design a customized plate using topological optimization method, then the shape of the plate was referenced from the stress concentrated area on an initial part created from thickened bone surface for optimal calculation, and then the plate was formulated as “V” pattern according to dimensions of standard mini-plate finally. To compare the biomechanical behavior of the “V” plate and other conventional mini-plates for angle fracture fixation, two conventional fixation systems were used: type A, one standard mini-plate, and type B, two standard mini-plates, and the stress, strain and displacement distributions within the three fixation systems were compared and discussed.

Results

The stress, strain and displacement distributions to the angle fractured mandible with three different fixation modalities were collected, respectively, and the maximum stress for each model emerged at the mandibular ramus or screw holes. Under the same loading conditions, the maximum stress on the customized fixation system decreased 74.3, 75.6 and 70.6% compared to type A, and 34.9, 34.1, and 39.6% compared to type B. All maximum von Mises stresses of mandible were well below the allowable stress of human bone, as well as maximum principal strain. And the displacement diagram of bony segments indicated the effect of treatment with different fixation systems.

Conclusions

The customized fixation system with topological optimized structure has good biomechanical behavior for mandibular angle fracture because the stress, strain and displacement within the plate could be reduced significantly comparing to conventional “one mini-plate” or “two mini-plates” systems. The design methodology for customized fixation system could be used for other fractures in mandible or other bones to acquire better mechanical behavior of the system and improve stable environment for bone healing. And together with SLM, the customized plate with optimal structure could be designed and fabricated rapidly to satisfy the urgent time requirements for treatment.

     

Neuron classification based on temporal firing patterns by the dynamical analysis with changing time resolution (DCT) method

Spike train data of many neurons can be obtained by multirecording techniques; however, the data make it difficult to estimate the connective structure in a large network. Neuron classification should be helpful in that regard, assuming that multiple neurons having similar connections with other neurons show a similar temporal firing pattern. We propose a novel method for classifying neurons based on temporal firing patterns of spike train data called the dynamical analysis with changing time resolution (DCT) method. The DCT method can evaluate temporal firing patterns by a simple algorithm with few arbitrary factors and automatically classify neurons by similarity of temporal firing patterns. In the DCT method, temporal firing patterns were objectively evaluated by analyzing their dependence on temporal resolution. We confirmed the effectiveness of the DCT method using actual spike train data.     

Determination of urinary malondialdehyde by isotope dilution LC-MS/MS with automated solid-phase extraction: a cautionary note on derivatization optimization

A highly sensitive quantitative LC-MS/MS method was developed for measuring urinary malondialdehyde (MDA). With the use of an isotope internal standard and online solid-phase extraction, urine samples can be directly analyzed within 10 min after 2,4-dinitrophenylhydrazine (DNPH) derivatization. The detection limit was estimated as 0.08 pmol. This method was further applied to assess the optimal addition of DNPH for derivatization and to measure urinary MDA in 80 coke oven emission (COE)-exposed and 67 nonexposed workers. Derivatization optimization revealed that to achieve complete derivatization reaction, an excess of DNPH is required (DNPH/MDA molar ratio: 893-8929) for urine samples that is about 100 times higher than that of MDA standard solutions (molar ratio: 10-80). Meanwhile, the mean urinary concentrations of MDA in COE-exposed workers were significantly higher than those in nonexposed workers (0.23±0.17 vs 0.14±0.05 μmol/mmol creatinine, P<0.005). Urinary MDA concentrations were also significantly associated with the COE (P<0.005) and smoking exposure (P<0.05). Taken together, this method is capable of routine high-throughput analysis and accurate quantification of MDA and would be useful for assessing the whole-body burden of oxidative stress. Our findings, however, raise the issue that derivatization optimization should be performed before it is put into routine biological analysis.     

The effect of administration time on malformations induced by three anticonvulsant agents in C57BL/6J mice with emphasis on forelimb ectrodactyly.

Exposure of C57BL/6J mice to three anticonvulsant derivatives, namely, dimethadione, sodium valproate, and sodium diphenylhydantoin, each induced postaxial forelimb ectrodactyly. The agents were administered at gestational days 9, 9 1/3, 9 2/3, and 10. It was determined that administration at day 9 2/3 induced the highest percentage of forelimb ectrodactyly for each of the three agents. The forelimb ectrodactyly response in the C57BL/6J strain was compared with the A/J strain (Collins et al., Teratology, 41:61-70, 1990); it was found that the C57BL/6J strain was more sensitive to dimethadione and the A/J strain was more sensitive to diphenylhydantoin and sodium valproate. The position of vertebral defects induced by sodium valproate correlated with the time of drug administration. The overall syndrome of malformations induced by the three anticonvulsant agents was relatively similar in the two mouse strains and differed between each of the anticonvulsant agents.     

Detection of Clavibacter michiganensis subsp. sepedonicus by AmpliDet RNA,a new technology based on real time monitoring of NASBA amplicons with a molecular beacon

AIMS: To develop a procedure for direct detection of viable cells of Clavibacter michiganensis subsp. sepedonicus (Cms), the causal organism of bacterial ring rot in potato, based on AmpliDet RNA, in which amplicons generated by nucleic acid sequence based amplification (NASBA) are monitored in real time with a molecular beacon. METHODS AND RESULTS: Five methods were evaluated and fine-tuned for extraction of RNA from Cms. The most efficient non-commercial RNA extraction method included an enzymatic breakdown of the cell wall followed by a phenol extraction. AmpliDet RNA enabled detection of 10,000 molecules of purified rRNA per reaction and 100 cfu of Cms per reaction in more complex samples. Two primer pairs were tested with DNA and RNA purified from Cms. One primer pair was able to distinguish live from dead cells. CONCLUSIONS: An AmpliDet RNA was developed which enabled fast and specific detection of viable cells of Cms in complex substrates at a detection limit of 100 cfu per reaction. SIGNIFICANCE AND IMPACT OF THE STUDY: This novel AmpliDet RNA is carried out in sealed tubes, thus reducing the risk of carry-over contamination. The method will be particularly suitable for studies on the epidemiology of Cms in which viable cells should be exclusively detected.     

Oral vaccination of African catfish with Vibrio anguillarum O2: effect on antigen uptake and immune response by absorption enhancers in lag time coated pellets

The impact on antigen uptake and antibody response by the addition of absorption enhancers to Vibrio anguillarum O2 antigen was studied in oral vaccination trials of African catfish (Clarias gariepinus). Oral vaccination was achieved by feeding lag time coated pellets. The lag time coat prevents premature release of the encapsulated vaccine in the tank, before ingestion of the pellets by the fish. To monitor the antigen uptake, a competitive ELISA was used. The antibody response was measured using an indirect ELISA. Feeding of bacterin-layered pellets without absorption enhancers resulted in a rather low antigen uptake and antibody levels. The addition of absorption enhancers such as sodium salicylate, sodium caprate and vitamin E TPGS increased the serum antigen levels and specific antibody levels in the systemic circulation. Skin mucus antibody levels were higher after oral vaccination compared to the IP and control group. The addition of absorption enhancers in the oral groups further increased the antibody levels obtained in the skin mucus.     

The effect of dose and time on the induction of genetic alterations insaccharomyces cerevisiae by aminoacridines in the presence and absence of visible light irradiation in comparison with the dose-effect-curves of mutagens with other type of action

Summary Aminoacridines induce frameshift mutations and are photodynamically active, depending on whether visible light is absent or present. Therefore, a test system which allows to compare quantitatively the genetic effects of aminoacridines irradiated or unirradiated by visible light ought to be susceptible to the different DNA alterations which can be induced by these substances. For this reason in most experiments mitotic gene conversion and only in some selected experiments reverse mutation was chosen as the indicator of genetic activity. In contrast to mutation systems mitotic gene conversion has never shown a response specific to only some types of mutagens. The three aminoacridine derivatives used-acridine orange (AO), proflavine (PF), and acridine yellow (AY)—were successful in the induction of convertants at two different loci. No locus-specificity could be observed. The time-dependent induction of convertants proceeds quickly but soon reaches—especially after treatment without light—a saturation point. The dose/effect-curve after treatment in the dark has a slope increasing with increasing concentration. Irradiation with visible light results in a dose/effect-curve consisting of three parts. At first the increase of convertants is nearly linear extending one (AY) to three (AO) orders of magnitude. After that a saturation effect begins at the point at which an effectiveness of the acridines in the dark is apparent. At high concentrations an induction of convertants can again be observed which is nearly the same as that after treatment in the dark. To determine whether the dose/effect-curves obtained for gene conversion refer to similar curves for gene mutations after treatment with AO at the same locus not only gene conversions but also reverse mutations were scored for. AO-treatment in the dark is ineffective in inducing reverse mutations. Irradiation with visible light results in a dose/effect-curve beeing parallel only in its first part to the dose/effect-curve obtained for gene conversion, while in its second part a mutation frequency decline can be observed. Comparing the dose/effect-curves of AO resulting from the induction of gene conversion and gene mutation, and taking into account that no mutants can be induced by AO-treatment in the dark, the increase in convertants at high acridine-concentrations can be explained as an addition of light-dependent and light-independent effects. That means, in mutation systems at low concentrations of aminoacridines irradiation with visible light should cause transitions, transversions and microlesions, at intermediate concentrations frameshift lesions should begin to appear, and at very high concentrations nearly exclusively frameshift lesions should occur. The dose/effect-curves of aminoacridines compared with those of other mutagens are very complex. The dose/effect-curves of the mutagens of other type of action tested are linear in a double logarithmic scale, and parallel for induced gene conversion and induced gene mutation. These results indicate that the gene conversion ability of a given compound depends on its mutagenic property. That means, many mutagens may exert specific genetic effects not directly but mainly in indirect ways by leading to DNA damage, a situation for repair synthesis resulting as well in mutations as recombinations.     

Interferon and cytotoxic factor (cytotoxin) released in the blood of mice infected with Mycobacterium bovis BCG. II. Influence of time after BCG inoculation on production of interferon and cytotoxin by capsular polysaccharide of Klebsiella pneumoniae or by bacterial lipopolysaccharide and on hyperreactivity to their lethal effects.

The time course of the occurrence of hyperreactivity in interferon and cytotoxin responses to the active substance (neutral fraction) of the capsular polysaccharide of Klebsiella pneumoniae (neutral CPS-K) and bacterial lipopolysaccharide (LPS) and of the hyperreactivity to their lethal effects was followed after infection with BCG in SMA and ICR strains of mice. The duration of these hyperreactivities of BCG-infected mice depended on the inoculum doses of BCG. The time patterns of the hyperreactivity to the lethal effects of neutral CPS-K and LPS were similar in both strains of mice, although the maximum toxicity of LPS by the intraperitoneal route in BCG-infected mice on a weight basis was stronger than that of neutral CPS-K. Irrespective of inducer and mouse strain, the time pattern of the hyperreactivity to produce cytotoxin was similar to that of the hyperreactivity to produce interferon. The patterns for these phenomena when neutral CPS-K was used as an inducer were also similar to those when LPS was used. In ICR mice the hyperreactivity in interferon and cytotoxin responses to either neutral CPS-K or LPS decayed significantly earlier than the hyperreactivity to their lethal effects, whereas in SMA mice the occurrence of both types of hyperreactivities seemed to be associated. Therefore, it is suggested that the mechanism for the hyperreactivity in interferon and cytotoxin responses to neutral CPS-K or LPS in BCG-infected mice is not necessarily the same as that for the hyperreactivity to their lethal effects.