Genetic diversity and relationships in cultivars of Lolium multiflorum Lam. using sequence-related amplified polymorphism markers.

Sequence-related amplified polymorphism (SRAP) markers were used to analyze and estimate the genetic variability, level of diversity, and relationships among 20 cultivars and strains of annual ryegrass (Lolium multiflorum Lam.). Eighteen SRAP primer combinations generated 334 amplification bands, of which 298 were polymorphic. The polymorphism information content ranged from 0.4715 (me10 + em1) to 0.5000 (me5 + em7), with an average of 0.4921. The genetic similarity coefficient ranged from 0.4304 to 0.8529, and coefficients between 0.65 and 0.90 accounted for 90.00%. The cluster analysis separated the accessions into five groups partly according to their germplasm resource origins.

Mechanical characteristics of harbor seal (Phoca vitulina) vibrissae under different circumstances and their implications on its sensing methodology.

In this paper, the mechanical properties of harbor seal vibrissae immersed in various solutions are investigated. As there are no nerves along the length of the vibrissae, all the perturbations have to be transmitted to their bases for sensing. Hence, quantification and understanding of the mechanical properties of the vibrissae are essential in determining the perturbations transmitted to the base of the vibrissae. Two experimental setups are devised for measurements of the different properties of the vibrissae. The first experimental setup is performed with a dynamic mechanical analysis machine. The measured properties in these experiments are the modulus of elasticity and the damping of the vibrissae. Dry, saline water-immersed, water-immersed and Hanks' balanced salt solution (HBSS)-immersed vibrissae are tested to determine the effects of these solutions on the properties of the vibrissae. Tests on the duration of immersion are also performed with saline water-immersed vibrissae. The second experimental setup is performed with a mini-shaker connected to a clamp, which rigidly holds the vibrissae at their bases. The measured properties in these experiments are the natural frequencies of the vibrissae. The results indicate that the moduli of elasticity of the vibrissae are found to decrease along their lengths. However, their damping does not vary along the lengths. HBSS-immersed and saline water-immersed vibrissae show similar characteristics on their properties. An analytical model for predicting the natural frequencies of the vibrissae is also derived. Strong agreement with previous studies on the underwater sensing principle of the harbor seal is also established.

Minimal alveolar concentration of sevoflurane for induction of isoelectric electroencephalogram in middle-aged adults.

BACKGROUND: We determined the minimal alveolar concentration (MAC) of sevoflurane inducing an isoelectric EEG in 50% of adult subjects (MACie). METHODS: We included 31 middle-aged subjects; 30 subjects finished the study protocol and received sevoflurane at preselected concentrations according to a modified Dixon 'up-and-down' design starting at 1.7 vol% with 0.2 vol% steps size. General anaesthesia was induced and maintained with sevoflurane; tracheal intubation was facilitated with cisatracurium. After a period of 30 min before skin incision, the state of isoelectric EEG was considered as significant when a burst suppression ratio of 100% lasted for >1 min. The haemodynamic responses to skin incision and the vasopressor requirement to maintain stable haemodynamic status were also analysed according to the EEG state. RESULTS: MACie was 3.5% (95% confidence interval, 3.4-3.7%) in middle-aged subjects. When compared with subjects not in isoelectric EEG state, subjects in isoelectric EEG state received more phenylephrine to maintain stable haemodynamics (10 of 10 compared with 7 of 20 subjects, P=0.001) and experienced less sympathetic responses to skin incision (1 of 10 compared with 11 of 20 subjects, P=0.024). CONCLUSIONS: MACie for sevoflurane was ∼2.1 times MAC for immobilization in phenobarbital premedicated middle-aged adults. Sevoflurane-induced isoelectric EEG state is associated with significant cardiovascular depression but reduced haemodynamic responses to skin incision.

Microdiaphragm resonating biosensors in higher frequency modes.

Influences of different vibration modes of microdiaphragm resonating biosensors on their detecting capability are investigated in this paper. In order to study the mass sensing capability of the sensor, gold layers with different thicknesses are deposited on the sensor's surface. The frequency shift due to this mass deposition in different frequency modes is measured. An increase in the sensitivity and the quality factor (Q-factor) is found with the increase in the vibration mode number of the sensor. The experimental results demonstrate that the mass sensitivity and quality factor of the device are 4.08 Hz/ng and 241.80 at the ninth mode. These are 2.76 and 10.26 times higher than the mass sensitivity and the Q-factor of the device at the first mode. The observations lead to this conclusion that the sensitivity of microdiaphragm resonating biosensors can be increased by working in higher modes without changing their physical parameters.

Microchip system for monitoring microbial physiological behaviour under drug influences.

Single-step real-time high-throughput monitoring of drug influences on bacterial cell behaviour has become important with growing interests in personalized therapy and medication. Conventional microchip assemblies to perform similar work do exist. However, most of these devices have complex set-ups incorporating micromixers, separators, pumps, or valves. These microcomponents can sometimes damage the entities being monitored because of the creation of unfavourable biological environments. This paper presents a microchip-based system that enables single-step mixing of two solutions in various ratios, without the need for additional microcomponents such as mixers and pumps, in order to screen effectively their combinatory effects on cell outcomes. In this work, in-vitro experiments were carried out using ampicillin at various concentrations to investigate their effects on Escherichia coli (E. coli). Results showed that the microchip provided effective screening, which yielded useful results such as effective dosages, ineffective dosages, and other possible outcomes; for instance, in this case, the occurrence of adaptive mutation of the bacteria at certain drug concentrations. Comparative microbiological laboratory tests were carried out as standard for confirmation of the results.

Sensitive electrochemical enzyme immunoassay microdevice based on architecture of dual ring electrodes with a sensing cavity chamber.

A novel electrochemical detection architecture was investigated for enzyme immunoassay sensors. Microchips with dual-ring working and counter electrodes, and a sensing cavity chamber were made on glass slides. The glass surface of the microchip was coated by 3-aminopropyltriethoxysilane (APTES). Goat IgG, as a example, was covalently captured on APTES-modified glass surfaces through glutaraldehyde (GA) as a cross-linker. Enzyme substrate, p-aminophenyl phosphate (PAPP) was prepared by electrolysis. The enzyme conversion from home-synthetic PAPP to p-aminophenol (PAP) was examined by differential pulse voltammetry (DPV). A competitive inhibition enzyme-linked immunosorbant assay (ELISA) was designed to test the system. Experimental results demonstrate that a detection limit of 118 fg/ml of goat IgG and a dynamic range of 118 fg/ml to 1.18 ng/ml, up to five orders of magnitude could be achieved. Due to its novel architecture design and electronic detection scheme, the method can be used to fabricate portable electrochemical ELISA lab-on-chip systems. The technology could have great potential in clinical diagnostic applications.

Pharmacokinetics and efficacy of low-dose all-trans retinoic acid in the treatment of acute promyelocytic leukemia.

A clinical trial was conducted in order to evaluate the therapeutic effect and side-effects of low-dose ATRA in the treatment of acute promyelocytic leukemia (APL). We compared the pharmacokinetic features in normal individuals with single oral ATRA at 15 mg/m2 and 45 mg/m2, respectively. The results showed that maximal plasma concentration (Cpmax) with oral 15 mg/m2 ATRA was high enough (10(-6) M) to induce APL cell differentiation. Based on these results, 27 cases of de novo APL patients were treated with continuous oral ATRA at the dose of 15-20 mg/m2/day and 24/26 evaluable cases (92%) achieved clinical CR after 13 to 67 days of ATRA treatment. No patient experienced RAS and DIC. The Cpmax with a single dose of ATRA on day 1 of treatment and immediately at CR obtained with continuous ATRA in three cases demonstrated similar values in one patient and an approximately two-fold decrease in two patients. More importantly, compared with a relatively well-matched historic group of 20 APL patients treated with high-dose ATRA, our results suggest that low-dose ATRA is as effective as high-dose in treating APL patients and may provide advantages through decreased hyperleukocytosis and other side-effects.

Non-destructive and Quantitative Investigation of Jingdezhen Blue and White Porcelains Using EDXRF.

The fabrication of the calibration source is a critical part for the non-destructive and quantitative investigation of blue and white porcelains using EDXRF. In order to minimize the effects on the results due to the matrix difference between the samples and the calibration source, broken porcelain pieces of the Ming and Qing dynasties with matrix conditions similar to those of the measured samples are used directly as calibration sources. The 13 trace elements, viz. Ti, Mn, Fe, Co, Ni, Cu, Zn, Ga, Pb, Rb, Sr, Y, and Zr, have been quantitatively measured for 20 imperial blue and white porcelains of the Qing dynasty and for 11 contemporary Jingdezhen porcelains. The data are then analyzed by the principal component analysis method. The clustering of the data and the identification of the porcelains are then investigated.