NaNog: A pluripotency homeobox (master) molecule.

One of the most intriguing aspects of cell biology is the state of pluripotency, where the cell is capable of self-renewal for as many times as deemed necessary , then at a specified time can differentiate into any type of cell. This fundamental process is required during organogenesis in foetal life and importantly during tissue repair in health and disease. Pluripotency is very tightly regulated, as any dysregulation can result in congenital defects, inability to repair damage, or cancer. Fuelled by the relatively recent interest in stem cell biology and tissue regeneration, the molecules implicated in regulating pluripotency have been the subject of extensive research. One of the important molecules involved in pluripotency, is NaNog, the subject of this article

Harmonic evaluation of traction system by Monte Carlo simulation

This paper presents a method to predict the harmonic current level of traction system with phase-controlled DC Drives by Monte Carlo simulation. Based on Behavioral Modeling Technique (BMT), a model for electrical unit of traction is proposed. The probability density functions (pdf) of speed and notch numbers are obtained from longtime field measurement. The mean and variance of harmonic current of single electrical unit is obtained based on the speed pdf and traction electrical unit model. The results of Monte Carlo simulation are in good accordance with the experimental and analytic conclusions. The harmonics of a different number of trains are systematically investigated. It is shown the Total Harmonic Distortion (THD) decreases with the increase of the number of trains and the harmonic current per train decreases with the train number because of the harmonic cancellation.published_or_final_versio

Modeling of electric railway vehicle for harmonic analysis of traction power-supply system using spline interpolation in frequency domain

It is essential to model nonlinear traction converter loads for harmonic analysis of traction systems. A behavioral model in frequency domain to represent electric railway vehicle based on testing and measurement is proposed for harmonic analysis. The harmonic current characteristics are represented by a set of polynomials generated from cubic smoothing spline interpolation. The purpose of this paper is to report and discuss the development of an electric railway model for harmonic analysis and demonstrate results from the simulation with this train load model. System simulation based on this model is performed and the results match satisfactorily with field measurement.published_or_final_versio

Probabilistic characterization of current harmonics of electrical traction power supply system by analytic method

Current harmonics of an urban railway traction system in Hong Kong are investigated by analytic approach. With the statistic knowledge of speed and notch number of the trains in the system, the mean and variance of harmonic current of individual trains are computed based on a behavior oriented model of the traction electrical unit. According to the Large Number Law and Central Limit Theorem, current harmonics at a substation, which is a vectorial summation of harmonics of random number of trains electrically connected to it, are normally distributed provided that the number of trains is large enough. A set of equations are established by which probability density functions (pdfs) of current harmonics at a substation are calculated and found to be in good accordance with results obtained by Monte Carlo simulation. This approach of harmonics evaluation for traction system with random loading has evident advantages of cheap, fast and convenience and with no compromise of accuracy.published_or_final_versio

Traction system scheduling to minimize harmonic current level at substation by genetic algorithm

Harmonics of individual trains are closely related to its loading, speed and operation mode. The harmonic current at substations is the sum of the individual components from all the trains electrically connected to the substation. There will be cancellation of the harmonics if the harmonics are not of the same phase angles. It is possible to schedule the traction system so as to minimize the harmonic distortion, improve the power factor and reduce the harmonic currents at substations. In this study genetic algorithm (GA) is used to find out the optimal schedule of the system with minimum harmonic levels. The optimized solution can be integrated into automatic train operation (ATO) controller to control the departure, speed regulation of each train of the system. Mathematical description of the problem is first presented and the genetic algorithm is introduced. The optimal solution is given at the end of this paper. It is demonstrated that the scheduling of traction system is applicable to harmonic reduction and GA is fit for such kinds of optimization problems. Such method of harmonics reduction can bring about considerable saving in filtering equipment.published_or_final_versio

Modulation of Sn concentration in ZnO nanorod array: intensification on the conductivity and humidity sensing properties

Tin (Sn)-doped zinc oxide (ZnO) nanorod arrays (TZO) were synthesized onto aluminum-doped ZnO-coated glass substrate via a facile sonicated sol–gel immersion method for humidity sensor applications. These nanorod arrays were grown at different Sn concentrations ranging from 0.6 to 3 at.%. X-ray diffraction patterns showed that the deposited TZO arrays exhibited a wurtzite structure. The stress/strain condition of the ZnO film metamorphosed from tensile strain/compressive stress to compressive strain/tensile stress when the Sn concentrations increased. Results indicated that 1 at.% Sn doping of TZO, which has the lowest tensile stress of 0.14 GPa, generated the highest conductivity of 1.31 S cm− 1. In addition, 1 at.% Sn doping of TZO possessed superior sensitivity to a humidity of 3.36. These results revealed that the optimum performance of a humidity-sensing device can be obtained mainly by controlling the amount of extrinsic element in a ZnO film

Urinary biomarker concentrations of captan, chlormequat, chlorpyrifos and cypermethrin in UK adults and children living near agricultural land

There is limited information on the exposure to pesticides experienced by UK residents living near agricultural land. This study aimed to investigate their pesticide exposure in relation to spray events. Farmers treating crops with captan, chlormequat, chlorpyrifos or cypermethrin provided spray event information. Adults and children residing ≤100 m from sprayed fields provided first-morning void urine samples during and outwith the spray season. Selected samples (1–2 days after a spray event and at other times (background samples)) were analysed and creatinine adjusted. Generalised Linear Mixed Models were used to investigate if urinary biomarkers of these pesticides were elevated after spray events. The final data set for statistical analysis contained 1518 urine samples from 140 participants, consisting of 523 spray event and 995 background samples which were analysed for pesticide urinary biomarkers. For captan and cypermethrin, the proportion of values below the limit of detection was greater than 80%, with no difference between spray event and background samples. For chlormequat and chlorpyrifos, the geometric mean urinary biomarker concentrations following spray events were 15.4 μg/g creatinine and 2.5 μg/g creatinine, respectively, compared with 16.5 μg/g creatinine and 3.0 μg/g creatinine for background samples within the spraying season. Outwith the spraying season, concentrations for chlorpyrifos were the same as those within spraying season backgrounds, but for chlormequat, lower concentrations were observed outwith the spraying season (12.3 μg/g creatinine). Overall, we observed no evidence indicative of additional urinary pesticide biomarker excretion as a result of spray events, suggesting that sources other than local spraying are responsible for the relatively low urinary pesticide biomarkers detected in the study population

Impact of Age and Body Site on Adult Female Skin Surface pH

Background: pH is known as an important parameter in epidermal barrier function and homeostasis. Aim: The impact of age and body site on skin surface pH (pH(SS)) of women was evaluated in vivo. Methods: Time domain dual lifetime referencing with luminescent sensor foils was used for pH(SS) measurements. pH(SS) was measured on the forehead, the temple, and the volar forearm of adult females (n = 97, 52.87 +/- 18.58 years, 20-97 years). Every single measurement contained 2,500 pH values due to the luminescence imaging technique used. Results: pH(SS) slightly increases with age on all three investigated body sites. There are no significant differences in pH(SS) between the three investigated body sites. Conclusion: Adult pH(SS) on the forehead, the temple and the volar forearm increases slightly with age. This knowledge is crucial for adapting medical skin care products. Copyright (C) 2012 S. Karger AG, Base

Clinical experience with the novel histone deacetylase inhibitor vorinostat (suberoylanilide hydroxamic acid) in patients with relapsed lymphoma

Preclinical studies indicate that vorinostat (suberoylanilide hydroxamic acid or SAHA) inhibits histone deacetylase (HDAC) activity, increases acetylated histones H2a, H2b, H3, and H4, and thereby induces differentiation and apoptosis in a variety of tumour cell lines, including murine erythroleukaemia, human bladder transitional cell carcinoma, and human breast adenocarcinoma. On the basis of these favourable preclinical findings, vorinostat has been selected as a candidate for clinical development with the potential to treat patients with selected malignances, including Hodgkin's disease and non-Hodgkin's lymphomas. Phase I clinical trials in patients with haematological malignances and solid tumours showed that both intravenous (i.v.) and oral formulations of vorinostat are well tolerated, can inhibit HDAC activity in peripheral blood mononuclear cells and tumour tissue biopsies, and produce objective tumour regression and symptomatic improvement with little clinical toxicity. The dose-limiting toxicities (DLT) of i.v. vorinostat were primarily haematologic and were rapidly reversible within 4–5 days of therapy cessation. In contrast, the DLT for oral vorinostat were primarily non-haematologic (including dehydration, anorexia, diarrhoea, fatigue) and were also rapidly reversible, usually within 3 days. Further research is warranted to optimise the dosing schedule for vorinostat, particularly with respect to dose, timing of administration, and duration of therapy, and to fully delineate the mechanism(s) of antitumour effect of vorinostat in various types of malignances. Several phase II studies are currently ongoing in patients with haematological malignances and solid tumours