Antibacterial activities of the extracts of Mimosa pudica L. an in-vitro study

Mimosa pudica L., also called sensitive plant or touch-me-not, belongs to the genus Mimosa (Family: Mimosaceae). This plant grows as a weed in nearly every parts of Vietnam and is used as a traditional medicine for the treatment of some diseases. This study aims to evaluate the antibacterial activity of the water and ethanol extracts of this plant by using disc diffusion method. The total flavonoid as quercetin equivalent (QE) per gram (dry weight) of these two extracts was also estimated. The result of tests for in-vitro antibacterial activity indicates that the ethanol extract showed significant activity against E.coli, S.aureus, B.subtilis and S.typhi with the zone of inhibition was 11mm, 19mm, 17mm and 16mm respectively. The water extract only inhibited the growth of S.aureus (14mm) and B.subtilis (15mm) and there was no resistance against E.coli and S.typhi. The analysis of total flavonoid content found that the ethanol extract contains higher amount of flavonoid than water extract and flavonoid is responsible mainly for the antibacterial activity of Mimosa pudica L

Ultrasonic-Assisted Cathodic Plasma Electrolysis Approach for Producing of Graphene Nanosheets

In this chapter, we review on the production of graphene by ultrasonic-assisted cathodic plasma electrolysis approach which involves a combination process of conventional electrolysis and plasma at ambient pressure and moderate temperature. Firstly, we review on the techniques for electrochemical preparation of graphene. Then, we briefly describe plasma electrolysis approach for producing of graphene. The mechanism, advantages, and disadvantages of this technique are discussed in detail

BoMb-OT: On Batch of Mini-batches Optimal Transport

Mini-batch optimal transport (m-OT) has been successfully used in practical applications that involve probability measures with intractable density, or probability measures with a very high number of supports. The m-OT solves several sparser optimal transport problems and then returns the average of their costs and transportation plans. Despite its scalability advantage, the m-OT does not consider the relationship between mini-batches which leads to undesirable estimation. Moreover, the m-OT does not approximate a proper metric between probability measures since the identity property is not satisfied. To address these problems, we propose a novel mini-batching scheme for optimal transport, named Batch of Mini-batches Optimal Transport (BoMb-OT), that finds the optimal coupling between mini-batches and it can be seen as an approximation to a well-defined distance on the space of probability measures. Furthermore, we show that the m-OT is a limit of the entropic regularized version of the BoMb-OT when the regularized parameter goes to infinity. Finally, we carry out extensive experiments to show that the BoMb-OT can estimate a better transportation plan between two original measures than the m-OT. It leads to a favorable performance of the BoMb-OT in the matching and color transfer tasks. Furthermore, we observe that the BoMb-OT also provides a better objective loss than the m-OT for doing approximate Bayesian computation, estimating parameters of interest in parametric generative models, and learning non-parametric generative models with gradient flow.Comment: 36 pages, 20 figure

A robust diagnosis method for speed sensor fault based on stator currents in the RFOC induction motor drive

A valid diagnosis method for the speed sensor failure (SSF) is an essential requirement to ensure the reliability of Fault-Tolerant Control (FTC) models in induction motor drive (IMD) systems. Most recent researches have focused on directly comparing the measured and estimated rotor speed signal to detect the speed sensor fault. However, using that such estimated value in both the fault diagnosis and the controller reconfiguration phases leads to the insufficient performance of FTC modes. In this paper, a novel diagnosis-technique based on the stator current model combined with a confusion prevention condition is proposed to detect the failure states of the speed sensor in the IMD systems. It helps the FTC mode to separate between the diagnosis and reconfiguration phases against a speed sensor fault. This proposed SSF diagnosis method can also effectively apply for IMs’ applications at the low-speed range where the speed sensor signal often suffers from noise. MATLAB/Simulink software has been used to implement the simulations in various speed ranges. The achieved results have demonstrated the capability and effectiveness of the proposed SSF method against speed sensor faults

An Improved Current-Sensorless Method for Induction Motor Drives Applying Hysteresis Current Controller

A novel strategy based on the feed-forward field-oriented control (FOC) method is proposed for the Hysteresis Current technique to control the induction motor (IM) drive without current sensors (CSs). A control scheme is proposed to estimate stator currents from reference rotor flux, rotor flux angle, and state variables as a replacement for the feedback-signal of CSs used in the hysteresis current controller (HCC). Here the rotor flux angle component is extracted from the feed-forward FOC loop. MATLAB/Simulink is applied to implement the simulations under many different operating conditions. The simulation results demonstrated the feasibility of the proposed method to obtain high performance in controlling the IM drives without the current sensors

Foreign direct investment in Vietnam: Is there any evidence of technological spillover effects

In the context of integrating more deeply into the world economy the Vietnamese policy makers have undertaken several measures to attract foreign direct investment to the country, with the culmination of FDI inflows in 2007 reaching over USD 20 billion, an increase of 69% over 2006. The policy has been taken on the ground that the FDI inflows will create employment and bring along the much needed technological advances, which will spill over to domestic firms. In this paper, we use a firm-level panel data constructed from the Census 2000-2005 to investigate not only the horizontal spillovers but also the backward and forward linkages. Adding to the current literature which focused mainly on the spillovers in the manufacturing sector, our paper provide the first estimates of the spillover effects in the service sector (at least in the context of developing countries). We also distinguish between the horizontal output spillovers (which capture demonstration effects and competition effects) and the horizontal employment spillover (which captures the labour mobility effect). The results obtained from our regression models are mixed. Different channels of spillovers are at work for the manufacturing and the service sectors. We find evidence of the positive backward technological spillovers for the manufacturing and positive horizontal spillovers for the service sector

Foreign direct investment in Vietnam: Is there any evidence of technological spillover effects

In the context of integrating more deeply into the world economy the Vietnamese policy makers have undertaken several measures to attract foreign direct investment to the country, with the culmination of FDI inflows in 2007 reaching over USD 20 billion, an increase of 69% over 2006. The policy has been taken on the ground that the FDI inflows will create employment and bring along the much needed technological advances, which will spill over to domestic firms. In this paper, we use a firm-level panel data constructed from the Census 2000-2005 to investigate not only the horizontal spillovers but also the backward and forward linkages. Adding to the current literature which focused mainly on the spillovers in the manufacturing sector, our paper provide the first estimates of the spillover effects in the service sector (at least in the context of developing countries). We also distinguish between the horizontal output spillovers (which capture demonstration effects and competition effects) and the horizontal employment spillover (which captures the labour mobility effect). The results obtained from our regression models are mixed. Different channels of spillovers are at work for the manufacturing and the service sectors. We find evidence of the positive backward technological spillovers for the manufacturing and positive horizontal spillovers for the service sector

Publisher Correction:Implementing a context-driven awareness programme addressing household air pollution and tobacco: a FRESH AIR study

In the original version of this Article, Table 2 was formatted in such a way that made it difficult to interpret. This has now been corrected in the PDF and HTML versions of the Article.</p

Rifampicin tolerance and growth fitness among isoniazid-resistant clinical Mycobacterium tuberculosis isolates: an in-vitro longitudinal study.

Antibiotic tolerance in Mycobacterium tuberculosis leads to less effective bacterial killing, poor treatment responses and resistant emergence. There is limited understanding of antibiotic tolerance in clinical isolates of M. tuberculosis . Therefore, we investigated the rifampicin tolerance of M. tuberculosis isolates, with or without pre-existing isoniazid-resistance. In-vitro rifampicin survival fractions determined by minimum duration of killing assay in isoniazid susceptible (n=119) and resistant (n=84) M. tuberculosis isolates. Rifampicin tolerance was correlated with bacterial growth, rifampicin minimum inhibitory concentrations (MICs) and isoniazid-resistant mutations. The longitudinal isoniazid-resistant isolates were analyzed for rifampicin tolerance based on collection time from patients and associated emergence of genetic variants. The median duration of rifampicin exposure reducing the M. tuberculosis surviving fraction by 90% (minimum duration of killing-MDK90) increased from 1.23 (95%CI 1.11; 1.37) and 1.31 (95%CI 1.14; 1.48) to 2.55 (95%CI 2.04; 2.97) and 1.98 (95%CI 1.69; 2.56) days, for IS and IR respectively, during 15 to 60 days of incubation respectively. Increase in MDK90 time indicated the presence of fast and slow growing tolerant sub-populations. A range of 6 log 10 -fold survival fraction enabled classification of tolerance as low, medium or high and revealed isoniazid-resistance association with increased tolerance with faster growth (OR=2.68 for low vs. medium, OR=4.42 for low vs. high, P -trend=0.0003). The high tolerance in longitudinal isoniazid-resistant isolates was specific to those collected during rifampicin treatment in patients and associated with bacterial genetic microvariants. Our study identifies a range of rifampicin tolerance and reveals that isoniazid resistance is associated with higher tolerance with growth fitness. Furthermore, rifampicin treatment may select isoniazid-resistant isolate microvariants with higher rifampicin tolerance, with survival potential similar to multi-drug resistant isolates. These findings suggest that isoniazid-resistant tuberculosis needs to be evaluated for rifampicin tolerance or needs further improvement in treatment regimen