Bioreduction of Cr (VI) by potent novel chromate resistant alkaliphilic Bacillus sp. strain KSUCr5 isolated from hypersaline Soda lakes

Isolation of Cr (VI) resistant alkaliphilic bacteria from sediment and water samples collected from Wadi Natrun hypersaline Soda lakes (located in northern Egypt), resulted in isolation of several alkaliphilic bacterial strains that can tolerate up to 2.94 g/l of Cr (VI) in alkaline medium. However, with increasing Cr (VI) concentration up to 29.4 g/l, only one strain, KSUCr5, was able to tolerate up to 22 g/l (75 mM) and with MIC value of 23.5 g/l (80 mM) in alkaline medium (pH 10.5) containing 10% NaCl. Based on the 16S rRNA gene analysis, strain KSUCr5 was identified as Bacillus sp. with 99% similarity and was referred to as Bacillus sp. KSUCr5. In addition, Bacillus sp. strain KSUCr5 showed high tolerance to several other heavy metals including Cd2+ (50 mM), Mo2+ (75 mM), Mn2+ (100 mM), Cu2+ (2 mM), Ni2+ (100 mM), Pb (75 mM), Co2+ (5 mM) and Zn2+ (2 mM). Strain KSUCr5 was shown to be of a high efficiency in detoxifying chromate, as it could rapidly reduce up to 40 mg/l of Cr(VI) to a non detectable level over 24 h. In addition, at initial Cr(VI) concentration of 60 to 80 and 100 mg/l, 100% of the chromate reduction was achieved within 48 and 72 h, respectively. Strain KSUCr5 could reduce Cr(VI) efficiently  over a wide range of initial Cr(VI) concentrations (10 to 300 mg/l) in alkaline medium under aerobic conditions without significant effect on the bacterial growth. It was able to reduce Cr(VI) in a wide range of NaCl (0 to 20%) with a maximum reduction yield at concentration of 0 to 1.5%, indicating the halo tolerance nature of the bacterium. It was found that addition of glucose and Na2CO3 to the culture medium caused a dramatic increase in Cr(VI)-reduction by Bacillus sp. strain KSUCr5. The maximum chromate removal was exhibited in alkaline medium (pH 10) containing 1.2% Na2CO3, 1.5% glucose and 1% NaCl and at incubation temperature of 35°C and culture shaking of 150 rpm. Under optimum Cr (VI) reduction conditions, Cr(VI) concentration of 80 mg/l was completely reduced within 24 h, with reduction rate of 3.3 mg h-1 which is one of the highest Cr(VI) reduction rate under high alkaline conditions, compared with other microorganisms that has been reported so far. Furthermore, the presence of other metals such as Ni2+, Mo2+, Cu2+ and Mn2+ at concentration of 100 mg/l together with Cr(VI) in the culture medium slightly increased Cr(VI)-reduction by the strain KSUCr5. Moreover, the isolate, Bacillus sp.  strain KSUCr5, exhibited an ability to repeatedly reduce hexavalent chromium without any amendment of nutrients, suggesting its potential application in continuous bioremediation of Cr(VI). The results reveal the possible isolation of potent heavy metals resistant bacteria from extreme environment such as hypersaline Soda lakes and their application in bioremediation of heavy metals.Key words: Chromate reduction, bioremediation, heavy metals, Bacillus sp., Soda lakes

A comparison of epithelial cell content of oral samples estimated using cytology and DNA methylation

Saliva and buccal samples are popular for epigenome wide association studies (EWAS) due to their ease of collection compared and their ability to sample a different cell lineage compared to blood. As these samples contain a mix of white blood cells and buccal epithelial cells that can vary within a population, this cellular heterogeneity may confound EWAS. This has been addressed by including cellular heterogeneity obtained through cytology at the time of collection or by using cellular deconvolution algorithms built on epigenetic data from specific cell types. However, to our knowledge, the two methods have not yet been compared. Here we show that the two methods are highly correlated in saliva and buccal samples (R = 0.84, P < 0.0001) by comparing data generated from cytological staining and Infinium MethylationEPIC arrays and the EpiDISH deconvolution algorithm from buccal and saliva samples collected from twenty adults. In addition, by using an expanded dataset from both sample types, we confirmed our previous finding that age has strong, non-linear negative correlation with epithelial cell proportion in both sample types. However, children and adults showed a large within-population variation in cellular heterogeneity. Our results validate the use of the EpiDISH algorithm in estimating the effect of cellular heterogeneity in EWAS and showed DNA methylation generally underestimates the epithelial cell content obtained from cytology

Increased prevalence of rotavirus among children associated gastroenteritis in Riyadh Saudi Arabia

The aim of this study is to assess the epidemiology along with the molecular structure of rotavirus causing pediatric diarrhea among Saudi patients. However, in this report we sited the epidemiological reflect coming from our project

Distinct Gene Expression and Epigenetic Signatures in Hepatocyte-like Cells Produced by Different Strategies from the Same Donor

Summary: Hepatocyte-like cells (HLCs) can be generated through directed differentiation or transdifferentiation. Employing two strategies, we generated induced pluripotent stem cell (iPSC)-HLCs and hiHeps from the same donor cell line. Both types of HLCs clustered distinctly from each other during gene expression profiling. In particular, differences existed in gene expression for phase II drug metabolism and lipid accumulation, underpinned by H3K27 acetylation status in iPSC-HLCs and hiHeps. While distinct phenotypes were achieved in vitro, both types of HLCs demonstrated similar phenotypes following transplantation into Fah-deficient mice. In conclusion, functional HLCs can be obtained from the same donor using two strategies. Global gene expression defined the differences between those populations in vitro. Importantly, both HLCs displayed partial but markedly improved hepatic function following transplantation in vivo, demonstrating plasticity and the potential for cell-based modeling in the dish and cell-based therapy in the future. : In this article, Hui and colleagues show that hiHeps and iPSC-HLCs generated from the same donor display different gene expression patterns that correlate with their hepatic functions. Distinct H3K27ac modifications partially explain the functional differences between the two types of HLCs. Importantly, both HLCs show improved hepatic gene expression after repopulation in murine livers. Keywords: transdifferentiation, directed differentiation, hepatocyte-like cells, gene expression patter

Wideband Endfire Antenna Array for 5G mmWave Mobile Terminals

In this paper, a compact endfire antenna array with low-profile, small clearance, and wideband operation is proposed for millimeter-wave (mmWave) fifth-generation (5G) mobile terminals. The wideband operation is achieved by exciting two identical bow-tie dipoles inserted on both sides of a multilayer substrate fed by an asymmetric open-end stripline to slotline transition. The antenna performance is significantly improved by introducing a set of vertical metallic vias. The proposed antenna element can achieve 29 % from 24.2 GHz to 32.4 GHz with a peak realized gain that varies from 3.5 dBi to 4.5 dBi. A linear 4-element antenna array is arranged and fabricated to verify the proposed antenna beamforming capabilities. The simulated and measured bandwidth achieves a wide range of 34.4 % (24-34 GHz) to support 26, 28, and 30 GHz 5G mmWave bands with an isolation level better than 20 dB and a peak realized gain over the interested bands ranging from 7.56 to 8.14 dBi. The simulated array scanning angle is ± 68 • at 28 GHz within 3-dB gain deterioration. Furthermore, the simulated spherical coverage has met the requirements of 3GPP standards which make the proposed antenna array a promising candidate to be integrated within mmWave 5G mobile devices. INDEX TERMS 5G, antenna array, beamforming, endfire, mmWave bands, mobile terminal, wideband

Friction phenomena and their impact on the shear behaviour of granular material

In the discrete element simulation of granular materials, the modelling of contacts is crucial for the prediction of the macroscopic material behaviour. From the tribological point of view, friction at contacts needs to be modelled carefully, as it depends on several factors, e.g. contact normal load or temperature to name only two. In discrete element method (DEM) simulations the usage of Coulomb’s law of friction is state of the art in modelling particle–particle contacts. Usually in Coulomb’s law, for all contacts only one constant coefficient of friction is used, which needs to reflect all tribological effects. Thus, whenever one of the influence factors of friction varies over a wide range, it can be expected that the usage of only one constant coefficient of friction in Coulomb’s law is an oversimplification of reality. For certain materials, e.g. steel, it is known that a dependency of the coefficient of friction on the contact normal load exists. A more tribological tangential contact law is implemented in DEM, where the interparticle friction coefficient depends on the averaged normal stress in the contact. Simulations of direct shear tests are conducted, using steel spheres of different size distributions. The strong influence of interparticle friction on the bulk friction is shown via a variation of the constant interparticle friction coefficient. Simulations with constant and stress-dependent interparticle friction are compared. For the stress-dependent interparticle friction, a normal stress dependency of the bulk friction is seen. In the literature, measurements of different granular materials and small normal loads also show a stress dependency of the bulk friction coefficient. With increasing applied normal stress, the bulk friction coefficient reduces both in the experiments and in the simulations

Decisions at the end of life: have we come of age?

Decision making is a complex process and it is particularly challenging to make decisions with, or for, patients who are near the end of their life. Some of those challenges will not be resolved - due to our human inability to foresee the future precisely and the human proclivity to change stated preferences when faced with reality. Other challenges of the decision-making process are manageable. This commentary offers a set of approaches which may lead to progress in this field

Cloud e-learning for mechatronics: CLEM

his paper describes results of the CLEM project, Cloud E-learning for Mechatronics. CLEM is an example of a domain-specific cloud that is especially tuned to the needs of VET (Vocational, Education and Training) teachers. An interesting development has been the creation of remote laboratories in the cloud. Learners can access such laboratories to support their practical learning of mechatronics without the need to set up laboratories at their own institutions. The cloud infrastructure enables multiple laboratories to come together virtually to create an ecosystem for educators and learners. From such a system, educators can pick and mix materials to create suitable courses for their students and the learners can experience different types of devices and laboratories through the cloud. The paper provides an overview of this new cloud-based e-learning approach and presents the results. The paper explains how the use of cloud computing has enabled the development of a new method, showing how a holistic e-learning experience can be obtained through use of static, dynamic and interactive material together with facilities for collaboration and innovation