Bioaccumulation of heavy metals by Dyera costulata cultivated in sewage sludge contaminated soil

High concentrations of heavy metals are harmful to plants, animals and humans and their potential accumulation in human tissues and bio-magnification through the food chain cause serious health hazards. An experiment was conducted in the glasshouse to evaluate the potential of Dyera costulata as a bioaccumulator to absorb heavy metals from sewage sludge contaminated soils. D. costulata seedlings were planted in the following growth media: T0 (control soil), T1 (100% sludge), T2 (80% sludge + 20% soil), T3 (60% sludge + 40% soil), T4 (40% sludge + 60% soil) and T5 (20% sludge + 80% soil). T4 showed the best growth performance in terms of height, basal diameter and number of leaves. The maximum reduction of Cd, Cr and Pb was found in the 100% sludge treatment. Zn, Cd, Ni and Cr were highly concentrated in the leaves, while Pb accumulated mainly in the stems. D. costulata showed high potential to retain high amounts of Zn, Ni and Cr in the leaves and Pb in the stems. The species had high translocation factor (TF) and low bioconcentration factor (BCF) values in the soil at higher metal concentrations as well as it was able to tolerate and accumulate high concentrations of Zn, Cd, Ni, Cr and Pb. It means that, this species is a good accumulator of heavy metals and can be considered as a potential bioaccumulator species.Key words: Phytoremediation, Dyera costulata, heavy metals, sewage sludge

Classical and quantum spinor cosmology with signature change

We study the classical and quantum cosmology of a universe in which the matter source is a massive Dirac spinor field and consider cases where such fields are either free or self-interacting. We focus attention on the spatially flat Robertson-Walker cosmology and classify the solutions of the Einstein-Dirac system in the case of zero, negative and positive cosmological constant $\Lambda$. For $\Lambda<0$, these solutions exhibit signature transitions from a Euclidean to a Lorentzian domain. In the case of massless spinor fields it is found that signature changing solutions do not exist when the field is free while in the case of a self-interacting spinor field such solutions may exist. The resulting quantum cosmology and the corresponding Wheeler-DeWitt equation are also studied for both free and self interacting spinor fields and closed form expressions for the wavefunction of the universe are presented. These solutions suggest a quantization rule for the energy.Comment: 13 pages, 4 figure

Efficacy of Probiotic Escherichia coli Nissle 1917 in Patients with Irritable Bowel Syndrome: a Double Blind Placebo-controlled Randomized Trial

AIM: to evaluate potential improvement effect for probiotic E. coliNissle 1917 in the management of refractory IBS in an Iranian population. METHODS: a double blind placebo controlled approach has been used in the current clinical trial. 139 confirmed IBS patients were included into the study, and were given probiotic E.coli Nissle 1917 for 6 weeks. 11 items Birmingham IBS Symptom Questionnairehas been used for evaluation of changes in the symptoms every 2 weeks. CONCLUSION: probiotic therapy with E.coli Nissle 1917 was not able to induce significant improvement in the symptoms of patients with non-categorized IBS. Nevertheless, when IBS patients were recategorized to subgroups according to their main symptoms, evaluation of the efficacy of the probiotic on some individual items in the symptom list reached the significance level. Prospective clinical trials are recommended to confirm our findings. RESULTS: sixty eight subjects (49) were males. Mean±SD age of the participants was 38±13.3 years. 49(35.3) of the patients were diarrhea-predominant. The total scores showed no significant difference between the intervention vs. control group(-6.7±6.8 vs. -6.7±6.5, respectively; p=0.95); neither did any of the questionnaire items any significant alterations in the two groups. After stratification of patients based on their IBS type, diarrhea-predominant patients showed a positive response to the probiotic improving their sleep (p=0.05 and 0.03 at weeks 2 and 6, respectively). Patients with constipation-predominant IBS showed no response to the probiotic; while patients with diarrhea-constipation mixed IBS showed unfavorable response to the probiotic in the need for strain to pass a motion compared to the placebo (p=0.03 and 0.02 at weeks 4 and 6, respectively)

Canonical wave packets in quantum cosmology

We discuss the construction of wave packets resulting from the solutions of a class of Wheeler-DeWitt equations in Robertson-Walker type cosmologies, for arbitrary curvature. We show that there always exists a ``canonical initial slope" for a given initial wave function, which optimizes some desirable properties of the resulting wave packet, most importantly good classical-quantum correspondence. This can be properly denoted as a canonical wave packet. We introduce a general method for finding these canonical initial slopes which is generalization of our earlier work.Comment: 19 pages, 8 figure

Comparison of quinolone and β-lactam resistance among Escherichia coli strains isolated from urinary tract infections

The growing frequency of antibiotic resistances is now a universal problem. Increasing resistance to new generations of β-lactam and quinolone antibiotics in multidrug- resistant Enterobacteriaceae isolates is considered an emergency health issue worldwide. The aim of this study was to evaluate plasmid-mediated quinolone resistance genes in ESBL-producing Escherichia coli isolated from urinary tract infections (UTIs). In our study ESBL- producing isolates were assessed by screening methods. After determination of antimicrobial susceptibility, detection of ESBLs and quinolone resistance genes was performed. A total of 97 ESBL-producing E. coli were determined. The blaTEM, blaSHV and blaCTX-M genes were detected in 90 isolates. The blaTEM was the most frequent- ly detected gene (46.4), followed by blaSHV (31.9) and blaCTX-M (14.4). The most prevalent quinolone resistance gene among ESBL-producing isolates was oqxAB which found in 67 isolates (69.1). The frequencies of the aac(6�)-Ib-cr, qnr and qepA were 65 (67), 8 (8.2) and 6 (6.2), respectively. Our data indicate that the prevalence of plasmid-mediated quinolone resistance genes in ESBL-positive isolates is increasing. The co-dissemination of PMQR and ESBL genes among E. coli isolates can be considered a threat to public health. Therefore, prescription of antibiotics against infectious disease should be managed carefully. © 2016, International Society of Musculoskeletal and Neuronal Interactions. All rights reserved

Fatigue strengthening of damaged steel members using wire arc additive manufacturing

In this study, a directed energy deposition (DED) process called wire arc additive manufacturing (WAAM) is employed for the fatigue strengthening of damaged steel members. Three steel specimens with central cracks were tested under a high-cycle fatigue loading (HCF) regime: (1) the reference specimen; (2) the WAAM-repaired specimen with an as-deposited profile, and (3) the WAAM-repaired specimen machined to reduce stress concentration factors (SCF). The corresponding finite element (FE) simulation of the WAAM process was calibrated using static experimental results, which revealed the main mechanism. The process was found to introduce compressive residual stresses at the crack tip owing to the thermal contraction of the repair. The FE results also revealed that stress concentration exists at the root of the as-deposited WAAM; this stress concentration can be mitigated by machining the WAAM to a pyramid-like shape. The fractography analysis indicated that the cracks were initiated at the WAAM-steel interface, and microscopic observations revealed that the microcracks were arrested by the porosities in the melted interface. The results of this pioneering study suggest that WAAM repair is a promising technique for combating fatigue damage in steel structures

Compactification and signature transition in Kaluza-Klein spinor cosmology

We study the classical and quantum cosmology of a 4+1-dimensional space-time with a non-zero cosmological constant coupled to a self interacting massive spinor field. We consider a spatially flat Robertson-Walker universe with the usual scale factor $R(t)$ and an internal scale factor $a(t)$ associated with the extra dimension. For a free spinor field the resulting equations admit exact solutions, whereas for a self interacting spinor field one should resort to a numerical method for exhibiting their behavior. These solutions give rise to a degenerate metric and exhibit signature transition from a Euclidean to a Lorentzian domain. Such transitions suggest a compactification mechanism for the internal and external scale factors such that $a\sim R^{-1}$ in the Lorentzian region. The corresponding quantum cosmology and the ensuing Wheeler-DeWitt equation have exact solutions in the mini-superspace when the spinor field is free, leading to wavepackets undergoing signature change. The question of stabilization of the extra dimension is also discussed.Comment: 12 pages, 1 figure, to appear in Annals of Physic

Accelerated gas-liquid visible light photoredox catalysis with continuous-flow photochemical microreactors

In this protocol, we describe the construction and use of an operationally simple photochemical microreactor for gas-liquid photoredox catalysis using visible light. The general procedure includes details on how to set up the microreactor appropriately with inlets for gaseous reagents and organic starting materials, and it includes examples of how to use it to achieve continuous-flow preparation of disulfides or trifluoromethylated heterocycles and thiols. The reported photomicroreactors are modular, inexpensive and can be prepared rapidly from commercially available parts within 1 h even by nonspecialists. Interestingly, typical reaction times of gas-liquid visible light photocatalytic reactions performed in microflow are lower (in the minute range) than comparable reactions performed as a batch process (in the hour range). This can be attributed to the improved irradiation efficiency of the reaction mixture and the enhanced gas-liquid mass transfer in the segmented gas-liquid flow regime

Emergence of Convolutional Neural Network in Future Medicine: Why and How. A Review on Brain Tumor Segmentation

Manual analysis of brain tumors magnetic resonance images is usually accompanied by some problem. Several techniques have been proposed for the brain tumor segmentation. This study will be focused on searching popular databases for related studies, theoretical and practical aspects of Convolutional Neural Network surveyed in brain tumor segmentation. Based on our findings, details about related studies including the datasets used, evaluation parameters, preferred architectures and complementary steps analyzed. Deep learning as a revolutionary idea in image processing, achieved brilliant results in brain tumor segmentation too. This can be continuing until the next revolutionary idea emerging. © 2018 Behrouz Alizadeh Savareh et al., published by De Gruyter Open