499 research outputs found

    Response of lettuce to Cd-enriched water and irrigation frequencies

    Get PDF
    This pot experiment was an attempt to investigate a broad response of lettuce to different cadmium (Cd) levels of irrigation water (0, 5, 10 and 20 mg l-1) under different irrigation intervals (1, 2 and 4 days). The results showed that increased level of soil Cd through irrigation eventually decreased the yield of lettuce in all cases; however, in some cases yield was increased with lower doses of Cd application. No injury symptoms were observed other than plant height and yield reduction. Shoot dry weight proved to be the most sensitive parameters to the cadmium, especially under water stress conditions. The results also showed that the concentrations of nutrient elements in lettuce shoot were suppressed by water stress. The presence of cadmium in irrigation water did not significantly affect the absorption of nutrient elements by plants except for Fe. Shoot Cd concentration and its uptake decreased with increasing irrigation frequencies and the reverse trend occurred with increasing Cd levels of irrigation water. However, the values were higher than recommended guideline in all conditions. Also, shoot Cd content showed a significant positive correlation with the final accumulated Cd concentration of soil and was expressed by a plateau model under the dry irrigation regime and linear models at other irrigation intervals. Overall, shoot Cd concentration was predicted by using a simple linear regression model regardless of evapotranspiration and transpiration rate of plant.Key words: Cadmium toxicity; chemical composition; irrigation frequency; lettuce

    Experimental Evaluation of Geocell and EPS Geofoam as Means of Protecting Pipes at the Bottom of Repeatedly Loaded Trenches

    Get PDF
    © 2020 American Society of Civil Engineers. With growing populations and continuing urban development, embedding pipes in the ground that are then overrun by traffic is inevitable. This paper describes full-scale prototype tests on high-density polyethylene (HDPE) flexible pipes (of 250 mm diameter), buried at shallow depth, under simulated traffic loading. The paper studies the effect of surface load diameter (0.6×, 0.8×, and 1× pipe diameter) and the amplitude of repeated load (400 or 800 kPa) on pipe behavior. The effects of expanded polystyrene (EPS) geofoam blocks of various densities and also of geocells as a three-dimensional (3D) reinforcement in reducing the pressure transferred to the pipe, the deformation of the pipe, and the surface settlement of the backfill were investigated. The results show that, with an increase in loading surface diameter, the pipe's vertical diametral strain, the pressure transferred to the pipe, and the surface settlement grow significantly, irrespective of applied pressure. Using an EPS block over the pipe increases the soil settlement but reduces transferred pressure onto the pipe and, consequentially, results in lower pipe deformations. The increase in density of an EPS block helps improve response but was still found to be insufficient to prevent increase in surface deflections. The use of geocell reinforcement beneath the loading surface not only reduces the pressure transferred to the pipe and decreases its deformation but also significantly negates the tendency of the EPS block to increase the soil surface settlement. Thus, a geocell reinforcement layer placed over two EPS geofoam blocks (with total thickness 0.3× and width 1.5× the pipe diameter) all above a pipe buried at a depth of twice the pipe diameter, was found to deliver an acceptable, stable response. By these means, the vertical pipe strain, transferred pressure over the pipe, and soil surface settlement were reduced, respectively, by 0.45, 0.37, and 0.53× those obtained for the comparable unmodified buried pipe installation and are within allowable limits

    Comparing efficacy of montelukast versus doxycycline in treatment of moderate acne

    Get PDF
    Background: Treatment of acne is an important issue for reducing the cosmetic and psychological burden of disease. Regarding the inflammatory effect of LT-B4 in acne lesions and action mechanism of Montelukast, this study was performed to determine the efficacy of Montelukastin acne treatment comparison with doxycycline. Materials and Methods: In a randomized clinical trial that was performed in Dermatology Clinic in a Training Tertiary Health Care Center in Tehran, Iran since January 2012 to May 2014, 52 patients with moderate acne were evaluated. The included patients were randomly assigned to receive doxycycline 100 mg/day plus 1 Clindamycin solution (Group 1) or Montelukast 5 mg daily plus 1 clindamycin solution (Group 2). The acne severity index was measured and compared between two groups at baseline (on admission), 1-month and 3 months later. Independent-Sample-T, Chi-Square, and Repeated-Measure ANOVA tests were used and were considered statistically significant at P < 0.05. Results: The mean age was 26.8 ± 7.1 in Group 1 and25 ± 4.8 in Group 2 (P = 0.1). 73 women and 26.7 4 men in Group 1 and 86.7 women, and 13.3 men in Group 2 (P = 0.01). The mean acne severity index at baseline was 18.2 ± 6.1 and 19 ± 4.2 in Montelukast and doxycycline group, respectively (P = 0.679). The mean acne severity index after 1-month was 10.5 ± 6.2 and 12.9 ± 3.3 in Montelukast and doxycycline group, respectively (P = 0). Finally, the mean acne severity index after 3 months follow-up was 8.6 ± 4.8 and 8.2 ± 1.2 in Montelukast and doxycycline group, respectively (P = 0.01). There was no significant difference between two groups regarding the amount of decrease in acne severity index across the study (P = 0.186). However, each groups showed a significant reduction in the acne severity index, separately (P = 0.001). Conclusion: It may be concluded that Montelukast is an effective and safe medication for moderate-level acne treatment. © 2015, Isfahan University of Medical Sciences(IUMS). All rights reserved

    The Antibacterial Effect of Low Temperature Stored Amnion on Growth of Escherichia Coli, Staphylococcus Aureus and Pseudomonas Aeruginosa

    Get PDF
    BACKGROUND AND OBJECTIVE: Amniotic membrane (AM) has a lot of applied properties like anti-bacterial characteristic mediated by peptides such as elafin. Because of limitations in use of freshly prepared tissue, there are various methods for long-term preservation of amniotic membrane. This study was conducted to determine the effect of cryopreservation, as one of the common methods of preservation of amniotic membrane, on its antibacterial property against the growth of commonly occurring bacteria in the clinic. METHODS: In this experimental study, the effect of fresh AM (from elective Cesarean) and cryopreserved (by 10% DMSO) AM on the growth of three standard bacterial strains including Escherichia coli ATCC 25922, Staphylococcus aureus, Pseudomonas aeruginosa and two clinical isolated strains of E.coli were evaluated using disk diffusion test. In this method, pieces of fresh or cryopreserved AM was placed in the culture plate after bacterial culturing. After incubation, the number of plates with inhibition zone and amount of inhibition zone were measured. The amount of elafin was measured in AM samples using ELISA. RESULTS: Fresh AM inhibit the growth of Pseudomonas aeruginosa and two clinical isolated strains of E.coli. However, it has no effect on the growth of standard strain of Escherichia coli and Staphylococcus aureus strain. There is no difference in the number of plates including inhibition zone between fresh and cryopreserved AM. The amount of elafin decreased significantly in cryopreserved AM (p<0.01). CONCLUSION: The results of this study showed that the anti-bacterial property of the AM depends on bacterial species. In addition, the cryopreservation process maintains anti-bacterial properties of amniotic stem cells

    Caon serum iron level, ferritin and total iron binding capacity level among nonpregnant women with and without melasma

    Get PDF
    Background: Melasma is a common acquired disorder characterized by symmetric, hyperpigmented patches with an irregular outline, occurring most commonly on the face. It is most prevalent among young to middle-aged women. Although iron overload affects skin pigmentation, effect of iron deficiency on skin is not clear. So, we evaluated serum iron level, ferritin and total iron binding capacity (TIBC) level among nonpregnant women with and without melasma. Materials and Methods: A cross-sectional case study was conducted in 2012 at university dermatologic department on 33 nonpregnant women with melasma (case) and 33 nonpregnant women without melasma (control). Serum iron level, TIBC and ferritin in the two groups was measured and compared. Results: Serum iron level was lower in the case group (85 ± 11) in comparison with control group (102 ± 9), but the difference was not significant (P: 0.9). Mean TIBC and Ferritin were higher in the case group (TIBC: 329.4 ± 29, ferritin: 6 ± 18) than the control group (TIBC: 329.3 ± 29, ferritin: 33 ± 6) without significant difference. Conclusion: Although the serum iron level was lower in nonpregnant women with mealsma, it was not significant compared with those without melasma. © 2015, Isfahan University of Medical Sciences(IUMS). All rights reserved

    Murine and human pluripotent stem cell-derived cardiac bodies form contractile myocardial tissue in vitro

    Get PDF
    AimsWe explored the use of highly purified murine and human pluripotent stem cell (PSC)-derived cardiomyocytes (CMs) to generate functional bioartificial cardiac tissue (BCT) and investigated the role of fibroblasts, ascorbic acid (AA), and mechanical stimuli on tissue formation, maturation, and functionality.Methods and resultsMurine and human embryonic/induced PSC-derived CMs were genetically enriched to generate three-dimensional CM aggregates, termed cardiac bodies (CBs). Addressing the critical limitation of major CM loss after single-cell dissociation, non-dissociated CBs were used for BCT generation, which resulted in a structurally and functionally homogenous syncytium. Continuous in situ characterization of BCTs, for 21 days, revealed that three critical factors cooperatively improve BCT formation and function: both (i) addition of fibroblasts and (ii) ascorbic acid supplementation support extracellular matrix remodelling and CB fusion, and (iii) increasing static stretch supports sarcomere alignment and CM coupling. All factors together considerably enhanced the contractility of murine and human BCTs, leading to a so far unparalleled active tension of 4.4 mN/mm2 in human BCTs using optimized conditions. Finally, advanced protocols were implemented for the generation of human PSC-derived cardiac tissue using a defined animal-free matrix composition.ConclusionBCT with contractile forces comparable with native myocardium can be generated from enriched, PSC-derived CMs, based on a novel concept of tissue formation from non-dissociated cardiac cell aggregates. In combination with the successful generation of tissue using a defined animal-free matrix, this represents a major step towards clinical applicability of stem cell-based heart tissue for myocardial repair. © 2013 The Author

    Preparation and thermal properties of mineral-supported polyethylene glycol as form-stable composite phase change materials (CPCMs) used in asphalt pavements

    Get PDF
    Tis work was supported by the National Natural Science Foundation of China (51704040, 51778071, 51608058), the Scientifc Research Project of Hunan Provincial Department of Education for Excellent Young Scholars (16B007), Open Fund of Key Laboratory of Special Environment Road Engineering of Hunan Province (Changsha University of Science & Technology, kf160501), and Open Fund of Key Laboratory of Biohydrometallurgy, Ministry of Education (Central South University, MOEKLB1708)

    Arylmethylene hydrazine derivatives containing 1,3-dimethylbarbituric moiety as novel urease inhibitors

    Get PDF
    A new series of arylmethylene hydrazine derivatives bearing 1,3-dimethylbarbituric moiety 7a�o were designed, synthesized, and evaluated for their in vitro urease inhibitory activity. All the title compounds displayed high anti-urease activity, with IC50 values in the range of 0.61 ± 0.06�4.56 ± 0.18 µM as compared to the two standard inhibitors hydroxyurea (IC50 = 100 ± 0.15 μM) and thiourea (IC50 = 23 ± 1.7 μM). Among the synthesized compounds, compound 7h with 2-nitro benzylidene group was found to be the most potent compound. Kinetic study of this compound revealed that it is a mix-mode inhibitor against urease. Evaluation of the interaction modes of the synthesized compounds in urease active site by molecular modeling revealed that that compounds with higher urease inhibitor activity (7h, 7m, 7c, 7l, 7i, and 7o, with IC50 of 0.61, 0.86, 1.2, 1.34, 1.33, 1.94 μM, respectively) could interact with higher number of residues, specially Arg609, Cys592 (as part of urease active site flap) and showed higher computed free energy, while compounds with lower urease activity (7f, 7n, 7g, and 7a with IC50 of 3.56, 4.56, 3.62 and 4.43 μM, respectively) and could not provide the proper interaction with Arg609, and Cys592 as the key interacting residues along with lower free binding energy. MD investigation revealed compound 7h interacted with Arg609 and Cys592 which are of the key residues at the root part of mobile flap covering the active site. Interacting with the mentioned residue for a significant amount of time, affects the flexibility of the mobile flap covering the active site and causes inhibition of the ureolytic activity. Furthermore, in silico physico-chemical study of compounds 7a�o predicted that all these compounds are drug-likeness with considerable orally availability. © 2021, The Author(s)

    Vermiculite bio-barriers for Cu and Zn remediation: an eco-friendly approach for freshwater and sediments protection

    Get PDF
    The increase in heavy metal contamination in freshwater systems causes serious environmental problems in most industrialized countries, and the effort to find ecofriendly techniques for reducing water and sediment contamination is fundamental for environmental protection. Permeable barriers made of natural clays can be used as low-cost and eco-friendly materials for adsorbing heavy metals from water solution and thus reducing the sediment contamination. This study discusses the application of permeable barriers made of vermiculite clay for heavy metals remediation at the interface between water and sediments and investigates the possibility to increase their efficiency by loading the vermiculite surface with a microbial biofilm of Pseudomonas putida, which is well known to be a heavy metal accumulator. Some batch assays were performed to verify the uptake capacity of two systems and their adsorption kinetics, and the results indicated that the vermiculite bio-barrier system had a higher removal capacity than the vermiculite barrier (?34.4 and 22.8 % for Cu and Zn, respectively). Moreover, the presence of P. putida biofilm strongly contributed to fasten the kinetics of metals adsorption onto vermiculite sheets. In open-system conditions, the presence of a vermiculite barrier at the interface between water and sediment could reduce the sediment contamination up to 20 and 23 % for Cu and Zn, respectively, highlighting the efficiency of these eco-friendly materials for environmental applications. Nevertheless, the contribution of microbial biofilm in open-system setup should be optimized, and some important considerations about biofilm attachment in a continuous-flow system have been discussed.This work has been produced thanks to the collaboration of Dip.SA (University of Bologna) and IBB (University of Minho). A particular acknowledgment is due to Dr. E. Rosales. The work was partially financed by the FCT Strategic Project Pest-OE/EQB/LA0023 and the Project ‘‘BioEnv—Biotechnology and Bioengineering for a sustainable world,’’ co-funded by the Programa Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER

    2018 Robotic Scene Segmentation Challenge

    Get PDF
    In 2015 we began a sub-challenge at the EndoVis workshop at MICCAI in Munich using endoscope images of ex-vivo tissue with automatically generated annotations from robot forward kinematics and instrument CAD models. However, the limited background variation and simple motion rendered the dataset uninformative in learning about which techniques would be suitable for segmentation in real surgery. In 2017, at the same workshop in Quebec we introduced the robotic instrument segmentation dataset with 10 teams participating in the challenge to perform binary, articulating parts and type segmentation of da Vinci instruments. This challenge included realistic instrument motion and more complex porcine tissue as background and was widely addressed with modifications on U-Nets and other popular CNN architectures. In 2018 we added to the complexity by introducing a set of anatomical objects and medical devices to the segmented classes. To avoid over-complicating the challenge, we continued with porcine data which is dramatically simpler than human tissue due to the lack of fatty tissue occluding many organs
    corecore