Evaluation of gut modulatory and bronchodilator activities of Amaranthus spinosus Linn.

Background The aqueous-methanolic extract of Amaranthus spinosus (A. spinosus Linn.,) whole plant, was studied for its laxative, spasmolytic and bronchodilator activities to validate some of its medicinal uses. Methods The crude extract of A. spinosus was studied in-vivo for bronchodilator and laxative activities and in-vitro using isolated tissue preparations which were mounted in tissue baths assembly containing physiological salt solutions, maintained at 37°C and aerated with carbogen, to assess the spasmolytic effect and to find out the possible underlying mechanisms. Results In the in-vivo experiments in mice, the administration of A. spinosus increased fecal output at doses of 100 and 300 mg/kg showing laxative activity. It also inhibited carbachol-induced bronchospasm in anesthetized rats at 1, 3, 10 and 30 mg/kg indicative of bronchodilator activity. When tested on isolated gut preparations, the plant extract showed a concentration-dependent (0.01-10.0 mg/ml) spasmogenic effect in spontaneously contracting rabbit jejunum and guinea-pig ileum. The spasmogenic effect was partially blocked in tissues pretreated with atropine (0.1 μM). When tested on K+ (80 mM)-induced sustained contractions in isolated rabbit jejunum, the plant extract caused complete relaxation and also produced a shift in the Ca++ concentration-response curves (CRCs) towards right, similar to diltiazem. In rabbit trachea, the plant extract completely inhibited K+ (80 mM) and carbachol (CCh, 1 μM)-induced contractions at 1 mg/ml but pretreatment of tissue with propranolol (1 μM), caused around 10 fold shift in the inhibitory CRCs of the plant extract constructed against CCh-induced contraction. The plant extract (up to 0.3 mg/ml) also increased both force and rate of spontaneous contractions of isolated guinea-pig atria, followed by relaxation at higher concentration (1.0-5.0 mg/ml). The cardio-stimulant effect was abolished in the presence of propranolol, similar to that of isoprenaline. Activity-directed fractionation revealed that the spasmolytic component(s) was separated in the organic fraction, whereas the spasmogenic component was concentrated in the aqueous fraction. Conclusion These results indicate that A. spinosus possesses laxative activity partially mediated through cholinergic action. The spasmolytic effect was mediated through calcium channel blocking (CCB), while bronchodilator activity through a combination of β-adrenergic and CCB pathways, which may explain the traditional uses of A. spinosus in gut and airways disorders

Organic–inorganic hybrid nanocomposite for enhanced photo-sensing of PFO-DBT:MEH-PPV:PC71BM blend-based photodetector

The sensing parameters of previously reported PFO-DBT:MEH-PPV:PC71BM ternary blend-based organic photodetector have been improved in the present study. Improvement has been successfully demonstrated by doping TiO2 nanoparticles in the PEDOT:PSS thin film. TiO2 nanoparticles of 50, 100 and 250 nm diameters have initially been dispersed in PEDOT:PSS, and the resulting suspension has been spun coated on glass substrates and subjected to UV/vis and PL study. Thin film of PEDOT:PSS–TiO2 (100 nm) has shown maximum quenching in PL spectra, along with fairly good visible-light absorption. For further studies, 5 wt% TiO2 (100 nm) nanoparticles dispersion in PEDOT:PSS has been utilized for the fabrication of ITO/PEDOT:PSS–TiO2/PFO-DBT:MEH-PPV:PC71BM/Al photodiode. The PEDOT:PSS–TiO2 suspension has been spun coated onto the ITO substrates primarily and annealed to densify the film by vaporizing water contents in the film. A ternary blend of PFO-DBT:MEH-PPV:PC71BM in optimized volumetric ratio has been sequentially spun-cast to serve as a photoactive film. Significantly improved values of the sensing parameters such as responsivity (4 mA/W) and photo-to-dark current ratio (~6.4 × 104) have also been found. Response/recovery times of the fabricated sensor remain almost the same (<1 s) as previously reported for PFO-DBT:MEH-PPV:PC71BM ternary blend

Multiphysics based Numerical Study of Atmospheric Ice Accretion on a Full Scale Horizontal Axis Wind Turbine Blade

Atmospheric icing on wind turbines have been recognized as a hindrance to the development of the wind power in cold regions, where uncertainty surrounding the effects of icing on energy production may prevent otherwise good wind resources from being utilized. This research paper is focused on to numerically simulate the rate and shape of atmospheric ice accretion on a full-scale horizontal axis wind turbine blade. Computational fluid dynamics based multiphase numerical analyses have been carried out where results showed a decrease in atmospheric ice growth rate along leading edge with the increase of blade profile size, both in terms of local ice mass and thickness. Streamlined ice shapes were observed near the blade root section, as compared to the blade tip section

Influence of relative humidity on the electrical response of PEDOT:PSS based organic field-effect transistor

We have investigated the influence of relative humidity on the electrical response of a bottom gate organic field-effect transistor (OFET) with poly(3,4-ethylenedioxythiophene)/poly(4-styrene sulfonate) (PEDOT:PSS) as an active channel material. For sensor fabrication, the organic polymer PEDOT:PSS has been spun-cast on highly doped n-Si wafer with preliminary thermally deposited gold, source and drain electrodes. The structural characterization and surface morphology study of active layer has been performed by XRD and FESEM, respectively. From the transfer characteristic curve, the p-type hole conductivity in PEDOT:PSS thin film is confirmed. Whereas from the output current-voltage (I�V) characteristic of the OFET, the Ion/Ioff ratio has been measured to be ?2.6, when operated at relative humidity (RH) ?60%. The humidity sensing characteristics of the OFET have further been investigated by exposing the proposed OFET to varied RH levels (40�80% RH) at room temperature (26.2 �C). Within the humidity range examined, the channel current has been observed to amplify by nearly 29.4 times of its magnitude. 2017 Elsevier B.V.Authors are thankful to the Ministry of Education for the financial support under High Impact Research (HIR) grant UM.S/625/3/HIR/MOE/26 with account number UM.0000080/HIR.C3 and University Malaya Research Grant (UMRG) under grant number RP007A-13AFR . Q. Zafar is thankful to Erasmus Mundus (EM) INTACT program for Post-Doc mobility. Dr. Qayyum Zafar was born in 1986 at Lahore-city, Pakistan. He graduated in Physics from Government College University (GCU), Lahore in 2008. He received his MS degree from Ghulam Ishaq Khan Institute of Engineering Sciences and Technology (GIKI), Swabi in 2011. He served as Research Associate at Nano sensors.catalysis lab at COMSATS Institute, Islamabad for one year. He obtained his PhD in Applied Physics (Organic Electronics) from Department of Physics, University of Malaya, Malaysia. He later joined Solar/Photovoltaic Materials Research Group as a Postdoctoral Research Fellow in 2015. Currently he is serving as ERASMUS MUNDUS (INTACT) postdoctoral Research Fellow at Department of Electrical Engineering, Frederick University, Cyprus. Dr. Shahino Mah Abdullah was born in Johor, Malaysia in 1987. He completed his B.Sc. and Ph.D. degrees in Physics from the University of Malaya, Malaysia. He joined Low Dimensional Materials Research Centre (LDMRC) at Department of Physics, University of Malaya as a postdoctoral research fellow in 2016. His research interests encompass fabrication of electrochemical and organic semiconducting devices including solar cells, light-emitting diodes, and field-effect transistors. Currently, he is a Research Fellow at International Institute of Advanced Islamic Studies (IAIS) Malaysia, with interest in Science, Technology, Environment and Ethics. Mohamad Izzat Azmer was born at Ipoh, Perak in 1989. He completed his BSc. (Hons.) in Materials Technology in 2013 at Universiti Teknologi Mara (UiTM), Shah Alam, Selangor, Malaysia. He has recently completed his MS applied Physics from Solar/Photovoltaic Materials Research Group, Department of Physics, University of Malaya, Malaysia. Dr. Mansoor Ani Najeeb received his Bachelors in Physiotherapy from Calicut University (India) and M.Tech in Biomedical Engineering from VIT University (India). He completed his Ph.D in Biomedical Engineering & Nanotechnology from Noorul Islam University (India). Prior to his Ph.D, he was working as an Assistant Professor at the Department of Biomedical Engineering, Noorul Islam University. He joined Solar/Photovoltaic Materials Research Group as a Postdoctoral Research Fellow in 2014. Currently, he is working as PostDoc Research Fellow at Center for Advanced Materials, Qatar University, Qatar . His current research interests are Organic Semiconductor based biosensors, Thin Films and Nano Biomaterials. Dr. Karwan Wasman Qadir was born in Dbis-Kerkuk, Kurdistan, Iraq in 1982. He did his B.Sc in Physics in 2005 and M.Sc in Solar Radiation Physics in 2010 from Salahaddin University, Erbil, Iraq. His M.Sc research title was Study and Analysis of Global Solar Radiation in Kurdistan Region-Iraq. He earned his PhD in Applied Physics from Universiti Malaya. Currently, he is working as lecturer and researcher at Salahaddin University, Erbil, Iraq. Dr. Khaulah Sulaiman is an Associate Professor at Department of Physics, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia. Her current research interests are organic semiconductor device physics, solution process-able organic semiconductor thin films, organic/metal interface and organic solar cells.Scopu

Citric acid enhances the phytoextraction of manganese and plant growth by alleviating the ultrastructural damages in Juncus effusus L.

Chelate-assisted phytoextraction by high biomass producing plant species enhances the removal of heavy metals from polluted environments. In this regard, Juncus effusus a wetland plant has great potential. This study evaluated the effects of elevated levels of manganese (Mn) on the vegetative growth, Mn uptake and antioxidant enzymes in J. effusus. We also studied the role of citric acid and EDTA on improving metal accumulation, plant growth and Mn toxicity stress alleviation. Three-week-old plantlets of J. effusus were subjected to various treatments in the hydroponics as: Mn (50, 100 and 500 μM) alone, Mn (500 μM) + citric acid (5 mM), and Mn (500 μM) + EDTA (5 mM). After 2 weeks of treatment, higher Mn concentrations significantly reduced the plant biomass and height. Both citric acid and EDTA restored the plant height as it was reduced at the highest Mn level. Only the citric acid (but not EDTA) was able to recover the plant biomass weight, which was also obvious from the microscopic visualization of mesophyll cells. There was a concentration dependent increase in Mn uptake in J. effusus plants, and relatively more deposition in roots compared to aerial parts. Although both EDTA and citric acid caused significant increase in Mn accumulation; however, the Mn translocation was enhanced markedly by EDTA. Elevated levels of Mn augmented the oxidative stress, which was evident from changes in the activities of antioxidative enzymes in plant shoots. Raised levels of lipid peroxidation and variable changes in the activities of antioxidant enzymes were recorded under Mn stress. Electron microscopic images revealed several modifications in the plants at cellular and sub-cellular level due to the oxidative damage induced by Mn. Changes in cell shape and size, chloroplast swelling, increased number of plastoglobuli and disruption of thylakoid were noticed. However, these plants showed a high degree of tolerance against Mn toxicity stress, and it removed substantial amounts of Mn from the media. The EDTA best enhanced the Mn uptake and translocation, while citric acid best recovered the plant growth

Haploid and Doubled Haploid Technology

The microspore culture technique has its wide applications in plant genetic research and breeding programmes in oilseed Brassicas due to its relative simplicity, efficiency in haploid and doubled haploid production, mutation and germplasm generation, and gene transformation. Various factors could influence microspore embryogenesis and haploid production including donor plant genotype, donor plant physiology, microspore developmental stage, culture conditions, culture environment and pretreatments. Stress is also an essential component during embryogenesis induction in microspore culture. Efficient plant regeneration from microspores mostly occurs through direct embryogenesis ensuring minimal occurrence of cytogenetic abnormalities. Appropriate stress conditions such as chilling, partial desiccation, cotyledon excision, and successive subculture of microspore-derived embryos could promote plant development in oilseed rape. Medium renovation, phytohormones and plant growth regulators, and chromosome doubling agents such as colchicine treatment also affect plant regeneration in Brassica species. Compared to colchicine treatments of microspore-derived embryos and plants, immediate colchicine treatment of isolated microspores results in high embryogenesis and diploidisation and low chimeric percentages. The ploidy level of microspore-derived plants of Brassica species could be estimated by different methods at various stages. Mutation breeding techniques are widely used in plant breeding for producing useful mutants and variants. Microspore culture also provides an ideal method for mutation because the mutated traits can be fixed in homozygous condition by chromosome doubling, which can enforce to obtain target mutation traits efficiently. Ultraviolet irradiation, mutagenic agents ethyl methane sulphonate and sodium azide could be applied to isolated microspores and the derived embryos of rapeseed. Utilization of microspore-derived embryos for production of desired traits such as the altered fatty acids, disease resistance and glucosinolate compositions through mutagenesis and selection is advancing and also discussed

Development of an efficient tissue culture protocol for callus formation and plant regeneration of wetland species Juncus effusus L.

Wetland species mat rush (Juncus effusus L.) is an important economic plant, but no information is available regarding plant regeneration, callus induction, and its proliferation from in vitro seed grown plantlets. The present study investigates the effects of growth regulator combinations and medium innovation on tissue culture system of five mat rush varieties. Addition of N6-benzyladenine (BA) and 2,4-dichlorophenoxyacetic acid (2,4-D) in Murashige and Skoog (MS) medium showed significantly positive effect on callus proliferation, plant regeneration, and its multiplication compared to the medium devoid of BA. The highest callus induction frequency (80.95%, 90.48%, 75.40%, 70.83%, and 83.33%) was observed in MS medium containing 0.5 mg L (2.2 μM) BA in Yinlin-1, Nonglin-4, Gangshan, Taicao, and Taiwan green, respectively. Various growth regulator combinations with successive subculture (medium replacement) were found essential to develop organogenic calluses and to regenerate shoots. The combination of 0.1 mg L BA (0.4 μM) and 2 mg L 2,4-D (9.0 μM) in MS medium was found best for callus proliferation for all the varieties under trial. The plant regeneration required two steps involving successive medium replacements as well as optimal hormonal balances. Successful plant regeneration (over 70%) was observed only by transferring the organogenic callus from regeneration medium I [MS medium containing 0.5 mg L BA (2. μM) and 1.0 mg L kinetin (KT; 4.6 μM)] to the regeneration medium II [MS medium containing 0.5 mg L BA (2.2 μM), 1.0 mg L KT (4.6 μM) and 3.0 mg L indoleacetic acid (IAA; 17.1 μM)]. Our results confirmed the importance of the ratio of auxin (IAA) to cytokinin (BA and KT) in the manipulation of shoot regeneration in J. effusus L. The maximum plant survival frequency and multiplication rates (90.97% and 5.40 and 94.23% and 8.25) were recorded in the presence of 0.5 mg L BA (2.2 μM) in the 1/2 MS multiplication medium for the varieties of Nonglin-4 and Taicao, respectively. About 100% survival rate was also observed for all the varieties in soil conditions. The efficient plant regeneration system developed here will be helpful for rapid micropropagation and further genetic improvement in J. effusus L

Drug design from the cryptic inhibitor envelope.

Conformational dynamics plays an important role in enzyme catalysis, allosteric regulation of protein functions and assembly of macromolecular complexes. Despite these well-established roles, such information has yet to be exploited for drug design. Here we show by nuclear magnetic resonance spectroscopy that inhibitors of LpxC--an essential enzyme of the lipid A biosynthetic pathway in Gram-negative bacteria and a validated novel antibiotic target--access alternative, minor population states in solution in addition to the ligand conformation observed in crystal structures. These conformations collectively delineate an inhibitor envelope that is invisible to crystallography, but is dynamically accessible by small molecules in solution. Drug design exploiting such a hidden inhibitor envelope has led to the development of potent antibiotics with inhibition constants in the single-digit picomolar range. The principle of the cryptic inhibitor envelope approach may be broadly applicable to other lead optimization campaigns to yield improved therapeutics