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https://www.readbyqxmd.com/read/29149723/residual-effects-of-biochar-on-growth-photosynthesis-and-cadmium-uptake-in-rice-oryza-sativa-l-under-cd-stress-with-different-water-conditions
#1
Muhammad Rizwan, Shafaqat Ali, Tahir Abbas, Muhammad Adrees, Muhammad Zia-Ur-Rehman, Muhammad Ibrahim, Farhat Abbas, Muhammad Farooq Qayyum, Rab Nawaz
Soil cadmium (Cd) contamination and drought stress are among the main issues hindering global food security. Biochar has been used to reduce metal uptake by plants and water stress mitigation, but long-term residual effects of biochar under Cd stress at different moisture levels needs to be investigated. A following rice (Oryza sativa L.) was grown after wheat on Cd-contaminated soil amended with different levels of biochar (0, 3.0, and 5.0%, w/w). Thirty five days old plants were irrigated with three moisture levels including zero drought as a control (1-2 cm water layer on soil), mild drought (MD, 50% of soil water holding capacity, WHC), and severe drought (SD, 35% of soil WHC) for an accompanying 35 days...
November 14, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/29149720/a-robust-strategy-for-preparation-of-sequential-stimuli-responsive-block-copolymer-prodrugs-via-thiolactone-chemistry-to-overcome-multiple-anticancer-drug-delivery-barriers
#2
Wendong Ke, Wei Yin, Zengshi Zha, Jean Felix Mukerabigwi, Weijian Chen, Yuheng Wang, Chuanxin He, Zhishen Ge
Block copolymer prodrugs (BCPs) have attracted considerable attentions in clinical translation of nanomedicine owing to their self-assembly into well-defined core-shell nanoparticles for improved pharmacokinetics, stability in blood circulation without drug leakage, and optimized biodistribution. However, a cascade of physiological barriers against specific delivery of drugs into tumor cells limit the final therapeutic efficacy. Herein, we report a robust and facile strategy based on thiolactone chemistry to fabricate well-defined BCPs with sequential tumor pH-promoted cellular internalization and intracellular stimuli-responsive drug release...
November 9, 2017: Biomaterials
https://www.readbyqxmd.com/read/29149714/influence-of-fe-ii-on-the-se-iv-sorption-under-oxic-anoxic-conditions-using-bentonite
#3
Jiangang He, Yanlin Shi, Xiaoyu Yang, Wanqiang Zhou, Yao Li, Chunli Liu
(79)Se, one of the key radionuclides for nuclear waste disposal, threatens the quality of the environment, as well as human health. Therefore, it needs to be permanently isolated from the biosphere. The aim of the study was to investigate the effects of Fe(II)/Fe(III) on the removal of (79)Se using bentonite in the pH range of 2.0-10.0 under oxic/anoxic conditions. Under oxic conditions, Se(IV) prefers to form inner-sphere complexes with Fe(III)-oxyhydroxide, derived from the oxidization of Fe(II) using oxygen...
October 27, 2017: Chemosphere
https://www.readbyqxmd.com/read/29149700/protective-role-of-biosynthesized-silver-nanoparticles-against-early-blight-disease-in-solanum-lycopersicum
#4
Madhuree Kumari, Shipra Pandey, Arpita Bhattacharya, Aradhana Mishra, C S Nautiyal
Tomato suffers a huge loss every year because of early blight disease. This study focuses on efficient inhibition of Alternaria solani, the causative agent of early blight disease in tomato in vitro and in vivo. Foliar spray of 5 μg/mL of biosynthesized silver nanoparticles in A. solani infected plants resulted in significant increase of 32.58% in fresh weight and 23.52% in total chlorophyll content of tomato as compared to A. solani infected plants. A decrease of 48.57, 30, 39.59 and 28.57% was observed in fungal spore count, lipid peroxidation, proline content and superoxide dismutase respectively in infected tomato plants after treatment with synthesized silver nanoparticles as compared to A...
November 10, 2017: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/29149667/tumor-acidosis-and-hypoxia-differently-modulate-the-inflammatory-program-measurements-in-vitro-and-in-vivo
#5
Anne Riemann, Sarah Reime, Oliver Thews
Inflammatory mediators produced by the tumor cells are of importance for immune response but also for malignant progression. The aim of the study was to analyze the expression of monocyte chemoattractant protein-1, interleukin-6 (IL-6), tumor necrosis factor-α, inducible isoform of nitric oxide synthase (iNOS), cyclooxygenase-2, and osteopontin in vitro in two different tumor cell lines under hypoxia (pO2≈1.5 mmHg) and/or acidosis (pH=6.6) for up to 24 hours since hypoxia and acidosis are common characteristics of solid tumors...
November 14, 2017: Neoplasia: An International Journal for Oncology Research
https://www.readbyqxmd.com/read/29149664/copper-phospholipid-interaction-at-cell-membrane-model-hydrophobic-surfaces
#6
Marina Mlakar, Vlado Cuculić, Sanja Frka, Blaženka Gašparović
Detailed investigation of Cu (II) binding with natural lipid phosphatidylglycerol (PG) in aqueous solution was carried out by voltammetric measurements at the mercury drop electrode, complemented by monolayer studies in a Langmuir trough and electrophoretic measurements, all used as models for hydrophobic cell membranes. Penetration of copper ions into the PG layer was facilitated by the formation of hydrophilic Cu-Phenanthroline (Phen) complex in the subphase, followed by the mixed ligand Cu-Phen-PG complex formation at the hydrophobic interface...
November 11, 2017: Bioelectrochemistry
https://www.readbyqxmd.com/read/29149640/change-to-ecosystem-properties-through-changing-the-dominant-species-impact-of-pteridium-aquilinum-control-and-heathland-restoration-treatments-on-selected-soil-properties
#7
G Milligan, K E Booth, E S Cox, R J Pakeman, M G Le Duc, L Connor, S Blackbird, R H Marrs
It is well known that soils are influenced by the plant species that grow in them. Here we consider the effects of management-induced changes to plant communities and their soils during restoration within a 20-year manipulative experiment where the aim was to change a late-successional community dominated by the weed, Pteridium aquilinum, to an earlier-successional grass-heath one. The ecological restoration treatments altered the above- and below-ground components of the community substantially. Untreated plots maintained a dense Pteridium cover with little understory vegetation, cutting treatments produce significant reductions of Pteridium, whereas herbicide (asulam) produced significant immediate reductions in Pteridium but regressed towards the untreated plots within 10 years...
November 14, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/29149570/seagrass-mediated-phosphorus-and-iron-solubilisation-in-tropical-sediments
#8
Kasper Elgetti Brodersen, Klaus Koren, Maria Mosshammer, Peter Ralph, Michael Kühl, Jakob Santner
Tropical seagrasses are nutrient limited owing to the strong phosphorus fixation capacity of carbonate-rich sediments, yet they form densely-vegetated, multi-species meadows in oligotrophic tropical waters. Using a novel combination of high-resolution, two-dimensional chemical imaging of O2, pH, iron, sulphide, calcium and phosphorus, we found that tropical seagrasses are able to mobilize the essential nutrients iron and phosphorus in their rhizosphere via multiple biogeochemical pathways. We show that tropical seagrasses mobilize phosphorus and iron within their rhizosphere via plant-induced local acidification, leading to dissolution of carbonates and release of phosphate, and via local stimulation of microbial sulphide production, causing reduction of insoluble Fe(III) oxyhydroxides to dissolved Fe(II) with concomitant phosphate release into the rhizosphere porewater...
November 17, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/29149563/zein-nanoparticles-uptake-by-hydroponically-grown-soybean-plants
#9
Kurt Ristroph, Carlos E Astete, Ede Bodoki, Cristina M Sabliov
In the interest of developing and characterizing a polymeric nanoparticle pesticide delivery vehicle to soybeans, zein nanoparticle (ZNP) uptake by the roots and biodistribution to the leaves of soybean plants was measured. Zein was tagged with fluorescein isothiocyanate (FITC) and made into nanoparticles (135±3 nm diameter. 0.202±0.034 PDI and 81±4 mV zeta-potential at pH 6) using an emulsion-diffusion method. After ten days of hydroponic exposure, association between particles and roots of plants was found to vary based on bulk nanoparticle concentration...
November 17, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/29149558/quantification-of-humic-substances-in-natural-water-using-nitrogen-doped-carbon-dots
#10
Yan-Fang Guan, Bao-Cheng Huang, Chen Qian, Han-Qing Yu
Dissolved organic matter (DOM) is ubiquitous in aqueous environments and plays a significant role in pollutant mitigation, transformation and organic geochemical circulation. DOM is also capable of forming carcinogenic by-products in the disinfection treatment processes of drinking water. Thus, efficient methods for DOM quantification are highly desired. In this work, a novel sensor for rapid and selective detection of humic substances (HS), a key component of DOM, based on fluorescence quenching of nitrogen-doped carbon quantum dots was developed...
November 17, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/29149495/a-redox-activated-g-quadruplex-dna-binder-based-on-a-platinum-iv-salphen-complex
#11
Ramon Vilar, Stephane Bandeira, Jorge Gonzalez Garcia, Evangelina Pensa, Tim Albrecht
There has been increasing interest in the development of small molecules that can selectively bind to G-quadruplex DNA structures. The latter have been associated to a number of key biological processes and therefore are proposed to be potential targets for drug development. In this paper we report the first example of a reduction-activated G-quadruplex DNA binder. We show that a new octahedral platinum(IV)-salphen complex does not interact with DNA in aqueous media at pH 7.4; however, upon addition of bio-reductants such as ascorbic acid or glutathione, the compound readily reduces to the corresponding square planar platinum(II) complex...
November 17, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/29149364/bioecological-aspects-and-heavy-metal-contamination-of-the-mollusk-donax-denticulatus-in-the-colombian-caribbean-coastline
#12
Juan Valdelamar-Villegas, Jesus Olivero-Verbel
Donax denticulatus is a key mollusk for the ecology of sandy beaches, serving as a controller of organic matter, microorganisms, and as bioindicator of heavy metals pollution. The goal of this study was to characterize some ecological aspects of D. denticulatus and its relationship with the content of heavy metals in their tissue, in three beaches of the Caribbean coast of Colombia. The results showed the study populations were different in terms of morphological characteristics and density (Berrugas-Sucre < Cartagena-Bolívar < Riohacha-Guajira), but not in sexual proportion; although density was clearly related to beach occupancy by tourists...
November 17, 2017: Bulletin of Environmental Contamination and Toxicology
https://www.readbyqxmd.com/read/29149176/a-simple-way-for-targeted-delivery-of-an-antibiotic-in-vitro-evaluation-of-a-nanoclay-based-composite
#13
Leslie Valdés, Irela Pérez, Louis Charles de Ménorval, Ernesto Altshuler, Jon Otto Fossum, Aramis Rivera
The sodium-modified form of fluorohectorite nanoclay (NaFh) is introduced as a potential drug carrier, demonstrating its ability for the controlled release of the broad-spectrum antibiotic Ciprofloxacin through in vitro tests. The new clay-drug composite is designed to target the local infections in the large intestine, where it delivers most of the incorporated drug thanks to its pH-sensitive behavior. The composite has been conceived to avoid the use of coating technology and to decrease the side-effects commonly associated to the burst-release of the ciprofloxacin at the stomach level...
2017: PloS One
https://www.readbyqxmd.com/read/29149065/calcined-chitosan-supported-layered-double-hydroxides-an-efficient-and-recyclable-adsorbent-for-the-removal-of-fluoride-from-an-aqueous-solution
#14
Hanjun Wu, Huali Zhang, Qingxue Yang, Dongsheng Wang, Weijun Zhang, Xiaofang Yang
In this work, calcined chitosan-supported layered double hydroxides (CSLDO) were synthesized through a co-precipitation method that restrained the particles' aggregation of LDHs and exhibited huge specific surface areas, which can enhance the fluoride adsorption capacity. CSLDOs were characterized by physical and chemical methods and used for fluoride adsorption in an aqueous solution. The results indicated that the nanoparticles were constructed first and then assembled to form a porous and layered structure, and chitosan-supported layered double hydroxides (CSLDHs) calcined at 400 °C (CSLDO400) showed the highest specific surface area of 116...
November 17, 2017: Materials
https://www.readbyqxmd.com/read/29148796/layer-by-layer-self-assembly-of-polyelectrolytic-block-copolymer-worms-on-a-planar-substrate
#15
Nicholas Penfold, Andrew J Parnell, Marta Molina, Pierre Verstraete, Johan Smets, Steven P Armes
Cationic and anionic block copolymer worms are prepared by polymerization-induced self-assembly (PISA) via reversible addition-fragmentation chain transfer (RAFT) aqueous dispersion copolymerization of 2-hydroxypropyl methacrylate (HPMA) and glycidyl methacrylate (GlyMA), using a binary mixture of a non-ionic poly(ethylene oxide) (PEO) macromolecular RAFT agent and either a cationic poly([2-(methacryloyloxy)ethyl] trimethylammonium chloride) (PQDMA) or an anionic poly(potassium 3-sulfopropyl methacrylate) (PKSPMA) macromolecular RAFT agent...
November 17, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/29148787/acid-base-properties-of-xanthohumol-a-computational-and-experimental-investigation
#16
Marta Arczewska, Daniel M Kamiński, Barbara Gieroba, Mariusz Gagoś
UV-vis spectrophotometry has been applied to determine acid dissociation constants of the prenylated chalcone xanthohumol. The pKa values were compared with those derived from pH-metric titrations. The order of the deprotonation site in the xanthohumol molecule was estimated by quantum mechanical calculations as 2'-OH, 4'-OH, and 4-OH. Furthermore, the electronic and spectroscopic properties of xanthohumol have been investigated on the basis of the time-dependent density functional theory (TDDFT). The TDDFT method, combined with a hybrid exchange-correlation functional using the B3LYP and CAM-B3LYP levels of theory in conjunction with the SMD solvation model, was used to optimize all geometries and predict the excitation energies of the neutral form and ionized species of the chalcone depending on pH value...
November 17, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/29148747/investigation-of-the-iron-peroxo-complex-in-the-fenton-reaction-kinetic-indication-decay-kinetics-and-hydroxyl-radical-yields
#17
Hanna Laura Wiegand, Christian Timon Orths, Klaus Kerpen, Holger Volker Lutze, Torsten Claus Schmidt
The Fenton reaction describes the reaction of Fe(II) with hydrogen peroxide. Several researchers proposed the formation of an intermediate iron-peroxo-complex but experimental evidence for its existence is still missing. The present study investigates formation and life time of this intermediate at various conditions such as different Fe(II)-concentrations, absence vs. presence of a hydroxyl radical scavenger (dimethylsulfoxide, DMSO), and different pH values. Obtained results indicate that the iron-peroxo-complex is formed under all experimental conditions...
November 17, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/29148740/effect-of-an-imposed-contact-on-secondary-structure-in-the-denatured-state-of-yeast-iso-1-cytochome-c
#18
Travis A Danielson, Jessica M Stine, Tanveer A Dar, Klara Briknarova, Bruce E Bowler
There is considerable evidence that long-range interactions stabilize residual protein structure under denaturing conditions. However, evaluation of the effect of a specific contact on structure in the denatured state has been difficult. Iso-1-cytochrome c variants with a Lys54-->His mutation form a particularly stable His-heme loop in the denatured state, suggestive of loop-induced residual structure. We have used multidimensional NMR methods to assign (1)H and (15)N backbone amide and (13)C backbone and side chain chemical shifts in the denatured state of iso-1-cytochrome c carrying the Lys54-->His mutation in 3 and 6 M guanidine hydrochloride and at both pH 6...
November 17, 2017: Biochemistry
https://www.readbyqxmd.com/read/29148725/chromophore-isomer-stabilization-is-critical-to-efficient-fluorescence-in-cyan-fluorescent-proteins
#19
Guillaume Gotthard, David von Stetten, Damien Clavel, Marjolaine Noirclerc-Savoye, Antoine Royant
ECFP, the first usable Cyan Fluorescent Protein, was obtained by adapting the tyrosine-based chromophore environment in Green Fluorescent Protein to that of a tryptophan-based one. This 1(st)-generation CFP was superseded by the popular Cerulean, CyPet and SCFP3A that were engineered by rational and random mutagenesis. Yet, the latter CFPs still exhibit suboptimal properties of pH sensitivity and reversible photobleaching behavior. These flaws were serendipitously corrected in the 3(rd)-generation CFP mTurquoise and its successors without obvi-ous rationale...
November 17, 2017: Biochemistry
https://www.readbyqxmd.com/read/29148700/selective-ph-responsive-core-sheath-nanofiber-membranes-for-chem-bio-med-applications-targeted-delivery-of-functional-molecules
#20
Daewoo Han, Andrew J Steckl
Core-sheath fibers using different Eudragit materials were successfully produced and their controlled multi-pH responses have been demonstrated. Coaxial fibers made of Eudragit L 100 (EL100) core and Eudragit S 100 (ES100) sheath provide protection and/or controlled release of core material at pH 6 by adjusting the sheath thickness (controlled by the flow rate of source polymer solution). Thickest sheath (~ 250 nm) provides the least core release ~ 1.25 %/hr, while the thinnest sheath (~ 140 nm) provides much quicker release ~ 16...
November 17, 2017: ACS Applied Materials & Interfaces
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