Effect of Adenine Sulphate Interaction on Growth and Development of Shoot Regeneration and Inhibition of Shoot Tip Necrosis Under In Vitro Condition in Adult Syzygium cumini L.—a Multipurpose Tree

An efficient method for cloning Syzygium cumini (above 40 years old) through mature nodal segments has been successfully developed and that could be exploited for large-scale production of this valuable multipurpose tree. Nodal segments from mature tree were taken as explants and cultured on MS basal medium with different cytokinins (BA, Kin, AdS). The application of BA proved to be the best responsive cytokinin for the induction of shoot buds and shoots, but the proliferated shoots exhibited slower and stunted growth accompanied with abscission of leaves and shoot tip necrosis (STN). The problem of leaf abscission and STN was considerably reduced by the application of an adjuvant, adenine sulphate (AdS) in the optimal medium which led to the production of a maximum of 14 shoots. Further improvement in shoot bud regeneration and improved growth pattern of the regenerating tissue was obtained on the media comprised of MS?+?BA (10 μM)?+?GA₃ (2.5 μM). A total number of 15 shoots with mean shoot length of 5.9 cm was obtained. The healthy elongated shoots were then rooted on MS basal augmented with NAA (5 μM). The plantlets obtained were healthy and were successfully acclimatized and transferred under field condition with 70 % survival rate.     

Controllable one-step synthesis of ZnO nanostructures using molybdophosphoric acid

ZnO nanostructures were synthesised in a hydrothermal reaction of zinc acetate in the presence of molybdophosphoric acid (H₃[PMo₁₂O₄₀]) as well as its vanadium-substituted acid (H₄[PMo₁₁VO₄₀]) at various times, temperatures, and concentrations. The ZnO nanostructures were characterised by X-ray diffraction, transmission electron microscopy, and Fourier transform infrared spectroscopy. The results demonstrated that the synthesised products are crystalline with a zincite hexagonal phase. Various ZnO nanostructures, such as nanoparticles, microrods, and nanosheets, were produced by changing the experimental conditions. The photocatalytic degradation of methyl orange was also investigated using the ZnO nanoparticles thus prepared. These particles exhibited high performance in the photocatalytic degradation of MO and almost 100 % decolourisation occurred within only 20 min.     

β-Cyclodextrin-based polyurethane (β-CDPU) polymers as solid media for adsorption and determination of Pb(II) ions in dust and water samples

In this work, β-CD-based polyurethane copolymers (β-CDPU) have been prepared by reacting β-CD with hexamethylene diisocyanate as cross-linked agent in dry DMF. This polymer showed high selectivity for preconcentration of Pb(II) at trace level prior to its flame atomic absorption spectrometric determination. The effect of several parameters such as pH, flow rate of sample, eluent kind and volume was investigated. The adsorption behaviors and mechanisms of Pb(II) on the samples were also studied. The maximum adsorption amount of Pb(II) was 8 mg g^?1 with the preconcentration factor of 250 for Pb(II). The Langmuir isotherm was proved to describe the adsorption data better than the Freundlich isotherm and a pseudo-first-order kinetic model fits the adsorption kinetic processes well. The calibration curve was linear in the range of (3–200 ng mL^?1) with a correlation coefficient of 0.9996. The limit of detection based on three times the standard deviation of the blank was 1.15 ng mL^?1. The relative standard deviations for the determination of 10 and 100 ng mL^?1 of Pb(II) were 3.60 and 0.43 % (n = 10), respectively. The method was successfully applied to the determination of lead in some environmental samples such as Tehran and Bushehr drinking water, river water and dust samples.     

Morphology of polyaniline nanofibers synthesized under different conditions

Polyaniline nanofibers are readily synthesized by bulk polymerization; ammonium per sulphate (APS) is used as oxidizing agent and hydrochloric acid as dopant without any hard or soft templates. A detailed study was conducted on the effect of a variety of synthetic conditions on the size and morphology of the polyaniline nanostructure. These conditions include the concentration of dopant, and the APS-to-aniline and acid-to-aniline molar ratios. The morphology of the nanofibers was confirmed by SEM and TEM. XRD and FT-IR and UV–visible spectroscopy were used for structural characterization of nanofibers. The results showed that not only the microstructure of the polyaniline product, but also other characteristics, for example conductivity, crystallinity, and, more importantly, the efficiency of the process are strongly affected by the synthetic conditions.     

Synthesis of CaWO4:Er3+@SiO2 and CaWO4:Tm3+@SiO2 nano-particles via a combustion pathway and study of their optical properties

Use of citric acid as a chelating agent and fuel, ammonium nitrate as fuel, boric acid as flux material and silica as supports, CaWO₄:Ln³⁺@SiO₂ (Ln = Er and Tm) nanoparticles were synthesized via a combustion reaction at 800 °C. Characterization of the samples was performed by X-ray diffractometer (XRD), reflectance UV–Vis spectrophotometer, fluorescence spectrophotometer (PL) and transmission electron microscope (TEM). XRD patterns showed that tetragonal crystalline structure of scheelite and silica supports were formed, and that the formation of a silica support could enhance the luminescence intensity of CaWO₄:Ln³⁺. The reflectance UV–Vis and PL spectra indicated the broad absorption band of WO₄ ^2? groups about 240 nm, the WO₄ ^2? wide excitation band with maximum at 240 nm, a broad emission band of WO₄ ^2? with maximum about 420 nm, and characteristic emissions of Ln³⁺ ions. According to the TEM analysis, CaWO₄:Er³⁺@SiO₂ and CaWO₄:Tm³⁺@SiO₂ nanoparticles have almost the same morphology with average particle sizes about 50 nm.     

Uncatalyzed synthesis of 3-amino-1,5-dihydro-2H-pyrrol-2-ones

Uncatalyzed one-pot pseudo-four-component reaction of ethyl pyruvate, anilines, and aldehydes in n-hexane as solvent, under reflux, affords a variety of 3-amino-1,5-dihydro-2H-pyrrol-2-ones in high yield. n-Hexane is an excellent driving force in preparation of the desired products. These compounds have biological and pharmacological properties and are also used in medicinal chemistry. Use of a non-toxic and inexpensive solvent, simple and efficient synthesis, clean work-up, and high yields of the products are the advantages of this method. We report the first catalyst-free method for synthesis this class of compounds.     

Synthesis of SnO2 nanostructures by ultrasonic-assisted sol–gel method

Fluorine doped SnO₂ nanostructures were grown using ultrasonic assisted sol–gel method. The gel was obtained by dissolving stannous chloride in methanol with ammonium fluoride as dopant followed by irradiation with ultrasonic vibrations. Obtained samples were characterized by structural, morphological and optical studies. All the peaks in the X-ray diffractograms are identified and indexed as tetragonal cassiterite structure. Negative slope of Williamson–Hall plots indicates compressive strain. Particle size of SnO₂ nanostructures is decreases with increases in concentration of fluorine doping. Atomic force microscopy, scanning electron microscopy and transmission electron microscopy studies confirm the formation of ring like porous structures and then hollow tube like growth with increase in the fluorine concentration. Peaks in Raman spectra also indicate strong confinement in SnO₂ particles. Distinct peaks in the PL spectra make the structure suitable for photovoltaic applications.     

TEAD–YAP Interaction Inhibitors and MDM2 Binders from DNA-Encoded Indole-Focused Ugi Peptidomimetics

DNA-encoded combinatorial synthesis provides efficient and dense coverage of chemical space around privileged molecular structures. The indole side chain of tryptophan plays a prominent role in key, or “hot spot”, regions of protein–protein interactions. A DNA-encoded combinatorial peptoid library was designed based on the Ugi four-component reaction by employing tryptophan-mimetic indole side chains to probe the surface of target proteins. Several peptoids were synthesized on a chemically stable hexathymidine adapter oligonucleotide “hexT”, encoded by DNA sequences, and substituted by azide-alkyne cycloaddition to yield a library of 8112 molecules. Selection experiments for the tumor-relevant proteins MDM2 and TEAD4 yielded MDM2 binders and a novel class of TEAD-YAP interaction inhibitors that perturbed the expression of a gene under the control of these Hippo pathway effectors.     

Programmable Live-Cell CRISPR Imaging with Toehold-Switch-Mediated Strand Displacement

The widespread application of CRISPR-Cas9 has transformed genome engineering. Nevertheless, the precision to control the targeting activity of Cas9 requires further improvement. We report a toehold-switch-based approach to engineer the conformation of single guide RNA (sgRNA) for programmable activation of Cas9. This activation circuit is responsive to multiple inputs and can regulate the conformation of the sgRNA through toehold-switch-mediated strand displacement. We demonstrate the orthogonal suppression and activation of Cas9 with orthogonal DNA inputs. Combination of toehold switches leads to a variety of intracellular Cas9 activation programs with simultaneous and orthogonal responses, through which multiple genome loci are displayed in different colors in a controllable manner. This approach provides a new route for programing CRISPR in living cells for genome imaging and engineering.     

Thermodynamic Consistency Test of Vapor–liquid Equilibrium Data of Binary Systems Including Carbon Dioxide (CO 2 ) and Ionic Liquids Using the Generic Redlich–Kwong Equation of State

The thermodynamic consistency test of solubility P–T–x data for binary mixtures including carbon dioxide (CO2) + a room temperature ionic liquid has been investigated. Experimental solubility data taken from the open literature for 32 binary mixtures of CO2/RTILs contains 80 isotherms. The applied consistency test is based on the fundamental Gibbs–Duhem equation with use of the generic Redlich–Kwong (GRK) equation of state (EoS) coupled with the van der Waals–Berthelot (GRK/vdWB) mixing rule. The optimum parameters were obtained by minimizing the summation of per cent relative deviations between modeled and experimental data, based on the bubble pressure algorithm. Modeling was found acceptable for all isotherms, which demonstrated the usability of the GRK equation of state. Results of the thermodynamic consistency test showed that 36 of the isothermal data sets were thermodynamically consistent, 37 were not fully consistent, 6 were thermodynamically inconsistent and only one data set was found to need another model.