Arabidopsis MCTP family member QUIRKY regulates the formation of the STRUBBELIG receptor kinase complex.

Intercellular communication plays a central role in organogenesis. Tissue morphogenesis in Arabidopsis (Arabidopsis thaliana) requires signaling mediated by a cell surface complex containing the atypical receptor kinase STRUBBELIG (SUB) and the multiple C2 domains and transmembrane region protein QUIRKY (QKY). QKY is required to stabilize SUB at the plasma membrane.

Mitochondrial Redox Balance of Fibroblasts Exposed to Ti-6Al-4V Microplates Subjected to Different Types of Anodizing.

Despite the high biocompatibility of titanium and its alloys, the need to remove titanium implants is increasingly being debated due to the potential for adverse effects associated with long-term retention. Therefore, new solutions are being sought to enhance the biocompatibility of titanium implants. One of them is to increase the thickness of the passive layer of the implant made of titanium dioxide.

Cell wall damage attenuates root hair patterning and tissue morphogenesis mediated by the receptor kinase STRUBBELIG.

Cell wall remodeling is essential for the control of growth and development as well as the regulation of stress responses. However, the underlying cell wall monitoring mechanisms remain poorly understood. Regulation of root hair fate and flower development in Arabidopsis thaliana requires signaling mediated by the atypical receptor kinase STRUBBELIG (SUB).

Controlling Emissive Properties by Intramolecular Hydrogen Bonds: Alkyl and Aryl meso-Substituted Porphycenes.

Porphycene, a porphyrin isomer, is an efficient fluorophore. However, four-fold meso substitution with alkyl groups decreases the fluorescence quantum yield by orders of magnitude. For aryl substituents, this effect is small.

Metal-Dependent Cytotoxic and Kinesin Spindle Protein Inhibitory Activity of Ru, Os, Rh, and Ir Half-Sandwich Complexes of Ispinesib-Derived Ligands.

Ispinesib is a potent inhibitor of kinesin spindle protein (KSP), which has been identified as a promising target for antimitotic anticancer drugs. Herein, we report the synthesis of half-sandwich complexes of Ru, Os, Rh, and Ir bearing the ispinesib-derived ,-bidentate ligands ()- and ()-2-(1-amino-2-methylpropyl)-3-benzyl-7-chloroquinazolin-4(3H)-one and studies on their chemical and biological properties. Using the enantiomerically pure ()- and ()-forms of the ligand, depending on the organometallic moiety, either the , or , diastereomers, respectively, were observed in the molecular structures of the Ru- and Os(cym) (cym = η--cymene) compounds, whereas the , or , diastereomers were found for the Rh- and Ir(Cp*) (Cp* = η-pentamethylcyclopentadienyl) derivatives.

Method development for determination of trace amounts of palladium in environmental water samples by ICP-MS/MS after pre-concentration on thiol-functionalized MCM-41 materials.

The anthropogenic cycle of Pd in the environment, its fate and impact is still unknown due to limitations of measurement techniques. For separation and pre-concentration of Pd(II) ions, mesoporous silica materials MCM-41 were synthesized and functionalized with different amounts of 3-mercaptopropyltrimethoxysilane (MPTMS) by co-condensation and grafting methods. The structural and textural properties of materials were characterized using XRD, TEM, SEM and BET techniques.

Toward Soluble 5,10-Diheterotruxenes: Synthesis and Reactivity of 5,10-Dioxatruxenes, 5,10-Dithiatruxenes, and 5,10-Diazatruxenes.

The following work presents three general approaches allowing, for the first time, the synthesis of 5,10-diheterotruxene derivatives containing two identical heteroatoms, namely, oxygen , nitrogen , or sulfur . Two of described pathways involve the photocyclization of the corresponding triene as a key step leading to a heptacyclic aromatic system. The third approach is based on the acidic condensation between ninhydrin and benzo[]heteroole .

The Arabidopsis receptor kinase STRUBBELIG regulates the response to cellulose deficiency.

Plant cells are encased in a semi-rigid cell wall of complex build. As a consequence, cell wall remodeling is essential for the control of growth and development as well as the regulation of abiotic and biotic stress responses. Plant cells actively sense physico-chemical changes in the cell wall and initiate corresponding cellular responses.

Synthesis and Reactivity of 5-Heterotruxenes Containing Sulfur or Nitrogen as the Heteroatom.

This paper presents an alternative path for the synthesis of 5-thiatruxene and the synthetic approach for 5-azatruxene not known so far. A new method for 5-thiatruxene improves the overall reaction yield from 17.5 to 22.

Speciation of Chromium in Alkaline Soil Extracts by an Ion-Pair Reversed Phase HPLC-ICP MS Method.

The aim of this work was to study by a hyphenated HPLC-ICP MS technique the chromium species released during alkaline extraction of various soils collected from a contaminated area of an old tannery. An ultrasound-assisted extraction procedure using 0.1 mol L Na₂CO₃ solution was developed for the release of chromium species from the soil.

Antioxidant properties of coffee substitutes rich in polyphenols and minerals.

The analysis of general content of polyphenols, minerals and antioxidant activity of infusions from selected coffee substitutes is presented. The obtained results showed that the coffee infusions prepared from acorns exhibit the highest radical scavenging capacities for DPPH (EC = 0.063-0.

Two Macrocycles in One Shot: Synthesis, Spectroscopy, Photophysics, and Tautomerism of 23-Oxahemiporphycene and 21-Oxacorrole-5-carbaldehyde.

The synthesis of 23-oxahemiporphycene, the first monooxa analogue of hemiporphycene, a structural isomer of porphyrin, is reported. Its generation under McMurry reaction conditions is surprisingly accompanied by the appearance of a formyl derivative of oxacorrole, 21-oxacorrole-5-carbaldehyde. A mechanism for the formation of the latter is proposed, relying on pinacol rearrangement of titanium pinacolate.

Selective Separation of Chromium Species from Soils by Single-Step Extraction Methods: a Critical Appraisal.

A critical appraisal of single-step extraction procedures of chromium species from soil was done in terms of their selectivity towards Cr(III) and Cr(VI) species. Samples of natural mineral and organic soil and samples of soil enriched with different chromium compounds of various solubility (in liquid or solid form) were used to simulate contamination of soil by liquid and solid wastes. The efficiency of extraction of Cr(III) and Cr(VI) species with various reagents, e.

Parent, Unsubstituted Hemiporphycene: Synthesis and Properties.

Among seven possible nitrogen-in constitutional isomers of porphyrin only one, porphycene, has been obtained so far in the free, unsubstituted form. Herein, the synthesis of another isomer, parent hemiporphycene (HPc), and its thorough structural, spectral, photophysical, electrochemical, and theoretical characterization are reported. Most of the properties of HPc are intermediate between those of porphyrin and porphycene, as evidenced by the values of inner-cavity dimensions, orbital-energy splittings, absorption coefficients, magnetic circular dichroism parameters, NH-stretching frequencies, fluorescence quantum yields, tautomerization rates, and redox potentials.

An ultrasound-assisted procedure for fast screening of mobile fractions of Cd, Pb and Ni in soil. Insight into method optimization and validation.

A fast ultrasound-assisted sequential extraction (UASE) procedure for the determination of cadmium, lead and nickel fractions in soil was developed and fully validated. The working parameters of an ultrasound probe were optimized by comparing the content of metals in soil extracts obtained by the UASE procedure with that obtained by the conventional (with the aid of a vertical rotor) modified Community Bureau of Reference (BCR) procedure. The content of metals in soil fractions was determined by electrothermal atomic absorption spectrometry.

Chromium Speciation in Wastewater and Sewage by Solid-Phase Extraction Using a New Diphenylcarbazone-Incorporated Resin.

A new procedure for the determination of chromium species in polluted environmental samples by flame atomic absorption spectrometry was developed in this work. A new material containing 1,5-diphenylcarbazone included in a polymeric matrix was prepared and employed as a solid-phase extraction material for selective separation of Cr(III) ions under dynamic conditions. Chromium(III) ions were retained on this sorbent with high efficiency and repeatability (95 %, RSD = 1 %) from solutions with pH 9.

Fast and simple procedure for fractionation of zinc in soil using an ultrasound probe and FAAS detection. Validation of the analytical method and evaluation of the uncertainty budget.

A new fast method for determination of mobile zinc fractions in soil is proposed in this work. The three-stage modified BCR procedure used for fractionation of zinc in soil was accelerated by using ultrasounds. The working parameters of an ultrasound probe, a power and a time of sonication, were optimized in order to acquire the content of analyte in soil extracts obtained by ultrasound-assisted sequential extraction (USE) consistent with that obtained by conventional modified Community Bureau of Reference (BCR) procedure.

Recent Advances in On-Line Methods Based on Extraction for Speciation Analysis of Chromium in Environmental Matrices.

The biological activity of Cr(III) and Cr(VI) species, their chemical behavior, and toxic effects are dissimilar. The speciation analysis of Cr(III) and Cr(VI) in environmental matrices is then of great importance and much research has been devoted to this area. This review presents recent developments in on-line speciation analysis of chromium in such samples.

Extraction of ranitidine and nizatidine with using imidazolium ionic liquids prior spectrophotometric and chromatographic detection.

A new extraction medium was proposed for liquid-liquid extraction of the histamine H2 receptor antagonists ranitidine (RNT) and nizatidine (NZT). The ionic liquids with low vapor pressure and favorable solvating properties for a range of compounds such as 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6] and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C4mim][Tf2N] were tested for isolation of analytes. The extraction parameters of RNT and NZT, namely, amount of ionic liquid, pH of sample solution, shaking and centrifugation time were optimized.

Ultrasound assisted extraction for determination of mobile fractions of copper in soil.

Background: For evaluation of the mobility of metals present in soil various approaches based on sequential extraction procedures (Tessier's, BCR or modified BCR) have been proposed, but they are very laborious and time-consuming.

Objective: The aim of this study was to develop a new fast extraction procedure for the determination of mobile fractions of copper in soil.

Material And Methods: The samples of soil that vary in terms of physicochemical properties and certified reference material (BCR-701) were used in this study.

Transformations of griseofulvin in strong acidic conditions--crystal structures of 2'-demethylgriseofulvin and dimerized griseofulvin.

The structure of griseofulvic acid, C16H15ClO6, at 100 K has orthorhombic (P2(1)2(1)2) symmetry. It is of interest with respect to biological activity. The structure displays intermolecular O-H.

Separation of ruthenium from environmental samples on polymeric sorbent based on imprinted Ru(III)-allyl acetoacetate complex.

A new ion imprinted polymer (IIP) for ruthenium recognition/pre-concentration was prepared via bulk polymerization using methacrylic acid as the functional monomer and ethylene glycol dimethacrylate as the cross-linking agent in the presence of Ru(III)-allyl acetoacetate complex as a template. The synthesized IIP was used as a new support for solid phase extraction (SPE) of ruthenium from environmental samples before electrothermal atomic absorption spectrometric determination. Variables affecting the SPE process, such as pH, load and elution flow rates, as well as concentration and volume of the eluting solution, were evaluated.

A dodecameric self-assembled calix[4]arene aggregate with two types of cavities.

Twelve molecules of β-carbonyl-para-octyl-calix[4]arene assemble in an aggregate containing two types of cavities filled by water molecules and they pack in a cubic structure. Both the aggregates and the packing resemble that observed for inverse micelles.

Assessment of ion imprinted polymers based on Pd(II) chelate complexes for preconcentration and FAAS determination of palladium.

New ion-imprinted polymeric (IIP) materials were synthesized by copolymerization of 4-vinylpyridine (VP) and styrene as functional monomers and divinylbenzene as a cross-linking agent with chelating complexes of Pd(II) in the presence of 2,2-azobisisobutyronitrile as an initiator. The complexes of Pd(II) with ammonium pyrrolidinedithiocarbamate (APDC), N,N'-diethylthiourea (DET), and dimethylglyoxime (DMG) were used for this purpose. Chloroform, ethanol, and cyclohexanol were applied as porogens.

Streptidinium sulfate monohydrate.

In streptidinium sulfate monohydrate {systematic name: 1,1'-[(1S,3R,4S,6R)-2,4,5,6-tetrahydroxycyclohexane-1,3-diyl]diguanidinium sulfate monohydrate}, C(8)H(20)N(6)O(4)(2+).SO(4)(2-).H(2)O, at 100 (2) K, the components are arranged in double helices based on hydrogen bonds.