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Novel approach to methyl 2-aryl-2-(arylhydrazono) acetates via methanolysis of dichlorodiazabutadienes was developed. Hydrogen bonding in methyl Z-2-phenyl-2-(phenyl-hydrazono) acetate was explored by DFT calculations and topological analysis of the electron density distribution within the framework of Bader’s theory (QTAIM method).

1-Aryl-3-(4-bromophenyl)-4,4-dichloro-1,2-diazabuta-1,3- dienes were synthesized via copper-catalyzed reaction of 4-bromobenzaldehyde arylhydrazones with CCl4. X-ray diffraction analysis revealed non-covalent Cl···Br interactions in the crystalline state and formation of 3D supramolecular framework; DFT calculations and topological analysis of the electron density distribution within the framework of Bader's theory (QTAIM method) confirmed these observations. Theoretical calculations showed that highly polarizable dichlorodiazadiene unit is capable of acting as a relatively strong halogen bond donor.

Schiff base condensation of 2-nitrobenzaldehyde with (para-substituted phenyl)hydrazine in the presence of CH3COONa in EtOH at 80 °C produces (E)-1-(para-substituted phenyl)-2-(2-nitrobenzylidene)hydrazines [−OCH3 (1), −CH3 (2), −H (3), −Br (4), −Cl (5), −F (6)]. CuCl catalyzed olefination of 1−6 with CCl4 in the presence of tetramethylethylenediamine (TMEDA) in DMSO leads to (E)-1-(2,2-dichloro-1-(2-nitrophenyl)vinyl)-2-(para-substituted phenyl)-diazenes [−OCH3 (7), −CH3 (8), −H (9), −Br (10), −Cl (11), −F (12)], respectively. 1–12 were characterized by 1H and 13C NMR spectroscopies, ESI-MS, elemental and X-ray diffraction (for 8, 9 and 12) analysis. The single crystal X-ray analysis of 8, 9 and 12 evidence the intramolecular N⋯Cl pnicogen bonds which is significantly strengthened in view of the planarity of the four atoms involved in the 1,4-membered synthon. The intermolecular halogen and hydrogen bonds also contribute to stabilize the crystal structures of 8, 9 and 12. In DMSO solution 1–12 exist in the E-isomeric form, which stabilized by inter- and intramolecular noncovalent interactions. Solvatochromic behavior on UV–vis absorption spectra of azo dyes 7–12 were studied in CH2Cl2, DMF and MeOH, which λmax is dependent on the attached substituents at para- position of aromatic moiety.

The new nickel coordination polymer [Ni(HL1) (CH3OH)2]n (1) and co-crystal H3L1∙DMF (2) were obtained by reaction of NiCl2·2H2O with 2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene) hydrazineyl)benzoic acid (H3L1) in the presence and absence of triethylamine, respectively, in a mixture of methanol and dimethylformamide (DMF) (20:1, v/v). Reaction of CuCl2·2H2O with H3L1 in the presence of 2,2'-(methylazanediyl)bis (ethan-1-ol) (HR) in methanol yields [Cu(HR)2(H2L1)2] (3), whereas treatment of this copper salt with sodium 2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazineyl)benzenesulfonate (NaH2L2) in a mixture of acetone and water (10:1, v/v) produces [Cu(HL2) (H2O)2]∙2(H2O)∙{(CH3)2C = O} (4). Compounds 1−4 were characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses, and tested as catalyst for the Henry reaction of aliphatic and aromatic aldehydes with nitroethane in different solvents such as acetonitrile, methanol or water. Good yields (up to 87%) and diasteroselectivities (syn/anti 77:23) were observed in the reactions catalyzed by 3 in water.

Two known lanthanide complexes, [KLa(HL 1 ) 2 {(CH 3 ) 2 NCHO} 2 (H 2 O) 3 ] ( 1 ) and [Sm(H 2 O) 9 ]( E -H 2 L 2 ) 3 ·2H 2 O ( 2 ) were prepared by reaction of lanthanum(III) and samarium(III) nitrates with potassium 3-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)-2-hydroxy-5-nitrobenzenesulfonate (KH 2 L 1 ) and potassium ( E,Z )-5-chloro-3-(2-(1,3-dioxo-1-phenylbutan-2-ylidene)hydrazinyl)-2-hydroxybenzenesulfonate (KH 2 L 2 ), respectively. Catalytic activities of 1 and 2 were evaluated in the cyanosilylation of aldehydes with trimethylsilyl cyanide in different solvents such as tetrahydrofuran, dichloromethane or methanol. Complex 1 was found to be efficient catalyst for the cyanosilylation reaction in methanol medium at room temperature, producing cyanohydrin trimethylsilyl ethers with good yields (76–99%).

Different solids consisting in hydrous zirconia were synthesized by the water in oil microemulsion technique (ME series). For comparative purposes, diverse solids were also obtained by the conventional sol-gel method (P-series). The solids were tested for liquid-phase selective hydrogenation of furfural to furfuryl alcohol, using propan-2-ol as the hydrogen donor (Meerwein–Ponndorf–Verley process). The best results corresponded to catalysts calcined at 200 °C which consisted in amorphous solids with surface areas of ca 200 m2/g. The presence of some surfactant remaining from the synthetic process in solids obtained through the microemulsion technique favored selectivity to furfuryl alcohol with values ≥98%. Results were explained by the steric hindrance of furfural by the surfactant molecules in micelles thus favoring the interaction of the substrate with hydroxyl groups in hydrous zirconia through the C O group. Application of microwave irradiation accelerated the reaction (15–30 times) as compared to conventional heating.

Convenient and environmentally friendly synthesis of Co9S8/PVA, CoxSy/EG and CoxSy/3-MPA nanocomposites were carried out in the presence of ultrasonic irradiation by the liquid phase synthesis of the sonochemical method. For the synthesis, cobalt acetate tetrahydrate [Co(CH3COO)2·4H2O] and sodium sulfide (Na2S·9H2O) were used as a cobalt and sulfur precursor, respectively. Polyvinyl alcohol (PVA), ethylene glycol (EG) and 3-mercaptopropionic acid (3-MPA) were used as a capping agent and surfactant. The structural, optical properties and morphology of nanocomposites were characterized using X-ray diffractometer (XRD), Ultraviolet/Visible Spectroscopy (UV–Vis), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The optical band gap of Co9S8/PVA is 1.81 eV and for CoxSy/EG is 2.42 eV, where the direct band gap of bulk cobalt sulfide is (0.78–0.9 eV). The wide band gap indicates that synthesised nanocomposites can be used in the fabrication of optical and photonic devices. The growth mechanisms of the Co9S8, CoS2 and Co3S4 nanoparticles were discussed by the reactions. The effects of sonication time and annealing temperature on the properties of the nanoparticles have been studied in detail.

Reaction of bis(4-hydrazinylphenyl)methane with 4-substitutedbenzaldehyde in the presence of CH3COONa in EtOH at 80 °C yields bis(4-((E)-2-(4-substitutedbenzylidene)hydrazinyl)phenyl) methane [−N(CH3)2 1, −F 2, −Cl 3, −NO2 4], which subsequently in the presence of CCl4, CuCl and tetramethylethylenediamine in DMSO undergoes Cu-catalyzed olefination products, bis(4-((E)-(2,2-dichloro-1-(4-substitutedphenyl)vinyl)diazenyl)phenyl)methane [−N(CH3)2 5, −F 6, −Cl 7, −NO2 8], respectively. All compounds were characterized by IR (for 1–4), 1H and 13C NMR spectroscopies, elemental and X-ray diffraction analysis (for 7 and 8). No only intermolecular hydrogen and intramolecular N⋯Cl tetrel bonds, but also the Cl⋯Cl and Cl⋯O types of halogen binding were found in the structures of 7 and 8, respectively. The collected data confirm that bis-azodyes 5–8 exist in DMSO solution and in solid state exclusively in the E-isomeric form, being stabilized by noncovalent interactions. Solvent effects on the UV–vis absorption spectra of 5−8 were studied in CH2Cl2, DMF and EtOH, which λmax is dependent on the type of substituents attached para-position of aromatic moiety.

NH3 is a type of foul smelling gas, when breathed beyond a comfortable level, is extremely hazardous to human health. Developing of room-temperature ammonia sensors are one of the challenging task in research. Manganese ferrites and cobalt doped manganese ferrites nanoparticles were successfully produced in this work, and used as a sensing material for ammonia gas sensor, also getting the better results at room temperature. The synthesized materials were confirmed by various characterization techniques namely XRD, SEM & EDAX, FTIR, and DRS. Three different weight percentage (1, 3, and 5 wt%) of Co is doped with MnFe2O4 nanomaterial and study the optical properties and the ammonia sensing ability comparatively. From that 5 wt% Co: MnFe2O4 nanoparticles shows good sensing percentage of about 75.3 %.

The new mononuclear nickel(II) complexes [Ni(HL 1 )(H 2 O) 2 (CH 3 OH)] ( 1 , NaH 2 L 1 = sodium ( Z )-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzenesulfonate) and [Ni(H 2 L 2 ) 2 (H 2 O) 4 ] [(CH 3 ) 2 S O) 2 ] ( 2 , H 3 L 2 = (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzoic acid) were synthesized and characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses. Both compounds 1 and 2 act as homogenous catalysts for the diastereoselective nitroaldol (Henry) reaction of aliphatic and aromatic aldehydes with nitroethane in different solvents such as acetonitrile, methanol or water. Complex 1 was found to be the more efficient catalyst for the Henry reaction in aqueous medium, providing β-nitroalcohols with good yields (67–82%) and diastereoselectivities ( syn/anti 59:41–70:30).

β-NiS nanoparticles (NPs) grown through SILAR technique into functionalized nitrile butadiene rubber (FNBR) were used for the synthesis of CuS-NiS/FNBR and Cu1.8S-Ni3S4/FNBR nanocomposites (NCs). The evaluated band gap decreased from 2.8 eV to 2.3 eV and 2.21 eV using 0.25 M of CuSO4 × 5H2O and 0.5 M of CuCl2 × 2H2O, respectively. The effect of copper precursors and concentration of Cu2+ ions on the particle size, chemical composition of NCs and properties has been discussed in detail. Different structural phases of nickel sulfide and copper sulfide were obtained using NiS/FNBR nanocomposites as a precursor for ion exchange reaction by Cu2+ ions. Properties of CuxS-NiySz/FNBR and CuS-NiySz/FNBR nanocomposites obtained after modification have been studied and compared with initial nanocomposite of NiS/FNBR. The average particle size increased from 8.5 nm to 13.5 nm and 15 nm after ion exchange modification. By EPR spectrum the superhyperfine splitting is seen in the spectrum of CuS-NiySz/FNBR, ACu = 107.3 G. In perpendicular section the bandwidth of the spectrum (ΔH) is equal to 930 G. Recording to SEM images very clearly imaged spherical nanoparticles have been observed.

Two known organotin(IV) complexes, [Sn(C6H5)3HL1] (1) and [Sn(C2H5)2(1κO,2κO-H3L2) (1κO2-H3L2) (μ3-O)]2 (2), were prepared upon interaction of Ph3SnCl and Et2SnO with 2-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)benzoic acid (H2L1) and 2-(2-(2,4,6-trioxotetrahydropyrimidin-5(2H)-ylidene) hydrazinyl)benzoic acid (H4L2), respectively, in toluene solution. Both complexes are applied as catalysts in cyanosilylation of aldehydes. Complex 2 shows a high catalytic activity in the cyanosilylation reaction of a variety of aliphatic and aromatic aldehydes with trimethylsilyl cyanide yielding to the corresponding cyanohydrin trimethylsilyl ethers (yields up to 99%) in methanol and at room temperature.

The new trinuclear [Co II (H 2 O) 2 (Me 2 NCHO) 2 {Co III (1κ NOO′ :2κ O″ -μ-HL)} 2 (1κ NOO′ )]·2H 2 O ( 1 ) and polymeric [Co II (1κ NOO′ :2κ O″ -μ-HL)(MeOH) 2 ] n ( 2 ) complexes were isolated by the reaction of ( Z )-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzoic acid (H 3 L) with CoCl 2 ·6H 2 O and Co(ClO 4 ) 2 ·6H 2 O, respectively, in a mixture of DMF/MeOH (1/10, v/v), in the presence of Et 3 N at room temperature, and characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses. In both structures the cobalt centres display distorted octahedral geometries. The structural units in 1 and 2 are connected via intermolecular hydrogen bonds involving the coordinated HL 2− and the bound and non-bound water molecules (in 1 ) or the methanol ligands (in 2 ) which provides supramolecular networks. 1 and 2 are catalyst precursors for the cyanosilylation reaction of a variety of both aromatic and aliphatic aldehydes with trimethylsilyl cyanide leading to the corresponding cyanohydrin trimethylsilyl ethers in high yields (up to 89%) in methanol and at room temperature.

We reported of synthesis and investigation of the new biologically active derivatives of dihydropyrimidines 2 and 3. The investigation of structures of compounds by various experiments of NMR spectroscopy revealed the splitting of the signals to doublets and multiplets that confirms the presence of diastereomers in solution of compound 2 and the presence of diastereomers and tautomers in solution of compound 3. The individual diastereomer of compound 3 has been isolated. Biological activity of the synthesized compounds was studied on various species of genus Aspergillus fungi.

This work covers the effects of annealing temperature on crystalline size, surface morphology, optical, structural and paramagnetic properties of NiS and Ni3S4 nanostructures grown through SILAR technique into FNBR matrix. Annealing at low temperature was performed in air and vacuum for 8 h. X-ray diffraction results confirm structural phase transitions (like NiS→Ni7S6 and Ni3S4→Ni9S8) and oxidation processes (by the formation of NiO-SO4-H2O) after thermal annealing of nanocomposites (NCs) in a vacuum and in air, respectively. By EDX spectrum the average Ni:S atomic ratio is approximately 1:1 for as-prepared NiS, 1:0.89 for NiS annealed in a vacuum and 1:0.91 for NiS annealed in air.

The new copper(II) complexes [Cu(HL1)(H2O)(CH3OH)] (1, H3L1 = (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzoic acid) and [Cu(HL2)(H2O)(CH3OH)] (2, NaH2L2 = sodium (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzenesulfonate) were synthesized and characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses. The coordination environment of the central copper(II) has a square pyramidal geometry, three sites being occupied by (HL1,2)2−, which chelates in the O,N,O fashion, while the two other sites are filled with the water and methanol ligands. Multiple intra- and intermolecular non-covalent interactions between the (HL1,2)2−, water and methanol ligands lead to supramolecular network. Both compounds 1 and 2 act as homogenous catalysts for the cyanosilylation reaction of a variety of both aromatic and aliphatic aldehydes with trimethylsilyl cyanide affording the corresponding cyanohydrin trimethylsilyl ethers in high yields (up to 90%) and at room temperature.

The new 1D copper(II) coordination polymers (CPs) [Cu(μ-L1)(H2O)]n (1, H2L1 = 2-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)benzoic acid) and [Cu(μ-H2L2)(H2O)]n (2, H4L2 = (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)terephthalic acid) and the known zwitterionic 1D CP [Cu2(H2O)2(μ-H2L3)(μ-L3)]n (3, H3L3 = 2-(2-(4,4-dimethyl-2,6-dioxocyclo-hexylidene)hydrazinyl)terephthalic acid) were synthesized and tested as homogeneous catalysts for cyanosilylation of a variety of aldehydes to the corresponding cyanohydrin trimethylsilyl ethers. Among these polymeric catalysts, 3, with a zwitterionic charater, is the most effective one, giving 86–99% yield of the ethers upon reaction of aliphatic and aromatic aldehydes with trimethylsilyl cyanide in methanol at room temperature in 4 h. Non-covalent interactions (cation-π and tetrel bondings) involving the aldehyde substrate are proposed to assist the cyanosilylation reaction.

Sodium 2-(2-(1-cyano-2-oxopropylidene)hydrazinyl)benzenesulfonate (NaHL) was synthesized by azocoupling of diazonium salt of 2-aminobenzenesulfonic acid with 3-oxobutanenitrile and characterized by IR, 1H and 13C NMR spectroscopies and ESI-MS analysis. In dimethylsulfoxide-d6 solution NaHL exists as a mixture of Z- and E-hydrazone forms in the amounts of 96 and 4%, respectively. Treatment of this isomeric mixture with copper(II) nitrate hydrate in the presence of ethylenediamine (en) provides unusual (E,Z) → E switching of NaHL to give [Cu(H2O)2(en)2](HL)2 (1). The process is interpreted on the basis of cooperative ionic interactions and resonance assisted hydrogen bonding (RAHB) → charge assisted hydrogen bonding (CAHB) transition.

New 2-amino-4-aryl-3-cyanopyridines were obtained by the three-component condensation of arylidenemalononitriles, malononitrile and (di)amine system or acetoacetanilide. Antibacterial activity of all synthesized compounds against the Gram-negative bacteria E. coli and the Gram-positive B. subtilis was tested, the only representative showed a substantial antimicrobial effect.

Ni/NiO nanochains were successfully synthesized by a facile and environmentally friendly chemical reduction method under different magnetic fields, followed by thermal oxidation at high temperatures. For the synthesis of Ni nanoparticles, hydrazine hydrate and sodium borohydride were used as reducing agents. In order to determine the size, structure, optical properties and morphology, the obtained products were characterized by X-ray diffraction (XRD), ultraviolet–visible Spectroscopy (UV–Vis), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Additionally, the effect of reaction time, different magnetic field intensity and oxidation temperature on the size and morphology of synthesized nanoparticles was investigated in detail. The average size of as-prepared Ni nanoparticles in nanochain decreases with increasing magnetic force. After oxidation of samples at 600 °C, the size of NiO formed on the surface of Ni nanochains increases with increasing magnetic force. This is related to the faster oxidation of small particles due to their high surface energy. According to TEM measurements, the average diameter of Ni/NiO nanochains (synthesized at 25 mT after oxidized at 600 °C) is in the range of 97–133 nm and spherical particles are assembled in the form of a chain-like, which confirms SEM results.

Three new water-soluble copper(II) complexes [Cu(HL)(H2O){(CH3)2NCHO}] (1), [Cu(H2L)2(im)4]·CH3OH (2) and [Cu(HL)(CH3OH)]2(μ2-py) (3) were synthesized from copper(II) nitrate and sodium (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzene-sulfonate (NaH2L), in the absence (for 1) and presence of imidazole (im) (for 2) or pyrazine (py) (for 3), and fully characterized. The complexes 1–3 have been tested as stereoselective C H activating catalysts for the model nitroaldol (Henry) condensation of nitroethane with various aldehydes in water. 1 was the most active catalyst affording 64−87% yields with syn/anti diasteroselectivities up to 77:23.

Nickel sulfide nanostructures have been successfully prepared with two different sulfur sources like thiourea (S C(NH 2 ) 2 ) and sodium sulfide by the successive ionic layer adsorption and reaction (SILAR) method. The functionalized nitrile-butadiene rubber (F-NBR) was used as stabilizing agent for formation of nickel sulfide semiconductor nanoparticles. The nanoparticle sizes correspond to 8.5 nm and 7 nm using thiourea and sodium sulfide respectively. The as-synthesized NiS and Ni 3 S 4 nanostructures were characterized by XRD, SEM, EDX, UV–vis and FTIR spectroscopy methods. A systematic investigation of the final end products has been done to elucidate the formation mechanism at different experimental parameters. Using thiourea the optical band gap of NiS for 4, 6 and 8 cycles were determined to be 3.12, 2.93 and 2.81 eV, respectively. The optical band gap of Ni 3 S 4 for 6 and 8 cycles were determined to be 2.8 and 2.15 eV, respectively.

Actinobacteria are the major source of bioactive secondary metabolites and are featured in the search for antimicrobial compounds. We used nuclear magnetic resonance (RMN)-metabolic profiling and multivariate data analysis (MVDA) to correlate the metabolites' production of Streptomyces sp. PNM-9 from the algae Dictyota sp. and their biological activity against the rice phytopathogenic bacteria Burkholderia spp. The compounds 2-methyl-N-(2'-phenylethyl)-butanamide (1) and 3-methyl-N-(2'-phenylethyl)-butanamide (2) were identified through MVDA and 2D NMR experiments in the organic extract of a 15-days LB media culture of Streptomyces sp. PNM-9. Compounds 1 and 2 were isolated and their structures confirmed by one- and two-dimensional NMR and mass spectrometry (MS) data. Compounds 1 and 2 were active against the rice pathogenic bacteria Burkholderia glumae (ATCC 33,617) displaying minimal inhibitory concentration (MIC) values of 2.43 mM and 1.21 mM, respectively. The metabolomics-guided approach employing NMR-metabolic profiling was useful for marine microbial bioprospecting and suggested Streptomyces sp. PNM-9 strain and its compounds as a potential control against phytopathogenic bacteria.

The European Commission and Competition Authorities of Germany, United Kingdom, France and Australia as well the Stigler Center of the University of Chicago have published major reports on competition policy in digital markets. The paper compares the approaches of these reports to identify consensus in characterizing these markets, identifying market failures and proposing policies and remedies for Digital Platforms (DPs). We identified nine areas of consensus using a maximum common denominator methodology. From merger control to platform and data interoperability, these reports explore the frontier of economics and law to underline the under-enforcement that has taken place across jurisdictions. There is a widespread dissatisfaction in the enforcement area, so the paper looks at several landmark cases to learn lessons for the future implementation of competition policy. We emphasize the large Transatlantic divide in enforcement of abuses of dominance between the US and EU and the fault lines in the US according to the administration. This shows that there is no consensus between the EU and US competition authorities. Regulatory measures have been proposed, and some have been implemented on data privacy and platform to business, sometimes in the intersection of competition policy with other policy areas, which shows the difficulty in partitioning public policies. But bringing them together is a challenge. None of the reports advocates deep structural measures, but there have been proposals by politicians and academics for the break-up of some of the big corporations of digital platforms, echoing past antitrust cases, mainly Microsoft. We discuss the pros and cons of this measure. Finally, we look at the way forward and further need to improve methodologies and processes of authorities to make them more agile and efficient.

Reaction between arylidenemalononitriles and acetoacetanilide in the presence of piperazine hydrate in methanol at room temperature affords new tricyclic pyrano[3,2-c]pyridine derivatives of (rac-1S*,2R*,3R*,7R*,8R*,11R*)-2,11-diaryl-4,10-diimino-8-methyl-5-phenyl-6-oxo-9-oxa-5-azatricyclo-[5.3.1.03,8]undecane-1,3-dicarbonitrile family in yields of 55–84%. The molecular structures of the products were confirmed by X-ray crystallography and NMR spectroscopy.

High-density polyethylene (HDPE) composites with different amounts of ZrO2 nanoparticles (1–20 vol%) were prepared by high-pressure thermal pressing. The effect of γ-irradiation on their structural and thermal properties was investigated using small-angle neutron scattering (SANS), X-ray diffraction (XRD), Raman spectroscopy, infrared spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). SANS analysis confirmed good dispersion of the nanoparticles in HDPE matrix. Upon exposure to γ-radiation only small changes in the lattice parameters and the crystalinity degree occurred for both HDPE and the nanocomposities. More significant changes for irradiated HDPE were observed in DSC-derived parameters, including the decrease in the melting point, and increase in crystalinity degree. This trend was even more pronounced for the nanocomposities. A possible explanation assuming resonant enchantment of polymer chain scission in the presence of ZrO2 nanoparticles is discussed. The extent of radiation-induced oxidation was essentially the same for pure HDPE and the nanocomposities, suggesting that the process is diffusion controlled. The thermal stability of the irradiated composites was somehow higher than that pure HDPE.

Pediatric tonsillectomy is a frequently performed procedure using a variety of surgical techniques. Despite decades of modern surgical experience and advances in tools and techniques, a consensus on which technique is superior for minimizing complications has not been established. In a 2014 study, the authors examined differing surgical techniques and devices to determine if there was a significant difference in the bleed rates based on technique and device [1]. In that study 7024 children were evaluated, of which a total of 1.4% (n = 99) of children experienced a postoperative hemorrhage that required a second surgery. There was no significant difference found between the four different techniques that were evaluated. Although the combined rates of post-operative hemorrhage requiring a second surgery was lower compared to many other published reports, we hypothesized that continued improvement in surgical techniques could eliminate post-operative hemorrhage completely. As follow up to that study, we decided on a collective change in technique, and subsequent analysis of our post-operative results with respect to only one outcome, post-operative hemorrhage requiring a second surgery. With a new standardized technique in place, we retrospectively evaluated one year of surgical outcomes. These procedures were performed using the technique of a modified and complete, intra-capsular Coblator tonsillectomy. Of the 783 tonsillectomies done in 12 months, we found there were 0 patients that had experienced a postoperative hemorrhage requiring a second surgery. Based on our previous study with a rate of 1.4% post-operative hemorrhage we would have expected to have 11 episodes of post-operative hemorrhage requiring a second surgery.

In spite of its impressive record in medicinal chemistry, the role of barbituric acid H 3 BA (pyrimidine-2,4,6(1 H ,3 H ,5 H )-trione) in coordination, organometallic and supramolecular chemistries has not yet been analyzed and reviewed. However, H 3 BA can be readily functionalized and provides rich opportunities to create coordination bonds and non-covalent interactions. Thus, derivatives of H 3 BA (barbituric acids, BAs) are widely used for the preparation of a wide range of complexes with various metals of almost all groups of the periodic table. The review systematizes information on the synthesis, tautomerism, acid–base properties of BAs and their use for the construction of organometallic and coordination compounds, as well as coordination polymers and supramolecular assemblies. The role of different metal ions and the structure of BAs in directing the preparative pathways and tuning particular structural properties of the resulting compounds are discussed. Some valuable applications of BAs, in particular in the construction of molecular receptors, magnetic and nonlinear optic materials, bioactive compounds, drug cocrystal design, catalysis and photochemistry are also envisaged.