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Two conformational polymorphs of [Cu(25dIpy)2Cl2] have been prepared, the anti-polymorph crystallized from 2-propanol at room temperature (green) and the syn-polymorph crystallized from acetonitrile at 60 °C (brown).

Polycyclic aromatic hydrocarbons (PAHs) were investigated in the outdoor air of charcoal-grilled meat-restaurants in Amman/Jordan. The studied restaurants were given the codes (S, Z, G, B, and J). PAHs were extracted using QuEChERS method and detected using GC/MS. They were found in almost all samples. Levels of PAHs in the stacks were found to depend on major factors like type and quantity of charcoal used, the amount of grilled meat after marinating, and sampling season. The results showed that PAHs concentrations in toxic equivalents (TEQs) in (ng TEQ/m3) were found in the following order: S restaurant (158) > B (114) > J (47) > G (20) > Z (15). The total emissions of PAHs in (g TEQ/year) for all restaurants samples were in the following order: S restaurant (16.5) > B (5.8) > J (1.8) > G (0.3) > Z (0.2) with B(a)P detected in restaurants S and B. This study is the first of its kind in the MENA region and provides alarming results about using charcoal for grilling where food and air contamination is unavoidable. Lowering consumption of grilled food is advisable in addition to the use of air filters for chimneys.

Background: A major focus of nanotechnology concerns is the expansion of the optimization of nanomaterials in purity, size and dispersity. Methods: In the current work, a two-step AgNP synthesis process was optimized at the mycelia-DI water suspension and AgNP formation reaction levels. Results: Biomass filtrate from the fungal strain Tritirachium oryzae W5H was able to reduce silver nitrate into AgNPs after a 72 h reaction, as indicated by the development of intense brown color and by UV-vis spectra. The biosynthesis ability of AgNPs was markedly better in the presence of a single carbon and nitrogen source in the culture medium compared to multiple sources of carbon and nitrogen. The optimization results of AgNP formation were indifferent between the two steps and were 20 g biomass, 40°C, pH 7.0, 96 h and 1.0 mM AgNO3. The TEM images of the prepared AgNPs illustrated the presence of 7-75 nm, monodispersed and spherical- to ovular-shaped Ag nanoparticles. Conclusion: The present work highlights the importance of investigating the process parameters by which the reductant mycelia-free filtrate was prepared. In addition, we explored the promising antibacterial action of the prepared AgNPs against bacterial infections.

Halogen bond interactions are investigated in four halopyridine iodine monochloride complexes nXPy(N)–ICl in the solid state, solution and in silico, where nXPy = n-halopyridine, X = I or Br and n ...

The concentration levels of 12 polychlorinated biphenyl (PCB) congeners in human gallbladder tissue and gallbladder stone samples gathered from patients in the Jordan University Hospital were measured. The total mean concentration of PCBs in gallbladder tissues samples was 491.36 µg/kg wet weight. The total mean concentration of PCBs in gallbladder stone samples was 504.03 µg/kg. Pentachlorobiphenyls were predominant PCB congeners, accounting for 23.85% of the total PCB concentration found in gallbladder tissue samples and 25.48% in gallbladder stone samples which represent the most toxic compound between all congeners dioxin-like PCBs. The TEQ values for PCBs in all samples were found in the range of (0.0001–11.72) µg TEQ/kg for gallbladder tissue samples and (0.00–12.84) µg TEQ/kg for gallbladder stone samples. The distribution coefficients of PCBs were calculated between gallbladder stones and gallbladder tissues in each sample. Kd (Cstone/Ctissue) values for PCBs were found in the range 0.22–3.18. The variations in Kd were found to be dependent mainly on type of gallbladder stone and obesity of patient. The results of this study show that both gallbladder stones and gallbladder tissues can be used to assess levels of background contamination especially if the stone was of pure cholesterol type (lipophilicity of the stones). Also a correlation between PCB concentrations and dysplasia in few samples implied that PCBs could be a potential contribution factor to gallbladder tissue mutations. This needs to be generalized by an extensive future study on representative number of gallbladder tissues with dysplasia.

One hundred soil samples were collected from five southern districts of Jordan during 2016 and 2017 to monitor the pesticides residues using LC-MS/MS. The used LC-MS/MS method was able to analyze 4...

Treatment of two equivalents of N,N′-bis(X-phenyl)oxamides (1) with one equivalent of [Zn(OAc)2(H2O)2] (2) in the presence of four equivalents of [nBu4N]OH produce the corresponding bis(N,N′-substituted oxamate) zincate(II) complexes with the general formula (nBu4N)2[Zn(X-phenyloxamide)2] (3) (a, X = 3-NO2; b, X = 4-NO2; c, X = 2,6 CH3; d, X = 3,4-CH3; e, X = 2-Br; f, X = 4-Br; g, X = 2-F; h, X = 4-F; i, X = 2-Cl; j, X = H). Complexes 3a–j have been characterized by elemental analysis, NMR (1H, 13C{1H}) and IR spectroscopy. In addition, 3a and 3f have been characterized by single crystal X-ray crystallography. The zinc (II) ion in the later complexes is four-coordinate with two ethanediamide-nitrogen atoms from two bidentate N,N′-disubstituted oxamate ligands at each metal center. In addition, the calculated electrostatic potentials of 3f rationalize the formation of chain structures via the Br…Br interaction. Complexes 3a–j showed a characteristic LLCT (π → π*) band in the UV-Vis spectra, which was confirmed by TD-DFT calculations. DFT calculations show that the Zn(II) orbitals are neither contributing to the HOMO nor to the LUMO, i.e. the HOMO and LUMO are mainly located on the ligands. The emission spectra analyses for Zn(II) complexes 3a–j show enhanced intensity and blue shifted emission compared to ligands 1a−j. The cyclic voltammetry measurements of complexes 3a–j showed reversible electrochemical processes for the (N,N′-substituted oxamate−2/−3) between −1.52 and −1.77 V using [NnBu4][B(C6F5)4] as the supporting electrolyte. It was found that the 3-nitro- (3a) and 4-nitro-functionalized (3b) derivatives resulted in a significantly higher Fc/Fc+ redox potential (E0′) compared to the more electron-rich 3, 4-dimethyl (3c) and 2,6-dimethyl (3d) derivatives.

C18H20BrNO, orthorhombic, Pbca (No. 61), a = 8.4285(4) Å, b = 19.2055(9) Å, c = 19.7809(12) Å, Z = 8, V = 3202.0(3) Å3, R gt (F) = 0.0427, wR ref (F 2) = 0.1025, T = 293(2) K.

Three-dimensionally orderedmacroporous biomaterials containing hydroxyapatite were synthesized using natural luffa cylindrical fibres (with diameter of 100-400 μm) as templates. The preliminary evaluation of this novel method for production of porous bioceramics showed promising potential applications in bone tissue engineering. The produced bioceramics were subjected to microstructural, physical, mechanical, and in vitro characterisation. Mercury intrusion porosimetry, supported by SEM analysis, showed the presence of bimodal porosity (smaller pores with diameters of 10 to 30 μm and cylindrical macropores with diameters from 100 to 400 μm) and 60% of the interconnected porosity. These porous calcium phosphate ceramics proved to be bioactive and exhibited mechanical properties comparable to those of natural spongy bones with compressive strength up to 3MPa and elastic modulus in compression around 0.05GPa. In vitro characterization of the porous ceramics showed cells attaching to the apatite crystals that make up the scaffold matrix. Cell adhesion resulted in elongated and highly stretched cells within the macropores with focal adhesion points on the scaffolds. Moreover, the cells adhered to the calcium phosphate cement (CPC) and developed cytoplasmic extensions as shown by SEM imagery. Their proliferation in the scaffolds in culture demonstrates that the scaffold architecture is suitable for Mesenchymal stem cells seeding and growth.

A new series of six-membered ring sulfonated polyimides with different combinations of two comonomers in the nonsulfonated diamine was prepared by one-step high-temperature polycondensation in m-cresol to improve the solubility of the resulting sulfonated polyimides. They are based on 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,4′-diaminostilbene-2,2-disulfonic acid sulfonated diamine, and equimolar mixture of 3,5,3′,5′-tetramethylbenzidine (TMB) and 4,4′-oxydianiline, bis(4-aminophenyl)methane, or bis(4-(aminophenoxy)-4-phenyl)isopropylidene nonsulfonated diamines. The introduction of TMB comonomer in the nonsulfonated diamine resulted in a remarkable improvement in the solubility of the resulting polyimides in comparison with the corresponding single-monomer nonsulfonated diamine polyimides. Flexible, transparent, and tough membranes were prepared by solution casting method from the different polyimides. The membranes were characterized with FTIR and 1H-NMR spectroscopy, differential scanning calorimetry, thermogravimetric analysis, water uptake, and ion-exchange capacity measurements. They exhibit high thermal stability and good correlation between the ion-exchange capacity and water uptake values.

Herein, we report the synthesis of spherical gold nanoparticles with tunable core size (23–79 nm) in the presence of polyethylene glycol-g-polyvinyl alcohol (PEG-g-PVA) grafted copolymer as a reducing, capping, and stabilizing agent in a one-step protocol. The resulted PEG-g-PVA-capped gold nanoparticles are monodispersed with an exceptional colloidal stability against salt addition, repeated centrifugation, and extensive dialysis. The effect of various synthesis parameters and the kinetic/mechanism of the nanoparticle formation are discussed.

Human platelet lysate (hPL) has been considered as the preferred supplement for the xeno-free stem cell culture for many years. However, the biological effect of hPL on the proliferation and differentiation of dental stem cells combined with the use of medical grade synthetic biomaterial is still under investigation. Thus, the optimal scaffold composition, cell type and specific growth conditions, yet need to be formulated. In this study, we aimed to investigate the regenerative potential of dental stem cells seeded on synthetic scaffolds and maintained in osteogenic media supplemented with either hPL or xeno-derived fetal bovine serum (FBS). Two types of dental stem cells were isolated from human impacted third molars and intact teeth; stem cells of apical papilla (SCAP) and periodontal ligament stem cells (PDLSCs). Cells were expanded in cell culture media supplemented with either hPL or FBS. Consequently, proliferative capacity, immunophenotypic characteristics and multilineage differentiation potential of the derived cells were evaluated on monolayer culture (2D) and on synthetic scaffolds fabricated from poly 'lactic-co-glycolic' acid (PLGA) (3D). The functionality of the induced cells was examined by measuring the concentration of osteogenic markers ALP, OCN and OPN at different time points. Our results indicate that the isolated dental stem cells showed similar mesenchymal characteristics when cultured on hPL or FBS-containing culture media. Scanning electron microscopy (SEM) and H&E staining revealed the proper adherence of the derived cells on the 3D scaffold cultures. Moreover, the increase in the concentration of osteogenic markers proved that hPL was able to produce functional osteoblasts in both culture conditions (2D and 3D), in a way similar to FBS culture. These results reveal that hPL provides a suitable substitute to the animal-derived serum, for the growth and functionality of both SCAP and PDLSCs. Thus the use of hPL, in combination with PLGA scaffolds, can be useful in future clinical trials for dental regeneration.

A series of phosphors with composition La 9.33− x − y − z Si 6 O 24 O 2 ( x =Er, y =Ce, z =Yb) with the silicate oxyapatite structure were synthesized by a sol–gel spin-coating technique. The products formed as well-crystallized laminae 6–8 nm thick. Spectroscopic measurements in the near-infrared showed that excitation through Ce 3+ enhances 1.53 μm emission of Er 3+ by a factor of 50, while the effect of Yb 3+ is to quench the luminescence.

There is a great need for skin substitutes in medicine today, especially in the treatment of burns and other acute skin injuries. The “ideal” skin substitute is still to come. Over the past decades, efforts have been directed toward fabricating tissue-engineered skin reconstitution therapies, many of which have a synthetic component. A wide variety of synthetic materials were tested as either skin replacements or supporting scaffolds for a multitude of biologic components. As a result, several patents were issued claiming the manufacture of “artificial skin.” Additionally, commercial skin substitutes were introduced into the market, each with its own advantages and disadvantages. This is a broad field within regenerative medicine that has great potential for novel outcomes. The ultimate goal is to be able to produce an “off-the-shelf” product that mimics uninjured skin, with functionally and aesthetically accepted results.

Chemical imidization of polyamic acid based on 1,5-diaminonaphthalene and a dianhydride was studied by UV−visible and FT-IR ATR techniques under various reaction conditions, such as polyamic acid concentration, solvent condition (dry vs humidity-exposed NMP), catalysts of tertiary amines with different degrees of steric crowding and base strength, and the concentration of the acetic anhydride and pyridine. With acetic anhydride and pyridine, the reaction was very similar to that of the model amic acids, with the simultaneous formation of bisimide groups and bisisoimide groups, followed by isomerization of bisisoimde groups to bisimide groups, which is very sensitive to the dryness of the solvent. The reaction with polymer films supported a similar trend. Chemical imidization seems to proceed by nucleophilic catalysis by tertiary amines, depending on the steric crowding as well as the base strength. Reducing steric crowding in the catalyst facilitates the formation of an acylammonium (or pyridinium) cation...

The title compound, C12H10N2O2, has a twisted conformation, with a dihedral angle between the planes of the pyridine and benzene rings of 78.4 (2)°. The nitro group is coplanar with the attached benzene ring within experimental error. The molecules form centrosymmetric dimers via Car—H...O interactions (H...O = 2.49 Å) and the dimers are π-stacked along the b axis [the separation between ring centroids is 3.788 (2) Å].

In order to characterize various depolymerization and imidization reactions involved during thermal and chemical imidazation of poly(amic acid) by UV-visible and fluorescence spectroscopies, several model compounds have been synthesized and characterized from 1,5-diaminonaphthalene (DAN) and phthalic anhydride. These model compounds include amic acid-amine, diamic acid, amine-imide, amic acid-imide, diimide, and diisoimide. Only DAN is found to be strongly fluorescent. The spectral changes occurring duriong chemical imidization of poly(amic acid) made from DAN and a fluorinated dianhydride were investigated

Large scale electrical power generation faces two serious problems: (i) energy conservation; and (ii) protection of the environment. High temperatures fuel cells have the potential to deal with both problems. The heat rejected by the fuel cell that would otherwise be wasted may be recovered to power a gas turbine in order to improve the energy conversion efficiency as well as power output of the combined fuel cell-gas turbine power plant. The added advantage of this approach would be to reduce thermal loading and the emission of greenhouse gases per MW electrical power generated. Serious research is being carried out worldwide to commercialise the fuel cell nevertheless there is still ample scope for studying the application of high temperature fuel cells in combination with the gas turbine for large scale electrical power generation. This paper presents the results of a parametric study of the fuel cell-gas turbine power plant to generate electricity. The paper should be of considerable interest to the designers and applications engineers working in power generation industry and other public utilities. The authors hope that the paper would lead to a stimulating discussion.Copyright © 2006 by ASME

Role d'espaceur inerte des motifs chlorure de vinylidene qui diminuent les associations intramoleculaires entre les dipoles carbonyl des motifs MMA du copolymere. Stabilite thermique minimale des copolymeres lorsque le nombre de motifs MMA et VDC adjacents est maximal; degradation thermique via une cyclisation intramoleculaire et perte de HCl pour donner une lactone a 5 chainons insatures