Synthesis,Characterization, and Crystal Structure of a New Coordination Polymer of Lead(II) Containing 2,6‐Pyridinedicarboxylic Acid

The reaction of solution 2,6‐pyridinedicarboxylic acid ( 1 ) and 2,2′‐Bipyridine with Pb(NO₃)₂ led to the coordination polymer [Pb(pydc)]_n ( 2 ) (pydcH₂ is 2,6‐pyridinedicarboxylic acid). This complex was characterized by elemental analysis, IR spectroscopy and single‐crystal structure of 2 . Crystal data for 2 at ?80 °C: monoclinic, space group P2₁/n, a = 977.2(1), b = 554.0(1), c = 1425.3(2) pm, β = 104.75(1)°, Z = 4, R₁= 0.0261. The units [Pb(pydc)] form infinite chains along [010].     

Synthesis, characterization and crystal structure determination of platinum(IV) complexes containing, bipyridine derivatives and chloride, [Pt(5,5′-dmbipy)Cl4] and [Pt(6-mbipy)Cl4]

The complex [Pt(5,5′-dmbipy)Cl₄] (1) (5,5′-dmbipy is 5,5′-dimethyl-2,2′-bipyridine) was prepared from the reaction of H₂PtCl₆·6H₂O with 5,5′-dimethyl-2,2′-bipyridine in methanol. The same method was employed to make [Pt(6-mbipy)Cl₄] (2) (6-mbipy is 6-methyl-2,2′-bipyridine). Both complexes were characterized by elemental analysis, IR, UV–Vis, ¹H NMR, ¹³C NMR and ¹⁹⁵Pt NMR spectroscopy. Their solid state structures were determined by the X-ray diffraction method.     

Anisotropic Heisenberg Magnet with Long-Range Interactions. Integrability and Phase Structure

We show that the xxz Heisenberg magnet withlong-range interactions in a magnetic field, isintegrable both classically and quantum mechanically.Explicit expressions are given for the involutiveintegrals of the motion. The nature of the spectrum andthe ground state are clarified and the partitionfunction is calculated exactly in the thermodynamiclimit. A detailed study of the phase structure of thesystem is also performed.     

PROPERTY （X^＋） FOR SECOND-ORDER NONLINEAR DIFFERENTIAL EQUATIONS OF GENERALIZED EULER TYPE

In this paper the generalized nonlinear Euler differential equation t2k(tu′)u′′+t(f (u)+k(tu′))u′+g(u) = 0 is considered. Here the functions f (u), g(u) and k(u) sat-isfy smoothness conditions which gu...     

Protective Effect of Portulaca oleracea on Streptozotocin-Induced Type I Diabetes-Associated Reproductive System Dysfunction and Inflammation

Background: Type-one diabetes (T1D), a chronic autoimmune disease with marked inflammatory responses, is associated with infertility complications and implications. Based on the anti-diabetic, antioxidant, and anti-hyperlipidemic potential of Portulaca oleracea (PO), this study aimed to evaluate the protective effect of this plant extract on streptozotocin-induced type-I-diabetes-associated reproductive system dysfunction and inflammation. Methods: Male rats were randomly divided into four experimental groups: control, diabetic, and treatment/s (PO extract at 100 or 300 mg/kg/daily). Then food and water consumption, body, testis and epididymis weights, histopathological evaluation, seminiferous tubules diameter, sperm count and motility, glucose levels, sex hormones, and inflammatory and oxidative stress markers were evaluated. Results: Our results showed that streptozotocin-induced diabetes significantly increased food and water consumption; increased glucose, MDA, TGF-β1, and TNF-α levels; and decreased the seminiferous tubules diameter, sperm count and motility, levels of LH, testosterone, total thiol, VEGF, and SOD activity. Interestingly, PO extract (phytochemically characterized by using liquid chromatography–mass spectrometry to detect bioactive molecules) significantly ameliorated these parameters and histopathological indexes’ damage in rats. Conclusion. Even if more preclinical assessments are needed to better characterize the mechanism/s of action, the results of this study will pave the way for the rational use of PO on diabetic-associated clinical complications and implications.     

Polythiophene/hexagonally ordered silica nanocomposite coating as a solid‐phase microextraction fiber for the determination of polycyclic aromatic hydrocarbons in water

A highly porous fiber coated with polythiophene/hexagonally ordered silica nanocomposite was prepared for solid‐phase microextraction (SPME). The prepared nanomaterial was immobilized onto a stainless‐steel wire for the fabrication of the SPME fiber. Polythiophene/hexagonally ordered silica nanocomposite fibers were used for the extraction of some polycyclic aromatic hydrocarbons from water samples. The extracted analytes were transferred to the injection port of a gas chromatograph using a laboratory‐designed SPME device. The results obtained prove the ability of the polythiophene/hexagonally ordered silica material as a new fiber for the sampling of organic compounds from water samples. This behavior is due most probably to the increased surface area of the polythiophene/hexagonally ordered silica nanocomposite. A one‐at‐a‐time optimization strategy was applied for optimizing the important extraction parameters such as extraction temperature, extraction time, ionic strength, stirring rate, and desorption temperature and time. Under the optimum conditions, the LOD of the proposed method is 0.1–3 pg/mL for analysis of polycyclic aromatic hydrocarbons from aqueous samples, and the calibration graphs were linear in a concentration range of 0.001–20 ng/mL (R² > 0.990) for most of the polycyclic aromatic hydrocarbons. The single fiber repeatability and fiber‐to‐fiber reproducibility were less than 8.6 and 19.1% (n = 5), respectively.     

A rapid and convenient synthesis of gem-bis(dithiocarbamate) derivatives from primary aliphatic amines,carbon disulfide,and aromatic aldehydes using boron trifluoride-diethyl etherate

An efficient route for the synthesis of gem-bis(dithiocarbamate) derivatives is developed using dithiocarbamic acid salts generated from primary aliphatic amines and CS₂. The method offers high yields, employs mild reaction conditions, and demonstrates excellent functional group compatibility. The structures of the products were confirmed spectroscopically and by X-ray analysis.     

Matrix‐grafted multiwalled carbon nanotubes/poly(methyl methacrylate) nanocomposites synthesized by in situ RAFT polymerization: A kinetic study

A new approach was developed to functionalize multiwalled carbon nanotubes (MWCNTs) with a polymerizable methyl methacrylate (MMA) groups, and the structure of functionalized MWCNTs were characterized by FTIR, Raman, XPS, and TEM. Using the strategy of “grafting through,” poly(methyl methacrylate) (PMMA) chains were grafted onto the surface of MWCNTs during the in situ synthesis of MWCNT/PMMA nanocomposites over reversible addition‐fragmentation chain transfer (RAFT) polymerization. Kinetics of RAFT‐mediated polymerization of MMA in the presence of MMA‐grafted MWCNTs was studied by using gas chromatography and gel permeation chromatography. To further study, attached polymers were detached and their molecular characteristics were compared to freely formed chains. Results of kinetic studies showed that the utilized commercial chain transfer agent strictly reduced the rate of polymerization as well as relatively controlled molecular weights and narrow molecular weight distributions of free chains. MWCNTs showed a radical activity, retarding the polymerization and reducing the rate of reaction. The effect of MWCNTs concentrations on molecular weights and polydispersity indexes (PDI) was different at the surface and in the bulk. The molecular weights of free chains increased, and the PDI was decreased with increasing MWCNTs. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 555–569, 2012     

A nanostructure-based electrochemical sensor for square wave voltammetric determination of N-acetylcysteine in pharmaceutical and biological samples

Ionics - In this study, a carbon paste electrode (CPE) was chemically modified with Pt/carbon nanotubes (CNTs) nanocomposite and 8,9-dihydroxy-7-methyl-12H-benzothiazolo [2,3-b] quinazolin-12-one...