The electrospun poly(ε‐caprolactone)/fluoridated hydroxyapatite nanocomposite for bone tissue engineering

Biodegradable cell‐incorporated scaffolds can guide the regeneration process of bone defects such as physiological resorption, tooth loss, and trauma which medically, socially, and economically hurt patients. Here, 0, 5, 10, and 15 wt% fluoridated hydroxyapatite (FHA) nanoparticles containing 25 wt% F^? and 75 wt% OH^? were incorporated into poly(ε‐caprolactone) (PCL) matrix to produce PCL/FHA nanocomposite scaffolds using electrospinning method. Then, scanning electron microscopy (SEM), X‐ray diffraction (XRD) pattern, and Fourier transform infrared spectroscopy (FTIR) were used to evaluate the morphology, phase structure, and functional groups of prepared electrospun scaffolds, respectively. Furthermore, the tensile strength and elastic modulus of electrospun scaffolds were investigated using the tensile test. Moreover, the biodegradation behavior of electrospun PCL/FHA scaffolds was studied by the evaluation of weight loss of mats and the alternation of pH in phosphate buffer saline (PBS) up to 30 days of incubation. Then, the biocompatibility of prepared mats was investigated by culturing MG‐63 osteoblast cell line and performing MTT assay. In addition, the adhesion of osteoblast cells on prepared electrospun scaffolds was studied using their SEM images. Results revealed that the fiber diameter of prepared electrospun PCL/FHA scaffolds alters between 700 and 900 nm. The mechanical assay illustrated the mat with 10 wt% FHA nanoparticles revealed the highest tensile strength and elastic modulus. The weight loss alternation of mats determined around 1% to 8% after 30 days of incubation. The biocompatibility and cell adhesion of mats improved by increasing the amounts of FHA nanoparticles.     

Expression of miRNAs Targeting <Emphasis Type="Italic">mTOR</Emphasis> and <Emphasis Type="Italic">S6K1</Emphasis> Genes of mTOR Signaling Pathway Including miR-96, miR-557, and miR-3182 in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer. Aberrant expression of genes in mTOR pathway and their targeting miRNAs plays an important role in TNBC. The aim of this study was to determine the expression of mTOR and S6K1 and their targeting miRNAs in breast cancer cell lines and clinical samples. miRNAs targeting 3′-UTR of mTOR and S6K1 mRNAs were predicted using bioinformatic algorithms. MDA-MB-231, MCF-7, and MCF-10A as well as 20 TNBC samples were analyzed for gene and miRNA expression using quantitative real-time PCR (RT-qPCR). A receiver operating characteristic (ROC) curve analysis was performed for evaluation of candidate miRNAs as diagnostic biomarkers. miR-96 and miR-557 targeting mTOR and S6K1 mRNAs, respectively, were selected, and miR-3182 was selected as the miRNA targeting both genes. The miRNAs were down-regulated in cell lines, while their target mRNAs were up-regulated. Similar findings were observed in clinical samples. The ROC curve analysis revealed decline in expression of these miRNAs. We suggest that miR-96, miR-557, and miR-3182 can be used as inhibitory agents for mTOR and S6K1 in TNBC-targeted therapy.     

New sensing material of molecularly imprinted polymer for the selective recognition of sulfamethoxazole in foods and plasma and employing the Taguchi optimization methodology to optimize the carbon paste electrode

A new man-tailored biomimetic sensor for sulfamethoxazole host–guest interactions and potentiometric transduction is presented. The host cavity was shaped on a polymeric surface assembled with methacrylic acid monomers by radical polymerization. Molecularly imprinted particles (MIP) were mixed with graphite powder, paraffin oil and ionic site. Using the Taguchi method, this study analyzed the optimum conditions for preparing the carbon paste electrode. The controllable factors used in this study consisted the weights of (1) MIP, (2) paraffin oil, (3) graphite, and (4) the ionic site. The percentage contribution of each controllable factor was also determined. MIP-modified electrode exhibited a Nernstian response (57.2 mVdecade^?1) in a wide concentration range of 6.0 × 10^?8 to 3.1 × 10^?3 mol L^?1 with a lower detection limit of 3.5 × 10^?9 mol L^?1. The sensor was successfully applied to the determination of sulfamethoxazole concentrations in foods and plasma.     

Efficient TMG catalyzed synthesis of 1,2,3-triazoles

A practical and efficient method for the synthesis of 1,2,3-triazoles via the cycloaddition reaction of azides and CH-acids in the presence of 1,1,3,3-tetramethylguanidine (TMG) in ethanol at 30 °C has been reported. The simple experimental procedure, short reaction times, and good yields are the advantages of the present method.     

Tungstate supported mesoporous silica SBA‐15 with imidazolium framework as a hybrid nanocatalyst for selective oxidation of sulfides in the presence of hydrogen peroxide

In this work, a new heterogeneous catalyst (SBA‐15/Im/WO₄^2?) was prepared, and then its performance in the oxidation of organic sulfides was studied (using 30% H₂O₂ as green oxidant under neutral reaction conditions). This organic–inorganic hybrid mesoporous material was characterized by various techniques, such as FT‐IR, inductively coupled plasma, X‐ray powder diffraction, high‐resolution‐transmission electron microscopy, N₂ adsorption–desorption and thermogravimetric analysis. The catalyst was also applied to the selective oxidation of various sulfides. The hybrid catalyst was easily recovered, and was very stable and retained good activity for at least five successive runs without any additional activation. Moreover, there was no remarkable decrease in the activity and selectivity of the catalyst. The products could be easily isolated by just removing the solvent after filtering the catalyst. The yields of the catalytic productions through this catalyst were in the range from 75% to 97%.     

Chlorofluorofullerenes (CFFs)

We have applied density functional theory calculations to devise stable arrangements of chlorofluorofullerenes (CFFs). In the case of C₆₀ClF and C₆₀Cl₂F₂, an extensive isomer search shows that the most stable configurations are those with two halogens located on the corannulene-like structure. In general, 1,2-adduct is more stable than 1,4-adduct and 1,2 addition across 6–6 bonds is more stable than 1,2 addition across 5–6 bonds. The formation of a CFF from chlorofullerene is exothermic while chlorination of a fluorofullerene is endothermic. For C₆₀Cl_18-3nF_3n (n = 0, 1, 2, 3, 4, 5, and 6), the binding energies decrease as the number of Cl atoms increases and the energy differences between isomers with the same formula are small. The ¹³C NMR patterns of C₆₀Cl_18-3nF_3n (n = 0, 1, 2, 3, 4, 5, and 6) are divided into two parts: δ_iso values of chlorinated and fluorinated carbons shift to low field and appear in the range of 65.1–100.2 and 84.5–97.4 ppm; two peaks related to C sites on the cyclohexatriene pole and the flattened equatorial belt separating the two hemispheres appear at 120.2–123.4 and 125.8–129.1 ppm, respectively. Negative nucleus independent chemical shift (NICS) in interior positions of rings or cages indicates the presence of induced diatropic ring currents which suggests that cyclohexatriene poles can be considered as benzenoid fragments. NICS yields minor value (?2.7 ppm) at the ring center of polar pentagons of C₆₀Cl₁₀F₁₀, and significantly negative values in the cage center.     

Nickel catalyst supported on mesoporous MgAl2O4 nanopowders synthesized via a homogenous precipitation method for dry reforming reaction

Research on Chemical Intermediates - Mesoporous MgAl2O4 nanopowders were synthesized via the homogenous precipitation method and employed as a support for Ni catalysts in the dry reforming...     

Chiral recognition of binaphthyl derivatives using electrokinetic chromatography and steady-state fluorescence anisotropy: effect of temperature

The effect of temperature on the chiral recognition of binaphthyl derivatives in the presence of poly sodium N-undecanoyl-LL-leucyl-leucinate (poly LL-SULL) is examined using electrokinetic chromatography (EKC) and steady-state fluorescence anisotropy. An examination of the effect of temperature suggests that the chiral recognition of 1,1'-binaphthyl-2,2'-diol enantiomers improves with increasing temperature, whereas lower temperatures resulted in better enantiosolectivity in the case of 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate enantiomers. In addition, steady-state fluorescence anisotropy results show that the anisotropy of the two enantiomers are different when complexed to poly-(LL) SULL. As would be expected, the enantiomer that binds stronger to the chiral pseudostationary phase, as evidenced by EKC experiments, had higher anisotropy values. The results of this study suggest that steady-state fluorescence anisotropy can be used to gain further insight into chiral recognition.     

Proposal of a New Hf(IV)/Zr(IV) Separation System by the Solvent Extraction Method

A liquid-liquid extraction study has been conducted to separate hafnium from zirconium, using Cyanex 301 in kerosene. Noticeably, it is the first time that Cyanex 301 is utilized to separate Hf(IV) from Zr(IV). In this series of experiments, several parameters influencing the separation have been investigated, such as the initial pH, the extractant concentration, the metal ion concentration, the temperature, the type of the diluents and the salt addition. Regarding the aging of the Zr(IV) and Hf(IV) solutions, the solutions with a maximum 3 d aging time could be used with no difficulties. It was observed that the initial pH increase caused an increase in the Zr(IV)/Hf(IV) separation factor. Moreover, the distribution decreased with the temperature increase, suggesting that the reaction is exothermic. In agreement with the resulting data, the optimum separation factor illustrates the value of 7 at a pH of 4.00 in the presence of NaCl as an added salt. The attractive characteristics of the presently designed method are the use of low acidic nitrate solutions, the lack of using thiocyanate and a higher extractability of hafnium-Cyanex 301 relative to zirconium-Cyanex 301 complexes.     

A class of homogeneous superspaces associated to odd involutions

Periodica Mathematica Hungarica - A new generalization of Grassmannians in supergeometry, called $$nu $$ -Grassmannians, are constructed by gluing $$nu $$ -domains. By a $$nu $$ -domain, we mean...