[The effect of four immunosuppressive drugs on oral manifestations after organ transplantation].

PURPOSE: To assess the prevalence of oral manifestations in a group of allogenic liver, kidney or haematopoietic stem cell transplantation recipients and patients, and analyze the possible oral manifestations associated with the use of 4 immunosuppressive drugs. METHODS: One hundred and eighteen patients submitted to liver, kidney and hematopoietic stem cell transplantation who used tacrolimus， sirolimus，cyclosporine or mycophenolate mofetil were enrolled. Through a questionnaire survey and oral examination, their oral manifestations were recorded, and the possible statistical associations with immunosuppressive drugs were analyzed using SPSS 21.0 software package. RESULTS: The prevalence of oral lichenoid lesions and cheilitis for the group of patients using tacrolimus after transplantation was significantly lower than the group of patients who did not used the agent(P＜0.01). The prevalence of oral lichenoid lesions for the group of patients who used cyclosporine was significantly higher than the group of patients who did not used the drug(P＜0.05), and the prevalence of cheilitis for the group of patients who used cyclosporine was significantly higher than the group of patients who did not used the drug(P＜0.01). The prevalence of oral lichenoid lesions and cheilitis for the group of patients who used tacrolimus was significantly lower than the group of patients who used cyclosporine(P＜0.01). The group of patients who used mycophenolate mofetil after transplantation had a significantly lower prevalence of dry mouth than the group of patients who did not used the drug(P＜0.01). The prevalence of oral manifestations in patients with sirolimus after transplantation was not significantly reduced. CONCLUSIONS: The use of tacrolimus improved the symptoms of oral lichenoid lesions and cheilitis and the effect was better than cyclosporine after transplantation. The use of mycophenolate mofetil improved dry mouth after organ transplantation.

Carbon nanotube hollow polyhedrons derived from ZIF-8@ZIF-67 coupled to electro-deposited gold nanoparticles for voltammetric determination of acetaminophen.

A comparative study was carried out on the electrochemical behavior of three carbonized zeolitic imidazolate frameworks (ZIFs) synthesized through solvothermal pyrolysis. An electrochemical sensor for acetaminophen (ACT) was subsequently developed. The sensor was made by coating the glassy carbon electrode (GCE) with cobalt-nitrogen co-doped carbon nanotube hollow polyhedron (Co-NCNHP), which was prepared from core shell ZIF-8@ZIF-67, before electrodeposition of gold nanoparticles. Due to the high specific surface area, good electrical conductivity and stability of both Co-NCNHP and the gold nanoparticles, the resultant sensor displayed excellent electrocatalytic activity towards ACT with the catalytic rate constant Kcat of 4.9 × 105 M-1 s-1, diffusion coefficient D of 1.8 × 10-6 cm2 s-1, high sensitivity of 1.75 µA µM-1 cm-2, and best at a working voltage of 0.35 V (vs. Ag/AgCl). Benefitting from the synergistic effect of both Co-NCNHP and gold nanoparticles, the modified GCE had a linear response in the 0.1 µM-250 µM ACT and detection limit of 0.05 µM (at S/N = 3). The sensor was successfully applied to quantify ACT in tablets and spiked urine samples with recoveries ranged between 96.0% and 105.2%. Graphical abstractSchematic representation of cobalt-nitrogen co-doped carbon nanotube hollow polyhedrons (Co-NCNHP) exhibiting superior electrocatalytic activity to carbonized ZIF-8 and carbonized ZIF-67. Co-NCNHP were coupled to electrodeposition gold nanoparticles to modify glassy carbon electrode for improving acetaminophen (ACT) redox.

A sensitive electrochemical sensor based on ZIF-8-acetylene black-chitosan nanocomposites for rutin detection.

Herein, we fabricated a sensitive rutin electrochemical sensor via modifying glassy carbon electrode (GCE) with zeolitic imidazolate framework-8 (ZIF-8) and acetylene black (AB) in the presence of chitosan (CS). The electrochemical activity and experimental parameters of the ZIF-8-AB-CS/GCE sensor were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Under the optimal conditions, the sensor presented a reasonable linear response in the range of 0.1-10 µM with a limit of detection (LOD) as low as 0.004 µM (S/N = 3). The sensor possessed good reproducibility and high stability, and was successfully applied to detect rutin tablet samples with satisfactory results, which was attributed to the synergistic effect between ZIF-8 and AB. Meanwhile, the sensor displayed a potential application for detection of other analytes in real samples. Furthermore, a probable interaction mechanism was proposed to account for the interaction between rutin and the nanocomposite electrode, which was not discussed in previous reports.

Preparation and evaluation of molecularly imprinted polymer of olivetol for solid phase extraction.

Molecularly imprinted polymer (MIP) was synthesized by bulk polymerization, using olivetol as template molecule, methyl acrylic acid (MAA) as monomer, ethylene glycol dimethacrylate (EDMA) as crosslinker, toluene and dodecanol as solvents. The resulted MIP was characterized by the equilibrium binding experiments, scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FTIR). The polymer was then applied to solid phase extraction (SPE) of olivetol from spiked wheat bran samples. From the equilibrium binding experiments, it was showed that MIP had a better recognizability for the template molecule. Scatchard analysis showed that MIP had specific adsorption to olivetol with two classes of binding sites. The high and low binding sites dissociation constants were 0.021 and 1.002 mmol/L. The corresponding maximum binding capacities were 18.74 and 135.9 micromol/g, respectively. Under the optimum condition of SPE, the recoveries of olivetol on MIP cartridge were in the range of 97.8% - 98.8%. The relative standard deviations (RSDs) were 2.8% -4.2%. The linearity range was between 0.1 and 100 mg/L. The limit of detection (S/N = 3) was 0.062 mg/L. MIP cartridge showed stronger selectivity, higher recovery and purified the sample more drastically compared with non-imprinted polymer (NIP) cartridge and commercial poly (styrene/divinyl-benzene) (PLS) cartridge.

A novel method to prepare monolithic molecular imprinted polymer fiber for solid-phase microextraction by microwave irradiation.

In this paper, a new approach to prepare monolithic molecularly imprinted polymer (MIP) fibers for solid-phase microextraction is proposed with the help of microwave irradiation. Imprinting polymerization was carried out within silica capillaries in 4.5 min, using dimethyl phthalate (DMP) as a template molecular, α-methacrylic acid as a functional monomer and ethylene dimethacrylate as a crosslinker, acetonitrile as the porogenic solvent. The synthesis was optimized by varying the ratio of template/monomer and different volume of porogen. The resulted MIP fibers were obtained after silica being etched away with a controlled length of 1 cm, and subsequently characterized by SEM. In order to increase the selective extraction of DMP, factors affecting the extraction including extraction time, salt concentration, desorption time, and desorption solvents were investigated for solid-phase microextraction procedures in detail. The selectivity coefficients, defined as the extraction amount ratio of MIP to its nonimprinting fiber, were 5.6, 2.6, and 1.4 for DMP and its counterpart including dibutyl phthalate and di-n-octylo-phthalate, respectively. The resulted fibers were also applied to detect DMP, dibutyl phthalate, and di-n-octylo-phthalate in bottled beverage samples coupled to HPLC and resulted in relative recoveries of up to 73.8-98.5%, respectively.