Fabrication of the First Disposable Three‐dimensional Paper‐based Concentration Cell as Ammonia Sensor with a New Method for Paper Hydrophobization by Laser Patterned Parafilm®

A new, simple and low‐cost method for patterning hydrophobic barriers in porous support such as paper by Parafilm® has been introduced. This method is then used for electrochemical paper‐based ammonia sensor construction. Ammonia sensor is based on electrochemical concentration cell which ammonia reaction with electrolyte in halves cell caused in concentration gradient and therefore potential difference dependent on ammonia concentration. The effect of concentrations of the involved chemicals, time periods of the required processes, the presence of Faraday cage as well as the effects of different salts used in the salt bridge on the response of the sensor, were investigated in order to find the optimized conditions.     

Synthesis and Neurotropic Activity of New Heterocyclic Systems: Pyridofuro[3,2-d]pyrrolo[1,2-a]pyrimidines,Pyridofuro[3,2-d]pyrido[1,2-a]pyrimidines and Pyridofuro[3′,2′:4,5]pyrimido[1,2-a]azepines

Background: Neurotic disturbances, anxiety, neurosis-like disorders, and stress situations are widespread. Benzodiazepine tranquillizers have been found to be among the most effective antianxiety drugs. The pharmacological action of benzodiazepines is due to their interaction with the supra-molecular membrane GABA-a-benzodiazepine receptor complex, linked to the Cl-ionophore. Benzodiazepines enhance GABA-ergic transmission and this has led to a study of the role of GABA in anxiety. The search for anxiolytics and anticonvulsive agents has involved glutamate-ergic, 5HT-ergic substances and neuropeptides. However, each of these well-known anxiolytics, anticonvulsants and cognition enhancers (nootropics) has repeatedly been reported to have many adverse side effects, therefore there is an urgent need to search for new drugs able to restore damaged cognitive functions without causing significant adverse reactions. Objective: Considering the relevance of epilepsy diffusion in the world, we have addressed our attention to the discovery of new drugs in this field Thus our aim is the synthesis and study of new compounds with antiepileptic (anticonvulsant) and not only, activity. Methods: For the synthesis of compounds classical organic methods were used and developed. For the evaluation of biological activity some anticonvulsant and psychotropic methods were used. Results: As a result of multistep reactions 26 new, five-membered heterocyclic systems were obtained. PASS prediction of anticonvulsant activity was performed for the whole set of the designed molecules and probability to be active Pa values were ranging from 0.275 to 0.43. The studied compounds exhibit protection against pentylenetetrazole (PTZ) seizures, anti-thiosemicarbazides effect as well as some psychotropic effect. The biological assays evidenced that some of the studied compounds showed a high anticonvulsant activity by antagonism with pentylenetetrazole. The toxicity of compounds is low and they do not induce muscle relaxation in the studied doses. According to the study of psychotropic activity it was found that the selected compounds have an activating behavior and anxiolytic effects on the models of “open field” and “elevated plus maze” (EPM). The data obtained indicate the anxiolytic (anti-anxiety) activity of the derivatives of pyrimidines, especially pronounced in compounds 6n, 6b, and 7c. The studied compounds increase the latent time of first immobilization on the model of “forced swimming” (FST) and exhibit some antidepressant effect similarly to diazepam. Docking studies revealed that compound 6k bound tightly in the active site of GABA_A receptor with a value of the scoring function that estimates free energy of binding (ΔG) at −7.95 kcal/mol, while compound 6n showed the best docking score and seems to be dual inhibitor of SERT transporter as well as 5-HT_1A receptor. Conclusions: Тhe selected compounds have an anticonvulsant, activating behavior and anxiolytic effects, at the same time exhibit some antidepressant effect.     

Composite of conducting polyaniline-isobutylated urea formaldehyde: Preparation and characterization

Composite of conductive polyaniline-isobutylated urea formaldehyde have been prepared by chemical oxidative emulsion polymerization of aniline in the presence of isobutylated urea formaldehyde resin (BUFR) in toluene-water solvents at room temperature. The mass loading of polyaniline was controlled by varying the BUFR/aniline charging ratio as well as oxidant (ammonium persulfate)/aniline molar ratio. Some factors capable of affecting the yield and conductivity of composite, such as amount of the oxidant, type of the dispersants (span-80 and span-20), and amount of resin and organic acid (para-toluene sulfonic acid) were investigated. The prepared composites were characterized by FTIR spectroscopy and scanning electron microscopy (SEM).     

Ni(II)-Schiff base/SBA-15: a nanostructure and reusable catalyst for one-pot three-component green synthesis of 3,4-dihydropyrano[3,2-c]chromene derivatives

Research on Chemical Intermediates - An efficient, rapid, and environmentally benign Ni(II)-Schiff base/SBA-15-catalyzed one-pot three-component cyclocondensation process was described via the...     

MnSb/GaSb(001)界面半金属特性的第一性原理研究

利用密度泛函理论计算六角NiAs型和立方闪锌矿型MnSb的电子和电磁特性,研究闪锌矿MnSb与GaSb(001)界面,并采用广义渐变近似计算了交换-相关项．闪锌矿结构的MnSb具有半金属铁磁特性,单分子磁矩4μB,MnSb/GaSb(001)界面同样具有半金属特性．界面中Mn原子的磁矩减小,界面中Sb原子磁矩等于两个相应界面磁矩的平均值．另外计算了能带排列在异质结中价带偏移大约1.25 eV.     

Sequential Ugi Four‐Component Reaction (4‐CR)/CH Activation Using (Diacetoxyiodo)benzene for the Synthesis of 3‐(Diphenylmethylidene)‐2,3‐dihydro‐1H‐indol‐2‐ones

A sequential Ugi four‐component reaction (4‐CR)/C? H activation using (diacetoxyiodo)benzene is reported. This process is a five‐component reaction of aromatic aldehydes, aniline derivatives, isocyanides, phenylpropiolic acid (3‐phenylprop‐2‐ynoic acid), and (diacetoxyiodo)benzene for the synthesis of 3‐(diphenylmethylidene)‐2,3‐dihydro‐1H‐indol‐2‐ones. This procedure offers several advantages such as good yields, high bond‐forming efficiency, selectivity, and short reaction times.