In Situ Synthesis of Self‐Assembled Gold Nanoparticles on Glass or Silicon Substrates through Reactive Inkjet Printing

A facile and low cost method for the synthesis of self‐assembled nanoparticles (NPs) with minimal size variation and chemical waste by using reactive inkjet printing was developed. Gold NPs with diameters as small as (8±2) nm can be made at low temperature (120 °C). The size of the resulting NPs can be readily controlled through the concentration of the gold precursor and oleylamine ink. The pure gold composition of the synthesized NPs was confirmed by energy‐dispersive X‐ray spectroscopy (EDXS) analysis. High‐resolution SEM (HRSEM) and TEM (HRTEM), and X‐ray diffraction revealed their size and face‐centered cubic (fcc) crystal structure, respectively. Owing to the high density of the NP film, UV/Vis spectroscopy showed a red shift in the intrinsic plasmonic resonance peak. We envision the extension of this approach to the synthesis of other nanomaterials and the production of tailored functional nanomaterials and devices.     

Synthesis and Anticancer Activity of New Substituted Pyrazoles and Their Derived 1,2,4‐Triazoles and Sugar Derivatives

New substituted pyrazole, thiazole, and 1,2,4‐triazole derivatives were synthesized. The sugar hydrazones, their acetylated derivatives as well as their derived acyclic C‐nucleoside analogs, and the thioglycosides of the 1,2,4‐traizole derivatives were also prepared. The antitumor activity of some of the synthesized compounds were studied, and a number of the tested compounds showed significant activities.     

Synthesis and Antitumor Activity of New Polysubstituted Thiophenes and 1,3,4‐Thiadiazoles Incorporating 2,6‐Pyridine Moieties

The versatile multifunctional unreported pyridine‐2,6‐bis(2‐cyano‐N‐phenyl‐3‐oxopropanethioamide) ( 3 ) was prepared starting from pyridine‐2,6‐bis‐(3‐oxopropanenitrile) ( 1 ). Several new series of polysubstituted thiophenes and 1,3,4‐thiadiazoles incorporating 2,6‐pyridine moiety were efficiently synthesized. The newly synthesized compounds were evaluated for their in vitro anticancer activity against human cancer cell lines: hepatocellular liver carcinoma (HEPG2) and Caucasian breast adenocarcinoma (MCF‐7). Some of the newly synthesized compounds exhibited better activity than doxorubicin as a reference drug.     

Unexpected Reaction Course of 3‐Amino‐5‐aryl‐1H‐pyrazoles with Dialkyl Dicyanofumarates

On treatment of 3‐amino‐5‐aryl‐1H‐pyrazoles 1 with dialkyl dicyanofumarates (=(E)‐but‐2‐enedioates) 4 in boiling 1,2‐dichloroethane, two competitive reactions occurred leading to 3‐aryl‐5‐cyano‐6,7‐dihydro‐6‐oxo‐1H‐pyrazolo[3,4‐b]pyridine‐4‐carboxylates 10 and 7‐amino‐2‐arylpyrazolo[1,5‐a]pyrimidine‐5,6‐dicarboxylates 11 . In DMF at room temperature, as well as at 100°, only compounds 10 were isolated. The formation of the major products of type 10 was rationalized via Michael addition of 1 as a C(4)‐nucleophile onto 4 , followed by HCN elimination and lactamization. On the other hand, the minor products 11 result from a Michael addition of 1 onto 4 via the NH₂ group, and subsequent HCN elimination and cyclization. The structures of the products have been established by X‐ray crystallography.     

Antioxidant activity of some N-heterocycles derived from 2-(1-(2-oxo-2H-chromen-3-yl)ethylidene) hydrazinecarbothioamide

Efficient and convenient synthesis of coumarin derivatives was accomplished via reactions of 2-(1-(2-oxo-2H-chromen-3-yl)ethylidene)hydrazinecarbothioamide with some carbon electrophiles, e.g. maleic anhydride, dimethyl acetylenedicarboxylate, 1,2-dichloroethane, 3′-nitro-w-bromoacetophenone, N-(4-acetylphenyl)-2-chloroacetamide, ethyl cyanoacetate/3-chlorobenzaldehyde and acetylacetone to construct some N-heterocycles such as thiazolidine, thiazole, pyrimidine and pyrazolone derivatives. The structures of all synthesized products were substantiated from their analytical and spectral data. The antioxidant activities of the synthesized compounds were examined.     

A Facile Access to Some New Pyrazole, 1,3,4-Thiadiazole,and Thiophene Derivatives via β-Ketosulfones

3-Bromoacetyl-1,5-diphenyl-1H-pyrazole-4-carbonitrile (1) reacts with sodium benzenesulfinate to give the corresponding ketosulfone 2. Treatment of 2 with hydrazonoyl chlorides 3a,b gives the 3,3′-bipyrazoles 5a,b. Ketosulfone 2 reacts also with arylidenemalononitriles to give the pyrazolylpyridones 10a,b. The reaction of compound 2 with phenylisothiocyanate and potassium hydroxide and treating intermediate with hydrazonoyl halides and with α-haloketones gives the 1,3,4-thiadiazoles 18a–c and thiophenes 21a–f, respectively.     

A Site‐Selective Doping Strategy of Carbon Anodes with Remarkable K‐Ion Storage Capacity

The limited potassium‐ion intercalation capacity of graphite hampers development of potassium‐ion batteries (PIB). Edge‐nitrogen doping is an effective approach to enhance K‐ion storage in carbonaceous materials. One shortcoming is the lack of precise control over producing the edge‐nitrogen configuration. Here, a molecular‐scale copolymer pyrolysis strategy is used to precisely control edge‐nitrogen doping in carbonaceous materials. This process results in defect‐rich, edge‐nitrogen doped carbons (ENDC) with a high nitrogen‐doping level (up to 10.5 at %) and a high edge‐nitrogen ratio (87.6 %). The optimized ENDC exhibits a high reversible capacity of 423 mAh g^?1, a high initial Coulombic efficiency of 65 %, superior rate capability, and long cycle life (93.8 % retention after three months). This strategy can be extended to design other edge‐heteroatom‐rich carbons through pyrolysis of copolymers for efficient storage of various mobile ions.     

Measurement of dose enhancement by neutron capture of boron in Cf interstitial brachytherapy

The effect of boron concentration in water on the gamma, fast and slow neutrons and alpha particles components at the central, forward and backward surfaces inside tumor phantom of 4.2 cm diameter and 4.4cm height, during brachytherapy by neutrons from ²⁵²Cf were investigated. The source was at the centre of a cubic shaped water phantom of 30 cm side. The study was carried for different concentrations of boron from H₃BO₃, Li₂B₄O₇ and H₃¹⁰BO₃. The effect of source to tumor distance on the different components of radiation was also measured. The results indicated that the use of ¹⁰B compounds enhances the damage and is recommended for successful boron neutron capture therapy (BNCT).     

Facile one‐pot syntheses of new polyfunctional pyrazolyl substituted and pyrazolofused pyridines

Ethyl 2‐cyano‐3‐(5‐chloro‐1,3‐diphenylpyrazol‐4‐yl)acrylate ( 1 ) undergoes both conjugate addition of a number of methylene‐active ethanenitriles and direct addition of other active methylene donors to the cyano carbon atom. These additions are the starting events of cascades of subsequent reactions eventually forming (i) novel polyfunctional pyrazolyl‐substituted monocyclic pyridines ( 4a , b and 6 ), (ii) 1,3‐benzothiazole and benzimidazole‐fused pyridines ( 11, 13 ) and (iii) pyrazolo[5,4‐b]pyridines ( 19b, 20 ) in one‐pot reactions in ethanolic solution containing catalytic amounts of piperidine.     

Intercomparative studies of brachytherapy techniques combined with CF Boron neutron capture therapy

In this work the depth dose distribution for γ-rays, slow and fast neutrons, nuclear recoils and -particles inside a tumor phantom filled with 100 ppm ¹⁰B in distilled water was measured. The depth dose distributions were measured and represented on three-dimensional plots when a ²⁵²Cf neutron source was situated in interstitial, surface and intracavitary brachytherapy techniques. Comparison of the three brachytherapy techniques when combined with BNCT revealed that the damage induced in the tumor by the -particles as nuclear recoils in the interstitial geometry is much more than the other two techniques.