One-pot synthesis of polyhydropyridine derivatives via Hantzsch four component condensation in water medium: Use of a recyclable Lewis acid [Ce(SO4)2.4H2O] catalyst

An efficient and eco-friendly method for the synthesis of polyhydroquinoline derivatives using Ce(SO4)2.4H2O as mild and heterogeneous Lewis acid catalyst via the Hantzsch reaction in very short reaction time is reported. A mixture of an appropriate aldehyde, dimedone, ethyl acetoacetate and malononitrile in the presence of the Ce(SO4)2.4H2O at reflux conditions in water based media resulted in good to excellent yields of the corresponding products. The catalyst can be used as selective for some aromatic aldehydes in the reaction conditions.KEY WORDS: Ce(SO4)2.4H2O, Polyhydroquinoline, Hantzsch reaction, Muticomponent reaction, Dihydropyridine Bull. Chem. Soc. Ethiop. 2012, 26(3), 461-465.DOI: http://dx.doi.org/10.4314/bcse.v26i3.16 &#160

Numerical and experimental analysis of a hybrid material acoustophoretic device for manipulation of microparticles.

Acoustophoretic microfluidic devices have been developed for accurate, label-free, contactless, and non-invasive manipulation of bioparticles in different biofluids. However, their widespread application is limited due to the need for the use of high quality microchannels made of materials with high specific acoustic impedances relative to the fluid (e.g., silicon or glass with small damping coefficient), manufactured by complex and expensive microfabrication processes. Soft polymers with a lower fabrication cost have been introduced to address the challenges of silicon- or glass-based acoustophoretic microfluidic systems. However, due to their small acoustic impedance, their efficacy for particle manipulation is shown to be limited. Here, we developed a new acoustophoretic microfluid system fabricated by a hybrid sound-hard (aluminum) and sound-soft (polydimethylsiloxane polymer) material. The performance of this hybrid device for manipulation of bead particles and cells was compared to the acoustophoretic devices made of acoustically hard materials. The results show that particles and cells in the hybrid material microchannel travel to a nodal plane with a much smaller energy density than conventional acoustic-hard devices but greater than polymeric microfluidic chips. Against conventional acoustic-hard chips, the nodal line in the hybrid microchannel could be easily tuned to be placed in an off-center position by changing the frequency, effective for particle separation from a host fluid in parallel flow stream models. It is also shown that the hybrid acoustophoretic device deals with smaller temperature rise which is safer for the actuation of bioparticles. This new device eliminates the limitations of each sound-soft and sound-hard materials in terms of cost, adjusting the position of nodal plane, temperature rise, fragility, production cost and disposability, making it desirable for developing the next generation of economically viable acoustophoretic products for ultrasound particle manipulation in bioengineering applications

H 4

An efficient and environmentally benign protocol for the one-pot, three-component synthesis of 12-aryl-8,9,10,12-tetrahydro-benzo[a]xanthen-11-one derivatives by condensation of aryl aldehydes, 2-naphthol and dimedone using H4SiW12O40 (SiWA) as a reusable catalyst with high catalytic activity was reported. The reaction was carried out at 100 ºC under solvent-free conditions within 15-40 min in 82-91% yield

Biotransformation of Monoterpenoids by Suspension Cultures of Lavandula angustifolia

Abstract Callus and suspension cultures of Lavandula angustifolia Mill. (Lamiaceae) were established and the effect of different culture media on growth rate was investigated. Terpenoids added to suspension culture to investigate their biotransformation. All samples were analyzed by gas chromatography (GC) and GC-mass spectroscopy (MS). Octan-1-ol, citronellol, linalool, borneol and geraniol were biotransformed products of octanal, citronellal, linalyl acetate, bornyl acetate and geranyl acetate, respectively. Citronellol, linalool, borneol, and menthol didn't change by L. angustifolia suspension cultures. Blue pigment production by cultures of L. angustifolia was also studied. Ester hydrolysis and oxidation were the main reactions which occurred in biotransformation process, which may be attributed to the presence of related or bifunctional enzymes. This technique is a possible way of the production of expensive or rare compounds from cheap and plentiful substrates

Predication of steady-state thermal characteristics of a resistance spot welding transformer in battery manufacturing application

This paper introduces a novel finite-element-method-based model designed to analyze the electromagnetic–thermal dynamics of resistance spot welding (RSW) transformers used in battery manufacturing. The RSW process, inherently multiphysics and sensitive to temperature fluctuations, involves phase changes within the metal materials. This complexity, combined with frequent electrode connections and disconnections during welding (variable structure), renders traditional steady-state analysis methods inadequate for accurately capturing temperature and electromagnetic parameters under thermal steady-state conditions, and the effect of changing power electronics parameters (frequency, number of cycles, and firing angle) on continuous operation is also unpredictable. The article proposes a method capable of determining temperature trends during electrode opening (rest period). It simplifies the temperature characteristics and material properties of the welding spot. These variations are equated and simplified as a constant temperature and an equivalent material, respectively. The proposed model, rooted in finite-element analysis and experimentally validated, enables a bidirectional electromagnetic–thermal simulation through steady-state thermal analysis. This simulation generates results for temperature and electromagnetic values during steady-state operation, demonstrating close agreement with experimental results. Consequently, the developed model showcases its capability in predicting the impacts and sensitivities of various factors, such as voltage cycle number, firing angle, and rest period duration within the RSW process

An Efficient, Simple and Green Zn(Phen)2Cl2 Complex Catalyzed Synthesis of 4-H-Benzo[b]pyrans in Water at Ambient Temperature

An efficient method for the synthesis of 4-H-benzo[b]pyrans has been developed by the use of Zn(Phen)2Cl2(2 mol%) as an ecofriendly catalyst. The mixture of an appropriate aldehyde, malononitrile and dimedone in the presence of the Zn(Phen)2Cl2 as an inorganic catalyst in water at room temperature resulted excellent yields of the corresponding products in 5 min. Very short experimental time of the reaction, excellent yields, use of water as a green solvent, simple work-up and uses no extra catalyst and purification are the advantages of this method

Achillea vermicularis a medicinal plant from Iranian Traditional Medicine induces apoptosis in MCF-7 cells

Background and objectives: Achillea is an ancient medicinal herb. The genus comprises about 100 species which are mostly distributed in northern hemisphere and some have been investigated for different biological activities. There are also several reports in Iranian Traditional Medicine (ITM) texts about its anti-tumor effect. The cytotoxic activity of the methanol extract of Achillea vermicularis Trin.  has been reported in previous studies against different tumor cell lines. Based on these reports, the species has been further investigated for apoptosis induction ability. Methods: The apoptosis induction ability has been evaluated through activated caspase 3 investigation in intact MCF-7 cells in vitro.  Results: The assay demonstrated signs of caspase 3 activation in MCF-7 cells. Conclusion: Achillea vermicularis is suggested for further mechanistic evaluations in apoptosis studies

Ethnobotanical survey of medicinal plants used traditionally in two villages of Hamedan, Iran

A notable amount of medicinal plants grow in Iran and local communities in different parts of the country have developed a deep knowledge of various uses of plants during their old history. Several ethnobotanical studies have been conducted by the Traditional Medicine and Material Medica Research Center (TMRC) to investigate the use of medicinal plants by local people. Some of these studies have been carried out in Kohgiluye va Boyer Ahmad, Azarbayjan-e-Sharghi and Golestan provinces. These ethnobotanical data have been collected by semi-structured interviews. In the present study, two villages of Hamedan province were investigated and eleven informants were interviewed. Our results have presented 45 traditionally used plant species, belonging to 23 plant families and 39 genera. Asteraceae and Fabaceae were the dominant locally used families. The plants were used both for medicinal and non-medicinal purposes and the most treated problems were digestive disorders and infections