Necessary optimality conditions and saddle points for approximate optimization in banach spaces

In this article we study approximate optimality in the setting of a Banach space. We study various solution concepts existing in the literature and develop very general necessary optimality conditions in terms of limiting subdifferentials. We also study saddle point conditions and relate them to various solution concepts. Part of this research was carried out when the author was a post-doctoral fellow at UAB, Barcelona by the Grant No. SB99-B0771103B of the Spanish Ministry of Education and Culture. The hospitality and the facilities provided at CODE, UAB is gratefully acknowledged.     

Thermal cyclization of 3-arylamino-3-(2-nitrophenyl)-propenal Schiff base hydrochlorides followed by triethyl phosphite mediated deoxygenation: a facile synthesis of quindolines

A simple and useful method for the synthesis of various 2-substituted quindolines starting from 2-nitroacetophenone is described.     

Mild and efficient deprotection of allyl ethers of phenols and hydroxycoumarins using a palladium on charcoal catalyst and ammonium formate

An efficient procedure for the cleavage of allyl phenyl ethers and allyl coumarinyl ethers using a catalytic amount of 10% Pd/C in combination with ammonium formate is described. Allyl ethers of phenols are deprotected in preference to those of alcohols and this method is compatible with several reducible functional groups such as CHO, COCH₃, CO₂Et and NHCOCH₃.     

Non-invasive diagnosis of type 2 diabetes in Helicobacter pylori infected patients using isotope-specific infrared absorption measurements

Helicobacter pylori causes several gastrointestinal diseases and may also contribute to the development of type 2 diabetes (T2D). Several studies suggest that there might be a potential link between H. pylori infection and T2D, but it still remains the subject of debate. Here, we first report the cumulative effect of H. pylori infection and T2D by exploiting the excretion kinetics of ¹³C/¹²C and ¹⁸O/¹⁶O isotope ratios of exhaled breath CO₂ in response to an oral dose of ¹³C-enriched glucose in individuals with T2D and non-diabetic controls (NDC) harbouring the H. pylori infection. Using a high-resolution integrated cavity output spectroscopy (ICOS) technique in the infrared region, we observed that the isotopic fractionations of ¹³C and ¹⁸O in breath CO₂ are distinctly altered in H. pylori infected T2D patients as well as in H. pylori infected NDC. Several optimal diagnostic cut-off points of ¹³C and ¹⁸O isotopes of breath CO₂ were also determined which exhibited the diagnostic sensitivity and specificity of ～97?% and thus suggesting that breath ¹³C and ¹⁸O isotopes might be considered as potential biomarkers for the non-invasive assessment of the gastric pathogen prior to the onset of T2D. This may open a new diagnostic strategy for treating these common diseases in an alternative way.     

Injectable hydrogels

Hydrogels are promising for a variety of medical applications due to their high water content and mechanical similarity to natural tissues. When made injectable, hydrogels can reduce the invasiveness of application, which in turn reduces surgical and recovery costs. Key schemes used to make hydrogels injectable include in situ formation due to physical and/or chemical cross‐linking. Advances in polymer science have provided new injectable hydrogels for applications in drug delivery and tissue engineering. A number of these injectable hydrogel systems have reached the clinic and impact the health care of many patients. However, a significant remaining challenge is translating the ever‐growing family of injectable hydrogels developed in laboratories around the world to the clinic. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012     

Zinc(II) complex immobilized on amine functionalized silica gel: a novel,highly efficient and recyclable catalyst for multicomponent click synthesis of 1,4-disubstituted 1,2,3-triazoles

We report a highly efficient and recyclable heterogeneous zinc catalytic system via covalent immobilization of 2-hydroxyacetophenone (2-HAP) onto an amine functionalized silica gel followed by metallation with zinc chloride and its catalytic application in three component click synthesis of 1,4-disubstituted 1,2,3-triazoles. The structure of the synthesized organic–inorganic hybrid material (SiO₂@APTES@2HAP-Zn) has been confirmed by various physicochemical characterization techniques, such as solid-state ¹³C CPMAS NMR spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), Brunauer–Emmett–Teller (BET) surface area analysis, scanning electron microscopy (SEM), atomic absorption spectroscopy (AAS), energy-dispersive X-ray fluorescence spectroscopy (ED-XRF), and elemental analysis. The newly designed catalyst works under mild reaction conditions and also exhibits excellent performance in terms of good product yield and high turnover number (TON). One of the most important attributes of the present methodology is that the catalyst can be recycled several times without appreciable loss in its activity as proved by FTIR spectroscopy and SEM analysis. Besides, the heterogeneity test also confirms that no leaching of active catalytic species occurs from the silica supported zinc catalyst which confirms its remarkable structural stability under the reaction conditions.     

Bio-inspired Design of Bidirectional Oxygen Reduction and Oxygen Evolution Reaction Molecular Electrocatalysts

The proper utilization of renewable energy sources has emerged as a major challenge in our pursuit of a sustainable and carbon-neutral energy landscape. Small molecule activation is a key component for proper utilization of renewable energy resources, where O₂/H₂O redox couple is reckoned to be a potential game changer. In this regard, electrocatalytic oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) have become the prime interest of catalyst designers. Typically, these ORR and OER electrocatalysts are developed distinctly; however, very soon, the requirement of a bidirectional ORR/OER electrocatalyst becomes obvious for practical applicability and rapid energy transduction purposes. A bidirectional catalyst is defined as a catalyst capable of driving a redox reaction in opposing directions. This review has portrayed the development of enzyme structure-inspired design of molecular bidirectional ORR/OER catalysts. The strategic incorporation of secondary and outer coordination sphere features has significantly enhanced the performance of these catalysts, which can be monitored via the key catalytic parameters. These bifunctional OER/ORR catalysts are vital for metal-air battery and fuel cell applications and appropriately poised to lay the foundation for an efficient, economical, and eco-friendly pathway for sustainable energy usage with the rational assembly of energy converting and storage devices.     

Recent Advances in 3D Printing of Photocurable Polymers: Types,Mechanism, and Tissue Engineering Application

The conversion of liquid resin into solid structures upon exposure to light of a specific wavelength is known as photopolymerization. In recent years, photopolymerization-based 3D printing has gained enormous attention for constructing complex tissue-specific constructs. Due to the economic and environmental benefits of the biopolymers employed, photo-curable 3D printing is considered an alternative method for replacing damaged tissues. However, the lack of suitable bio-based photopolymers, their characterization, effective crosslinking strategies, and optimal printing conditions are hindering the extensive application of 3D printed materials in the global market. This review highlights the present status of various photopolymers, their synthesis, and their optimization parameters for biomedical applications. Moreover, a glimpse of various photopolymerization techniques currently employed for 3D printing is also discussed. Furthermore, various naturally derived nanomaterials reinforced polymerization and their influence on printability and shape fidelity are also reviewed. Finally, the ultimate use of those photopolymerized hydrogel scaffolds in tissue engineering is also discussed. Taken together, it is believed that photopolymerized 3D printing has a great future, whereas conventional 3D printing requires considerable sophistication, and this review can provide readers with a comprehensive approach to developing light-mediated 3D printing for tissue-engineering applications.