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In this study, Magnetic core‐shell dendritic mesoporous silica nanospheres immobilized with imidazolium‐based di‐cationic ionic liquid (Fe3O4@SiO2@DSiO2‐Im‐IL) possessing a large surface area and numerous active site for adsorption of various molecules to carry out organic transformations have been successfully developed. The synthesized nanocatalyst was found to be easily recyclable by applying external magnetic force. The structure, morphology, thermal stability, and magnetic behavior of the synthesized magnetic nanocatalyst were confirmed by different physiochemical techniques like FT‐IR, P‐XRD, FE‐SEM, TGA, VSM, BET, and TEM analysis. The efficiency of the developed heterogeneous nanocatalyst has been investigated for the green synthesis of numerous benzopyran derivatives by employing different aldehydes and active methylene compounds. The catalyst exhibits marvellous activity and efficiency in terms of high product yield, less catalyst use, and wide substrate scope even at room temperature. Finally, after the successful formation of the product, the catalyst was regenerated by utilizing an external magnetic field. The catalyst has been reused multiple times without any noteworthy loss in its activity which confirms the stability of the developed catalyst. The preparation of the catalyst is cost‐effective, and shows atom economy with the utilization of green solvent and without any waste production, which authenticates that it could be a greener pathway for the synthesis of the benzopyran derivatives. [ABSTRACT FROM AUTHOR]

The present work describes the synthesis of a material consisting of a bisimidazolium ionic liquid supported on graphene oxide. The prepared nanocomposite was characterized by different physicochemical techniques such as FT-IR, XRD, CHN, SEM, TEM and EDAX. The synthesized nanocomposite was further utilized as an effective heterogeneous catalyst for the synthesis of tetraketone derivatives, which are biologically significant, using dimedone and aryl aldehydes as the substrates at 50 °C and a green solvent. One of the tetraketone products has been confirmed by single crystal XRD. The catalyst displayed high reaction yields, facile separation, short reaction time, good stability and recoverability up to six consecutive reaction rounds with no discernible loss in its catalytic activity. [ABSTRACT FROM AUTHOR]

In this work, a simple and stepwise strategy has been adopted for the successful synthesis of diamine functionalized porous graphene oxide sheets decorated with ultra-small palladium oxide nanoparticles. The successful synthesis, stepwise functionalization, morphology and elemental composition have been authenticated by using numerous physicochemical characterization techniques such as FT-IR, TGA, powder XRD, SEM, HR-TEM, EDAX, elemental mapping, CHNS, ICP-MS and XPS analyses. The prepared nano-catalyst has been employed as a recyclable catalyst for the oxidative amidation of aldehydes with amines. The main features of this nano-catalyst include mild reaction conditions, simple work-up procedure, high product yield without any hazardous by-products and recyclability for several catalytic cycles. It could be believed that the unique porous architecture of the nano-catalyst was responsible for the enhanced specific surface area which favors a quick response and improved interaction between the catalytic active moieties and the reactants. [ABSTRACT FROM AUTHOR]

In this study, 1-(3-aminopropyl)-imidazole-functionalized porous graphene oxide nanosheets (GONs) decorated with palladium nanoparticles (Pd NPs; size, ∼11 nm) have been developed. This has been accomplished via covalent immobilization of amine-terminated imidazolium moieties over GONs, which were further decorated with Pd NPs by employing chemical reduction method. To authenticate the successful preparation of a nanocatalyst (i.e., GO-Imd-Pd), numerous physicochemical characterization techniques, such as FT-IR, XRD, TEM, TGA, SEM, EDAX, XPS, CHN, ICP-MS, and BET surface area analysis, have been utilized. The synthesized hybrid nanomaterial could validate its supremacy as a highly efficacious and heterogeneous nanocatalyst for the oxidative amidation of aldehydes. The prepared hybrid nanomaterial could offer Lewis acidic sites, which could help in the activation of reactant molecules, thereby delivering a high yield of the product. The prepared hybrid nanomaterial could be effortlessly separated from the reaction mixture by simple centrifugation technique. Also, the prepared nanocatalyst showed magnificent recyclability up to six catalytic runs without any perceptible loss in its activity and showed no sign of disintegration. [ABSTRACT FROM AUTHOR]

This work describes the synthesis of magnetic graphene oxide (MGO), where iron oxide (Fe3O4) nanoparticles were uniformly deposited over the sheets of the graphene oxide (GO). Further, the introduction of aminopropyltrimethoxysilane (APTMS) on the surface of MGO was successfully done and results in the formation of amine-functionalized magnetic graphene oxide (MGO–NH2). The synthesized heterogeneous magnetic nanocomposite was characterized by numerous physicochemical and morphological techniques such as powder X-ray diffraction, Fourier transform infrared, thermogravimetric analysis, transmission electron microscopy, vibrating sample magnetometer, scanning electron microscopy, CHN analyzer, and energy-dispersive X-ray analysis. The synthesized nanocomposite was proved to be an effectual catalyst in the nucleophilic ring opening reactions of styrene oxide with derivatives of amines under green solvent. The present catalyst displayed good catalytic activity, short reaction time, higher regioselectivity, excellent yields and could be reutilized up to seven catalytic rounds with no substantial loss in its activity. The excellent properties of the catalyst are due to the dual character of acidic groups (existence of carboxyl groups on the sheet edges) and basic groups (amine groups anchored on the surface of GO). On completion of the reaction, the prepared nanocomposite could be effortlessly recovered from the reaction mixture by utilizing an external magnet, owing to the ferromagnetic property of Fe3O4. [ABSTRACT FROM AUTHOR]

In this work, an efficient and facile strategy has been adopted for the stepwise synthesis of the RGO–MSiO2/PdO hybrid nanomaterial (HY-NM). Herein, a hybrid nanostructure of mesoporous silica over graphene oxide (GO) sheets has been developed followed by immobilizing palladium oxide nanoparticles (PdO NPs), and then it has been utilized for catalyzing a multicomponent reaction (MCR). To authenticate the successful synthesis of the HY-NM and successive immobilization of PdO NPs, various physicochemical characterization techniques were utilized such as SEM, EDAX, HR-TEM, HR-XRD, TGA, BET, FT-IR, and XPS analysis. The activity of the HY-NM has been determined by performing the catalyst-mediated synthesis of β-substituted indole derivatives (yield 90–98%). The excellent catalytic activity of the prepared HY-NM could be observed due to its high surface area and large porosity, which facilitates the penetration and interaction of reactant molecules with the catalytic active species. This protocol eliminates the requirement of further purification after the isolation of the product from the reaction mixture. The ease of handling, recyclability of the catalyst, and simple work-up procedure are the main features of this protocol. The synthesized HY-NM could be recycled for multiple catalytic cycles making it a very effective heterogeneous catalyst. [ABSTRACT FROM AUTHOR]

In the present study, diamine-functionalized magnetic core–shell dendritic mesoporous silica nanospheres have been successfully synthesized by an oil–water biphasic stratification-coating strategy. The shape, size and morphology of the synthesized magnetic nanocatalyst could be characterized by various physicochemical techniques such as, field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The characteristic information about the successful immobilization of various functionalities on the nanospheres could be obtained with the help of X-ray powder diffraction (XRD) patterns, Fourier transform-infrared spectroscopy (FT-IR), energy dispersive X-ray spectroscopy (EDX) and thermo-gravimetric analysis (TGA). The details about the magnetic behaviour and surface area of the nanocatalyst could be acquired by vibrating sample magnetometry (VSM) and BET surface analysis, respectively. The synthesized diamine-functionalized magnetic nanoparticles were then explored as a highly efficient catalyst for the Knoevenagel condensation and one-pot synthesis of polyhydroquinolines using aromatic/heteroaromatic aldehydes and aliphatic aldehydes with active methylene compounds under very mild conditions. The synthesized magnetic core–shell dendritic mesoporous silica nanospheres had large surface areas. This large surface area and pore volume could facilitate a proper interaction and penetration of the reactant molecules with the basic amine groups present on the dendritic mesoporous silica nanospheres. The supported nanocatalyst revealed no sign of leaching of the amine groups present inside the dendrimers and therefore, could be reused up to nine times without any noteworthy loss in catalytic activity. [ABSTRACT FROM AUTHOR]

Presents an algorithm for use in natural language document retrieval systems which automatically determines if the conjunction "and" in a statement representing an information need should be translated into a Boolean "and" or "or." The results of an experiment that used the algorithm are reported, and further research is suggested. (CLB)

It is generally recognized that the conjunction "and" plays an ambiguous role in natural language. When considered within the domain of Boolean document retrieval, this ambiguity makes the automatic Boolean interpretation of statements representing information needs a difficult task. The human analyst is able to resolve this ambiguity with relative ease. However, the processes employed appear complex and are not well understood. This article examines a semantic property of the conjunction, i.e., the semantic similarity between the conjuncts with a view to automatically resolving this ambiguity. Specifically, the idea examined is that if the two conjuncts are semantically similar then the conjunction is best interpreted as a Boolean OR, otherwise as an AND. The study resulted in an algorithm which utilizes semantic information and some syntactic information (both of which are derivable from a standard dictionary) to obtain the appropriate Boolean interpretation. The algorithm was successful when evaluated against human decisions, in addition to contributing the algorithm, this article draws attention to the effects of this ambiguity on the derivation of appropriate Boolean search specifications from natural-language statements representing information needs. [ABSTRACT FROM AUTHOR]

In this work, an efficient and facile strategy has been adopted for the stepwise synthesis of the RGO-MSiO2/PdO hybrid nanomaterial (HY-NM). Herein, a hybrid nanostructure of mesoporous silica over graphene oxide (GO) sheets has been developed followed by immobilizing palladium oxide nanoparticles (PdO NPs), and then it has been utilized for catalyzing a multicomponent reaction (MCR). To authenticate the successful synthesis of the HY-NM and successive immobilization of PdO NPs, various physicochemical characterization techniques were utilized such as SEM, EDAX, HR-TEM, HR-XRD, TGA, BET, FT-IR, and XPS analysis. The activity of the HY-NM has been determined by performing the catalyst-mediated synthesis of β-substituted indole derivatives (yield 90-98%). The excellent catalytic activity of the prepared HY-NM could be observed due to its high surface area and large porosity, which facilitates the penetration and interaction of reactant molecules with the catalytic active species. This protocol eliminates the requirement of further purification after the isolation of the product from the reaction mixture. The ease of handling, recyclability of the catalyst, and simple work-up procedure are the main features of this protocol. The synthesized HY-NM could be recycled for multiple catalytic cycles making it a very effective heterogeneous catalyst.

In this work, Ru x Pd y alloy nanoparticles were uniformly decorated on a two-dimensional reduced graphene oxide (rGO) sheet by an in situ chemical co-reduction process. The resulting products were characterized by various physiochemical techniques such as X-ray diffraction, Raman spectroscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma atomic absorption spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. Further, the synthesized Ru x Pd y @rGO nanocomposites have been employed as a heterogeneous catalyst for three different catalytic reactions: (1) dehydrogenation of aqueous ammonia borane (AB); (2) hydrogenation of aromatic nitro compounds using ammonia borane as the hydrogen source, and (3) for the synthesis of aromatic azo derivatives. The present work illustrates the sustainable anchoring of metal nanoparticles over the surface of rGO nanosheets, which could be used for multifarious catalytic reactions., Competing Interests: The authors declare no competing financial interest., (© 2021 American Chemical Society.)

Breast cancer forms the commonest cancer in females in Jaipur region. Two hundred cases of breast malignancy were recorded in a single year (1990). This constituted 8.30% of total cancers and 19.40% of all female cancers. The commonest age group was 45-54 years (37.0%) followed by 35-44 years (24.50%). Only 13.50% were below the age of 35 years. Majority of the patients (97.50%) were married and 76.0% got married below the age of 20 years, 26.50% got married below the age of 15 years. Most (75.0%) has menarche between the age of 13 and 16 years. Menstrual irregularities were present in only 17.50% of the cases. More than 6 pregnancies had in 33.50% patients and 50.50% had 3-5 pregnancies. Only 4.50% had no issue. Most of the women (68.50%) had their first live child between 18 and 25 years and 13.50% had below 18 years. Majority reported having breastfed their children for 1-2 years. Only 12.0% and 5.0% women reported having any problem with breast during lactation and otherwise respectively. A family history of cancer was present in 10.0% of the cases. A personal delay of more than two years in seeking medical help was observed in only 6.0% of the cases while 22.50% sought medical advice within a week time. Risk factors which are implicated in the aetiology of breast cancer in the western setting might not necessarily hold true in our country. More epidemiological studies are required to elicit correlation, if any, in the Indian context.