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Indoles are one of the most important heterocycles because of their widespread occurrence in bioactive natural products, synthetic drugs and organic materials. Therefore, development of efficient strategies for synthesizing functionalized indoles has been of great importance in organic synthesis. Copper, being a transition metal, meet the goal due to its low toxicity, high catalytic activity and cost‐effectiveness. In this review, we focus on last five year (2019–2023) advancement in copper‐catalyzed annulations for the construction of indole core involving various N‐containing substrates, which include anilines, o‐alkynylanilines, o‐aminophenylpropynols, o‐alkynylnitroarenes, o‐nitrochalcones, azidoalkynes, isonitriles, nitriles, enamines, imines, etc. Mechanistic aspects of the reactions have also been highlighted for better understanding of the reaction pathways. [ABSTRACT FROM AUTHOR]

Pseudopeptides are a versatile class of organic building blocks having potential applications in a wide range of domains. In the current study, N and C termini protected l-alanine based short pseudopeptide was synthesized, where 5-aminoisophthalic acid (5-AIA), a rigid non-proteogenic γ-amino butyric acid was incorporated as C-terminal residue. The single crystal X-ray analysis revealed that the l-Ala residue of the aforesaid peptide adopts ϕ and ψ values characteristic of polyproline II conformation. Self-assembly of the pseudopeptide seems to represent a supramolecular helical architecture via NH⋯O, CH⋯O hydrogen bonding and π–π interactions. [ABSTRACT FROM AUTHOR]

Due to the advantages of tuning the electronic structure and reducing charge carrier recombination, metal doping into semiconductor metal oxides has been considered an efficient method for enhancing photocatalytic activity and photo-induced conductivity. In this paper, we focus on the effect of cobalt doping on the photocatalytic performance and photo-induced conductivity of ZnO QD. It was found that after Co doping, the photocatalytic activity of ZnO QD was remarkably higher than that of undoped ZnO QD when measured with methylene blue (MB) dye. The study showed that the complete degradation of the dye using 5 mol% cobalt doped ZnO QD occurred in just 6 min, which is 4 times faster than that of undoped ZnO QD. The extent of dye mineralization was supported by chemical oxygen demand (COD) study, which revealed that the dye was almost entirely mineralized. Furthermore, the photoconductivity and photosensitivity of 5 mol% doped Co doped ZnO QD were increased by 20 and 7 times, respectively, over that of undoped ZnO QD. The outstanding boost in photocatalytic activity and photoconductivity is caused by the tunable band gap mediated photo response, which increases light harvesting and thus the generation of a large number of electron hole pairs. Another possible explanation is that sub-energy levels formed between the conduction and valence bands act as a trap for electrons and holes, promoting charge separation by limiting photogenerated charge carrier recombination. [ABSTRACT FROM AUTHOR]

The emotion and sentiment associated with comic scenes can provide potential information for inferring the context of comic stories, which is an essential pre-requisite for developing comics' automatic content understanding tools. Here, we address this open area of comic research by exploiting the multi-modal nature of comics. The general assumptions for multi-modal sentiment analysis methods are that both image and text modalities are always present at the test phase. However, this assumption is not always satisfied for comics since comic characters' facial expressions, gestures, etc., are not always clearly visible. Also, the dialogues between comic characters are often challenging to comprehend the underlying context. To deal with these constraints of comic emotion analysis, we propose a multi-task-based framework, namely EmoComicNet , to fuse multi-modal information (i.e., both image and text) if it is available. However, the proposed EmoComicNet is designed to perform even when any modality is weak or completely missing. The proposed method potentially improves the overall performance. Besides, EmoComicNet can also deal with the problem of weak or absent modality during the training phase. • Although the emotion and sentiment related to comic scenes play an essential role in several aspects of comic research, it is still an open research area. • Here, we explore the problem of automatically predicting the emotion and sentiment associated with comic scenes. • We propose a multi-task deep neural network that amalgamates texts and images to predict discrete emotion labels associated with comic scenes. • We also derive some additional visual and textual features to model those external sources of knowledge appropriately. • The higher accuracy values in terms of all the standard metrics reflect the efficiency of the proposed algorithm. [ABSTRACT FROM AUTHOR]

ZnO is considered a promising pseudocapacitive material for supercapacitor devices because of its high specific energy density, low cost, non-toxicity, eco-friendliness, and widespread availability. However, its poor electronic and ionic conductivity limits its power density and cycling stability as a supercapacitor device, restricting its use in energy storage systems. Herein we report a novel hybrid nanocomposite electrode material developed by three-dimensional conducting wrapping of ZnO nanoparticles with graphene sheet to significantly improve the supercapacitor efficiency. The wrapping of ZnO nanospheres by graphene sheets creates highly conductive pathways by bridging individual ZnO together, thereby improving the rate and cycling performance of supercapacitors. The fabricated supercapacitor device using this ZnO–RGO hybrid exhibited a high specific capacitance of 1012 F/g at a current density of 1 A/g. Furthermore, the ZnO–RGO hybrid is capable of achieving an outstanding power density of 3534.6 W/kg, an energy density of 50.6 Wh/kg and a Coulombic efficiency of 96.4%. These findings exhibit the potential of the ZnO–RGO hybrid nanocomposites as an electrode in high-performance supercapacitors. [ABSTRACT FROM AUTHOR]

An achiral tripeptide, namely, Boc-γ-Abu-m-ABA-Aib-OMe (γ-Abu: γ−amino butyric acid; m-ABA: meta-aminobenzoic acid) was synthesized by solution phase procedure. The α, γ-hybrid peptide was designed in such a way that two dissimilar γ−amino acids, one flexible and another rigid, were positioned sidewise along with α-amino isobutyric acid (Aib) as C-terminal residue. The single crystal X-ray diffraction analysis revealed that two kinks were generated around centrally placed m-ABA. Interestingly, the peptide self-assembled via three intermolecular N–H···O and one intermolecular C–H···O hydrogen bonding interactions to supramlecular helical architecture. [ABSTRACT FROM AUTHOR]

Paper documents are ideal sources of useful information and have a profound impact on every aspect of human lives. These documents may be printed or handwritten and contain information as combinations of texts, figures, tables, charts, etc. This paper proposes a method to segment text lines from both flatbed scanned/camera-captured heavily warped printed and handwritten documents. This work uses the concept of semantic segmentation with the help of a multi-scale convolutional neural network. The results of line segmentation using the proposed method outperform a number of similar proposals already reported in the literature. The performance and efficacy of the proposed method have been corroborated by the test result on a variety of publicly available datasets, including ICDAR, Alireza, IUPR, cBAD, Tobacco-800, IAM, and our dataset. [ABSTRACT FROM AUTHOR]

Background: COVID-19 outbreak has drawn out institutions to closure with several challenges for university students of undergraduate level in Dhaka city including an emergency shift from traditional learning to online learning, which associated digital divide, left several arguments in response to technological inefficiency, pedagogic inefficiency of teachers, inappropriate study environment and so on. Previous literature shows that the COVID-19 is imposing a threat to mental health all over the nation since its spread. This study intended to evaluate the emerging reasons for psychological distress among university students of undergraduate level in Dhaka, also assess the execution methods, barriers of online learning, and lastly, the attitudes of students regarding online learning throughout the pandemic.Methods: A mixed methodology was used to conduct the research. Primary data has been collected using simple purposive sampling on 180 undergraduate students, 9 interviews were taken including 6 in-depth interviews of different university undergraduates from Dhaka city and also 3 (KIIs) from specialists of pedagogy and medical anthropology, and a high official from Bangladesh Telecommunication Regulatory Commission (BTRC).Results: Based on the Kessler K-10 distress scale, the study found that the prevalence of no psychological distress (16.67%) followed by mild (40%), moderate (30.56%), and severe psychological distress (12.78%).Conclusion: The results concluded considering several reasons for mild to severe psychological distress. The findings suggest some recommendations to accumulate the process of online learning effectively and also strategies to regulate the preferred mode of learning in future. [ABSTRACT FROM AUTHOR]

A protected tripeptide Boc-l-Leu-5-AIA-Aib-OMe was synthesized where 5-aminoisophthalic acid (5-AIA), a rigid non-coded aromatic γ-amino acid is incorporated as central residue. The single crystal X-ray diffraction study indicates that the peptide self-assembles into supramolecular sheet through intermolecular hydrogen bonding interaction N–H⋯O and π···π interaction. [ABSTRACT FROM AUTHOR]

Most of the recent research works on comic document images have focused on the reading and distribution of comics digitally due to the evolution of technologies. In this work, the extraction of narrative text boxes and speech balloons, which contain the conversations among comic characters along with their feelings, is presented. Due to the huge variety of drawing styles, the shape of these speech balloons is complex, and extraction is difficult. We present a shape-aware dual-stream convolutional neural network for the segmentation of narrative text boxes and speech balloons of various shapes. In our dual-stream architecture, an added shape module processes edge information of the speech balloons and narrative texts with the main module. Later, the concatenation of these two modules produces more accurate segmentation of speech balloons and narrative text boxes. The proposed method achieves significant performance improvements in terms of both region accuracy (mIOU) and boundary accuracy (F-measure and Hausdorff distance) compared to other state-of-the-art methods on various publicly available comic datasets (namely eBDtheque, DCM and Manga 109 dataset subset) in different languages. In addition, we have developed a new dataset (BCBId) for comics in Bangla, the eighth most spoken language in the world, and propose a method for the development of ground-truth images in a semiautomatic way. [ABSTRACT FROM AUTHOR]

The current study is conceptualized to assess the perception of the general population towards health insurance providers and the policy features, to segment them based on their attitudes. The mixed-method design is used in this study. One fifty health insurance users response were analyzed. The data analysis technique includes focus group discussion, henry garret ranking method, factor analysis and cluster analysis. This study concludes that health insurance providers needs to devise insurance policies incorporating the features of home health, telemedicine and income protection features. The existing users should be offered customization option due to covid-19 to prevent customer switch. [ABSTRACT FROM AUTHOR]

Indanone-containing scaffolds are attractive synthetic targets because of their wide occurrence in many natural products, drugs and functional materials. In the last few years, enormous efforts have been devoted to the development of the 1-indanone core. The present review aims to cover the last four years' (2017–2020) efforts towards the construction of 1-indanone skeletons based on transition-metal-catalyzed annulation strategies. In this context, important transition-metal based photocatalytic cyclizations have also been discussed. In most cases, the general reaction mechanisms, key intermediates, and application of several novel ligands are highlighted. Interestingly, some of the methodologies have been useful in the synthesis of natural products and compounds of biological relevance. [ABSTRACT FROM AUTHOR]

A tripeptide Boc-L-Pro-m-ABA-Aib-OMe was synthesized where meta-aminobenzoic acid (m-ABA), a rigid non-coded γ-amino acid is placed as middle residue. Single crystal X-ray diffraction study indicates that the peptide self-assembles into helical motif through intermolecular hydrogen bonding interaction N–H···O, C–H···O, π···π interaction and van der Waals interaction. HR-TEM image reveals the formation of fibril in the solid state. [ABSTRACT FROM AUTHOR]

In this article, we propose a hierarchical fault localization technique using a deep neural network (DNN). First, we prioritize the functions of a program based on their suspiciousness score. Subsequently, the fault is localized to specific statements within the top k suspected functions, where the value of k is determined heuristically. We use two function-level features to train a DNN for fault localization at the function level. Subsequently, the invocation information of the statements of the top-k functions is used to train another neural network to localize the faulty statement. We also report an extension to our approach for localizing multiple faults. This involves partitioning the failed test cases into clusters such that they target different faults. Our empirical evaluation indicates that our proposed approach requires examining 30.05 to 50.74% less code on an average, as compared to related fault localization techniques. [ABSTRACT FROM AUTHOR]

Ninhydrin (1,2,3‐indanetrione hydrate) is a powerful electrophile having enormousapplications in organic and bio‐organic sciences. In the last few years, reactivity of various ninhydrin adducts have been exploited extensively for the development of diverse organic scaffolds. The present review focuses on the applications of readily accessible ninhydrin adducts as building block towards the synthesis of a variety of compounds including N‐inserted compounds, spiro‐heterocycles, medium ring compounds, polycyclic molecules, propellanes, cycloadducts, allylic anions, axially chiral molecules etc. Interestingly, some of the compounds have profound biological activities and a few display important photophysical properties. Most of the reactions described here are simple and carried out with easily available starting materials under green conditions. [ABSTRACT FROM AUTHOR]

N-(N-benzoyl glycinyl)-N,N′-dicyclohexylurea was synthesised by conjugating N-benzoyl glycine and dicyclohexylcarbodiimide (DCC) using triethylamine as base catalyst. A single crystal X-ray diffraction study reveals that the compound self-assembles into a supramolecular sheet structure by intermolecular N–H · · · O, C–H · · · O hydrogen bonding and non-bonding van der Waals interactions. A high resolution transmission electronic microscopic (HR-TEM) image of the compound exhibits formation of fibrils in the solid state. [ABSTRACT FROM AUTHOR]

An unduly large number of test cases are required for effective testing of programmes containing complex decision statements. In this context, modified condition/decision coverage (MC/DC) testing has been acknowledged to provide effective testing using a test suite whose size is linear in the number of the clauses present in a predicate. MC/DC testing is well‐accepted and is mandated by several testing standards. T‐way testing is another prominent testing technique that helps to limit the combinatorial explosion of black‐box test cases. Its application to white‐box testing promises to provide effective testing with a comparatively small number of test cases. The authors empirically investigate the effectiveness of MC/DC testing vis‐à‐vis white‐box pairwise, 3‐way and 4‐way testing. [ABSTRACT FROM AUTHOR]

Rhodium-catalyzed C –H activation involves mild reaction conditions, high efficiency, versatility, and regioselectivity. Consequently, this strategy is gradually becoming a powerful tool for constructing diverse heterocyclic scaffolds. In fact, N -heterocycles, especially indoles, are ubiquitous in natural products and pharmaceuticals. The present review summarizes recent advances (2019–2023) in Rh-catalyzed annulation of various substrates for the synthesis of indole skeletons. Annulations involving substrates, such as, anilines, anilides, amidines, N -nitrosoanilines, ortho -alkynylanilines, aryl hydrazines, nitrones/nitroarenes, 1-phenylpyrazolidinones etc. with suitable reaction partner efficiently afforded functionalized indoles. The reactions discussed in this review employed readily available starting materials that are environmentally benign and easy to handle. Moreover, mechanistic rationale for most of the reactions was highlighted for clear understanding of the readers. [Display omitted] • This review summarizes recent advances (2019–2023) in Rh-catalyzed reactions for the synthesis of indole skeletons. • Annulation involving anilines, anilides, amidines, N -nitrosoanilines, ortho -alkynylanilines, aryl hydrazines, nitrones/nitroarenes etc. Was described. • Mechanistic rationale for most of the reactions was highlighted for better understanding of reaction pathway. • Some of the reactions are practical for the synthesis of biologically active heterocycles. [ABSTRACT FROM AUTHOR]

Object-Oriented languages such as Java language introduce advantageous features which overcome the demerits of procedural languages to some extent. Therefore, Java language is now going to be used by the industries to develop their critical safety system software products. In this paper, we propose some code transformation methodologies, which are implemented in Java language to test Java written code. We apply Java Distributed Concolic testing technique to improve the code coverage, which is more powerful than non-distributed concolic testing in terms of speed of test case generation. We develop a Java coverage analyzer according to the test cases produced by Java distributed concolic testers. This version of the MC/DC analyzer is more powerful than that of procedural languages. Our core idea is to integrate the existing and developed modules to produce a single tool for measuring MC/DC score. This novel idea automates the flow of testing 100%. Our experimental results present different scenarios, and suggest the stronger one. On an average, for forty-five Java programs using three nodes in the client–server architecture, we achieved higher MC/DC score. [ABSTRACT FROM AUTHOR]

An unexpected migration of a ninhydrin carbon bearing a phenolic subunit has been observed when phenolic adducts of ninhydrin reacted with 2-aminophenol in butan-1-ol at the reflux temperature. The products were unambiguously assigned as 2-(1,3-dioxoisoindolin-2-yl)phenyl benzoates on the basis of NMR spectroscopy and X-ray crystallographic analysis. [ABSTRACT FROM AUTHOR]

Primary cilia (PCs) that are present in most human cells and perform sensory function or signal transduction are lost in many solid tumors. Previously, we identified VDAC1, best known to regulate mitochondrial bioenergetics, to negatively regulate ciliogenesis. Here, we show that downregulation of VDAC1 in pancreatic cancer-derived Panc1 and glioblastoma-derived U-87MG cells significantly increased ciliation. Those PCs were significantly longer than the control cells. Such increased ciliation possibly inhibited cell cycle, which contributed to reduced proliferation of these cells. VDAC1-depletion also led to longer PCs in quiescent RPE1 cells. Therefore, serum-induced PC disassembly was slower in VDAC1-depleted RPE1 cells. Overall, this study reiterates the importance of VDAC1 in modulating tumorigenesis, due to its novel role in regulating PC disassembly and cilia length. [Display omitted] [ABSTRACT FROM AUTHOR]

In the real-time systems and safety critical domains, software quality assurance adheres to protocols such as DO-178C standard. Regarding these issues, concolic testing generates test cases that can attain high coverage using an augmented approach based on Modified Condition/Decision Coverage (MC/DC). In this paper, we propose a framework to compute MC/DC percentage for test case generation. To achieve an increase in MC/DC, we transform the input Java program, J, into its transformed version, J ′ , using Java Program Code Transformer (JPCT). Then, we use JCUTE tool to generate test cases. At last, we use Java Coverage Analyzer (JCA) to compute MC/DC percentage. The Java program code transformer adds additional empty nested if-else conditional statements for each decision that causes variation in MC/DC percentage. In later step, these extra conditional statements get stripped-off. This approach resolves some of the bottleneck issues associated with traditional concolic testers. In our experimental study, we have experimented with forty Java programs. We have computed the difference of MC/DC%, for both the scenarios (i.e. with code transformation and without code transformation). Our approach (i.e. with code transformation achieves) 24.09% average increase in MC/DC% over the traditional approach (i.e. without code transformation). [ABSTRACT FROM AUTHOR]

While the terminally protected tripeptide Boc-Phe-Gly-m-ABA-OMe I (m-ABA, meta-amino benzoic acid) is an excellent gelator of aromatic organic solvents, another similar tripeptide Boc-Leu-Gly-m-ABA-OMe II, where the Phe residue of peptide I is replaced by Leu, cannot form gels with the same solvents. The morphology of the gels of peptide I, characterised by the field-emission scanning electron microscopy and high-resolution transmission electron microscopy, reveals the formation of nanofibrous networks which are known to encapsulate solvent molecules to form gels. The wide-angle X-ray scattering studies of the gels suggest the β-sheet-mediated self-assembly of peptide I in the formation of a nanofibrous network, where π-stacking interactions of Phe play an important role in the self-assembly and gel formation. The dried gel of peptide I observed between crossed polarisers after binding with a physiological dye, Congo red, shows a bluish-green birefringence, a characteristic of amyloid fibrils. [ABSTRACT FROM AUTHOR]

Single crystal X-ray diffraction studies show that the three designed tripeptides Boc-Leu-Aib-m-NA-NO2 (I), Boc-Phe-Aib-m-NA-NO2 (II) and Boc-Pro-Aib-m-ABA-OMe (III) (Aib, α-aminoisobutyric acid; m-NA, m-nitroaniline; m-ABA, m-aminobenzoic acid; Boc, t-butyloxycarbonyl) containing aromatic rings in the backbones adopt β-turn structures that are self-assembled through intermolecular hydrogen bonds and van der Waals interactions to create layers of β-sheets. Solvent-dependent NMR titration and CD studies show that the β-turn structures of the peptides also exist in the solution phase. The field emission scanning electron microscopic and transmission electron microscopic images of the peptides in the solid state reveal fibrillar structures of flat morphology that are formed through β-sheet mediated self-assembly of the preorganised β-turn building blocks. [ABSTRACT FROM AUTHOR]

Abstract: Single crystal X-ray diffraction studies reveal that the incorporation of meta-amino benzoic acid in the middle of a helix forming hexapeptide sequence such as in peptide I Boc-Ile(1)-Aib(2)-Val(3)-m-ABA(4)-Ile(5)-Aib(6)-Leu(7)-OMe (Aib: α-amino isobutyric acid; m-ABA: meta-amino benzoic acid) breaks the helix propagation to produce a turn-linker-turn (T-L-T) foldamer in the solid state. In the crystalline state two conformational isomers of peptide I self-assemble in antiparallel fashion through intermolecular hydrogen bonds and aromatic π–π interactions to form a molecular duplex. The duplexes are further interconnected through intermolecular hydrogen bonds to form a layer of peptides. The layers are stacked one on top of the other through van der Waals interactions to form hydrophilic channels filled with solvent methanol. [Copyright &y& Elsevier]

Abstract: Single crystal X-ray diffraction study reveals that the water soluble tetrapeptide H2N–Ile–Aib–Leu–m-ABA–CO2H, containing non-coded Aib (α-amino isobutyric acid) and m-ABA (meta-amino benzoic acid), crystallizes with two smallest possible diastereomeric β-hairpin molecules in the asymmetric unit. Although in both of the molecules the chiralities at Ile(1) and Leu(3) are S, a conformational reversal in the back bone chain is observed to produce the β-hairpins with β-turn conformations of type II and II′. Interestingly Aib which is known to adopt helical conformation, adopts unusual semi-extended conformation with : −49.5(5)°, ψ: 135.2(5)° in type II and : 50.6(6)°, ψ: −137.0(4)° in type II′ for occupying the i +1 position of the β-turns. The two hairpin molecules are further interlocked through intermolecular hydrogen bonds and electrostatic interactions between – and −+NH3 groups to form dimeric supramolecular β-hairpin aggregate in the crystal state. The CD measurement and 2D NMR study of the peptide in aqueous medium support the existence of β-hairpin structure in water. [Copyright &y& Elsevier]

Abstract: Single crystal X-ray diffraction studies and solvent dependent NMR titration reveal that the designed peptides I and II, Boc-Xx(1)-Aib(2)-Yy(3)-NH(CH2)2NH-Yy(3)-Aib(2)-Xx(1)-Boc, where Xx and Yy are Ile and Leu in peptide I and Leu and Val in peptide II, respectively, fold into a turn-linker-turn (T-L-T) conformation both in the solid state and in solution. In the crystalline state the T-L-T foldamers of peptide I and II self-assemble to form a three-dimensional framework of channels. The insides of the channels are hydrophilic and found to contain solvent CHCl3 hydrogen bonded to exposed Clocated at the turn regions. [Copyright &y& Elsevier]

Stirring of N-(2-carboxybenzoyl)anthranilic acid with anilines and amines such as p-toluidine, benzylamine, methyl esters of Leu, Phe, Ile and Val in presence of DCC produces N-2 substituted 3-phenyliminoisoindolinones in very good yields. Single crystal X-ray diffraction studies and solution phase NMR and CD studies reveal that the 3-phenyliminoisoindolinone moiety is a turn-inducing scaffold which should be useful for reverse-turn mimetics. [ABSTRACT FROM AUTHOR]

A set of three peptides 1-3 of general formula PhCO-Gly-Xx-OCH2Ph, where Xx is Gly in peptide 1, Ala in 2 and Aib (α-animo isobutyric acid) in 3 has been chosen to study the selfassembly and the morphology of the solid biomaterials. FT-IR and single crystal X-ray diffraction studies reveal that the peptides 1-3 self-assemble to form supramolecular β-sheet structures through intermolecular hydrogen bonds and aromatic π-π interactions. Field emission scanning electron micrographs (FE-SEM) of the dried materials of the peptides 1-3 show the formation of flat ribbon like structures which are formed through β-sheet mediated selfassembly. [ABSTRACT FROM AUTHOR]

The pseudopeptide Gly-m-ABA (m-ABA = m-amino benzoic acid) has been chosen to study the formation of supramolecular structures through self-assembly. Single crystal X-ray diffraction studies reveal that the pseudopeptide Boc-Gly-m-ABA-OMe (1), where both N- and C-terminus are protected, self-assembles to a supramolecular helical structure, whereas the pseudopeptide Boc-Gly-m-ABA-OH (2) with free -CO2H at the C-terminus produces molecular staircase through self-assembly. Again the terminally unprotected pseudopeptide +NH3-Gly-m-ABA-CO2- (3) aggregates to a water mediated supramolecular β-sheet structure stabilized by intermolecular hydrogen bonds and p-p interactions. The study reveals that the terminally modified Gly-m-ABA generates various kinds of self-assembling building blocks that can fabricate different types of supramolecular architectures such as helix, β-sheet and staircase. [ABSTRACT FROM AUTHOR]

Single crystal X-ray diffraction studies show that the β-turn structure of tetrapeptide I, Boc-Gly-Phe-Aib-Leu-OMe (Aib: α-amino isobutyric acid) self-assembles to a supramolecular helix through intermolecular hydrogen bonding along the crystallographic a axis. By contrast the β-turn structure of an isomeric tetrapeptide II, Boc-Gly-Leu-Aib-Phe-OMe self-assembles to a supramolecular β-sheet-like structure via a two-dimensional (a, b axis) intermolecular hydrogen bonding network and π-π interactions. FT-IR studies of the peptides revealed that both of them form intermolecularly hydrogen bonded supramolecular structures in the solid state. Field emission scanning electron micrographs (FE-SEM) of the dried fibrous materials of the peptides show different morphologies, non-twisted filaments in case of peptide I and non-twisted filaments and ribbon-like structures in case of peptide II. [ABSTRACT FROM AUTHOR]

Abstract: Single crystal X-ray diffraction studies show that among the three terminally protected model tripeptides I–III, Boc-Ile-Aib-Xx–OMe (Xx in peptide I: Val; II: Leu; III: Phe) with a centrally placed non-coded amino acid Aib (Aib: α-amino isobutyric acid), peptide I displays a conformational preference for β-turn, peptide II forms a hydrated β-turn representing the solvent mediated intermediate for the interconversion between β-turn and β-strand and peptide III adopts a completely unfolded β-strand like structure. By varying the steric bulk of the third residue, Xx(3), various conformations related to the structural interconversion between the β-turn and β-strand have been isolated. The peptide conformations in the solution phase have been probed by solvent dependent NMR titration and CD spectroscopy. Morphological studies with scanning electron microscopy (SEM) reveal that among the three peptides only peptide III can form filamentous fibrils in the solid state. [Copyright &y& Elsevier]

The rickshaw-puller is the person who drives the rickshaw and carries passengers from one place to another to earn financial capital. The research aims to examine Dhaka city's older rickshaw-pullers' demographic, social, and economic situations to gain an understanding of their living arrangements along with suggestions to enhance their livelihood conditions. The study uses purposive sampling to explore the living arrangements of older rickshaw-pullers in Dhaka city by collecting primary data from forty respondents. The major findings showed natural disasters and the search for better living standards are the two determining factors behind migration. However, most of the respondents did not have any prior experience in pulling rickshaws. Major problems noted to borrow money as a substantial portion of their earnings was spent on their medical treatments. Both short-term and long-term rehabilitation to other occupations is an urgent requirement considering their age. Future research needs to provide a comparison between young adult rickshaw-pullers and older ones and how this relates to their need for social services. [ABSTRACT FROM AUTHOR]

The article describes the incubation process of a Lissemys punctata vittata egg, focusing on the artificial incubation setup, the shorter-than-expected incubation period of 222 days, and the hatching of the egg, which contrasts with previous records.

A range of benzodiazonines is simply prepared in one-pot from phenolic adducts of ninhydrin by base-catalyzed rearrangement and subsequent condensation of 1,3-propanediamine. [ABSTRACT FROM AUTHOR]

The article presents chemical equations of "Facile Synthesis of Benzimidazo[2,1-a]isoindoles (III) from Phenolic Adducts of Ninhydrin (I)" by S. Das and others, published in the periodical "Heterocycles" in 2014.

The energy consumption of computer systems has become an important economic and environmental issue. Many researchers have focused on the energy consumption of hardware, but what about the software? Software energy consumption is widely adopted for Green computation of practical experimentation in research laboratories. But current researchers fail to build a consistent concept base for software energy consumption of critical applications. While branch coverage and concolic testing are very critical practices to validate the safety critical systems, very little effort is given to measure their energy consumption. The computation of the energy consumption of these techniques is an important issue in Green IT and Green Software Engineering. The contribution of this paper is to automate the computation and analysis of the energy consumption of the testing technique while enhancing the branch coverage using concolic testing. We implement our proposed automation framework in a tool, named Green Analysis of Branch Coverage Enhancement. The empirical study with forty Java programs and the evaluation results show that our developed tool achieves an average increase of 13.5 % in branch coverage. The average energy consumption of our automated tool is approximately 5.6 kJ to compute the branch coverage for all the forty experimental programs. [ABSTRACT FROM AUTHOR]

This article has detailed the growth of virgin copper chromite nanoparticles (CuCr 2 O 4 NPs) and reduced graphene oxide sheet (rGO)-based CuCr 2 O 4 nanocomposite through the process of reflux condensation method and calcination process. When exposed to visible light, these two synthesized nanomaterials exhibit enhanced photocatalytic activity which helps in the degradation of organic dyes such as methylene blue. Numerous characterization methods, including FTIR, UV–visible analysis, and XRD, verify the creation of these nanomaterials. The CuCr 2 O 4 -rGO nanocomposite's semiconductor nature is confirmed by the band gap analysis using Tauc's formula. The CuCr 2 O 4 NPs grown on the rGO surface have a dimension of 6 nm, according to the TEM study and particle distribution graph. To find the reason for the enhanced photo-activity, we have proposed a photocatalytic mechanism which is supported by photoluminescence result. Recyclability in five more cycles is used to measure the stability of the nanocomposite, and it is found that photocatalytic efficiency does not significantly decline up to five cycles. When exploring the CuCr 2 O 4 -rGO nanocomposite as a material for supercapacitor electrodes, it showcased a remarkable specific capacity of 681.43 F/g at 0.5 A g−1. Moreover, the CuCr 2 O 4 -rGO nanocomposite electrode displayed a long-term life cycle, retaining 93.8 % of its initial capacity after 1200 cycles, paired with a commendable Coulombic efficiency of 95.31 % and outstanding power and energy density of 1504 W/kg and 23.66 Wh/kg respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

• Novel spiropyranocoumarin and benzofuranyl coumarin scaffolds are synthesized. • Ninhydrin core is employed as the pivotal framework for assembling various phenols. • Spiro pyranocoumarin self-assembled to form sheet-like arrangement. • Benzofuranyl coumarin exhibited helix-like architecture in the crystalline state. • SEM images of spiropyranocoumarin and benzofuranyl coumarin showed flat fibrillar and vesicular morphology. Pyrano and furanocoumarins are oxygen-containing heterocycles frequently found in natural products and biologically active molecules. In the present work, ninhydrin core is employed for the first time as the pivotal framework to construct benzopyrano/furano coumarin skeleton. It has been found that substrates like phenol, p -/ m -cresol, m -methoxyphenol, p -chlorophenol etc. reacted with ninhydrin-4-hydroxycoumarin adduct 3 in AcOH/H 2 SO 4 to furnish a new class of spiropyranocoumarins 5a-f via condensation/cyclization sequence. Under similar conditions, reaction of adduct 3 with 3,5-dihydroxybenzoic acid delivered benzofuranyl coumarin 6 through ring closing/ring opening mechanism. Structures of the synthesized compounds were characterized by IR, 1H and 13C NMR spectroscopy. Single crystal X-ray diffraction study revealed that spiropyranocoumarin 5b self-assembled to form sheet-like arrangement. However, benzofuranyl coumarin 6 was found to display helix-like architecture in the crystalline state. Scanning electron microscopy (SEM) images of compound 5b exhibited flat fibrillar morphology, whereas compound 6 revealed formation of vesicular structure. These types of small heterocyclic molecules are decent candidates for producing promising soft materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Although ninhydrin is an essential analytical tool in biochemical and forensic sciences, for the past several years, it has been employed as efficient building block for diverse organic scaffolds. In the present work, the ortho selectivity of ninhydrin-phenol adducts has been exploited to obtain 2-(2′-hydroxyaryl)benzimidazoles which are well known excited state intramolecular proton transfer (ESIPT) fluorophores. Under acidic condition, 3-(2-hydroxyaroyl)isoindolin-1-one intermediate generated in situ from ninhydrin-phenol adducts was treated with o-phenylenediamine resulting benzimidazole scaffolds via a two-step one pot strategy. [ABSTRACT FROM AUTHOR]

Synthesis of fluorescent molecules has drawn considerable attention due to their potential applications in life and material sciences. Here we report a metal‐free approach to a new class of fluorophore, namely, 6‐(2‐hydroxyaryl)isoindolo[2,1‐a]quinoxalin‐11(5H)‐ones exploiting ninhydrin ring system via base promoted tandem cyclization. The readily obtainable phenolic adducts of ninhydrin undergoes smooth reaction with o‐phenylenediamine in refluxing ethylene glycol/Et3N via breaking of C−C bond, N‐insertion, followed by heterocyclization to furnish the fully unsaturated isoindoloquinoxaline framework. Structures of the products are in good agreement with their IR, 1H NMR, 13C NMR, and mass spectral data. The photophysical properties of the synthesized compounds were studied by UV‐vis absorption and fluorescence spectroscopic techniques under ambient conditions, and the results reveal an interesting property of large Stokes shift. Ninhydrin ring system is utilized successfully to develop a new class of fluorophore, namely, 6‐(2‐hydroxyaryl)isoindolo[2,1‐a]quinoxalin‐11(5H)‐ones via base promoted tandem cyclization. The readily prepared phenolic adducts of ninhydrin undergoes smooth reaction with o‐phenylenediamine in refluxing ethylene glycol/Et3N via breaking of C−C bond, N‐insertion, followed by heterocyclization to furnish the fully unsaturated isoindoloquinoxaline framework. The photophysical properties of the newly synthesized compounds were studied which disclose the interesting property of large Stokes shift with all the compounds. [ABSTRACT FROM AUTHOR]

Ninhydrin was successfully employed to develop two different benzimidazole-embedded heterocyclic skeletons via reaction of arylated ninhydrin and o -phenylenediamine under acidic condition. While ninhydrin adduct of 2-iodophenol consumed two equivalent of o -phenylenediamine to furnish benzimidazole linked quinoxaline skeleton, under same reaction conditions corresponding 2-methoxynaphthalene adduct afforded benzimidazo[2,1- a ]isoquinolinone framework. The hybrid heterocycles were identified as 2-(3-(2-(1 H -benzo[ d ]imidazole-2-yl)phenyl)quinoxalin-2-yl)-6-iodophenol 3 and 6-hydroxy-6-(2-methoxynaphthalen-1-yl)benzo [ 4 , 5 ]imidazo[2,1- a ]isoquinolin-5(6 H )-one 4 by IR, NMR and single crystal X-ray diffraction studies. Fluorescence measurements reveal that compound 3 and 4 display differential fluorescence behaviour, particularly towards the presence of Zn 2+ ion. [ABSTRACT FROM AUTHOR]

• New isoquinoline-based compounds were synthesized from readily available ninhydrin. • X-ray diffraction analysis indicated that compound 1 self-assembled to form zipper architecture, while compound 4 displays helical arrangement. • The molecular interactions were explored using the Hirshfeld surface analysis. • SEM study revealed that compound 1 forms vesicular structure, whereas structurally analogous compounds 3 and 4 exhibit fibrillar morphology. Isoquinoline skeletons are ubiquitous in natural products and pharmaceuticals with broad range of biological activity. In the present work, novel isoquinoline compounds are synthesized via the insertion of suitable nucleophile into the ninhydrin core. The reaction of ninhydrin with acetamide in refluxing AcOH afforded indanedione linked isoquinoline derivative 1. On the other hand, treatment of ninhydrin-4-methoxyphenol adduct 2 with ortho phenylenediamine in EtOH/AcOH led to the formation of isoquinoline fused benzimidazole scaffold 3. In DMSO‑ d 6 medium, compound 3 get oxidized to the corresponding isoquinolinone form 4. Single crystal X-ray diffraction study revealed that isoquinoline derivative 1 self-assembled to form zipper arrangement. Interestingly, fused isoquinoline scaffold 4 was found to display supramolecular helical arrangement in the crystalline state. The role of weak intermolecular interactions for development of supramolecular structure has been analysed and quatified using Hirshfeld surface analysis. The scanning electron microscopy (SEM) images of compound 1 show the formation of vesicular structure, whereas structurally analogous compounds 3 and 4 exhibit fibrilllar morphology. [Display omitted] [ABSTRACT FROM AUTHOR]

• Potential of ninhydrin derivatives for tailoring diverse supramolecular architectures is unveiled. • Solid state structures of ninhydrin-acetamide adduct, ninhydrin- p -cresol adduct and N-inserted ninhydrin derivative are analyzed. • First cocrystal of ninhydrin family with 2-aminopyridine is disclosed. • SEM images indicate the surface morphology is greatly influenced by substitution of ninhydrin core. The present work discloses the self-assembly behaviour of differently substituted ninhydrin-based compounds in the solid state for the first time. Ninhydrin core with tunable functionalities generates varied noncovalent interactions leading to different supramolecular assembly. Single crystal X-ray diffraction study revealed that, ninhydrin-acetamide adduct 1 self-assembled to form corrugated sheet structure, whereas ninhydrin- p -cresol adduct 2 (cis dihydroxy hemiketal) containing water of crystallization was found to form water-mediated supramolecular helical architecture. On the other hand, easily achievable N-inserted ninhydrin derivative 3 derived from adduct 2 and o -aminophenol adopted helical arrangement in the crystalline state. Interestingly, novel cocrystal 4 obtained from adduct 2 was found to display helical motif through well directed hydrogen bonding with 2-aminopyridine. The supramolecular diversity arising due to the change in substitution of ninhydrin core structure was also reflected in scanning electron microscopy images. Image, graphical abstract [ABSTRACT FROM AUTHOR]

In the present work, a range of phenolic compounds have been reacted with ninhydrin in acid medium to afford different indanone-based molecules via regioselective C–C bond formation. Ninhydrin reacts with 2,7-Dihydroxynaphthalene and 4-cyanophenol in AcOH producing ortho selective adduct 3a and 3b respectively; however, unlike 3a remaining as cyclic hemiketal structure, 3b exists as ring-opened diketo form. On the other hand, ortho -substituted phenols like o- cresol, guaiacol, o -chloro/iodophenol condense with ninhydrin to accomplish para selective diarylated adducts 5a-d , whereas 3-methoxy phenol provides corresponding monoarylated adduct 5e as the major product. Different hydroxy benzoic acids deliver versatile scaffolds like diarylated indanone, indenofuran, benzofuran or spirolactone 7a-e depending upon the substitution pattern and acidity of the reaction medium. All the compounds are characterized by 1H and 13C NMR spectra. In the solid state, scissors-shaped molecule 5a has been found to form inclusion complex with disordered o- cresol molecule and function as building unit of supramolecular network. In the crystal structure of spirolactone 7d , anti-parallel motif of dipolar ··· dipolar (C O(δ−) ··· C(δ+) = O) interaction results ladder-like arrangement. Image 1 • Ninhydrin-phenols assembly regioselectively delivered diverse organic scaffolds. • Indanone, indenofuran, benzofuran, spirolactone skeleton generated tuning substitution and acidity of medium. • X-ray crystal structure of two representative compounds analyzed. [ABSTRACT FROM AUTHOR]

The article examines the dietary habits and behavior of the Indian Ratsnake. Topics include the snake's wide range of prey, including amphibians, mammals, and reptiles, its habitat preferences ranging from arid to wet environments, and a specific observation of nocturnal predation on the Asian Common Toad.