Category: amides-buliding-blocks

Integrative analysis of transcriptomics and metabolomics to reveal the melanogenesis pathway of muscle and related meat characters in Wuliangshan black-boned chickens was written by Dou, Tengfei;Yan, Shixiong;Liu, Lixian;Wang, Kun;Jian, Zonghui;Xu, Zhiqiang;Zhao, Jingying;Wang, Qiuting;Sun, Shuai;Talpur, Mir Zulqarnain;Duan, Xiaohua;Gu, Dahai;He, Yang;Du, Yanli;Abdulwahid, Alsoufi Mohammed;Li, Qihua;Rong, Hua;Cao, Weina;Su, Zhengchang;Zhao, Guiping;Liu, Ranran;Zhao, Sumei;Huang, Ying;te Pas, Marinus F. W.;Ge, Changrong;Jia, Junjing. And the article was included in BMC Genomics in 2022.Category: amides-buliding-blocks The following contents are mentioned in the article:

Melanin is an important antioxidant in food and has been used in medicine and cosmetol. Chicken meat with high melanin content from black-boned chickens have been considered a high nutritious food with potential medicinal properties. The mol. mechanism of melanogenesis of skeletal muscle in black-boned chickens remain poorly understood. This study investigated the biol. gene-metabolite associations regulating the muscle melanogenesis pathways in Wuliangshan black-boned chickens with two normal boned chicken breeds as control. We identified 25 differentially expressed genes and 11 transcription factors in the melanogenesis pathways. High levels of the meat favor compounds inosine monophosphate, hypoxanthine, lysophospholipid, hydroxyoctadecadienoic acid, and NMN were found in Wuliangshan black-boned chickens. Integrative anal. of transcriptomics and metabolomics revealed the dual physiol. functions of the PDZK1 gene, involved in pigmentation and/or melanogenesis and regulating the phospholipid signaling processes in muscle of black boned chickens. This study involved multiple reactions and reactants, such as ((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7Category: amides-buliding-blocks).

((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7) belongs to amides. Amides include many other important biological compounds, as well as many drugs like paracetamol, penicillin and LSD. Low-molecular-weight amides, such as dimethylformamide, are common solvents. In simple aromatic amides, fragmentation occurs on both sides of the carbonyl group. If a hydrogen is available in N-substituted aromatic amides, it tends to migrate and form an aromatic amine and the loss of a ketene.Category: amides-buliding-blocks

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Characterization of volatile and non-volatile fractions of spices using evolved gas analysis and multi-shot analytical pyrolysis was written by Mattonai, Marco;Watanabe, Atsushi;Ribechini, Erika. And the article was included in Microchemical Journal in 2020.Application In Synthesis of (2E,4E)-N-Isobutyldeca-2,4-dienamide The following contents are mentioned in the article:

In the present work, evolved gas anal.-mass spectrometry (EGA-MS) and anal. pyrolysis coupled with gas chromatog./mass spectrometry (Py-GC/MS) were used to characterize both the volatile and non-volatile fractions of six com. available spices. Anal. of spices is usually performed through the study of their headspace composition by solid phase microextraction (SPME). In this new approach, EGA-MS was used to establish thermal degradation regions, and Py-GC/MS was used to obtain compositional information on each region sep. using double-shot pyrolysis. This study demonstrates that EGA-MS and Py-GC/MS provide the same advantages of solid-phase micro extraction and increase the range of detectable products by performing high-temperature desorption and degradation of the non-volatile fraction of spices. Our approach provided both qual. and semi-quant. data that could be used in the future to improve authentication studies by considering the results not only of headspace composition, but also on the pyrolytic behavior of the lignocellulosic matrix. This study involved multiple reactions and reactants, such as (2E,4E)-N-Isobutyldeca-2,4-dienamide (cas: 18836-52-7Application In Synthesis of (2E,4E)-N-Isobutyldeca-2,4-dienamide).

(2E,4E)-N-Isobutyldeca-2,4-dienamide (cas: 18836-52-7) belongs to amides. In primary and secondary amides, the presence of N–H dipoles allows amides to function as H-bond donors as well. Thus amides can participate in hydrogen bonding with water and other protic solvents; the oxygen atom can accept hydrogen bonds from water and the N–H hydrogen atoms can donate H-bonds. Amides can be recrystallised from large quantities of water, ethanol, ethanol/ether, aqueous ethanol, chloroform/toluene, chloroform or acetic acid. The likely impurities are the parent acids or the alkyl esters from which they have been made. The former can be removed by thorough washing with aqueous ammonia followed by recrystallisation, whereas elimination of the latter is by trituration or recrystallisation from an organic solvent.Application In Synthesis of (2E,4E)-N-Isobutyldeca-2,4-dienamide

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Metabolic rewiring is associated with HPV-specific profiles in cervical cancer cell lines was written by Pappa, Kalliopi I.;Daskalakis, George;Anagnou, Nicholas P.. And the article was included in Scientific Reports in 2021.Category: amides-buliding-blocks The following contents are mentioned in the article:

Both HPV-pos. and HPV-neg. cervical cancers are associated with aberrant metabolism, although the oncogenic drivers remain elusive. Here we show the assessment of the metabolomic profiles of four distinct cervical cell lines, a normal and three cancer cell lines, one HPV-neg. (C33A) and two HPV-pos. (SiHa HPV16+, HeLa HPV18+), employing an ultra performance liquid chromatog. and a high resolution mass spectrometry. Out of the total 462 metabolites, 248 to 326 exhibited statistically significant differences, while Random Forests anal. identified unique mols. for each cell line. The two HPV+ cell lines exhibited features of Warburg metabolism, consistent with the role of the HPV E6 protein. SiHa and HeLa cells displayed purine salvage pathway activity, while C33A cells revealed synthesis of cytidine, via a novel mechanism. These data document a highly dynamic HPV-specific rewiring of metabolic pathways occurring in cervical cancer. Therefore, this approach can eventually provide novel mechanistic insights into cervical carcinogenesis. This study involved multiple reactions and reactants, such as ((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7Category: amides-buliding-blocks).

((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7) belongs to amides. Because of the greater electronegativity of oxygen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors. Amides are not in general accessible by the direct condensation of amines with carboxylic acids for two reasons: first, both components are readily deactivated by a transfer of a proton from the acid to the amine and second, the hydroxy unit on the carbonyl of the acid is a relatively poor leaving group. Nevertheless, the formation of five- and six-membered rings is often surprisingly simple provided that other factors can be brought into play to assist in the condensation.Category: amides-buliding-blocks

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Inhibitory effects of metabolites isolated from Artemisia dracunculus L. against the human carbonic anhydrase I (hCA I) and II (hCA II) was written by Aydin, Tuba;Yurtvermez, Bayram;Senturk, Murat;Kazaz, Cavit;Cakir, Ahmet. And the article was included in Records of Natural Products in 2019.Application In Synthesis of (2E,4E)-N-Isobutyldeca-2,4-dienamide The following contents are mentioned in the article:

Tarragon or Dragon′s-wort (Artemisia dracunculus L.) is widely used as spice and in traditional medicine in various regions of the world. Inhibitory effects of the n-hexane, dichloromethane, ethanol and methanol extracts of the leaves of tarragon on the human carbonic anhydrase (hCA) I and II enzymes were investigated. Dichloromethane extract exhibited the strongest activity with lowest IC50 value (0.020 and 0.031 μg/mL, resp.). The chromatog. studies on the dichloromethane extract of tarragon allowed the isolation of six known strong inhibitors of hCA isoenzymes as trans-anethole, stigmasterol, herniarin, (2E,4E)-N-isobutylundeca-2,4-dien-8,10- diynamide, (2E,4E)-1-(piperidin-1-yl)undeca-2,4-diene-8,10-diyn-1-one and 1-(4′-methoxyphenyl)-1,2,3- trihydroxypropane. The compound, 1-(4′-methoxyphenyl)-1,2,3-trihydroxypropane was isolated from tarragon for the first time in this study. Among the tested compounds, 1-(4′-methoxyphenyl)-1,2,3-trihydroxypropane showed the highest inhibitiory impact on both hCA isoenzymes. Also its IC50 values were found lower than pos. control, acetazolamide. This study involved multiple reactions and reactants, such as (2E,4E)-N-Isobutyldeca-2,4-dienamide (cas: 18836-52-7Application In Synthesis of (2E,4E)-N-Isobutyldeca-2,4-dienamide).

(2E,4E)-N-Isobutyldeca-2,4-dienamide (cas: 18836-52-7) belongs to amides. The solubilities of amides and esters are roughly comparable. Typically amides are less soluble than comparable amines and carboxylic acids since these compounds can both donate and accept hydrogen bonds. Tertiary amides, with the important exception of N,N-dimethylformamide, exhibit low solubility in water. Amides can be recrystallised from large quantities of water, ethanol, ethanol/ether, aqueous ethanol, chloroform/toluene, chloroform or acetic acid. The likely impurities are the parent acids or the alkyl esters from which they have been made. The former can be removed by thorough washing with aqueous ammonia followed by recrystallisation, whereas elimination of the latter is by trituration or recrystallisation from an organic solvent.Application In Synthesis of (2E,4E)-N-Isobutyldeca-2,4-dienamide

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Metabolic engineering of Escherichia coli for biosynthesis of β-nicotinamide mononucleotide from nicotinamide was written by Liu, Yang;Yu, Bo. And the article was included in Microbial Biotechnology in 2021.Name: ((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate The following contents are mentioned in the article:

The β-NMN (NMN) is a key intermediate of an essential coenzyme for cellular redox reactions, NAD. Administration of NMN is reported to improve various symptoms, such as diabetes and age-related physiol. decline. Thus, NMN is attracting much attention as a promising nutraceutical. Here, we engineered an Escherichia coli strain to produce NMN from cheap substrate nicotinamide (NAM) and glucose. The supply of in vivo precursor phosphoribosyl pyrophosphate (PRPP) and ATP was enhanced by strengthening the metabolic flux from glucose. A nicotinamide phosphoribosyltransferase with high activity was newly screened, which is the key enzyme for converting NAM to NMN with PRPP as cofactor. Notably, the E. coli endogenous protein YgcS, which function is primarily in the uptake of sugars, was firstly proven to be beneficial for NMN production in this study. Fine-tuning regulation of ygcS gene expression in the engineered E. coli strain increased NMN production Combined with process optimization of whole-cell biocatalysts reaction, a final NMN titer of 496.2 mg l^-1 was obtained. This study involved multiple reactions and reactants, such as ((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7Name: ((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate).

((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7) belongs to amides. In primary and secondary amides, the presence of N–H dipoles allows amides to function as H-bond donors as well. Thus amides can participate in hydrogen bonding with water and other protic solvents; the oxygen atom can accept hydrogen bonds from water and the N–H hydrogen atoms can donate H-bonds. Amides can be recrystallised from large quantities of water, ethanol, ethanol/ether, aqueous ethanol, chloroform/toluene, chloroform or acetic acid. The likely impurities are the parent acids or the alkyl esters from which they have been made. The former can be removed by thorough washing with aqueous ammonia followed by recrystallisation, whereas elimination of the latter is by trituration or recrystallisation from an organic solvent.Name: ((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Metabolic engineering of Escherichia coli for biosynthesis of β-nicotinamide mononucleotide from nicotinamide was written by Liu, Yang;Yu, Bo. And the article was included in Microbial Biotechnology in 2021.SDS of cas: 1094-61-7 The following contents are mentioned in the article:

The β-NMN (NMN) is a key intermediate of an essential coenzyme for cellular redox reactions, NAD. Administration of NMN is reported to improve various symptoms, such as diabetes and age-related physiol. decline. Thus, NMN is attracting much attention as a promising nutraceutical. Here, we engineered an Escherichia coli strain to produce NMN from cheap substrate nicotinamide (NAM) and glucose. The supply of in vivo precursor phosphoribosyl pyrophosphate (PRPP) and ATP was enhanced by strengthening the metabolic flux from glucose. A nicotinamide phosphoribosyltransferase with high activity was newly screened, which is the key enzyme for converting NAM to NMN with PRPP as cofactor. Notably, the E. coli endogenous protein YgcS, which function is primarily in the uptake of sugars, was firstly proven to be beneficial for NMN production in this study. Fine-tuning regulation of ygcS gene expression in the engineered E. coli strain increased NMN production Combined with process optimization of whole-cell biocatalysts reaction, a final NMN titer of 496.2 mg l^-1 was obtained. This study involved multiple reactions and reactants, such as ((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7SDS of cas: 1094-61-7).

((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7) belongs to amides. Because of the greater electronegativity of oxygen, the carbonyl (C=O) is a stronger dipole than the N–C dipole. The presence of a C=O dipole and, to a lesser extent a N–C dipole, allows amides to act as H-bond acceptors. Amides can be freed from solvent or water by drying below their melting points. These purifications can also be used for sulfonamides and acid hydrazides.SDS of cas: 1094-61-7

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Metabolic profiling of Piper species by direct analysis using real time mass spectrometry combined with principal component analysis was written by Chandra, Preeti;Bajpai, Vikas;Srivastva, Mukesh;Kumar, K. B. Ramesh;Kumar, Brijesh. And the article was included in Analytical Methods in 2014.Related Products of 18836-52-7 The following contents are mentioned in the article:

Piper nigrum (black pepper), Piper longum (Indian tipali) and Piper chaba (Bangla tipali) are widely used medicinal herbs in traditional Indian systems of medicine. P. longum as well as P. chaba are considered to be inferior substitutes of P. nigrum. A rapid anal. method for metabolic profiling was developed to generate chem. fingerprints as an alternative means to the only available morphol. basis for the identification of these species. Direct anal. using real time mass spectrometry was applied to generate the chem. fingerprints of various parts viz. fruit, leaf and root of these Piper species followed by multivariate anal. for discrimination. Principal component anal. of DARTMS data served as a reliable method for species identification. Phytochem. anal. showed the presence mainly of alkaloids in various parts of Piper species. The results showed that different Piper species could be successfully differentiated using DARTMS fingerprinting together with principal component anal. and this method is promising for the rapid identification and quality control of Piper species. This study involved multiple reactions and reactants, such as (2E,4E)-N-Isobutyldeca-2,4-dienamide (cas: 18836-52-7Related Products of 18836-52-7).

(2E,4E)-N-Isobutyldeca-2,4-dienamide (cas: 18836-52-7) belongs to amides. Amides include many other important biological compounds, as well as many drugs like paracetamol, penicillin and LSD. Low-molecular-weight amides, such as dimethylformamide, are common solvents. Amides can be recrystallised from large quantities of water, ethanol, ethanol/ether, aqueous ethanol, chloroform/toluene, chloroform or acetic acid. The likely impurities are the parent acids or the alkyl esters from which they have been made. The former can be removed by thorough washing with aqueous ammonia followed by recrystallisation, whereas elimination of the latter is by trituration or recrystallisation from an organic solvent.Related Products of 18836-52-7

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Nicotinamide mononucleotide (NMN) and NMN-rich product supplementation alleviate p-chlorophenylalanine-induced sleep disorders was written by Shen, Chun-Yan;Li, Xiao-Yi;Ma, Pan-Yu;Li, Hong-Lei;Xiao, Bing;Cai, Wei-Feng;Xing, Xue-Feng. And the article was included in Journal of Functional Foods in 2022.HPLC of Formula: 1094-61-7 The following contents are mentioned in the article:

NMN (NMN) has various beneficial effects, while its protective effects against insomnia remain elusive. NMN and NMN-rich products (NMNP) alleviated depression-like behavior and stimulated sodium pentobarbital-induced sleeping of p-chlorophenylalanine (PCPA)-induced mice. NMN and NMNP restored brain damages and reduced oxidative stress. NAD+ concentration, silent mating type information regulation 2 homolog 1 (SIRT1) expression, 5-hydroxytryptamine (5-HT) level and 5-HT1A expression in hippocampus of PCPA-induced mice were up-regulated by NMN and NMNP. NMN and NMNP also modulated γ-gminobutyric acid (GABA) and glutamate production by increasing GABAA receptor α2 and glutamic acid decarboxylase 65/67 expression. NMNP, composed 23.9% of NMN, was more powerful than NMN in activating GABAergic system. NMN and NMNP exhibited prominent enhancement on immune system through boosting NO secretion and IL-1β expression. These data suggested that NMN and NMNP exerted sedative effects via regulating oxidative stress, SIRT1 pathway, 5-HTergic, GABAergic and immune systems simultaneously. This study involved multiple reactions and reactants, such as ((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7HPLC of Formula: 1094-61-7).

((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7) belongs to amides. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, such as in the amino acids asparagine and glutamine. In simple aromatic amides, fragmentation occurs on both sides of the carbonyl group. If a hydrogen is available in N-substituted aromatic amides, it tends to migrate and form an aromatic amine and the loss of a ketene.HPLC of Formula: 1094-61-7

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Nicotinamide mononucleotide (NMN) and NMN-rich product supplementation alleviate p-chlorophenylalanine-induced sleep disorders was written by Shen, Chun-Yan;Li, Xiao-Yi;Ma, Pan-Yu;Li, Hong-Lei;Xiao, Bing;Cai, Wei-Feng;Xing, Xue-Feng. And the article was included in Journal of Functional Foods in 2022.Recommanded Product: 1094-61-7 The following contents are mentioned in the article:

NMN (NMN) has various beneficial effects, while its protective effects against insomnia remain elusive. NMN and NMN-rich products (NMNP) alleviated depression-like behavior and stimulated sodium pentobarbital-induced sleeping of p-chlorophenylalanine (PCPA)-induced mice. NMN and NMNP restored brain damages and reduced oxidative stress. NAD+ concentration, silent mating type information regulation 2 homolog 1 (SIRT1) expression, 5-hydroxytryptamine (5-HT) level and 5-HT1A expression in hippocampus of PCPA-induced mice were up-regulated by NMN and NMNP. NMN and NMNP also modulated γ-gminobutyric acid (GABA) and glutamate production by increasing GABAA receptor α2 and glutamic acid decarboxylase 65/67 expression. NMNP, composed 23.9% of NMN, was more powerful than NMN in activating GABAergic system. NMN and NMNP exhibited prominent enhancement on immune system through boosting NO secretion and IL-1β expression. These data suggested that NMN and NMNP exerted sedative effects via regulating oxidative stress, SIRT1 pathway, 5-HTergic, GABAergic and immune systems simultaneously. This study involved multiple reactions and reactants, such as ((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7Recommanded Product: 1094-61-7).

((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7) belongs to amides. Compared to amines, amides are very weak bases and do not have clearly defined acid–base properties in water. On the other hand, amides are much stronger bases than esters, aldehydes, and ketones. As a result of interactions such as these, the water solubility of amides is greater than that of corresponding hydrocarbons. These hydrogen bonds are also have an important role in the secondary structure of proteins.Recommanded Product: 1094-61-7

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics

Supplementation with NAD+ and Its Precursors to Prevent Cognitive Decline across Disease Contexts was written by Campbell, Jared M.. And the article was included in Nutrients in 2022.Computed Properties of C11H15N2O8P The following contents are mentioned in the article:

The preservation of cognitive ability by increasing NAD (NAD+) levels through supplementation with NAD+ precursors has been identified as a promising treatment strategy for a number of conditions; principally, age-related cognitive decline (including Alzheimer’s disease and vascular dementia), but also diabetes, stroke, and traumatic brain injury. Candidate factors have included NAD+ itself, its reduced form NADH, nicotinamide (NAM), NMN (NMN), nicotinamide riboside (NR), and niacin (or nicotinic acid). This review summarises the research findings for each source of cognitive impairment for which NAD+ precursor supplementation has been investigated as a therapy. The findings are mostly pos. but have been made primarily in animal models, with some reports of null or adverse effects. Given the increasing popularity and availability of these factors as nutritional supplements, further properly controlled clin. research is needed to provide definitive answers regarding this strategy’s likely impact on human cognitive health when used to address different sources of impairment. This study involved multiple reactions and reactants, such as ((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7Computed Properties of C11H15N2O8P).

((2R,3S,4R,5R)-5-(3-Carbamoylpyridin-1-ium-1-yl)-3,4-dihydroxytetrahydrofuran-2-yl)methyl hydrogen phosphate (cas: 1094-61-7) belongs to amides. The solubilities of amides and esters are roughly comparable. Typically amides are less soluble than comparable amines and carboxylic acids since these compounds can both donate and accept hydrogen bonds. Tertiary amides, with the important exception of N,N-dimethylformamide, exhibit low solubility in water. Amides can be freed from solvent or water by drying below their melting points. These purifications can also be used for sulfonamides and acid hydrazides.Computed Properties of C11H15N2O8P

Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics