Tag: 300-400

A study on the uptake of methylene blue by biodegradable and eco-friendly carboxylated starch grafted polyvinyl pyrrolidone was written by Haq, Fazal;Farid, Arshad;Ullah, Naveed;Kiran, Mehwish;Khan, Rizwan Ullah;Aziz, Tariq;Mehmood, Sahid;Haroon, Muhammad;Mubashir, Muhammad;Bokhari, Awais;Chuah, Lai Fatt;Show, Pau Loke. And the article was included in Environmental Research in 2022.Recommanded Product: 61-73-4 This article mentions the following:

This study is based on the removal of methylene blue (MB) from aqueous solution by cost effective and biodegradable adsorbent carboxymethyl starch grafted polyvinyl pyrolidone (Car-St-g-PVP). The Car-St-g-PVP was synthesized by grafting vinyl pyrolidone onto carboxymethyl starch by free radical polymerization reaction. The structure and different properties of Car-St-g-PVP were determined by 1H NMR, FT-IR, XRD, TGA and SEM. A series of batch experiments were conducted for the removal of MB, The adsorption affecting factors such as temperature, contact time, initial concentration of MB dye, dose of Car-St-g-PVP and pH were studied in detail. The other parameters like the thermodn. study, kinetics and isothermal models were fitted to the exptl. data. The results showed that pseudo 2nd order kinetics and Langmuir ‘s adsorption isotherms were best fitted to exptl. data with regression coefficient R2 viz. 0.99 and 0.97. The kinetic study showed that the adsorption mechanism favored chemisorption. The Gibbs free energy (ΔG°) for the adsorption process was found to be -7.31 kJ/mol, -8.23 kJ/mol, -9.00 kJ/mol and -10.10 kJ/mol at 25°C, 35°C, 45°C and 55°C resp. The neg. values of ΔG° suggested the spontaneous nature of the adsorption process. Similarly, the pos. values of entropy (ΔS°) and enthalpy (ΔH°) 91.27 J/k.mol and 19.90 kJ/mol showed the increasing randomness and endothermic nature of the adsorption process. The value of separation factor (RL) was found to be less than one (RL < 1), which supported the feasibility of the adsorption process. The maximum MB removal percentage (% R) was found to be 98.6%. So, these findings show that Car-St-g-PVP can be meritoriously used for the treatment of MB from wastewater. In the experiment, the researchers used many compounds, for example, 3,7-Bis(dimethylamino)phenothiazin-5-ium chloride (cas: 61-73-4Recommanded Product: 61-73-4).

3,7-Bis(dimethylamino)phenothiazin-5-ium chloride (cas: 61-73-4) belongs to organic chlorides. Chlorinated organic compounds are found in nearly every class of biomolecules and natural products including alkaloids, terpenes, amino acids, flavonoids, steroids, and fatty acids. Aliphatic organochlorides are often alkylating agents as chlorine can act as a leaving group, which can result in cellular damage.Recommanded Product: 61-73-4

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Platinum-catalyzed hydrosilylation of allyl aryl ethers: kinetic investigation at moderately high dilution was written by Coqueret, Xavier;Wegner, Gerhard. And the article was included in Organometallics in 1991.Related Products of 12083-92-0 This article mentions the following:

A kinetic investigation of the platinum-catalyzed hydrosilylation of some allyl aryl ethers by dimethylsilyl end groups of a monofunctional model oligomer or of a telechelic poly(dimethylsiloxane) was performed with use of quant. IR spectrophotometry. The reactivity of (allyloxy)benzene (I), examined at low inital concentration of reactants in toluene (ca. 10^-2 equiv·L^-1), with dichloro(dicyclopentadiene)platinum(II) as a precursor of the catalyst was found to be different from the reactivity of the allylic groups of 3,5-(CH₂:CHCH₂O)₂C₆H₃CO₂Me (II). The reaction rate can be expressed by v(I) = k₃[Pt][Si-H]² in the case of reactions with I and by v(II) = k₄[Pt]²[Si-H]² for reactions with II. In addition to the determination of the values of the phenomenol. rate constants deduced from measurements carried out under mild conditions, the obtained results lead to the proposal of some special features for the effective catalytic process. In the experiment, the researchers used many compounds, for example, Dichlorodi(cyclopenta-1,3-dien-1-yl)platinate(II) (cas: 12083-92-0Related Products of 12083-92-0).

Dichlorodi(cyclopenta-1,3-dien-1-yl)platinate(II) (cas: 12083-92-0) belongs to organic chlorides. Chlorination modifies the physical properties of hydrocarbons in several ways. These compounds are typically denser than water due to the higher atomic weight of chlorine versus hydrogen. Aliphatic organochlorides are often alkylating agents as chlorine can act as a leaving group, which can result in cellular damage.Related Products of 12083-92-0

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Synthesis and characterization of ladder-like copolymethyl-epoxysilsesquioxane was written by Cao, Ming;Li, Ze;Zhang, Yong;Xie, Ping;Dai, Daorong;Zhang, Rongben;Lin, Yuhui;Chung, Neal Tai-shung. And the article was included in Reactive & Functional Polymers in 2000.Reference of 12083-92-0 This article mentions the following:

A new kind of copolymethyl-epoxysilsesquioxane (CPMES) was synthesized for the first time by a hydrosilation reaction of allyl glycidyl ether (AGE) with the ladder-like polymethylhydrosilsesquioxane (Me-H-T) in the presence of dicyclopentadienylplatinum dichloride (Cp₂PtCl₂) as catalyst. The graft polymer was characterized by IR spectroscopy, ¹H-NMR, ²⁹Si-NMR, x-ray diffraction (XRD), gel-permeation chromatog. (GPC), vapor pressure osmometry (VPO), thermogravimetric anal. (TGA) and differential scanning calorimetry (DSC). CPMES possesses good solubility in organic solvents, and a greatly improved thermostability compared with polymethyl-epoxysiloxane with a single backbone. In the experiment, the researchers used many compounds, for example, Dichlorodi(cyclopenta-1,3-dien-1-yl)platinate(II) (cas: 12083-92-0Reference of 12083-92-0).

Dichlorodi(cyclopenta-1,3-dien-1-yl)platinate(II) (cas: 12083-92-0) belongs to organic chlorides. An organic chloride is an organic compound containing at least one covalently bonded atom of chlorine. Their wide structural variety and divergent chemical properties lead to a broad range of names and applications. Aliphatic organochlorides are often alkylating agents as chlorine can act as a leaving group, which can result in cellular damage.Reference of 12083-92-0

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Simultaneous determination of triclosan, triclocarban, triclocarban metabolites and byproducts in urine and serum by ultra-high-performance liquid chromatography/electrospray ionization tandem mass spectrometry was written by Luo, Qiong;Zhang, Hongna;Zhou, Yanqiu;Liu, Zehua;Cai, Zongwei. And the article was included in Rapid Communications in Mass Spectrometry in 2021.Name: 1-(4-Chlorophenyl)-3-(3,4-dichlorophenyl)urea This article mentions the following:

Rationale : Triclosan (TCS) and triclocarban (TCC) are ubiquitous antimicrobial agents incorporated in consumer and personal care products. Due to their human health risks, it is essential to develop a sensitive and accurate anal. method to simultaneously quantify TCS, TCC, as well as their metabolites and byproducts in urine and serum samples. Methods : The quant. parameters of TCS, TCC, TCC metabolites and byproducts (2â€?OH-TCC, 3â€?OH-TCC, 6-OH-TCC, DHC, DCC, NCC) were optimized by using ultra-high-performance liquid chromatog./electrospray ionization tandem mass spectrometry (UHPLC/ESI-MS/MS). Enzymic hydrolysis of the samples was optimized based on enzyme dosage and incubation time. The efficiencies of solid-phase extraction (SPE) and liquid-liquid extraction (LLE) were compared. The effectiveness of the established method was evaluated, and method application was validated using real urine and serum samples. Results : The conjugates were sufficiently hydrolyzed under 500 U/mL β-glucuronidase and 80 U/mL sulfatase at 37°C for 4 h. Compared with the LLE method, SPE achieved higher extraction efficiency in both urine and serum samples. The optimized SPE-UHPLC/ESI-MS/MS method showed low limits of detection (LODs) in the range 0.001-0.3 ng/mL and good linearity (R² > 0.99) at 0.01-150 ng/mL in both matrixes. Excellent recoveries of 82.0%-120.7% (urine) and 76.7%-113.9% (serum) were obtained with low relative standard deviation (RSD, <7.6%) for inter-day and intra-day injections. This method was applicable to quantify target compounds in multiple biol. urine and serum samples. Notably, TCS and TCC were detected with average concentrations of 8.37 and 10.46 ng/mL, resp., in 15 Chinese female urine samples, with the simultaneous detection of TCC metabolites and byproducts. Conclusions : A reliable method was established to simultaneously determine TCS, TCC, TCC metabolites and byproducts in urine and serum samples by using UHPLC/ESI-MS/MS. This sensitive methodol. provides the basis for the evaluation of TCS and TCC exposure at the metabolic level. In the experiment, the researchers used many compounds, for example, 1-(4-Chlorophenyl)-3-(3,4-dichlorophenyl)urea (cas: 101-20-2Name: 1-(4-Chlorophenyl)-3-(3,4-dichlorophenyl)urea).

1-(4-Chlorophenyl)-3-(3,4-dichlorophenyl)urea (cas: 101-20-2) belongs to organic chlorides. Organochlorines are organic compounds having multiple chlorine atoms. They were the first synthetic pesticides that were used in agriculture. They are resistant to most microbial and chemical degradations.While alkyl bromides and iodides are more reactive, alkyl chlorides tend to be less expensive and more readily available. Alkyl chlorides readily undergo attack by nucleophiles.Name: 1-(4-Chlorophenyl)-3-(3,4-dichlorophenyl)urea

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Structure of olefin-metal complexes was written by Baenziger, Norman C.;Doyle, J. R.;Richards, G. F.;Carpenter, C. L.. And the article was included in U.S. Dept. Com., Office Tech. Serv., PB Rept. in 1961.Application In Synthesis of Dichlorodi(cyclopenta-1,3-dien-1-yl)platinate(II) This article mentions the following:

Refinements of determined x-ray values for the structures of VIIa and norbornadiene.PdCl₂ were carried out; the structure of IIa was determined from single crystal studies. In the experiment, the researchers used many compounds, for example, Dichlorodi(cyclopenta-1,3-dien-1-yl)platinate(II) (cas: 12083-92-0Application In Synthesis of Dichlorodi(cyclopenta-1,3-dien-1-yl)platinate(II)).

Dichlorodi(cyclopenta-1,3-dien-1-yl)platinate(II) (cas: 12083-92-0) belongs to organic chlorides. Chlorinated organic compounds are found in nearly every class of biomolecules and natural products including alkaloids, terpenes, amino acids, flavonoids, steroids, and fatty acids. Aryl chlorides may be prepared by the Friedel-Crafts halogenation, using chlorine and a Lewis acid catalyst.Application In Synthesis of Dichlorodi(cyclopenta-1,3-dien-1-yl)platinate(II)

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Molecular sieving through ‘layer-by-layer’ self-assembly of polyelectrolytes and highly crosslinked graphene oxide was written by Maiti, Subhasish;Bose, Suryasarathi. And the article was included in Functional Composite Materials in 2022.Electric Literature of C16H18ClN3S This article mentions the following:

Lack of access to potable water and abating levels of ground water level demands the reuse of unconventional water sources after remediating it in a sustainable way. In this context, purifying brackish, land and sea water seems a feasible solution to the ever-growing population. In this work, a novel composite membrane was fabricated by ‘layer-by-layer’ self-assembly of poly-dopamine (PDA) and polystyrene sulfonate (PSS) supported on a highly crosslinked graphene oxide (GO) membrane to sieve ions to purify contaminated water as well as enhance the resistance towards chlorine. This GO membrane was sandwiched between layers of various nanoporous polyvinylidene difluoride (PVDF) membranes obtained by selectively etching out the PMMA component from the demixed blends. The blend membranes were designed following the melt-extrusion process and subsequent quenching to facilitate confined crystallization of PVDF and selective etching of PMMA. The membranes with different pore sizes were tuned on varying the composition in blends and a gradient in microstructure was achieved by stitching the membranes. Pure water flux, salt rejection, dye removal, and antibacterial activity were performed to study the membrane’s efficiency. The GO membrane was chem. crosslinked with methylenediamine to impart dimensional stability and to enhance rejection efficiency through the nanoslits that GO offers. Besides effective rejection, the sandwiched membrane was modified with ‘layer-by-layer’ self-assembly of polyelectrolytes on the surface to improve the chlorine tolerance performance. This strategy resulted in an excellent salt (about 95% and 97% for monovalent and divalent ion, resp.) and dye rejection (100% for both cationic and anionic dye), besides facilitating excellent chlorine tolerance performance. Moreover, this modified membrane showed superior antifouling properties (flux recovery ratio is more than 90%) and excellent antibacterial performance (near about 3 log reduction). Thus the concept of using layer-by-layer self-assembly of polycations (PDA) and polyanions (PSS) onto a hierarchical chem. modified GO sandwiched PVDF membrane proved to be a productive strategy to purify contaminated water. Thus the membrane can be a potential candidate for domestic as well as industrial application. In the experiment, the researchers used many compounds, for example, 3,7-Bis(dimethylamino)phenothiazin-5-ium chloride (cas: 61-73-4Electric Literature of C16H18ClN3S).

3,7-Bis(dimethylamino)phenothiazin-5-ium chloride (cas: 61-73-4) belongs to organic chlorides. Organic chlorides are compounds containing a carbon-chlorine bond, which are widely used in the oil field as a wax dissolver. Alkanes and aryl alkanes may be chlorinated under free radical conditions, with UV light. However, the extent of chlorination is difficult to control.Electric Literature of C16H18ClN3S

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Translational feasibility and efficacy of nasal photodynamic disinfection of SARS-CoV-2 was written by Pires, Layla;Wilson, Brian C.;Bremner, Rod;Lang, Amanda;Larouche, Jeremie;McDonald, Ryan;Pearson, Joel D.;Trcka, Daniel;Wrana, Jeff;Wu, James;Whyne, Cari M.. And the article was included in Scientific Reports in 2022.Reference of 61-73-4 This article mentions the following:

The lack of therapeutic options to fight Covid-19 has contributed to the current global pandemic. Despite the emergence of effective vaccines, development of broad-spectrum antiviral treatment remains a significant challenge, in which antimicrobial photodynamic therapy (aPDT) may play a role, especially at early stages of infection. aPDT of the nares with methylene blue (MB) and non-thermal light has been successfully utilized to inactivate both bacterial and viral pathogens in the perioperative setting. Here, we investigated the effect of MB-aPDT to inactivate human betacoronavirus OC43 and SARS-CoV-2 in vitro and in a proof-of-principle COVID-19 clin. trial to test, in a variety of settings, the practicality, tech. feasibility, and short-term efficacy of the method. aPDT yielded inactivation of up to 6-Logs in vitro, as measured by RT-qPCR and infectivity assay. From a photo-physics perspective, the in vitro results suggest that the response is not dependent on the virus itself, motivating potential use of aPDT for local destruction of SARS-CoV-2 and its variants. In the clin. trial we observed variable effects on viral RNA in nasal-swab samples as assessed by RT-qPCR attributed to aPDT-induced RNA fragmentation causing falsely-elevated counts. However, the viral infectivity in clin. nares swabs was reduced in 90% of samples and undetectable in 70% of samples. This is the first demonstration based on quant. clin. viral infectivity measurements that MB-aPDT is a safe, easily delivered and effective front-line technique that can reduce local SARS-CoV-2 viral load. In the experiment, the researchers used many compounds, for example, 3,7-Bis(dimethylamino)phenothiazin-5-ium chloride (cas: 61-73-4Reference of 61-73-4).

3,7-Bis(dimethylamino)phenothiazin-5-ium chloride (cas: 61-73-4) belongs to organic chlorides. Organic chlorides can cause corrosion in pipelines, valves and condensers, and cause catalyst poisoning. The hydrocarbon processing industry (HPI) and others are affected by damage caused by these substances. Aryl chlorides may be prepared by the Friedel-Crafts halogenation, using chlorine and a Lewis acid catalyst.Reference of 61-73-4

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Associations between a mixture of phenols and phthalates and child behaviour in a French mother-child cohort with repeated assessment of exposure was written by Guilbert, Ariane;Rolland, Matthieu;Pin, Isabelle;Thomsen, Cathrine;Sakhi, Amrit K.;Sabaredzovic, Azemira;Slama, Remy;Guichardet, Karine;Philippat, Claire. And the article was included in Environment International in 2021.SDS of cas: 101-20-2 This article mentions the following:

Synthetic phenols and phthalates can interfere with biol. pathways involved in brain development. Despite the high within-subject temporal variability of urinary concentrations observed for their metabolites, studies investigating effects of phenols and phthalates on child behavior often relied on a limited number of spot biospecimens to assess exposure. Besides, the majority did not consider mixture effects. To study the combined effect of prenatal exposure to synthetic phenols and phthalates on child behavior using repeated exposure measurements. We assessed concentrations of 12 phenols, 13 phthalate and 2 non-phthalate plasticizer metabolites in within-subject pools of multiple urine samples (median = 21 samples per individual pool) collected at two distinct time points during pregnancy in 416 mother-child pairs from the French SEPAGES cohort. Child behavior was evaluated at two years using the Child Behavior Checklist 1.5-5 (CBCL). Associations between a mixture of biomarkers of exposure and externalizing and internalizing behavior scores were studied using adjusted Weighted Quantile Sum (WQS) regressions with a repeated holdout validation (100 repetitions). The pos. WQS indexes were associated with both the externalizing and internalizing behavior scores in the whole population, indicating greater risk of behavioral problems. Stratification for child sex suggested stronger associations in girls than boys. On average, girls externalizing and internalizing scores increased by 3.67 points (95% CI: 1.24, 6.10) and 2.47 points (95%CI: 0.60, 4.33) resp., for an increase of one tertile in the WQS index, compared with 1.70 points (95%CI: -0.42, 3.81) and 1.17 points (95%CI: -0.50, 2.84) in boys. Main contributors for the associations observed in girls were bisphenol A (weight of 18%), triclosan (17%) and monoethyl phthalate (MEP, 15%) for the externalizing score and MEP (19%), mono-benzyl phthalate (MBzP, 19%) and mono-Bu phthalate (MnBP, 16%) for the internalizing score. Our results suggest adverse associations between in utero exposure to a mixture of phenols and phthalates and child behavior, mainly in girls. Public health consequences may be substantial due to the widespread exposure of the population to these compounds In the experiment, the researchers used many compounds, for example, 1-(4-Chlorophenyl)-3-(3,4-dichlorophenyl)urea (cas: 101-20-2SDS of cas: 101-20-2).

1-(4-Chlorophenyl)-3-(3,4-dichlorophenyl)urea (cas: 101-20-2) belongs to organic chlorides. Organic chlorides can be used in production of: PVC, pesticides, chloromethane, teflon, insulators. Alkanes and aryl alkanes may be chlorinated under free radical conditions, with UV light. However, the extent of chlorination is difficult to control.SDS of cas: 101-20-2

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Effect of endocrine disrupting chemicals on vitronectin-receptor (integrin alphaVbeta3)-mediated cell adhesion of human umbilical vein endothelial cells was written by Kenda, Masa;Pecar Fonovic, Ursa;Kos, Janko;Sollner Dolenc, Marija. And the article was included in Toxicology In Vitro in 2022.Synthetic Route of C13H9Cl3N2O This article mentions the following:

Endocrine disrupting chems. (EDCs) are associated with cancer development and progression due to their promotion of increased cell invasiveness and metastasis formation. However, the effects of EDCs on cell adhesion mediated through integrins have not been well studied to date. Their actions are implicated by binding sites for hormones on the vitronectin receptor (VTNR; or integrin αvβ3), which is involved in tumor angiogenesis and metastasis. VTNR-expressing human umbilical vein endothelial cells (HUVECs) were used to determine the effects of EDCs and endogenous hormones on cell adhesion to vitronectin-coated surfaces, and on VTNR activation. Cell adhesion was significantly increased for bisphenol A, triclocarban, and triclosan (10, 100 nM; p < 0.05), with similar trends for bisphenols AF and S (10, 100 nM; p > 0.05). No changes in cell adhesion were seen for 5α-dihydrotestosterone, 17β-estradiol, triiodothyronine, imatinib and paroxetine. These data indicate that EDC-mediated increases in HUVEC adhesion to vitronectin are not mediated through androgenic, estrogenic, or thyroid activities, nor through activation of VTNR. Although these effects of EDCs on HUVEC adhesion require further investigation of the underlying mechanism(s) of action to define their biol. relevance, the low-dose effects and nonmonotonic responses revealed here define the need for further investigation of these EDCs. In the experiment, the researchers used many compounds, for example, 1-(4-Chlorophenyl)-3-(3,4-dichlorophenyl)urea (cas: 101-20-2Synthetic Route of C13H9Cl3N2O).

1-(4-Chlorophenyl)-3-(3,4-dichlorophenyl)urea (cas: 101-20-2) belongs to organic chlorides. Organochlorines stimulate the central nervous system and cause convulsions, tremor, nausea, and mental confusion. Examples are dichlorodiphenyltrichloroethane (DDT), chlordane, lindane, endosulfan, and dieldrin. Organochlorine compounds are lipophylic, meaning they are more soluble in fat than in water. This gives them a high tenancy to accumulate in the food chain (biomagnification).Synthetic Route of C13H9Cl3N2O

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics

Species and Life-Stage Sensitivity of Chinese Rare Minnow (Gobiocypris rarus) to Chemical Exposure: A Critical Review was written by Bai, Yunfei;Lian, Deru;Su, Tenghui;Wang, Yolina Yu Lin;Zhang, Dainan;Wang, Zhen;Gimeno, Sylvia;You, Jing. And the article was included in Environmental Toxicology and Chemistry in 2021.Formula: C13H9Cl3N2O This article mentions the following:

Chem. production and consumption in Asia are increasing at an unprecedented rate, calling for regulations on chem. management. Under the New Chem. Substance Notification in China, information on ecotoxicol. effects of chems. is mandatory for the simplified registration of chems. with the requirement that one ecotoxicol. test is conducted locally. It is now mandatory to use the native fish species Chinese rare minnow (Gobiocypris rarus). However, its chem. sensitivity compared to that of fathead minnow (Pimephales promelas) or zebrafish (Danio rerio) is still unclear. We performed a holistic literature review on toxicity data with G. rarus from 1997 to 2020. Species sensitivity among G. rarus, P. promelas, and D. rerio and life-stage sensitivity of G. rarus were systematically investigated for various chems. using both chem. ratio distribution and probabilistic chem. toxicity distribution approaches. Comparatively, the Chinese native fish species G. rarus was more sensitive than D. rerio, particularly to metals. Juvenile and adult G. rarus were more sensitive than its larvae and embryos. The observed lower sensitivity of G. rarus embryo was likely due to the thick embryonic chorion, discrepant methods of collecting embryos, and the paucity of toxicity data, implying the necessity to standardize G. rarus embryo tests and validate the sensitivity with various types of chems. This unique review allows us to conclude that G. rarus studies could be used in worldwide registrations and that further investigations are needed to use G. rarus embryos as alternatives to the fish test. Environ Toxicol Chem 2021;00:1-14. 2021 SETAC In the experiment, the researchers used many compounds, for example, 1-(4-Chlorophenyl)-3-(3,4-dichlorophenyl)urea (cas: 101-20-2Formula: C13H9Cl3N2O).

1-(4-Chlorophenyl)-3-(3,4-dichlorophenyl)urea (cas: 101-20-2) belongs to organic chlorides. Chlorinated organic compounds are found in nearly every class of biomolecules and natural products including alkaloids, terpenes, amino acids, flavonoids, steroids, and fatty acids. Alkanes and aryl alkanes may be chlorinated under free radical conditions, with UV light. However, the extent of chlorination is difficult to control.Formula: C13H9Cl3N2O

Referemce:
Chloride – Wikipedia,
Chlorides – an overview | ScienceDirect Topics