Log in

Relevant bibliographies by topics / Dendrimers. Chemical kinetics. Nuclear magnetic resonance spectroscopy / Journal articles

To see the other types of publications on this topic, follow the link: Dendrimers. Chemical kinetics. Nuclear magnetic resonance spectroscopy.

Journal articles on the topic 'Dendrimers. Chemical kinetics. Nuclear magnetic resonance spectroscopy'

Author: Grafiati

Published: 4 June 2021

Last updated: 15 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 35 journal articles for your research on the topic 'Dendrimers. Chemical kinetics. Nuclear magnetic resonance spectroscopy.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Hajjaji, Mohamed, Abdellah Beraa, Yannick Coppel, Régis Laurent, and Anne-Marie Caminade. "Adsorption capacity of sodic- and dendrimers-modified stevensite." Clay Minerals 53, no. 3 (2018): 525–44. http://dx.doi.org/10.1180/clm.2018.39.

Full text

Abstract:

ABSTRACTThe adsorption capacities of nano-sized organoclays composed of a stevensite-rich clay (R), phosphorus dendrimers (GC1 and GC2) and Na+-saturated clay were evaluated for their capacity to adsorb chromate and methylene blue (MB) in the range of 298–318 K. The adsorption kinetics and the isotherms were analysed based on kinetic equations and isotherm models and by adopting a non-linear regression procedure. In addition, the organoclays and the Na+-saturated clays were characterized principally by solid-state nuclear magnetic resonance spectroscopy. The pseudo-second-order rate equation d

APA, Harvard, Vancouver, ISO, and other styles

2

Van Den Thillart, G., and A. Van Waarde. "Nuclear magnetic resonance spectroscopy of living systems: applications in comparative physiology." Physiological Reviews 76, no. 3 (1996): 799–837. http://dx.doi.org/10.1152/physrev.1996.76.3.799.

Full text

Abstract:

The most attractive feature of nuclear magnetic resonance spectroscopy (MRS) is the noninvasive and nondestructive measurement of chemical compounds in intact tissues. MRS already has many applications in comparative physiology, usually based on observation of 31P, since levels of phosphorus compounds indicate tissue energy status and are changed during exercise, fatigue, recovery, hypometabolism, anesthesia, hypoxia, hypercapnia, and osmotic and acid stress. Nuclei other than 31P may also be monitored, such as 1H, 13C, 15N, 19F, or 23Na, and applied in biological research. Particularly, 13C-M

APA, Harvard, Vancouver, ISO, and other styles

3

Catchen, Gary L. "Perturbed-Angular-Correlation Spectroscopy: Renaissance of a Nuclear Technique." MRS Bulletin 20, no. 7 (1995): 37–46. http://dx.doi.org/10.1557/s0883769400037167.

Full text

Abstract:

During the past decade, perturbed-angular-correlation (PAC) spectroscopy has emerged as an important technique in several areas of materials science. PAC spectroscopy is used to measure the effects of local fields at well-defined lattice sites in a crystal. These measurements can provide unique information about the structures, kinetics, and energetics associated with point defects, the mechanisms of phase transitions, and the strengths and symmetries of chemical bonds of atoms on surfaces and at interfaces. In what follows, I describe the PAC technique in the context of several examples of th

APA, Harvard, Vancouver, ISO, and other styles

4

Gajjar, Dhaval G., Rinkesh M. Patel, Hema N. Patel, and Pravinkumar M. Patel. "Designing, characterization, and thermal behavior of triazine-based dendrimers." Journal of Polymer Engineering 35, no. 1 (2015): 41–52. http://dx.doi.org/10.1515/polyeng-2014-0123.

Full text

Abstract:

Abstract Different generations of dendritic architecture with piperazine in core moiety and hydroxyl groups on the periphery were designed by divergent method. 1,4-biz(4,6-trichloro-1,3,5-triazin-2-yl)piperazine was synthesized as a core for dendrimer synthesis. Dendrimer was then grown to G3 from core compound using diethanolamine and cyanuric chloride as branching units. Dendrimer generations were characterized by infrared (IR) spectroscopy [Fourier transform IR (FTIR)], 1H-nuclear magnetic resonance (NMR), 13C-NMR, electrospray ionization-mass spectrometry (ESI-MS), and elemental analysis.

APA, Harvard, Vancouver, ISO, and other styles

5

Fan, Yaqin, Chunlan Tang, Qing Hu, Yonglin Lei, and Jichuan Huo. "Evaluation on Curing Properties and Kinetics of Isophthalonitrile Oxide." Polish Journal of Chemical Technology 20, no. 3 (2018): 37–46. http://dx.doi.org/10.2478/pjct-2018-0036.

Full text

Abstract:

Abstract N,N-dihydroxybenzene-1,3-dicarboximidoyl dichloride was synthesized from benzene-1,3-dicarboxaldehyde and characterized by fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H and 13C NMR). The elastomer was prepared through the 1,3-dipolar cycloaddition of reaction between liquid polybutadiene (LPB) and isophthalonitrile oxide in this work. The tensile strength of different elastomer was enhanced from 0.14 MPa to 0.33 MPa as the elongation at break decreased from 145% to 73%, and the modulus increased from 0.09 kPa to 0.47 kPa. The parameters of kinetic

APA, Harvard, Vancouver, ISO, and other styles

6

Tiecher, Tales, Mohsin Zafar, Fábio Joel Kochem Mallmann, et al. "Animal manure phosphorus characterization by sequential chemical fractionation, release kinetics and 31P-NMR analysis." Revista Brasileira de Ciência do Solo 38, no. 5 (2014): 1506–14. http://dx.doi.org/10.1590/s0100-06832014000500016.

Full text

Abstract:

Phosphate release kinetics from manures are of global interest because sustainable plant nutrition with phosphate will be a major concern in the future. Although information on the bioavailability and chemical composition of P present in manure used as fertilizer are important to understand its dynamics in the soil, such studies are still scarce. Therefore, P extraction was evaluated in this study by sequential chemical fractionation, desorption with anion-cation exchange resin and 31P nuclear magnetic resonance (31P-NMR) spectroscopy to assess the P forms in three different dry manure types (

APA, Harvard, Vancouver, ISO, and other styles

7

Whittier, Sean K., Alvan C. Hengge, and J. Patrick Loria. "Conformational Motions Regulate Phosphoryl Transfer in Related Protein Tyrosine Phosphatases." Science 341, no. 6148 (2013): 899–903. http://dx.doi.org/10.1126/science.1241735.

Full text

Abstract:

Many studies have implicated a role for conformational motions during the catalytic cycle, acting to optimize the binding pocket or facilitate product release, but a more intimate role in the chemical reaction has not been described. We address this by monitoring active-site loop motion in two protein tyrosine phosphatases (PTPs) using nuclear magnetic resonance spectroscopy. The PTPs, YopH and PTP1B, have very different catalytic rates; however, we find in both that the active-site loop closes to its catalytically competent position at rates that mirror the phosphotyrosine cleavage kinetics.

APA, Harvard, Vancouver, ISO, and other styles

8

Patel, Rakesh B., Umesh P. Tarpada, and Dipak K. Raval. "Study on copolymers synthesized from 2,3-epoxypropyl-3-(2-furyl) acrylate – styrene and their glass fiber reinforced composites." Journal of Polymer Engineering 33, no. 4 (2013): 303–14. http://dx.doi.org/10.1515/polyeng-2013-0054.

Full text

Abstract:

Abstract 3-(2-Furyl) acrylic acid (FAA) and 2,3-epoxypropyl-3-(2-furyl) acrylate (EPFA) were synthesized. EPFA was characterized by Fourier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance (1HNMR) spectroscopy. Copolymerization of prepared EPFA was carried out with styrene as the comonomer, by varying the mole ratio of EPFA:styrene at different reaction times, using benzoyl peroxide as an initiator at 80°C in toluene. FAA, EPFA and copolymers were characterized by FTIR and 1HNMR spectroscopy, as well as viscosity, gel permeation chromatography (GPC) and epoxy equivalent

APA, Harvard, Vancouver, ISO, and other styles

9

Korzhnev, Dmitry M., Tomasz L. Religa, Wiktor Banachewicz, Alan R. Fersht, and Lewis E. Kay. "A Transient and Low-Populated Protein-Folding Intermediate at Atomic Resolution." Science 329, no. 5997 (2010): 1312–16. http://dx.doi.org/10.1126/science.1191723.

Full text

Abstract:

Proteins can sample conformational states that are critical for function but are seldom detected directly because of their low occupancies and short lifetimes. In this work, we used chemical shifts and bond-vector orientation constraints obtained from nuclear magnetic resonance relaxation dispersion spectroscopy, in concert with a chemical shift–based method for structure elucidation, to determine an atomic-resolution structure of an “invisible” folding intermediate of a small protein module: the FF domain. The structure reveals non-native elements preventing formation of the native conformati

APA, Harvard, Vancouver, ISO, and other styles

10

Wang, C. X., and Q. P. Song. "Removal of Cu(II) ions from aqueous solutions using N-carboxymethyl chitosan." Water Science and Technology 66, no. 9 (2012): 2027–32. http://dx.doi.org/10.2166/wst.2012.419.

Full text

Abstract:

N-carboxymethyl chitosan (NCMC) was synthesized by reacting chitosan with chloroacetic acid in water under triethylamine (Et3N) as catalyst. The chemical structures of NCMC were characterized by Fourier transform infrared (FT-IR) and hydrogen-1 nuclear magnetic resonance (1H-NMR) spectroscopy and confirmed that carboxymethylation occurred on the amino groups. Samples of NCMC were used for removal of Cu(II) from aqueous solution. The effects of degree of substitution of NCMC, initial pH value and adsorption kinetics on the adsorption were studied. Adsorption experiments showed that NCMC has a h

APA, Harvard, Vancouver, ISO, and other styles

11

Paganini, A. T., J. M. Foley, and R. A. Meyer. "Linear dependence of muscle phosphocreatine kinetics on oxidative capacity." American Journal of Physiology-Cell Physiology 272, no. 2 (1997): C501—C510. http://dx.doi.org/10.1152/ajpcell.1997.272.2.c501.

Full text

Abstract:

The influence of muscle oxidative capacity on phosphocreatine (PCr) changes during and after stimulation was examined in the superficial (fast-twitch) section of rat gastrocnemius muscles. Muscle mitochondrial enzymes were increased in one group of rats by 8-10 wk of training on a running wheel (to a final regimen of 50 min/day at 38 m/min, 5 days/wk) and decreased in another group by chemical thyroidectomy [0.025% methimazole (MMI) in drinking water for 8 wk]. After these treatments, muscle citrate synthase activity was 179 and 29%, respectively, of that in corresponding control groups. Muscl

APA, Harvard, Vancouver, ISO, and other styles

12

Saliba, Daniel, and Mazen Al-Ghoul. "Kinetics of intercalation of fluorescent probes in magnesium–aluminium layered double hydroxide within a multiscale reaction–diffusion framework." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 374, no. 2080 (2016): 20160138. http://dx.doi.org/10.1098/rsta.2016.0138.

Full text

Abstract:

We report the synthesis of magnesium–aluminium layered double hydroxide (LDH) using a reaction–diffusion framework (RDF) that exploits the multiscale coupling of molecular diffusion with chemical reactions, nucleation and growth of crystals. In an RDF, the hydroxide anions are allowed to diffuse into an organic gel matrix containing the salt mixture needed for the precipitation of the LDH. The chemical structure and composition of the synthesized magnesium–aluminium LDHs are determined using powder X-ray diffraction (PXRD), thermo-gravimetric analysis, differential scanning calorimetry, solid-

APA, Harvard, Vancouver, ISO, and other styles

13

Chmela, Štefan, Agnesa Fiedlerová, Tibor Liptaj, Yohann Catel, and Norbert Moszner. "Determination of homopolymerization kinetics and copolymerization with methyl methacrylate of diethyl 9-(methacryloyloxy)-2-oxo-nonylphosphonate, 9-(methacryloyloxy)-2-oxo-nonylphosphonic acid and diethyl 9-(methacryloyloxy)-nonylphosphonate." e-Polymers 18, no. 3 (2018): 205–16. http://dx.doi.org/10.1515/epoly-2017-0155.

Full text

Abstract:

AbstractThe three polymerizable monomers diethyl 9-(methacryloyloxy)-2-oxo-nonylphosphonate M1, 9-(methacryloyloxy)-2-oxo-nonylphosphonic acid M2 and diethyl 9-(methacryloyloxy)-nonylphosphonate M3 are examined for their free radical polymerization and copolymerization activity in methanol between 40 and 65°C. Polymerization proceeds readily through a thermal free radical initiation. The intensity exponents for the monomer and initiator are only slightly over 1 and approximately 0.5, respectively. This is in accordance with the results typically observed for an ideal free radical polymerizatio

APA, Harvard, Vancouver, ISO, and other styles

14

Castiglione Morelli, Maria Antonietta, Angela Ostuni, Brunella Giangaspero, Stefano Cecchini, Augusto Carluccio, and Raffaele Boni. "Relationships between Seminal Plasma Metabolites, Semen Characteristics and Sperm Kinetics in Donkey (Equus asinus)." Animals 11, no. 1 (2021): 201. http://dx.doi.org/10.3390/ani11010201.

Full text

Abstract:

This study aimed to evaluate donkey seminal plasma metabolites and relate this information to the main characteristics of sperm quality. Sperm kinetics from 10 donkey stallions were analyzed with a computerized system at the time of collection (T0) and after 24 h storage at 4 °C (T24). Seminal plasma was frozen at −80 °C for subsequent proton nuclear magnetic resonance (1H NMR) spectroscopy. On three stallions, semen collection was repeated monthly for three times and sperm analysis also included mitochondrial activity and oxidative status. One stallion was azoospermic and a second semen colle

APA, Harvard, Vancouver, ISO, and other styles

15

Frukhtbeyn, S., K. Van Dongen, and J. Sun. "Stoichiometry and Kinetics of Sequential Dimethacrylate Enzymolysis." Journal of Dental Research 98, no. 9 (2019): 1037–44. http://dx.doi.org/10.1177/0022034519858975.

Full text

Abstract:

The increasing use of methacrylate-based materials in tissue engineering and dental restorations demands detailed evaluation of enzymolysis of these materials due to toxicity, durability, and biocompatibility concerns. The objective of this study is to develop tools for assessing and ranking the enzymolysis kinetics of dimethacrylate (DMA) compounds. Triethyleneglycol DMA and diurethane DMA are employed as model DMAs for kinetic studies of 2-step enzymolysis by 2 esterases, pseudocholine esterase and cholesterol esterase. In addition, the intermediate hydrolysis products, mono-methacrylates (m

APA, Harvard, Vancouver, ISO, and other styles

16

Bou Orm, Nadine, Thomas Gréa, Marwa Hamandi, et al. "Design of Hybrid PAH Nanoadsorbents by Surface Functionalization of ZrO2 Nanoparticles with Phosphonic Acids." Nanomaterials 11, no. 4 (2021): 952. http://dx.doi.org/10.3390/nano11040952.

Full text

Abstract:

This study focuses on the preparation of innovative nanocomposite materials based on surface modification of commercial nano-ZrO2 optimized from Brønsted acid–base surface reactions. This surface modification was carried out by direct grafting of suitable phosphonic acids bearing a vinylic or phenylic substituent in aqueous solution. Different loading quantities of the anchoring organophosphorus compounds were applied for each materials synthesis. The resulting nanohybrids were thoroughly characterized by infrared spectroscopy (DRIFT), solid-state nuclear magnetic resonance (NMR), nitrogen ads

APA, Harvard, Vancouver, ISO, and other styles

17

Ahmed, Abdul Baquee, and Iman Bhaduri. "CHEMICAL MODIFICATION, CHARACTERIZATION AND EVALUATION OF MUCOADHESIVE POTENTIALITY OF ASSAM BORA RICE STARCH." International Journal of Pharmacy and Pharmaceutical Sciences 9, no. 9 (2017): 132. http://dx.doi.org/10.22159/ijpps.2017v9i9.20108.

Full text

Abstract:

Objective: The objective of the present study was to chemical modification, characterization and evaluation of mucoadhesive potentiality of Assam bora rice starch as potential excipients in the sustained release drug delivery system. Methods: The starch was isolated from Assam bora rice and esterified using thioglycolic acid and characterized by Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC) and Nuclear magnetic resonance (NMR). The 10% w/v gel formulation based on modified bora rice starch loaded with irinotecan (0.6%) was prepared and evaluated for v

APA, Harvard, Vancouver, ISO, and other styles

18

Wang, Xiujuan, Xiuting Zheng, Meng Song, and Sizhu Wu. "A study on the relationship between polycarbonate microstructure and performance as determined by a combined experimental and molecular dynamics simulation method." e-Polymers 14, no. 6 (2014): 407–15. http://dx.doi.org/10.1515/epoly-2014-0065.

Full text

Abstract:

AbstractThe influence of the microstructure of polycarbonate (PC) on performance was systematically investigated by both experimental method and molecular simulation. Yield stress, impact strength, molecular weight, and transmittance were used to distinguish the degradation processes between different PCs, and thermal degradation kinetics was studied to obtain the activation energy. At the molecular level, through 13C nuclear magnetic resonance (NMR) spectroscopy, it was observed that PCs have a more polar group of benzene rings, resulting in the high density, dielectric constant, and tensile

APA, Harvard, Vancouver, ISO, and other styles

19

Vala, Masoud Mohamadi, Yadollah Bayat, and Mohammad Bayat. "Synthesis and Thermal Decomposition Kinetics of Epoxy Poly Glycidyl Nitrate as an Energetic Binder." Defence Science Journal 70, no. 4 (2020): 461–68. http://dx.doi.org/10.14429/dsj.70.15470.

Full text

Abstract:

An energetic binder epoxy poly glycidyl nitrate (e-PGN) with a molecular weight of about 1244 gr/mol was synthesised via end modified poly glycidyl nitrate (PGN) is presented in the paper. This structure was characterised by the number of epoxy groups, infrared spectroscopy, and nuclear magnetic resonance. The thermal degradation behavior of e-PGN was studied by thermo gravimetric analysis (TG) and differential scanning calorimetry (DSC) under nitrogen atmosphere at different heating rates. The glass transition temperature (Tg) was measured to determine the compatibility of energetic plasticiz

APA, Harvard, Vancouver, ISO, and other styles

20

Wiśniewska-Wrona, Maria, and Mirosława El Fray. "FUNCTIONAL THREE-COMPONENT POLYMERIC BIOCOMPOSITES FOR THE TREATMENT OF BEDSORES." Progress on Chemistry and Application of Chitin and its Derivatives XXIII (September 10, 2018): 185–206. http://dx.doi.org/10.15259/pcacd.23.019.

Full text

Abstract:

Presented here are the results of investigations into the preparation of three-component dressing materials from various biopolymers in the form of a single-layer film which is suitable as a carrier for pain-relieving (lidocaine) and bacteriostatic (sulphanilamid) therapeutic agents. Physical-chemical, biological and usable properties of the prepared materials were tested and assessed. The amount of added active substance was adopted based on the dose recommended by the Polish Pharmacopeia for external medicinal preparations. Antibacterial activity against gram (-) Escherichia coli and gram (+

APA, Harvard, Vancouver, ISO, and other styles

21

Errich, A., K. Azzaoui, E. Mejdoubi, et al. "Toxic heavy metals removal using a hydroxyapatite and hydroxyethyl cellulose modified with a new Gum Arabic." Indonesian Journal of Science and Technology 6, no. 1 (2021): 41–64. http://dx.doi.org/10.17509/ijost.v6i1.31480.

Full text

Abstract:

The objective of this work was to develop a process that allows the synthesis of an apatitic material of controlled composition and morphology, which could be used for medical and environmental applications. The adsorbent was synthesized, and characterized using scanning electron microscopy, nuclear magnetic resonance, Thermal analysis and other techniques, Atomic Force Microscopy, X-ray photoelectron spectroscopy and Total organic carbon. Different experimental parameters such as the effect of the amount of adsorbent, solution pH and temperatures and contact times were studied. Pseudo-order k

APA, Harvard, Vancouver, ISO, and other styles

22

Wang, Jun, Shuangshuang Gu, Na Pang, Fangqin Wang, and Fuan Wu. "A study of esterification of caffeic acid with methanol using p-toluenesulfonic acid as a catalyst." Journal of the Serbian Chemical Society 78, no. 7 (2013): 1023–34. http://dx.doi.org/10.2298/jsc120802101w.

Full text

Abstract:

Caffeic acid (CA) can be considered as an important natural antioxidant. However, the low solubility and stability of CA in various solvent systems is a major limiting factor governing the overall application in the lipid industry, so the synthesis of methyl caffeate (MC)using CA and methanol is a feasible way to improve its lipophilicity. Here, the reaction conditions and kinetic parameters for the synthesis of MC using p-toluenesulfonic acid (PTSA) as a catalyst were firstly investigated, and the product was confirmed byliquid chromatography-mass spectrometry (LC-MS),Fourier transform infrar

APA, Harvard, Vancouver, ISO, and other styles

23

León-Boigues, Laia, Luis Andrés Pérez, and Carmen Mijangos. "In Situ Synthesis of Poly(butyl methacrylate) in Anodic Aluminum Oxide Nanoreactors by Radical Polymerization: A Comparative Kinetics Analysis by Differential Scanning Calorimetry and 1H-NMR." Polymers 13, no. 4 (2021): 602. http://dx.doi.org/10.3390/polym13040602.

Full text

Abstract:

In this work, we explore the ability to generate well-defined poly(butyl methacrylate) (PBMA) nanostructures by “in situ” polymerization of butyl methacrylate monomer (BMA). PBMA nanostructures of high and low aspect ratios have been successfully obtained through the free radical polymerization (FRP) of a BMA monomer in anodic aluminum oxide (AAO) nanoreactors of suitable size. A polymerization kinetics process has been followed by differential scanning calorimetry (DSC) and proton Nuclear Magnetic Resonance spectroscopy (1H-NMR).The determination of the kinetics of polymerization through DSC

APA, Harvard, Vancouver, ISO, and other styles

24

Alberdi-Cedeño, Jon, María L. Ibargoitia, and María D. Guillén. "Oxylipins Associated to Current Diseases Detected for the First Time in the Oxidation of Corn Oil as a Model System of Oils Rich in Omega-6 Polyunsaturated Groups. A Global, Broad and in-Depth Study by 1H NMR Spectroscopy." Antioxidants 9, no. 6 (2020): 544. http://dx.doi.org/10.3390/antiox9060544.

Full text

Abstract:

For the first time, an important number of oxylipins have been identified and quantified in corn oil submitted to mild oxidative conditions at each time of their oxidation process. This oil can be considered as a model system of edible oils rich in polyunsaturated omega-6 groups. The study was carried out using 1H nuclear magnetic resonance spectroscopy (1H NMR), which does not require chemical modification of the sample. These newly detected oxylipins include dihydroperoxy-non-conjugated-dienes, hydroperoxy-epoxy-, hydroxy-epoxy- and keto-epoxy-monoenes as well as E-epoxy-monoenes, some of wh

APA, Harvard, Vancouver, ISO, and other styles

25

Qi, Liu, Wang, et al. "Synthesis of the Hydrophobic Cationic Polyacrylamide (PADD) Initiated by Ultrasonic and its Flocculation and Treatment of Coal Mine Wastewater." Processes 8, no. 1 (2020): 62. http://dx.doi.org/10.3390/pr8010062.

Full text

Abstract:

In this study, a new type of hydrophobic cationic polyacrylamide P (AM-DMC-DABC) (PADD) was synthesized by ultrasonic (US)-initiated polymerization, which is used for the separation and removal of coal mine wastewater. The acrylamide (AM), methacryloyloxyethyl trimethyl ammonium chloride (DMC) and acryloyloxyethyl dimethylbenzyl ammonium chloride (DABC) were used as monomers to prepare). The factors that affecting the US initiated polymerization of PADD were analyzed. Fourier transform infrared spectroscopy (FT-IR), 1H nuclear magnetic resonance (1H NMR) and scanning electron microscopy (SEM)

APA, Harvard, Vancouver, ISO, and other styles

26

Ribeiro, Ana C. F., and Miguel A. Esteso. "Transport Properties for Pharmaceutical Controlled-Release Systems: A Brief Review of the Importance of Their Study in Biological Systems." Biomolecules 8, no. 4 (2018): 178. http://dx.doi.org/10.3390/biom8040178.

Full text

Abstract:

: The goal of this work was to comprehensive study the transport properties of controlled-release systems for the safe and reliable delivery of drugs. Special emphasis has been placed on the measurement of the diffusion of drugs, alone or in combination with carrier molecules for enhanced solubility and facilitated transport. These studies have provided detailed comprehensive information—both kinetic and thermodynamic—for the design and operation of systems for the controlled release and delivery of drugs. Cyclodextrins are among the most important carriers used in these systems. The basis for

APA, Harvard, Vancouver, ISO, and other styles

27

Al-Muntasheri, Ghaithan A., Hisham A. Nasr-El-Din, and Pacelli L. J. Zitha. "Gelation Kinetics and Performance Evaluation of an Organically Crosslinked Gel at High Temperature and Pressure." SPE Journal 13, no. 03 (2008): 337–45. http://dx.doi.org/10.2118/104071-pa.

Full text

Abstract:

Summary Organically crosslinked gels have been used to control water production in high temperature applications. These chemical systems are based on the crosslinking of a polyacrylamide-based polymer/copolymer with an organic crosslinker. Polyethyleneimine (PEI) has been used as an organic crosslinker for polyacrylamide-based copolymers to provide thermally stable gels. Literature reported that PEI can form aqueous gels with polyacrylamide (PAM) at room temperature. In this paper, we show for the first time the possibility of crosslinking polyacrylamide with PEI at temperatures up to 140°C (2

APA, Harvard, Vancouver, ISO, and other styles

28

BUCK, MATTHIAS. "Trifluoroethanol and colleagues: cosolvents come of age. Recent studies with peptides and proteins." Quarterly Reviews of Biophysics 31, no. 3 (1998): 297–355. http://dx.doi.org/10.1017/s003358359800345x.

Full text

Abstract:

Alcohol based cosolvents, such as trifluoroethanol (TFE) have been used for many decades to denature proteins and to stabilize structures in peptides. Nuclear magnetic resonance spectroscopy and site directed mutagenesis have recently made it possible to characterize the effects of TFE and of other alcohols on polypeptide structure and dynamics at high resolution. This review examines such studies, particularly of hen lysozyme and β-lactoglobulin. It presents an overview of what has been learnt about conformational preferences of the polypeptide chain, the interactions that stabilize structure

APA, Harvard, Vancouver, ISO, and other styles

29

McCloy, John S., José Marcial, Deepak Patil, et al. "Glass structure and crystallization in boro-alumino-silicate glasses containing rare earth and transition metal cations: a US-UK collaborative program." MRS Advances 4, no. 17-18 (2019): 1029–43. http://dx.doi.org/10.1557/adv.2019.99.

Full text

Abstract:

ABSTRACTNuclear wastes generated from reprocessing of used nuclear fuel tend to contain a large fraction of rare earth (RE, e.g., Nd3+), transition (TM, e.g., Mo6+, Zr4+), alkali (A, e.g., Cs+), and alkaline earth cations (AE, e.g., Ba2+, Sr2+). Various strategies have been considered for immobilizing such waste streams, varying from nominally crystal-free glass to glass-ceramic to multi-phase ceramic waste forms. For glass and glass-ceramic waste forms, the added glass-forming system is generally alkali-alkaline earth-aluminoborosilicate (i.e., Na-Ca-Al-B-Si oxide). In a US-UK collaborative p

APA, Harvard, Vancouver, ISO, and other styles

30

DE BONI, Luis A. B., Teresa M. R. MARIA, M. M. Pereira, and Isaac N. L. da Silva. "THE PRODUCTION OF BIODIESEL MONITORED WITH REAL-TIME LASER SPECTROSCOPY. CONFIRMATION OF THE TECHNIQUE WITH PROTON NUCLEAR MAGNETIC RESONANCE." SOUTHERN BRAZILIAN JOURNAL OF CHEMISTRY 21, no. 21 (2013). http://dx.doi.org/10.48141/sbjchem.v21.n21.2013.20_revista2013.pdf.

Full text

Abstract:

Biodiesel is a synthetic fuel usually produced by the transesterification reaction. This study was undertaken in order to monitor the kinetics of the transesterification reaction between soybean oil and methanol catalyzed by KOH and determine when the reaction reached chemical equilibrium. A series of reactions was monitored with a laser spectrometer used to analyze the absorption and scattering of light in real-time. The monitoring system combined the information received through multiple sensors. The correlation of the present technique with 1H-NMR spectra confirmed that the reaction was app

APA, Harvard, Vancouver, ISO, and other styles

31

Hoshino, Taiki, Yasushi Okamoto, Atsushi Yamamoto, and Hiroyasu Masunaga. "Heterogeneous dynamics in the curing process of epoxy resins." Scientific Reports 11, no. 1 (2021). http://dx.doi.org/10.1038/s41598-021-89155-x.

Full text

Abstract:

AbstractEpoxy resin is indispensable for modern industry because of its excellent mechanical properties, chemical resistance, and excellent moldability. To date, various methods have been used to investigate the physical properties of the cured product and the kinetics of the curing process, but its microscopic dynamics have been insufficiently studied. In this study, the microscopic dynamics in the curing process of a catalytic epoxy resin were investigated under different temperature conditions utilizing X-ray photon correlation spectroscopy. Our results revealed that the temperature conditi

APA, Harvard, Vancouver, ISO, and other styles

32

Park, Chulhun, Jong Hoon Lee, Gang Jin, et al. "Release kinetics of hydroxypropyl methylcellulose governing drug release and hydrodynamic changes of matrix tablet." Current Drug Delivery 18 (August 20, 2021). http://dx.doi.org/10.2174/1567201818666210820101549.

Full text

Abstract:

Background: Hydrophilic hydroxypropyl methylcellulose (HPMC) matrix tablets are the standard role model of the oral controlled-release formulation. Nevertheless, the HPMC kinetics for the mechanistic understanding of drug release and hydrodynamic behaviors are rarely investigated. This study aims to investigate the release behaviors of both HPMC and paracetamol (model drug) from the hydrophilic matrix tablet. Methods: Two different viscosity grades of HPMC were used (Low viscosity: 6 cps, High viscosity: 4,000 cps). Three different ratios of drug/HPMC (H:38.08%, M:22.85%, and L:15.23% (w/w) of

APA, Harvard, Vancouver, ISO, and other styles

33

Krajnc, Matjaž, Ida Poljanšek, and Blaž Likozar. "Comparison of conventional and controlled bulk polymerization of styrene by N-methyl-2-pyrrolidone and 1-dodecanethiol." e-Polymers 8, no. 1 (2008). http://dx.doi.org/10.1515/epoly.2008.8.1.1679.

Full text

Abstract:

AbstractControlled radical polymerization of styrene was initiated using Nmethyl- 2-pyrrolidone (NM2P) and 1-dodecanethiol (1DT). This polymerization system exhibited “living” characteristics, namely the molecular weight averages of resulting polymers increased linearly with conversion, which has been determined by gel permeation chromatography (GPC) analysis. The polymer was additionally characterized with Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H NMR) spectroscopy. Kinetics of controlled radical polymerization has been studied and the temperatur

APA, Harvard, Vancouver, ISO, and other styles

34

Rashid, Rozina, Uroosa Ejaz, Firdous Imran Ali, et al. "Combined pretreatment of sugarcane bagasse using alkali and ionic liquid to increase hemicellulose content and xylanase production." BMC Biotechnology 20, no. 1 (2020). http://dx.doi.org/10.1186/s12896-020-00657-4.

Full text

Abstract:

Abstract Background Lignin in sugarcane bagasse (SB) hinders its utilization by microorganism, therefore, pretreatment methods are employed to make fermentable components accessible to the microbes. Multivariate analysis of different chemical pretreatment methods can aid to select the most appropriate strategy to valorize a particular biomass. Results Amongst methods tested, the pretreatment by using sodium hydroxide in combination with methyltrioctylammonium chloride, an ionic liquid, (NaOH+IL) was the most significant for xylanase production by Bacillus aestuarii UE25. Investigation of optim

APA, Harvard, Vancouver, ISO, and other styles

35

Llàcer Navarro, Saül, Koyuru Nakayama, Alexander Idström, Lars Evenäs, Anna Ström, and Tiina Nypelö. "The effect of sulfate half-ester groups on cellulose nanocrystal periodate oxidation." Cellulose, August 17, 2021. http://dx.doi.org/10.1007/s10570-021-04115-y.

Full text

Abstract:

AbstractPeriodate oxidation introduces aldehyde functionality to cellulose. The use of dialdehyde cellulose has been demonstrated for crosslinking and as a chemical intermediate towards functionalized cellulose. Commercially available cellulose nanocrystals (CNCs) typically carry a surface sulfate half-ester functionality, which results from their manufacture via sulfuric acid hydrolysis and subsequent esterification. The sulfate half-ester group is a bulky group carrying a net negative charge above pH 2 that modifies the colloidal and electro-chemical properties of the CNCs. Periodate oxidati

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!