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Quatsome nanovesicles, formed through the self-assembly of cholesterol (CHOL) and cetyltrimethylammonium bromide (CTAB) in water, have shown long-term stability in terms of size and morphology, while at the same time exhibiting high CHOL-CTAB intermolecular binding energies. We hypothesize that CHOL/CTAB quatsomes are indeed thermodynamically stable nanovesicles, and investigate the mechanism underlying their formation., This work was supported by funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 712949 (TECNIOspring PLUS) and from the Agency for Business Competitiveness of the Government of Catalonia. The production of quatsomes and part of their characterization has been performed by the ICTS “NANBIOSIS”, more specifically by the Biomaterial Processing and Nanostructuring Unit (U6), Unit of the CIBER in Bioengineering, Biomaterials & Nanomedicine (CIBER-BBN) located at the Institute of Materials Science of Barcelona (ICMAB-CSIC). ICMAB-CSIC acknowledges support from the MINECO through the Severo Ochoa Programme for Centres of Excellence in R&D (SEV-2015-0496 and CEX2019-000917-S). Authors acknowledge financial support from the Spanish Ministry of Science and Innovation through grants “MOL4BIO” (PID2019-105622RB-I00), “SimBioSoft” (PID2021-124297NB-C33) and the FUNFUTURE-FIP-2020 Severo Ochoa project, from Generalitat de Catalunya through grant 2017-SGR-918, from CSIC through grant 2019AEP133, and from the European Commission through the H2020 PHOENIX project (contract no. 953110). We acknowledge the support of the Israel scienceIsrael science Foundation, grant 1117/2016, and thank Dr. Inbal Ionita for her professional assistance in the cryo-TEM analysis. We thank Jannik Nedergaard Pedersen and Beatrice Plazzotta for help with the SAXS measurements. The simulations reported here were performed using the Cori Supercomputing facility of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).

A catanionic surfactant system is an aqueous solution or dispersion of cationic and anionic surfactants that spontaneously self-assemble into structures such as micelles, vesicles, and coacervates. Their structural diversity varies depending on the ratios of cationic and anionic surfactants (compositions), the chemical structure of the constituent molecules, etc. Herein, two types of catanionic surfactant systems were systematically characterized: (i) cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS), both typical ionic surfactants; and (ii) dodecylmethylimidazolium ammonium bromide ([C

Molecular interactions between 4-OH-cinnamate and cetrimonium in solution result in improved adsorption of the cinnamate on mild steel, developing a protective mechanism against the diffusion of corrosive chloride to the oxide surface. Fundamental understanding of this mechanism should allow new design routes for the development of eco-friendly corrosion inhibitors.Via classic molecular dynamics, simulations were carried out for cetrimonium and 4-OH-cinnamate in aqueous solutions at different ionic strengths and the results were validated with experimental SAXS data. Self-aggregation of cetrimonium 4-OH-cinnamate on a hydrated hematite surface was then simulated and results were compared with cryo-TEM imaging for the same compound. Finally, the effect of the adsorbed aggregates on chloride diffusion to the oxide surface was modelled.Simulations showed the encapsulation of 4-OH-cinnamate into cetrimonium micelles, consistent with experiments. The newly formed micelles adsorb onto a hydrated iron oxide surface by forming hydrogen bonds between their carboxylate outer-shell groups and the surface hydroxyls. As the adsorbate concentrations increase, there is a morphological transition from spherical to wormlike adsorbed aggregates. The wormlike structure can block chloride ions, demonstrating a synergistic inhibitory mechanism between both cetrimonium and 4-OH-cinnamate. Encapsulation and delivery of active compounds to certain targets, such as carcinogenic tumors, have been well studied in biochemistry research, we demonstrate that the same mechanism can be applied to the design of efficient corrosion inhibitors, optimizing their delivery to the metal surface.

The influence of mercury on the morphology and formation mechanism of gold amalgams in the presence of different reducing agents (ascorbic acid and sodium borohydride) was systematically studied. In the presence of cetyltrimethylammonium bromide (CTAB), chemical reducing agents not only reduced mercury ions in the solution but also replaced the CTAB molecules on the surface of the gold nanorod. The stability of the reducing agents in the colloidal system and the combining capacity of the reducing agent to the gold nanoparticles can affect the alloying process of mercury and gold, thereby forming a rod-shaped or spherical gold amalgam. Once CTAB was removed, a similar transformation process occurs between the gold nanorods and mercury. In addition, without the presence of a stabilizer, mercury that cannot be dispersed undergoes Ostwald ripening growth, which causes the gold amalgam nanoalloys to form a tip-to-tip structure as a result of mercury enrichment because of the weak shielding effects occurring at the tips of the gold nanorods. After the CTAB molecules were substituted with ascorbic acid and alkylthiol molecules, the question of whether the shielding effect weakened or disappeared was also investigated. By investigation, this research found that, in comparison to the blocking effect of CTAB molecules, the binding ability of the reducing agent to gold plays a dominant role in the nanoamalgam formation process.

The major goal of this study was to find predictors of plasmon positions in silver nanorod (NR) optical absorption spectra. The goal of this study is to use an adaptive neural fuzzy inference system to identify the various input parameters for longitudinal surface plasmon resonance (LSPR) and transverse surface plasmon resonance (TSP). A seed strategy has been used for preparation of the silver NRs. During the preparation, the seed particles are synthesized in the presence of cetyltrimethylammonium bromide (CTAB). To produce the silver NRs, metal salt (AgNO3) has been added, as well as ascorbic acid (AA) and CTAB. Skillful prediction could play a pivotal role in the plasmon NR production management. The combination of CTAB and the seeds has the largest influence on the TSPR. The combination of CTAB and AA has the largest influence on the LSPR. The study considering different input parameters simultaneously, to the best of our knowledge, is the first on a small scale and should attract great general interest.

Soil-transmitted helminths and Schistosoma haematobium affect more than 3 billion people globally and mainly occur in sub-Saharan Africa. The present study assessed the overall infection status of a 1716-student cohort of school-children in Zanzibar and applied mass drug administration (MDA) to the cohort from 2007 to 2009. Schools in Pemba, Zanzibar, had a much higher prevalence of soil-transmitted helminth infections than those in Unguja, and the Chaani, Ghana, and Machui schools of Unguja exhibited high S. haematobium infection rates. The MDA program only partially controlled parasite infections, owing to high rates of re-infection. The infection rate of S. haematobium across all 10 schools, for example, was only reduced by 1.8%, and even this change not significant, even though the S. haematobiuminfection rates of the Chaani and Mzambarauni schools were significantly reduced from 64.4 and 23.4%, respectively, at the first screening, to 7.3 and 2.3% at the last screening. The overall infection rate of Ascaris lumbricoides was reduced from 36.0% at the first screening to 22.6% at the last screening. However, the infection rates for both Trichuris trichiuraand hookworm were generally unaffected by MDA. In the future, parasite control programs should involve strategically designed MDA schedules and holistic intervention (e.g., sanitation improvement, hygiene behavior changes, and control of intermediated hosts).

Summary: Objective: Aim to explore the association of dyslipidemias with GBP prevalence, number and size in a large Chinese population in Beijing. Dyslipidemias include hypercholesterolemia, hypertriglyceridemia, increased low density lipoprotein (LDL) and decreased high density lipoproteins (HDL). Methods: Prevalence of GBP and its association with dyslipidemias were retrospectively investigated among subjects who underwent check-up at Health Screening Center of Xuanwu Hospital between January 2014 and December 2017. Results: This study enrolled 97117 participants. Prevalence of GBP was 7.3%. There were significant differences in increased LDL (595/7107 vs 6004/90010, P = 0.000) and increased cholesterol (TC) (403/7107 vs 4846/90010,P = 0.000) between GBP group and control group, but not in decreased HDL and increased triglyceride (TG). Logistic regression analysis showed that gender, age, BMI, SBP, DBP and LDL were independently associated with GBP. People with increases LDL had 1.488 times higher risk for GBP formation. Trend of dyslipidemias prevalence change according to age was similar with that of GBP. Increased LDL group had higher GBP prevalence rate (9.0% vs 7.2%, p = 0.000), multiple GBP proportion (2.9% vs 2.2%, p = 0.000) and large polyps with diameter ≥ 5 mm proportion (3.7% vs 2.6%,p = 0.000). Comparing with control group, there was higher proportion of large polyps in Increased TC group (3.2% vs 2.7%, p = 0.019) and decreased HDL group (3.0% vs 2.6%,p = 0.028). Increased TG group had not difference with its control group in GBP prevalence, number or size. Conclusion: Dyslipidemias is associated with GBP formation. Dyslipidemias change according to age is consistent with GBP prevalence. Increased LDL was a more related risk factor rather than decreased HDL, increased TC or TG. Keywords: Risk factors, Gallbladder polyps, Dyslipidemias, Chinese population, Beijing

Although worm-like micelles were invented 35 years ago, its formation pathway remains unclear. Inspired by the fact that a single molecular level experiment could provide meaningful and additional information, especially in a heterogeneous subpopulation, herein, we present a single molecular level study on the formation of wormlike micelles by cetyltrimethylammonium bromide (CTAB) and sodium salicylate (NaSal) in water. Our results indicated a coexistence of normal spherical micelles along with a big wormlike micelle in its formation path. More interestingly, we have two unique insights into the formation mechanism, which are inaccessible in ensemble averaged experiments: (i) at extremely low concentrations of the surfactant, [CTAB]/[NaSal] ∼ 0.06, the wormlike micelle attains the highest size; and (ii) the relative concentration of wormlike micelles is highest when [CTAB]/[NaSal] ∼ 2.

Background Borderline personality disorder (BPD) usually emerges during adolescence and is associated with severe morbidity. Individuals with BPD are also vulnerable to develop eating disorders as well as mood disorders. Objective To study the prevalence of borderline personality and its association with binge-eating and bipolar spectrum disorder in college students. Methods A questionnaire based survey was conducted on a convenience sample of 500 college students (>18 years of age) in medical and engineering campus. Participants were screened on self-report measures including McLean Screening Instrument for BPD (MSI-BPD), Mood Disorder Questionnaire (MDQ) and Binge-Eating Disorder Screener (BEDS-7) for BPD, bipolar spectrum disorder (BSD) and binge-eating disorder (BED), respectively. Results The prevalence of BPD was 76 (15.2%, 95% CI 12.3 to 18.6), BSD was 43 (8.6%, 95% CI 6.4 to 11.5) and BED was 48 (9.6%, 95% CI 7.2 to 12.6). There was a significantly higher proportion of BSD (OR 23.6, 95% CI 11.3 to 49.3) and BED (OR 3.4, 95% CI 1.8 to 6.5) among those with BPD than those without. Conclusions BPD was found in 15% of adolescents and they have higher proportion of BED and BSD. Early identification may help in planning early intervention strategies to reduce associated morbidity.

In recent years, there has been increasing interest in daily-use chemical products providing a pleasant scent. The added fragrance molecules may induce microstructural transitions of surfactant aggregates, which further affect the physical and chemical properties of the products. Here, the effects of four types of aromatic alcohols (cinnamyl alcohol, phenyl ethanol, phenyl methanol and anisyl alcohol) on cetyltrimethylammonium bromide (CTAB)/KBr aggregates were studied. The combined results from rheology, dynamic light scattering, and transmission electron microscopy measurements showed that cinnamyl alcohol induced significant micellar growth, while increases in micellar growth were less obvious for the other aromatic alcohols. The changes in the interfacial molarities of water, aromatic alcohol, and bromide ions during such transitions were studied using the chemical trapping method. Transitions resulting from added cinnamyl alcohol were accompanied by significant declines in interfacial water and bromide ion molarities, and a rise in interfacial alcohol molarity. The marked decrease in interfacial water molarity was not observed in previous studies of the octanol induced formation of wormlike micelles and vesicles, indicating that a different mechanism was presented in the current system. Nuclear magnetic resonance investigation showed that π–π stacking between cinnamyl alcohols, but not cation–π interactions between alcohols and CTAB headgroups, facilitated the tight packing of alcohol molecules in CTAB aggregates and the repulsion of water from the interfacial region. The current study may provide a theoretical basis for the morphological regulation of surfactant aggregates in the presence of additives.

Hypothesis The previously observed effects of nonpolar additives on the scission energy and rheological properties of surfactant wormlike micelles can be explained in terms of the spatial distribution of the additive within the micelles. The dependence of the scission energy with the molecular organization of the system can be analyzed with a molecular theory capable of describing the thermodynamics and structure of the micelles. Theory A new theoretical method to determine the scission energy of surfactant wormlike micelles is introduced. This methodology is based on a molecular theory that explicitly considers molecular details of all components of the micelles, and their inter- and intramolecular interactions without the use of fitting and/or empirical macroscopic parameters. Findings The predicted effects of the concentration, molecular structure and hydrophobicity of the additive on the scission energy of cetyltrimethylammonium bromide (CTAB) wormlike micelles are found to be in qualitative agreement with previous experimental observations. In particular, our theory captures the decrease of micellar length with increasing content of highly hydrophobic additives and the non-monotonic dependence of the viscosity with additive hydrophobicity. The latter effect arises because highly and mildly hydrophobic additives affect the scission energy of wormlike micelles via markedly different molecular mechanisms.

In this work, we characterize the micellization and morphology transition induced in aqueous cetyltrimethylammonium bromide (CTAB) solution by the addition of the antioxidant propyl gallate (PG) using tensiometry, rheology, and small-angle neutron scattering (SANS) techniques combined with the molecular dynamics (MD) simulation approach. The adsorption of CTAB at the air-water interface in the presence of varying [PG] revealed a progressive decrease in the critical micelle concentration (CMC), while the changes in different interfacial parameters indicated enhancement of the hydrophobicity induced by PG in the CTAB micellar system. The dynamic rheology behavior indicated an increase in the flow viscosity (η) as a function of [PG]. Moreover, the rheological components (storage modulus, G', and loss modulus, G″) depicted the viscoelastic features. SANS measurements depicted the existence of ellipsoidal micelles with varying sizes and aggregation number (Nagg) as a function of [PG] and temperature. Computational simulation performed using density functional theory (DFT) calculations and molecular dynamics (MD) provided an insight into the atomic composition of the examined system. The molecular electrostatic potential (MEP) analysis depicted a close proximity of CTAB, i.e., emphasized favorable interactions between the quaternary nitrogen of CTAB and the hydroxyl group of the PG monomer, further validated by the two-dimensional nuclear Overhauser enhancement spectroscopy (2D-NOESY), which showed the penetration of PG inside the CTAB micelles. In addition, various dynamic properties, viz., the radial distribution function (RDF), the radius of gyration (Rg), and solvent-accessible surface area (SASA), showed a significant microstructural evolution of the ellipsoidal micelles in the examined CTAB-PG system, where the changes in the micellar morphology with a more elongated hydrophobic chain and the increased Rg and SASA values indicated the notable intercalation of PG in the CTAB micelles.

Objective Catheter-associated urinary tract infection (CAUTI) is a common nosocomial infection. However, there has been no randomized control trial (RCT) comparing the efficacy of periurethral cleaning solutions for reducing CAUTI. This study aimed to compare the efficacy of normal saline solution (NSS) and Savlon solution. Methods A non-inferiority cross-over RCT was conducted to compare the 2 solutions by the incidence of significant bacteriuria (SB) on day 5 after Foley catheterization. Patients admitted to a tertiary referral hospital from June 2018 to August 2019 participated in the study. The acceptable prespecified non-inferiority margin was 10%. Results There were 265 and 275 patients in the NSS and Savlon groups, respectively. The incidence of CAUTI was 2.65/1000 catheter-days, and the median duration of catheterization was 5 days (IQR 4, 7). There was no significant difference between the incidence of SB in the NSS and Savlon groups, as indicated by the adjusted difference of 0.6 (95% CI: -3.1-4.2). Conclusion This study was the first RCT in patients from multiple hospital units to compare the efficacy of the 2 solutions in the periurethral cleaning process. The study demonstrated non-inferiority of NSS to Savlon solution. Thai Clinical Trials Registry Study ID TCTR20180518001.

Gold nanorods (GNRs) have gained interest as a promising carrier for antibiotics. Gold nanorods may reduce the development of antimicrobial resistance in certain microbial species. Although applications of GNRs to mitigate oral biofilms are under development, their use in the oral cavity may have adverse effects. The aim of this study was to evaluate the potential penetration of GNRs into the tooth enamel structure using confocal laser scanning microscopy (CLSM) and scanning transmission electron microscopy (STEM).Our approach was to synthesize GNRs with cationic [cetyltrimethylammoniumbromide (CTAB)] and anionic [11-mercaptoundecanoic acid (MUDA)] surface coatings. We hypothesized that penetration would be surface coating dependent.Regardless of the chemical modification of the GNRs of size ∼20 nm × 8 nm, exposure of these materials did not result in superficial penetration into the enamel.Within the limitations of this study, it is concluded that the use of CLSM and STEM is a feasible approach to investigate the penetration of nanomaterials into the tooth structure.Exposure of the enamel with chemically modified GNRs of size ∼20 nm × 8 nm will not result in superficial penetration into the enamel.

Catanionic vesicles are emerging interesting structures for bioapplications. They self-generate by a pairing of oppositely charged ionic surfactants that assemble into hollow structures. Specifically, the anionic-cationic surfactant pair assumes a double-tailed zwitterionic behavior. In this work, the multilamellar-to-unilamellar thermal transition of several mixed aqueous systems, with a slight excess of the anionic one, were investigated. Interestingly, it was found that the anionic counterion underwent a dissociation as a consequence of a temperature increase, leading to the mentioned thermal transition. The present work proposed the spectroscopic techniques, specifically multinuclear NMR and PGSTE (pulsed gradient stimulated echo), as a key tool to study such systems, with high accuracy and effectiveness, while requiring a small amount of the sample. The results presented herein evidence encouraging perspectives, forecasting the application of the studied vesicular nanoreservoirs, for e.g., drug delivery.

The increasing impact of metallic nanoparticles in life sciences has stimulated the development of new techniques and multiple improvements of the existing methods of manufacturing nanoparticles with tailored properties. Nanoparticles can be synthesized through a variety of physical and chemical methods. The choice of preparation procedure will depend on the physical and chemical characteristics required on the final product, such as size, dispersion, chemical miscibility, optical properties, among others. Here we review basic practical procedures used for the preparation of protected and unprotected metallic nanoparticles and describe a number of experimental procedures based on colloidal chemistry methods. These include gold nanoparticle synthesis by reduction with trisodium citrate, ascorbic acid, or sugars in aqueous phase; nanoparticle passivation with alkanethiols, cetyltrimethylammonium bromide, or bovin serum albumin. We also describe microwave-assisted synthesis, nanoparticle synthesis in ethylene glycol, template-assisted synthesis with dendrimers and briefly describe how to control nanoparticle shape (star-shaped and branched nanoparticles).

International audience; Applications of asymmetrical flow field-flow fractionation (AF4) continue to expand rapidly in the fields of nanotechnology and biotechnology. In particular, AF4 has proven valuable for the separation and analysis of particles, biomolecular species (e.g., proteins, bacteria) and polymers (natural and synthetic), ranging in size from a few nanometers to several micrometers. The separation of non-spheroidal structures (e.g., rods, tubes, etc.) with primary dimensions in the nanometer regime, is a particularly challenging application deserving of greater study and consideration. The goal of the present study was to advance current understanding of the mechanism of separation of rod-like nano-objects in the AF4 channel. To achieve this, we have systematically investigated a series of commercially available cetyltrimethylammonium bromide stabilized gold nanorods (AuNRs), with aspect ratios from 1.7 to 10. Results show clearly that the retention time is principally dependent on the translational diffusion coefficient of the AuNRs. Equations used to calculate translational and rotational diffusion coefficients (cylinder and prolate ellipsoid models) yield similarly good fits to experimental data. Well characterized gold nanorods (length and diameter by transmission electron microscopy) can be used as calibrants for AF4 measurements allowing one to determine the aspect ratio of nanorod samples based on their retention times.

An Electrochemical nonenzymatic sensor was fabricated based on cetyltrimethylammonium bromide (CTAB), chitosan (Chit) and carbon nanotube (CNT) nanocomposite modified glassy carbon electrode. Scanning electron microscopy morphology showed that CNT well dispersed in Chit, while CTAB micelles assembled on the surface of the CNT. Due to the synergetic effect of the three components, excellent electrocatalytic activity towards the oxidation of hydroxymethanesulfinate (HMS) in the presence of both fixed and varying concentrations of sulfite was achieved. An enhanced peak current and expanded peak-to-peak separation between HMS and sulfite was observed. Differential pulse voltammetry was applied to quantify HMS and the calibration curve was linear in the range of 30-800 µM with a detection limit of 9.6 µM. The method was applied in the determination of HMS in food samples collected from local markets, and the results have no remarkable difference with the reference HPLC method.

We report on a chemiluminescence (CL) system based on simultaneous enhancing effect of Si-doped carbon dots (Si-CDs) and cetyltrimethylammonium bromide (CTAB) on HCO3−-H2O2 reaction. The possible CL mechanism is investigated and discussed. Excited-state Si-CDs was found to be the final emitting species, which are probably produced via electron and hole injection by oxy-radicals. The effect of several other heteroatom-doped CDs and undoped CDs was also investigated and compared with Si-CDs. Furthermore, it was found that catecholamines such as dopamine, adrenaline and noradrenaline remarkably diminish the CL intensity of Si-CD-HCO3−-H2O2-CTAB system. By taking advantage of this fact, a sensitive probe was designed for determination of dopamine, adrenaline and noradrenaline with a limit of detection of 0.07, 0.60 and 0.01 μM, respectively. The method was applied to the determination of catecholamines in human plasma samples.

In this work, magnetic graphene/mesoporous silica composites with carbon-functionalized pore-walls (denoted as MG@mSiO2-C composites) were synthesized and applied as restricted access matrix solid phase extraction (RAM-SPE) adsorbents for the determination of miglitol and voglibose in rat plasma by LC-MS/MS. The MG@mSiO2-C composites were synthesized by using the template (Cetyltrimethyl Ammonium Bromide, CTAB) as carbon source with sulfuric acid pretreated. The obtained nano-composites were proven to have many unique properties such as large specific surface area of 277.1 cm2 g−1, uniform mesopores with average pore size of 3.35 nm, and carbon-functionalized pore-walls. Taking advantage of the hydrophilic interaction between carbon and glycans, α-glucosidase inhibitors (miglitol and voglibose) could be directly extracted from rat plasma with no need of other pre-treatment procedures. The SPE conditions such as the adsorbent amount, elution solvent type, adsorption time and elution time were optimized. For both miglitol and voglibose, good linearities of 10–2000 ng mL−1 were obtained with determination coefficients (R2) > 0.99. The intra-day and inter-day RSDs were 3.3–6.9% (n = 6) and 6.0–8.0% (n = 6), respectively. The recoveries were in the range of 99.9–100.4% and the sensitivities were as low as 2–2.5 ng mL−1 (LOD). This MG@mSiO2-C composites-based RAM-SPE method offers high extraction efficiency for the determination of α-glucosidase inhibitor in plasma.

This study presents the results of the electrochemical degradation of the emulsifier cetrimonium chloride (CTAC) on a boron-doped diamond (BDD) anode under different current densities and flow rates. Higher values of these parameters result in a more rapid removal. Nevertheless, operation at low current reduces the required applied charge and increases the chemical oxygen demand (COD) removal efficiency, as there is less development of ineffective parasitic reactions. On the other hand, high flow rates reduce the required volumetric applied charge and increase the COD removal current efficiency. In order to assist and enrich the study, an economic analysis has been performed. For short expected plant lifespans, operation at low current is advantageous due to the lower investment required, whereas for longer expected lifespans, the operational costs make the lower current densities less costly. High flow rates are always advantageous from a financial point of view.

Diastolic dysfunction (DD) is increasingly common. However, its metabolic determinants are poorly known. This study aims to determine which metabolic and inflammatory features predict DD in initially healthy adults. We prospectively analyzed the association between metabolic features and DD in 728 initially healthy adults aged 30–60 from Eastern France enrolled in the STANISLAS population-based cohort. Clinical and biological cardiovascular features were collected at baseline (1994–1995). DD was assessed twenty years later (2011–2016) by echocardiography using current international guidelines. For replication purposes, 1463 subjects from the Malmo Preventive Project cohort were analyzed. In the STANISLAS cohort, 191 subjects (26.2%) developed DD. In age-sex-adjusted logistic models, significant predictors of DD were body mass index (BMI, odds ratio for 1-standard-deviation increase (OR) 1.28, 95% CI 1.08–1.52), waist circumference (WC, OR 1.48, 95% CI 1.18–1.84), waist-hip ratio (OR 1.53, 95% CI 1.16–2.02), systolic blood pressure (OR 1.19, 95% CI 1.00–1.43) and triglycerides (TG, OR 1.18, 95% CI 1.00–1.40). Subjects with elevated WC (> 80th percentile) and TG (> 50th percentile) had a twofold higher DD risk (age-sex-adjusted odds ratio 2.00, 95% CI 1.20–3.31, P = 0.008), whereas no such interplay was observed for BMI. In the Malmo cohort, BMI was similarly associated with DD; participants with both elevated BMI and TG were at higher DD risk (age-sex-adjusted odds ratio 1.61, 95% CI 1.18–2.20, P = 0.002). Subjects with elevated WC and TG may have a higher long-term DD risk. Prevention targeting visceral obesity may help reduce the incidence of DD.

The current work aims to explore the thermodynamic and conformational aspects for the binding of fluoroquinolone antibacterial drug, levofloxacin (LFC), with bovine serum albumin (BSA) using calorimetric, spectroscopic (UV-visible, fluorescence, circular dichroism, and 1H NMR), dynamic light scattering (DLS) and computational methods (molecular docking). The binding of LFC with BSA at two sequential sites with higher affinity (~103M-1) at the first site has been explored by calorimetry whereas the binding at a single site with affinity of the order of ~104M-1 has been observed from fluorescence spectroscopy. The calorimetric study in the presence of additives along with docking analysis reveals the significant role of electrostatic, hydrogen bonding, and hydrophobic interactions in the association process. The slight conformational changes in protein as well as the changes in the water network structure around the binding cavity of protein have been observed from spectroscopic and DLS measurements. The LFC induced quenching of BSA fluorescence was observed to be initiated mainly through the static quenching process and this suggests the formation of ground state LFC-BSA association complex. The stronger interactions of LFC in the cavity of Sudlow site I (subdomain IIA) of protein have been explored from site marker calorimetric and molecular docking study.

The mechanism and detailed processes of DNA compaction and decompaction are essential for the life activities, as well as for the researches in the molecular biology, genetics and biomedicine. The compaction of two kinds of DNA molecules caused by Cetyltrimethyl Ammonium Bromide (CTAB) and their decompaction induced with sodium dodecyl sulfate (SDS) or excessive amount of CTAB have been investigated with multiple perspectives such as the UV-VIS spectrophotometry, dynamic light scattering, and zeta potential. The compaction phenomenon of DNA can easily be observed when the CTAB combines with the DNA, not just when the molar ratio QCTAB/QDNA is approximately equal to 1 as the conventional recognition, but also when QCTAB/QDNA

A stacking technique is proposed to improve the poor detection sensitivity of capillary zone electrophoresis (CZE) with UV detection. A long injection (e.g., 12.4 cm plug) of model anionic analytes prepared in a dilute solution of hexadecyltrimethylammonium bromide (CTAB) was enriched 26–34-x (compared to a typical or 2.1 mm sample injection) via the injection of a micellar solution of sodium dodecyl sulfate (SDS) prior to CZE separation. During sample injection, the CTAB formed a stationary pseudophase coating, which trapped the analytes at the inner walls of a fused silica capillary. The SDS micelles then released the CTAB admicelles via the formation of solution CTAB-SDS catanionic micelles during SDS plug injection and voltage application. As the SDS micelles moved through the sample zone, the formation of the catanionic micelles then released and accumulated the analytes at the front of the injected SDS zone. The stacking technique is called electroosmotic flow (EOF) assisted pseudophase to pseudophase microextraction because the EOF was essential for the formation of CTAB-SDS catanionic micelles for microextraction. Also, the CTAB and SDS aggregates are both pseudophases, which were used to retain and release the analytes from the capillary wall, respectively.

Introduction The aim of this study was to determine the antimicrobial activity of mixed alkaline tetrasodium EDTA (EDTANa4)/sodium hypochlorite (NaOCl) solutions with and without the addition of cetrimide (CTR) against Enterococcus faecalis biofilms. Methods The antimicrobial solutions were evaluated on a 3-week biofilm of E. faecalis grown on radicular dentin blocks. The irrigating solutions were 2.5% NaOCl group, 20% EDTANa4 group, 10% EDTANa4 group, 2.5% NaOCl/10% EDTANa4 group, 2.5% NaOCl/5% EDTANa4 group, 2.5% NaOCl/10% EDTANa4/0.2% CTR group, 2.5% NaOCl/5% EDTANa4/0.2% CTR group, and 0.9% saline solution group. Cell viability was determined by adenosine triphosphate assay, and culture techniques were used to determine colony-forming unit (CFU) counts. In groups with positive growth, the Pearson linear correlation coefficient r (−1 ≤ r ≤ 1) between relative light units (RLUs) and log10 (CFUs + 1) was calculated. The results of the bioluminescence adenosine triphosphate assay and CFUs of the groups were analyzed by means of analysis of variance and the Duncan test. Results There was Pearson correlation between RLUs and log10 (CFUs + 1). A similar reduction of RLUs in all NaOCl groups was seen, giving statistical differences with respect to the control. In the NaOCl groups there was no bacterial growth. The lowest antimicrobial efficacy was found for the EDTANa4 groups. Conclusions Mixed alkaline EDTANa4/NaOCl solutions with and without the addition of CTR do not interfere with the antimicrobial activity of NaOCl.

Microfluidic Y-junctions were used to study mechanical mechanisms involved in pig gastric mucin (PGM) plug removal from within one of two bifurcation branches with 2-phase air and liquid flow. Water control experiments showed moderate plug removal due to shear from vortex formation in the blockage branch and suggest a PGM yield stress of 35Pa, as determined by computational fluid dynamics. Addition of hexadecyltrimethylammonium bromide (CTAB) surfactant improved clearing effectiveness due to bubbling in 1mm diameter channels and foaming in 500μm diameter channels. Plug removal mechanisms have been identified as vortex shear, bubble scouring, and then foam scouring as air flow rate is increased with constant liquid flow. The onset of bubbling and foaming is attributed to a flow regime transition from slug to slug-annular. Flow rates explored for 1mm channels are typically experienced by bronchioles in generations 8 and 9 of lungs. Results have implications on treatment of cystic fibrosis and other lung diseases.

The synergy effects of hydrodynamic conditions and cetyl trimethylammonium bromide (CTAB) on the distribution behavior of bisphenol A (BPA) in sediment have been investigated using particle entrainment simulator (PES) and water bath shaker. The results showed that when the concentration of CTAB is below its critical micelle concentration (CMC), the shear stress has almost no effect on the equilibrium sorption amount of BPA on sediment, which is mainly related to the surfactant concentration. The sorption rates in the rapid sorption phase increased with increasing CTAB content and shear stress. When the concentration of CTAB exceeded CMC, equilibrium sorption amount and corresponding time of BPA on sediment both decreased with increasing shear stress, mainly because the hydrodynamic conditions enhanced the solubilization ability of the surfactant on BPA. It was also found that the sorption rate constant showed a linear increase trend with increasing shear stress.

Intrinsically disordered proteins (IDPs) are under intense analysis due to their structural flexibility and importance in biological functions. Minuscule modulation in the microenvironment induces significant conformational changes in IDPs, and these non-native conformations of the IDPs often induce aggregation and cause cell death. Changes in the membrane composition often change the microenvironment, which promote conformational change and aggregation of IDPs. κ-Casein, an important milk protein, belongs to the class of IDPs containing net negative charges. In this present work, we have studied the interaction of κ-casein with cetyltrimethyl ammonium bromide (CTAB), a positively charged surfactant, utilizing various steady state fluorescence, time-resolved fluorescence and circular dichroism spectroscopy. Our results clearly indicate that κ-casein undergoes at least two conformational transitions in presence of various concentrations of CTAB. The intrinsically disordered κ-casein assumes a partially folded conformation at lower concentration of CTAB, which adopts an unstructured conformation at higher concentration of CTAB. The partially folded conformation of κ-casein at a lower CTAB concentration might be induced by the favorable electrostatic interaction between the positively charged surfactant headgroup and net negative charges of the protein, whereas surfactant nature of CTAB is being pronounced at higher concentration of CTAB.

Gold nanoparticles having a rod-like morphology are regularly investigated as potential nano-therapeutic materials owing to their interesting optical properties, facile surface modification, tunable aspect ratios, and low cytotoxicity. Gold nanorods are historically prepared starting from HAuCl4 in the presence of ascorbic acid, silver nitrate, and the growth directing surfactant, cetyltrimethylammonium bromide (CTAB). While CTAB drives a rod-like morphology, it is known to be cytotoxic. This inherent toxicity is often addressed by removing or masking the native CTAB surfactant present on the nanorod surface. In the current study we have investigated a less toxic alternative surfactant, dodecylethyldimethylammonium bromide (C12EDMAB), as a possible growth-directing agent. Monodisperse gold nanorods having various lengths have been grown in the presence of C12EDMAB. SEM data suggests that the quantity of C12EDMAB on the rod's surface is much higher than that of CTAB. Toxicity assays were performed on HEp-2 and A549 cells showing lower toxicity at select concentrations for C12EDMAB coated rods.

Triple-negative breast cancers (TNBC) are aggressive cancers, which do not control by hormonal therapy or therapies that target HER-2 receptors. Curcumin (Cur) has shown cytotoxic effects in multiple cancer cell lines. However, its medical uses remain limited due to low aqueous solubility and poor bioavailability. Therefore, present study was aimed to fabricate the small positive charge curcumin nanoparticles (CN) by nanoprecipitation methods using PLGA and CTAB, and to evaluate its anticancer efficacy and underlying the mechanism in triple negative breast cancer cell lines (MDA-MB-231 cells). In in-vitro drug release assay, Cur was released from CN by flicking diffusion and anomalous transport process. CN showed a higher cellular incorporation than free Cur resulted in higher cytotoxicity. Checking the anticancer activity at the molecular level, Cur has shown to induce the reactive oxygen species production that subsequently causes the DNA damage and resulting in p38-MAPK activation. The p38-MAPK induce the expression of p16/INKK4a, p21/waf1/cip1 and p53 resulting in a reduction in the level of CDK2, CDK4, cyclin D1 and cyclin E and subsequently cell cycle arrest at G1/S and G2/M phase. It also reduces the expression of DNA repair gene, i.e. BRCA1, BRCA2, Rad51, Rad50, Mre11 and NBS1 resulting in apoptosis induction due to persistent DNA damage. This study presents an effective delivery of curcumin in TNBC cancer cells and it could open the new frontiers in clinical cancer chemotherapy.

Surfactant Modified Zeolite (SMZ) represents a versatile, cost-effective permeable reactive material, capable of treating multiple classes of contaminants. The potential for HDTMA-Br, a cationic surfactant commonly used to modify zeolite, to desorb from the zeolite surface has been identified as a potential issue for the ongoing use of SMZ in water remediation contexts. This paper investigates the toxicity of HDTMA-Br towards enteric virus surrogates, F-RNA bacteriophage MS2 and E. coli, Bacillus subtilis, and soil microflora. The concentration of surfactant desorbing from SMZ was quantified through a bioassay using E. coli. Results showed HDTMA-Br concentrations of ≥10-5M were toxic to MS2, ≥10-4M were toxic to E. coli and ≥10-6M were toxic to B. subtilis. No toxic relationship was established between HDTMA-Br and soil microflora. Desorption of ≥10-4M of HDTMA-Br was shown for the two SMZ samples under the mixing conditions used. Effects of this surfactant on total soil microflora were ambiguous since no toxic relationship could be established, however, HDTMA-Br, at concentrations desorbing from SMZ, were shown to impact the soil bacterium B. subtilis. Further research is required to determine the effect of this surfactant on microbial populations and species diversity in soils.

Clinoptilolite nano-particles (CNP) were modified by hexadecyltrimethyl ammonium bromide surfactant (HDTMA) and dithizone (DZ). The modified zeolite was then used for the modification of carbon paste electrode (CPE). The resulted CNP-HDTMA-DZ-CPE was finally used for the voltammetric determination of Sn(II) in aqueous solution. The raw and modified CNP was characterized by SEM-EDX, BET, TG-DTG and FTIR techniques. The best voltammetric response was obtained in 0.1molL-1 NaNO3+HCl at pH 2.2 as supporting electrolyte. The electrode showed a linear response in the concentration range of 1×10-8 to 1×10-2molL-1Sn(II) with LOD about 9×10-9molL-1Sn(II). The electrode showed good selectivity and applicability for the determination of Sn(II) in real samples such as river water, an steel company wastewater, tomato paste and a canned tuna fish.

In this study, we exploited a one-pot method to fabricate cetyltrimethylammonium bromide (CTAB)-loaded Janus silver mesoporous silica nanoparticles (Janus Ag-MSNs@CTAB). These bullet-like nanoparticles had a silver head (80nm in diameter) attached to a mesoporous silica stick (200-300nm in length). The CTAB-loaded nanobullets exhibited a marked affinity for the bacterial cell surface and the simultaneously sustained release behavior of CTAB and silver ions. The minimum inhibitory concentrations (MIC) of Janus Ag-MSNs@CTAB were determined to be 10μg/mL and 20μg/mL for E. coli and S. Aureus, respectively. Importantly, Janus Ag-MSNs@CTAB provided a single-particle nanoplatform with a synergistic effect against both Gram-positive and Gram-negative bacteria. A thorough investigation indicated that CTAB induces a dramatic loss of bacterial membrane integrity, which facilitated the internalization of silver. This report described an efficient and convenient method of synthesizing Janus silver mesoporous silica nanoparticles, and these nanobullets show promising potential in biomedical applications.

Reverse micellar extraction is an efficient and economical alternative for protein purification. In this study, microbial transglutaminase (MTGase) from crude materials was purified using reverse micellar extraction, and the molecular interaction mechanism in reverse micellar extraction of MTGase was explored. By using a molecular simulation study, the interaction mechanism of forward extraction was investigated. The molecular simulation results reveal the interaction of MTGase-water-surfactant is the major driving force for the forward extraction. Further, the effect of ionic strength on molecular interactions in backward extraction was investigated using 1H low-field nuclear magnetic resonance (LF-NMR) and circular dichroism (CD) spectra. In backward extraction, the interactions between water and the other two molecules (MTGase and surfactant molecules) are enhanced while the interactions between target molecules (MTGase) and the other two molecules (water and surfactant molecules) are weakened as the ionic strength increases. Moreover, the effect of size exclusion on backward extraction was also investigated. The results demonstrate size exclusion has limit effect at high ionic strength, and the weakened interaction of MTGase-water-surfactant is the main reason causing the release of the target molecules in backward extraction. This work might provide valuable reference to the MTGase purification and downstream processing.

In this study, a tiny coiled cupper wire as a novel solid phase microextraction (SPME) fiber was coated with mesoporous silica/cetyltrimethylammonium bromide (MCM-41/CTAB) as an adsorbent by electrochemically assisted self-assembly method and used for the preconcentration of polycyclic aromatic hydrocarbons (PAHs) as model analytes prior to chromatographic determination. Deposition of MCM-41/CTAB on the coiled SPME (C-SPME) fiber resulted in easily controlled and reproducible SPME coatings. Non-calcined MCM-41/CTAB on C-SPME plays a key role in the adsorption of PAHs. Under the optimized experimental conditions, low detection limits (36-1220pgL-1), and wide linear dynamic ranges (R2>0.98) were achieved in the range of 0.25-25,000, 0.12-15,000, 0.56-32,000, 4.1-100,000ngL-1 for phenanthrene, anthracene, fluoranthene and pyrene respectively. The reusability of proposed fiber as well as relative standard deviations for repetitive determination of the target analytes was evaluated. The proposed method was successfully applied for determination of PAHs in several real samples.

In this study, a different method was applied for boron removal by using vermiculite as the adsorbent. Vermiculite, which was used in the experiments, was not modified with adsorption agents before boron adsorption using a separate process. Hexadecyltrimethylammonium bromide (HDTMA) and Gallic acid (GA) were used as adsorption agents for vermiculite by maintaining the solid/liquid ratio at 12.5 g/L. HDTMA/GA concentration, contact time, pH, initial boron concentration, inert electrolyte and temperature effects on boron adsorption were analyzed. A three-factor, three-level Box-Behnken design model combined with response surface method (RSM) was employed to examine and optimize process variables for boron adsorption from aqueous solution by vermiculite using HDTMA and GA. Solution pH (2–12), temperature (25–60 °C) and initial boron concentration (50–8,000 mg/L) were chosen as independent variables and coded x1, x2 and x3 at three levels (−1, 0 and 1). Analysis of variance was used to test the significance of variables and their interactions with 95% confidence limit (α = 0.05). According to the regression coefficients, a second-order empirical equation was evaluated between the adsorption capacity (qi) and the coded variables tested (xi). Optimum values of the variables were also evaluated for maximum boron adsorption by vermiculite-HDTMA (HDTMA-Verm) and vermiculite-GA (GA-Verm).

Isolation of nucleic acids from Chlorella is difficult, given the chemically complex nature of their cell walls and variable production of metabolites. Immobilization of microalgae in polymers adds additional difficulty. Here, we modified, amended, and standardized methods for isolation of nucleic acids and compared the yield of DNA and RNA from free-living and encapsulated microalgae C. sorokiniana. Isolation of nucleic acids from immobilized cells required two steps in dissolving the alginate matrix, releasing the cells, and mechanical disruption with glass beads. For DNA extraction, we used modified versions of a commercial kit along with the hexadecyltrimethylammonium bromide (CTAB) method. For RNA extraction, we used the commercial TRI reagent procedure and the CTAB-dithiotreitol method. Quantity and quality of nucleic acids in extracts varied with growth conditions, isolation procedures, and time of incubation of the original culture. There were consistently higher amounts of DNA and RNA in extracts from immobilized cells. Quantitatively, the modified procedure with the commercial Promega kit was the most reliable procedure for isolating DNA and a modified commercial TRI reagent procedure was the choice for isolating RNA. All four procedures eliminated proteins efficiently and had low levels of contamination from residual polysaccharides from the matrices and/or metabolites naturally produced by the microalgae. All DNA extracts under both growth conditions, time of incubation, and two isolation methods successfully amplified the 18S ribosomal RNA by PCR and quantitative reverse transcription (RT-qPCR).

A green type composite biosorbent composed of pine, oak, hornbeam, and fir sawdust biomasses modified with cetyltrimethylammonium bromide (CTAB) was first used for biosorption of an unsafe synthetic food dye, Food Green 3 from liquid medium in this study. Batch studies were carried by observing the effects of pH, dye concentration, biosorbent amount, and contact time. The equilibrium data were analyzed using Freundlich, Langmuir, and Dubinin-Radushkevich equations. Freundlich model gave a better conformity than other equations. The maximum dye removal potential of biosorbent was found to be 36.6 mg/g based on Langmuir isotherm. The pseudo-first-order, pseudo-second-order, Elovich, and intra-particle diffusion models were applied to clarify the process kinetics of biosorption. The mechanism studies suggested the biosorption process obeying Elovich kinetics and involving pore diffusion. The estimated values of biosorption free energy from Dubinin-Radushkevich isotherm (E value

Natural rubber Latex (Lax) is a colloidal dispersion of polymer particles in liquid and shows good biodegradable, biocompatibility, and non-toxicity. Natural polymers are the most important materials used in food packaging, micro/nano-drug delivery, tissue engineering, agriculture, and coating. In the present study, natural compounds extracted from plant Lax were designed to function as drug carriers using various surfactants via emulation and solvent evaporation method. Calotropis gigantea belongs to the family Apocynaceae and has received considerable attention in modern medicine, ayurvedeic, siddha, and traditional medicine. Since, we were isolated biodegradable, non-toxic, and biocompatible materials as latex from Calotropis gigantea plant. The Lax was separated as per their solubility nature and it was designed as a carrier using surfactant namely; Sorbitanmonolaurate (Span-20), sodium lauryl sulfate (SLS), and cetyltrimethylammonium bromide (CTAB). The isolated compounds from Lax of Calotropis gigantea were analyzed using high-performance liquid chromatography. To confirm the encapsulation efficiency and in vitro drug release of the carriers, doxorubicin (DOX) was used as a model natural drug. The hybrid nanocarriers were successfully synthesized through simple solvent evaporation using three surfactants, and the morphology was characterized by SEM and TEM technique. The functionality and crystalline nature of the nanocarriers were confirmed using FTIR and XRD, respectively. Within 90min, the maximum amount of DOX was encapsulated in the carriers, and prolonged cumulative drug release by the nanocarriers was observed. The formulated natural carriers were found to have potentially effective cytotoxic effects on lung cancer cells.

This study described the preparation of silica-coated Au nanorods (AuNR/SiO2) in a colloidal solution, assessed their property of photothermal conversion, and investigated their ability to kill cancer cells using photothermal conversion. Au-seed nanoparticles were produced by reducing hydrogen tetrachloroaurate (HAuCl4) with sodium borohydride (NaBH4) in aqueous n-hexadecyltrimethylammonium bromide (CTAB) solution. AuNRs were then fabricated by reducing HAuCl4 and silver nitrate (AgNO3) with l-ascorbic acid in the aqueous CTAB solution in the presence of Au-seed nanoparticles. The as-prepared AuNRs were washed by a process composed mainly of centrifugation to remove the CTAB. The washed AuNRs were coated with silica by mixing the AuNR colloidal solution, an aqueous solution of (3-aminopropyl)trimethoxysilane, and tetraethylorthosilicate/ethanol solution with a water/ethanol solution. We found that the addition of AuNR/SiO2 in water, in mice, and in a culture medium with cancer cells, followed by irradiation with a laser, cause an increase in temperature, demonstrating that AuNR/SiO2 have the ability of photothermal conversion. In addition, the cancer cells in the culture medium were found to be killed due to the increase in temperature caused by the photothermal conversion.