Green-Synthesized Characterization, Antioxidant and Antibacterial Applications of CtAC/MNPs-Ag Nanocomposites.

The emergence of antibiotic resistance, caused by the improper use of antibiotics, is a significant challenge in combating infectious diseases, leading to millions of annual fatalities. The occurrence of antimicrobial side effects catalyzes the investigation of novel antimicrobial compounds and sources of drugs. Consequently, the research on biological activity that is conducted on plants, plant extracts, and compounds that are produced from plant components is of utmost significance. In this study, CtAC/MNPs were obtained by the reaction of activated carbon (AC) obtained from the fruits of the Celtis tournefortii (Ct) plant and magnetic nanoparticles (MNPs), and a CtAC/MNPs-Ag nanocomposite was synthesized by the reduction in silver ions added to the reaction. The synthesized CtAC/MNPs and CtAC/MNPs-Ag nanocomposites were analyzed spectroscopically (FTIR, XRD), microscopically (SEM, EDX), optically (DLS), electrochemically (zeta potential) and magnetically (VSM). The antibacterial activities of CtAC/MNPs and CtAC/MNPs-Ag nanocomposites against S. aureus and E. coli were investigated by microdilution method using minimal inhibitory concentration (MIC) and disk diffusion methods. Antioxidant activity study, including total phenolic content and DPPH and cuprac assays, revealed the remarkable effect of the CtAC/MNPs-Ag nanocomposite. This study has the advantages of obtaining CtAC/MNPs and CtAC/MNPs-Ag nanocomposites in a short time without requiring energy, and most importantly, the reaction takes place without using any toxic substances. In addition, according to the data obtained in the study, the CtAC/MNPs-Ag nanocomposite is thought to shed light on biomedical research.

Cationic surfactant-assisted foam fractionation enhances the removal of short-chain perfluoroalkyl substances from impacted water.

Several studies have demonstrated that air-bubbling and foam fractionation techniques can efficiently remove long-chain PFAS from contaminated water. However, removing short-chain PFAS is challenging due to its lower surface activity and inability to form self-assembly structures at the air-water interface. In this study, we tested various additives, including salts, surfactants, and polymers, to improve short-chain PFAS (e.g., perfluorobutanesulfonic acid (PFBS) and perfluorobutanoic acid (PFBA)) removal in non-foaming solutions using a bench-scale system. We found that in the presence of cetyltrimethylammonium chloride (CTAC) and salt, air-bubbling can significantly remove 0.5 µg L-1 of PFBS and PFBA in deionized water by >99% (15 min) and 81% (60 min), respectively. The decline of surface tension and the formation of thin foam-like layers during bubbling, controlled by the concentration of CTAC, significantly improved the removal of short-chain PFAS. Adding anionic and neutral surfactants showed no removal of short-chain PFAS during bubbling, suggesting the importance of the electrostatic interactions between short-chain PFAS and the cationic CTAC. We observed a 1:1 M ratio between CTAC and PFBS removed from the solution, suggesting the formation of ion pairs in the solution and enhancing the surface activity of the overall neutral (PFAS-CTAC) complex. A mass balance of the system revealed that the primary mechanism by which PFAS was removed from non-foaming waters was through aerosol generation (70-100%). Using the optimized condition, PFAS mixtures (short- and long-chain PFAS, including five recently regulated PFAS by USPEA, 2 nM each) in deionized water and natural groundwater were successfully removed to below detection (>99% removal; <2 ng L-1), except for PFBA (25-73% removal). These results provide an improved understanding of the mechanism by which PFAS is removed during foam fractionation and highlight the need for capturing aerosols enriched with PFAS to prevent secondary contamination.

Synthesis, Characterization and Potential Antimicrobial Activity of Selenium Nanoparticles Stabilized with Cetyltrimethylammonium Chloride.

Selenium nanoparticles (Se NPs) have a number of unique properties that determine the use of the resulting nanomaterials in various fields. The focus of this paper is the stabilization of Se NPs with cetyltrimethylammonium chloride (CTAC). Se NPs were obtained by chemical reduction in an aqueous medium. The influence of the concentration of precursors and synthesis conditions on the size of Se NPs and the process of micelle formation was established. Transmission electron microscopy was used to study the morphology of Se NPs. The influence of the pH of the medium and the concentration of ions in the sol on the stability of Se micelles was studied. According to the results of this study, the concentration of positively charged ions has a greater effect on the particle size in the positive Se NPs sol than in the negative Se NPs sol. The potential antibacterial and fungicidal properties of the samples were studied on Escherichia coli, Micrococcus luteus and Mucor. Concentrations of Se NPs stabilized with CTAC with potential bactericidal and fungicidal effects were discovered. Considering the revealed potential antimicrobial activity, the synthesized Se NPs-CTAC molecular complex can be further studied and applied in the development of veterinary drugs, pharmaceuticals, and cosmetics.

Calcium scoring in low-dose ungated chest CT scans using convolutional long-short term memory networks.

We aimed to develop a novel deep-learning based method for automatic coronary artery calcium (CAC) quantification in low-dose ungated computed tomography attenuation correction maps (CTAC). In this study, we used convolutional long-short -term memory deep neural network (conv-LSTM) to automatically derive coronary artery calcium score (CAC) from both standard CAC scans and low-dose ungated scans (CT-attenuation correction maps). We trained convLSTM to segment CAC using 9543 scans. A U-Net model was trained as a reference method. Both models were validated in the OrCaCs dataset (n=32) and in the held-out cohort (n=507) without prior coronary interventions who had CTAC standard CAC scan acquired contemporarily. Cohen's kappa coefficients and concordance matrices were used to assess agreement in four CAC score categories (very low: <10, low:10-100; moderate:101-400 and high >400). The median time to derive results on a central processing unit (CPU) was significantly shorter for the conv-LSTM model- 6.18s (inter quartile range [IQR]: 5.99, 6.3) than for UNet (10.1s, IQR: 9.82, 15.9s, p<0.0001). The memory consumption during training was much lower for our model (13.11Gb) in comparison with UNet (22.31 Gb). Conv-LSTM performed comparably to UNet in terms of agreement with expert annotations, but with significantly shorter inference times and lower memory consumption.

Facile and controllable synthesis of monodisperse gold nanoparticle bipyramid for electrochemical dopamine sensor.

We demonstrated potential features of gold nanoparticle bipyramid (AuNB) for an electrochemical biosensor. The facile synthesis method and controllable shape and size of the AuNB are achieved through the optimization of cetyltrimethylammonium chloride (CTAC) surfactant over citric acid (CA) ratio determining the control of typically spherical Au seed size and its transition into a penta-twinned crystal structure. We observe that the optimized ratio of CTAC and CA facilitates flocculation control in which Au seeds with size as tiny as ∼14.8 nm could be attained and finally transformed into AuNB structures with an average length of ∼55 nm with high reproducibility. To improve the electrochemical sensing performance of a screen-printed carbon electrode, surface modification with AuNB via distinctive linking procedures effectively enhanced the electroactive surface area by 40%. Carried out for the detection of dopamine, a neurotransmitter frequently linked to the risk of Parkinson's, Alzheimer's, and Huntington's diseases, the AuNB decorated-carbon electrode shows outstanding electrocatalytic activity that improves sensing performance, including high sensitivity, low detection limit, wide dynamic range, high selectivity against different analytes, such as ascorbic acid, uric acid and urea, and excellent reproducibility.

Evaluation of three methods for delineation and attenuation estimation of the sinus region in MR-based attenuation correction for brain PET-MR imaging.

BACKGROUND: Attenuation correction is crucial in quantitative positron emission tomography-magnetic resonance (PET-MRI) imaging. We evaluated three methods to improve the segmentation and modelling of the attenuation coefficients in the nasal sinus region. Two methods (cuboid and template method) included a MRI-CT conversion model for assigning the attenuation coefficients in the nasal sinus region, whereas one used fixed attenuation coefficient assignment (bulk method). METHODS: The study population consisted of data of 10 subjects which had undergone PET-CT and PET-MRI. PET images were reconstructed with and without time-of-flight (TOF) using CT-based attenuation correction (CTAC) as reference. Comparison was done visually, using DICE coefficients, correlation, analyzing attenuation coefficients, and quantitative analysis of PET and bias atlas images. RESULTS: The median DICE coefficients were 0.824, 0.853, 0.849 for the bulk, cuboid and template method, respectively. The median attenuation coefficients were 0.0841 cm-1, 0.0876 cm-1, 0.0861 cm-1 and 0.0852 cm-1, for CTAC, bulk, cuboid and template method, respectively. The cuboid and template methods showed error of less than 2.5% in attenuation coefficients. An increased correlation to CTAC was shown with the cuboid and template methods. In the regional analysis, improvement in at least 49% and 80% of VOI was seen with non-TOF and TOF imaging. All methods showed errors less than 2.5% in non-TOF and less than 2% in TOF reconstructions. CONCLUSIONS: We evaluated two proof-of-concept methods for improving quantitative accuracy in PET/MRI imaging and showed that bias can be further reduced by inclusion of TOF. Largest improvements were seen in the regions of olfactory bulb, Heschl's gyri, lingual gyrus and cerebellar vermis. However, the overall effect of inclusion of the sinus region as separate class in MRAC to PET quantification in the brain was considered modest.

Application of a Flexible PET Scanner Combined with 3 T MRI Using Non-local Means Reconstruction: Qualitative and Quantitative Comparison with Whole-Body PET/CT.

PURPOSE: Flexible positron emission tomography (fxPET) employing a non-local means reconstruction algorithm was designed to fit existing magnetic resonance imaging (MRI) systems. We aimed to compare the qualitative and quantitative performance of fxPET among fxPET with MR-based attenuation correction (MRAC), fxPET with CT-based attenuation correction (CTAC) using CT as a part of WB PET/CT, and whole-body (WB) PET/CT. PROCEDURES: Sixteen patients with suspected head and neck cancer underwent 2-deoxy-2-[18F]fluoro-D-glucose WB PET/CT scans, followed by fxPET and 3 T MRI scans. Phantom data were compared among the three datasets. For registration accuracy, we measured the distance between the center of the tumor determined by fxPET and that in MRI. We compared image quality, detection rates, and quantitative values including maximal standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and tumor-to-muscle ratio (TMR) among the three datasets. RESULTS: The phantom data in fxPET, except the percent contrast recoveries of 17-mm and 22-mm hot spheres, were inferior to those in WB PET/CT. The mean registration accuracy was 4.4 mm between fxPET using MRAC and MRI. The image quality was comparable between two fxPET datasets, but significantly inferior to WB PET/CT (p < 0.0001). In contrast, detection rates were comparable among the three datasets. SUVmax was significantly higher, and MTV and TLG were significantly lower in the two fxPET datasets compared with the WB PET/CT dataset (p < 0.005). There were no significant differences in SUVmax, MTV, and TLG between the two fxPET datasets or in TMR among the three datasets. All quantitative values had significantly positive correlations. CONCLUSIONS: Compared with WB PET/CT, the phantom data and image quality were inferior in fxPET. However, the results of the detection rates and quantitative values suggested the clinical feasibility of fxPET.

Alteration of Cell Membrane Permeability by Cetyltrimethylammonium Chloride Induces Cell Death in Clinically Important Candida Species.

The increased incidence of healthcare-related Candida infection has necessitated the use of effective disinfectants/antiseptics in healthcare settings as a preventive measure to decontaminate the hospital environment and stop the persistent colonization of the offending pathogens. Quanternary ammonium surfactants (QASs), with their promising antimicrobial efficacy, are considered as intriguing and appealing candidates for disinfectants. From this perspective, the present study investigated the antifungal efficacy and action mechanism of the QAS cetyltrimethylammonium chloride (CTAC) against three clinically important Candida species: C. albicans, C. tropicalis, and C. glabrata. CTAC exhibited phenomenal antifungal activity against all tested Candida spp., with minimum inhibitory concentrations (MIC) and minimum fungicidal concentrations (MFC) between 2 and 8 µg/mL. The time−kill kinetics of CTAC (at 2XMIC) demonstrated that an exposure time of 2 h was required to kill 99.9% of the inoculums in all tested strains. An important observation was that CTAC treatment did not influence intracellular reactive oxygen species (ROS), signifying that its phenomenal anticandidal efficacy was not mediated via oxidative stress. In addition, sorbitol supplementation increased CTAC's MIC values against all tested Candida strains by three times (8−32 µg/mL), indicating that CTAC's possible antifungal activity involves fungus cell membrane destruction. Interestingly, the increased fluorescence intensity of CTAC-treated cells in both propidium iodide (PI) and DAPI staining assays indicated the impairment of cell plasma membrane and nuclear membrane integrity by CTAC, respectively. Additionally, CTAC at MIC and 2XMIC was sufficient (>80%) to disrupt the mature biofilms of all tested spp., and it inhibited the yeast-to-hyphae transition at sub-MIC in C. albicans. Finally, the non-hemolytic activity of CTAC (upto 32 µg/mL) in human blood cells and HBECs signified its non-toxic nature at the investigated concentrations. Furthermore, thymol and citral, two phytocompounds, together with CTAC, showed synergistic fungicidal effectiveness against C. albicans planktonic cells. Altogether, the data of the present study appreciably broaden our understanding of the antifungal action mechanism of CTAC and support its future translation as a potential disinfectant against Candida-associated healthcare infections.

Percutaneous Venous Reconstruction for Central Thrombosis-Associated Chylothorax: A Safe and Efficacious Option.

Central thrombosis-associated chylothorax is underrecognized in children and frequently refractory to conservative management. Central venous catheterizations are the predominate cause. We present 3 cases highlighting endovascular techniques used to treat persistent chylous effusions. (Level of Difficulty: Advanced.).

[Effects of CT-based Attenuation Correction on PET Images Using Data-driven Respiratory Gating].

PURPOSE: We applied deviceless, positron emission tomography/computed tomography(PET/CT) data-driven respiratory gating (DDG) to validate the effects of misalignment between PET and CT at various respiratory phases. METHODS: A lung lesion was simulated using an NEMA IEC body phantom in which the background comprised hot spheres containing polystyrene foam beads. We acquired PET images as the phantom moved downwards and then stopped. Attenuation on computed tomography images acquired at the inspiratory, stationary, and expiratory phases was corrected after the phantom stopped moving. Normalized mean square error (NMSE), recovery coefficients (RCmax and RCmean) and volume were analyzed on DDG-PET images using CT-based attenuation correction. RESULTS: The NMSE was closest to 0 in PET images corrected using the expiratory CT image. The RCmax was<1.0, and the RCmean was closest to 1.0 only in PET images corrected using the expiratory CT image. Volume was either underestimated or overestimated more according to the size of the spheres when the alignment of CT and PET images was greater. CONCLUSION: We recommend using the expiratory but not the inspiratory phase when using DDG for PET/CT correction.

Functional and radiological outcomes after treatment with custom-made acetabular components in patients with Paprosky type 3 acetabular defects: short-term results.

BACKGROUND: Severe acetabular defects require special treatment with either impaction bone grafting, metal augmented cups or cup-cage constructs. Even these options are often not adequate, especially in hips with Paprosky type 3 defects with loss of anterior and posterior columns. This study investigates the clinical and radiological outcomes of custom-made acetabular components (© Materialise NV, Leuven, Belgium) for Paprosky type 3 defects. METHODS: Sixteen patients were eligible for this trial, nine of whom agreed to be included. All of them completed one year of follow-up. The Harris hip score and the Oxford hip score were used to compare pre- and postoperative functional outcomes. Radiological follow-up comprised anteversion and inclination of the implanted cup and offset measurements in both hips (femoral, medial, ischial offset and center of rotation). Statistical analyses were performed with IBM SPSS Statistics. RESULTS: The mean follow-up time of the nine patients was 12.2 months (range: 10-18). The Oxford hip score and Harris hip score improved from 19.8 and 50.1 to 29.4 and 68.8, respectively (p = 0.009 and 0.01). There were complications in three cases (33.3%), which led to one re-revision (11.1%). Radiologic follow-up showed restoration of the height of the center of rotation and of the global offset. Significant difference was detected in the femoral offset. CONCLUSIONS: The functional and radiological outcomes are promising. However, long-term outcomes still need to be examined. LEVEL OF EVIDENCE: Therapeutic Level IV.

Validation of PET/MRI attenuation correction methodology in the study of brain tumours.

BACKGROUND: This study aims to compare proton density weighted magnetic resonance imaging (MRI) zero echo time (ZTE) and head atlas attenuation correction (AC) to the reference standard computed tomography (CT) based AC for 11C-methionine positron emission tomography (PET)/MRI. METHODS: A retrospective cohort of 14 patients with suspected or confirmed brain tumour and 11C-Methionine PET/MRI was included in the study. For each scan, three AC maps were generated: ZTE-AC, atlas-AC and reference standard CT-AC. Maximum and mean standardised uptake values (SUV) were measured in the hotspot, mirror region and frontal cortex. In postoperative patients (n = 8), SUV values were additionally obtained adjacent to the metal implant and mirror region. Standardised uptake ratios (SUR) hotspot/mirror, hotspot/cortex and metal/mirror were then calculated and analysed with Bland-Altman, Pearson correlation and intraclass correlation reliability in the overall group and subgroups. RESULTS: ZTE-AC demonstrated narrower SD and 95% CI (Bland-Altman) than atlas-AC in the hotspot analysis for all groups (ZTE overall ≤ 2.84, - 1.41 to 1.70; metal ≤ 1.67, - 3.00 to 2.20; non-metal ≤ 3.04, - 0.96 to 3.38; Atlas overall ≤ 4.56, - 1.05 to 3.83; metal ≤ 3.87, - 3.81 to 4.64; non-metal ≤ 4.90, - 1.68 to 5.86). The mean bias for both ZTE-AC and atlas-AC was ≤ 2.4% compared to CT-AC. In the metal region analysis, ZTE-AC demonstrated a narrower mean bias range-closer to zero-and narrower SD and 95% CI (ZTE 0.21-0.48, ≤ 2.50, - 1.70 to 2.57; Atlas 0.56-1.54, ≤ 4.01, - 1.81 to 4.89). The mean bias for both ZTE-AC and atlas-AC was within 1.6%. A perfect correlation (Pearson correlation) was found for both ZTE-AC and atlas-AC compared to CT-AC in the hotspot and metal analysis (ZTE ρ 1.00, p < 0.0001; atlas ρ 1.00, p < 0.0001). An almost perfect intraclass correlation coefficient for absolute agreement was found between Atlas-, ZTE and CT maps for maxSUR and meanSUR values in all the analyses (ICC > 0.99). CONCLUSIONS: Both ZTE and atlas-AC showed a good performance against CT-AC in patients with brain tumour.

DNA-Biofunctionalization of CTAC-Capped Gold Nanocubes.

Clinical diagnostics and disease control are fields that strongly depend on technologies for rapid, sensitive, and selective detection of biological or chemical analytes. Nanoparticles have become an integral part in various biomedical detection devices and nanotherapeutics. An increasing focus is laid on gold nanoparticles as they express less cytotoxicity, high stability, and hold unique optical properties with the ability of signal transduction of biological recognition events with enhanced analytical performance. Strong electromagnetic field enhancements can be found in close proximity to the nanoparticle that can be exploited to enhance signals for e.g., metal-enhanced fluorescence or Raman spectroscopy. Even stronger field enhancements can be achieved with sharp-edged nanoparticles, which are synthesized with the help of facet blocking agents, such as cetyltrimethylammonium bromide/chloride (CTAB/CTAC). However, chemical modification of the nanoparticle surface is necessary to reduce the particle's cytotoxicity, stabilize it against aggregation, and to bioconjugate it with biomolecules to increase its biocompatibility and/or specificity for analytical applications. Here, a reliable two-step protocol following a ligand exchange with bis (p-sulfonatophenyl) phenyl phosphine (BSPP) as the intermediate capping-agent is demonstrated, which results in the reliable biofunctionalization of CTAC-capped gold nanocubes with thiol-modified DNA. The functionalized nanocubes have been characterized regarding their electric potential, plasmonic properties, and stability against high concentrations of NaCl and MgCl2.

Microstructure design of CTAC:FA and BTAC:FA lamellar gels for optimized rheological performance utilizing automated formulation platform.

OBJECTIVES: The main objective of this paper was to optimize hair conditioner performance through variation of composition utilizing automated cosmetic formulation platform and advanced characterization techniques as well as develop understanding of how performance (wet combing and wet lubrication) of hair conditioner is affected by its rheology (i.e. yield stress) and controlled breakdown of the formulations (dilution). The experimental results show that yield stress greatly impacts rheology, stability and performance of the lamellar gels for hair conditioning. METHODS: All samples were prepared on the Chemspeed Flex Formax. A mechanical rheometer was used to measure bulk viscosity and yield stress in each sample. Dia-stron tensile tester was used to measure the lamellar gels ability to reduce combing force. Potential stronger lamellar gel network formation in the formed lamellar gels potentially leads to higher yield stress exhibited. Viscosity values were also measured after a controlled breakdown (i.e. dilution) of each sample. This was also carried out using a mechanical rheometer. RESULTS: Yield stress of the formulations was engineered through composition variation and was recorded in each system. The highest yield stress value is 251.179 Pa at a BTAC/CA ratio of 6:10, and the lowest yield stress is 50.14 Pa at a BTAC/CA ratio of 6:5. The highest yield stress value is 50.14 Pa at a CTAC/CA ratio of 6:10, and the lowest yield stress is 19.98 Pa at a CTAC/CA ratio of 2:10. The highest overall yield stress values can also be observed in the BTAC/CA system, whereas the CTAC/CA system has relatively lower yield stress values. Dilution of each formulation caused a breakdown in viscosity of each formulation with the formulations with highest yield stress maintaining higher viscosity than the other formulations. The formulations with highest yield stress in each system which also maintains the highest dilution viscosity (6% BTAC/10% CA and 6% CTAC/10% CA) have the best effect on reducing overall combing force, that is from dry hair tress to wet hair tress and after product is rinsed off. At a BTAC/CA system of ratio 6:5, there is an 89% reduction in combing force and a 95% reduction in combing force in the BTAC/CA system of ratio 6:10. At a CTAC/CA system of ratio 2:10, there is a 65% reduction in combing force and a 88% reduction in combing force in the CTAC/CA system of ratio 6:10. A 'conditioned' soft feel was observed on each hair tress as the sample was applied and after it was rinsed off. CONCLUSIONS: The overall performance of the lamellar gels for hair conditioning can be engineered through optimization of the formulation microstructure and formulation microstructure breakdown on dilution.

OBJECTIF: L'objectif principal de ce document est d'optimiser les performances des après-shampooing grâce à la variation de sa composition en utilisant une plateforme de formulation cosmétique automatisée et des techniques de caractérisation avancées, ainsi qu'en comprenant mieux comment les performances (peignage humide et lubrification humide) de l'après-shampooing sont affectées par sa rhéologie (c.-à-d. limite élastique) et répartition contrôlée des formulations (dilution). Les résultats expérimentaux montrent que la limite d'élasticité a un impact important sur la rhéologie, la stabilité et les performances des gels lamellaires pour le conditionnement des cheveux. MÉTHODÉS: Tous les échantillons ont été préparés sur le Chemspeed Flex Formax. Un rhéomètre mécanique a été utilisé pour mesurer la viscosité en vrac et la limite élastique dans chaque échantillon. Un testeur de traction Dia-stron a été utilisé pour mesurer la capacité des gels lamellaires à réduire la force de peignage. La formation d'un réseau de gel lamellaire potentiellement plus fort dans les gels lamellaires formés conduit potentiellement à une limite d'élasticité plus élevée. Les valeurs de viscosité ont également été mesurées après une dilution de chaque échantillon. Cela a également été réalisé à l'aide d'un rhéomètre mécanique. RÉSULTATS: La limite d'élasticité des formulations a été modifiée par variation de la composition et a été enregistrée dans chaque système. La limite d'élasticité la plus élevée est de 251,179 Pa à un rapport BTAC/CA de 6,10 et la limite d'élasticité la plus basse est 50,14 Pa à un rapport BTAC/CA de 6: 5. La valeur de limite d'élasticité la plus élevée est de 50,14 Pa à un rapport CTAC/CA de 6,10 et la contrainte d'élasticité la plus basse est de 19,98 Pa à un rapport CTAC/CA de 2:10. Les valeurs globales de contrainte d'écoulement les plus élevées peuvent également être observées dans le système BTAC/CA tandis que le système CTAC/CA a des valeurs de contrainte d'écoulement relativement plus faibles. La dilution de chaque formulation a provoqué une dégradation de la viscosité de chaque formulation, les formulations ayant la limite d'élasticité la plus élevée conservant une viscosité plus élevée que les autres formulations. Les formulations avec la limite d'élasticité la plus élevée dans chaque système qui maintient également la viscosité de dilution la plus élevée (6% BTAC/10% CA et 6% CTAC/10% CA) a le meilleur effet sur la réduction de la force de peignage globale, c'est-à-dire des cheveux secs aux cheveux mouillés tressées et après que le produit soit rincé. Dans un système BTAC/CA de rapport 6: 5, il y a une réduction de 89% de la force de peignage et une réduction de 95% de la force de peignage dans le système BTAC/CA de rapport 6:10. Dans un système CTAC/CA de rapport 2:10, il y a une réduction de 65% de la force de peignage et une réduction de 88% de la force de peignage dans le système CTAC/CA de rapport 6:10. Une sensation de douceur a été observée sur chaque tresse lors de l'application de l'échantillon et après le rinçage. CONCLUSION: Les performances globales des gels lamellaires pour le conditionnement des cheveux peuvent être conçues par l'optimisation de la microstructure de formulation et la décomposition de la microstructure de formulation lors de la dilution.

Enhanced nitrate adsorption by using cetyltrimethylammonium chloride pre-loaded activated carbon.

This paper used cetyltrimethylammonium chloride (CTAC) pre-loaded activated carbon (AC) to research nitrate adsorption. Effects of various parameters such as AC types, AC dosage as well as initial pH were studied. The results indicated that the ACs modified by CTAC can get higher nitrate removal. Even pH is neutral and basic, an accepted removal about 2.5 mg/g can be observed. The more CTAC pre-loaded on the AC surface, the higher nitrate adsorption capacity can be obtained. pH is regarded as a key factor affecting interactions between adsorbent and adsorbate, and the results confirmed that the nitrate adsorption on modified AC decreases gradually with the growth of initial pH. Besides, the acidic pH condition is much favoured for adsorption while the results gained a nitrate adsorption about 4.28 mg/g at pH = 3 condition. Sorption mechanism of nitrate on CTAC modified AC was investigated through two kinetic modellings including pseudo-second-order and Weber and Morris intra-particle diffusion model. The results imply that the generalized kinetic models tally well with experimental data. Additionally, interference of co-existing anions is examined, and the results showed that higher co-anions concentration would bring a heavier depression of the nitrate uptake due to its competing for adsorption sites.

Clinical utility of the normal database of 123I-iodoamphetamine brain perfusion single photon emission computed tomography for statistical analysis using computed tomography-based attenuation correction: a multicenter study.

OBJECTIVES: We have established a common normal database (NDB) with applicability in multicenter settings for the statistical analysis of brain perfusion single photon emission computed tomography (SPECT) with triple energy window scatter correction, computed tomography-based attenuation correction (CTAC), and spatial resolution compensation. This study aimed to compare the CTAC normal database (CTAC-NDB) with conventional normal databases for the statistical analysis of 123I-iodoamphetamine (123I-IMP) brain perfusion SPECT at three institutions and to assess the clinical efficiency of CTAC-NDB. METHODS: We recruited 45 patients (26 men and 19 women; mean age, 74.2 ± 3.9 years; Mini-Mental State Examination score, 19.8 ± 6.1) with Alzheimer's disease (AD, n = 26), dementia with Lewy bodies (DLB, n = 9), and mild cognitive impairment (n = 10) from three institutions. Three-dimensional stereotactic surface projection (3D-SSP) technique was used to analyze data obtained from the 123I-IMP brain perfusion SPECT images compared with both CTAC-NDB and conventional NDB. We visually assessed each 3D-SSP z score map to determine the changes in specific findings, such as AD/DLB pattern. Furthermore, the stereotactic extraction estimation analysis software was used to measure the regional z score severity and extent as a semiquantitative assessment. RESULTS: In the visual assessment, all cases exhibited clearer findings with CTAC-NDB than with conventional NDB in the parietotemporal association cortex as well as in the inferior temporal, frontal, and lateral occipital cortices. Contrarily, the findings from the medial cerebral regions, including the precuneus and the posterior cingulate, became indistinct in 71% of the cases and remained unchanged in 25% of the cases. In the semiquantitative analysis, a similar tendency was observed in the mean z score in the three institutions included in the study. CONCLUSION: Using the CTAC-NDB, the findings in the vicinity of the cranium became increasingly clear, whereas those in the medial surface of the brain became less defined or remained unchanged. These findings were confirmed via a semiquantitative analysis. Moreover, similar changes in the reduction pattern were observed in the three institutions. Therefore, the new database with CTAC might be applicable in other institutions. Data collected in this study may serve as a CTAC-NDB.

Count-based method for specific binding ratio calculation in [I-123]FP-CIT SPECT analysis.

OBJECTIVE: To calculate the specific binding ratio (SBR) appropriately in dopamine transporter (DAT) imaging, a method for extracting the striatal volume of interest (VOI) was developed. METHODS: This study included 200 patients (72 ± 10 years) who were suspected of parkinsonian syndromes (PS) or dementia with Lewy body (DLB). The patients were divided into three groups of PS with dopaminergic degeneration, DLB and non-PS after [123I]ioflupane (FP-CIT) SPECT and clinical follow-up. The image data were reconstructed with CT attenuation correction and scatter correction, and with only CT attenuation correction (CTAC). The new method extracted striatal VOI according to the high-level counts and the average striatum volume, and calculated SBR using the reference occipital counts. The SBR values for each patient were obtained using the Tossici-Bolt method (SBRBolt) and our method. Reproducibility of SBR calculation using our method was compared by two operators. RESULTS: The mean SBR values for the PS and DLB groups were significantly different from that of the non-PS group with both methods. The coefficients of variation of the SBR were significantly smaller with the proposed method compared with those of SBRBolt (p < 0.001), except for the CTAC images. There were no differences in SBR between the two operators using our method. The diagnostic accuracies with our method for the PS and DLB groups were 98.4 and 96.0%, respectively. CONCLUSION: Our new method for SBR calculation in the FP-CIT SPECT showed less coefficients of variation with high reproducibility, which would be useful for clinical diagnosis and in assessing the severity of diseases in follow-up studies.

[Development of a Striatal and Skull Phantom for Quantitative 123I-FP-CIT SPECT].

BACKGROUND: 123Iodine-labelled N-(3-fluoropropyl) -2ß-carbomethoxy-3ß-(4-iodophenyl) nortropane (123I-FP-CIT) single photon emission computerized tomography (SPECT) images are used for differential diagnosis such as Parkinson's disease (PD). Specific binding ratio (SBR) is affected by scattering and attenuation in SPECT imaging, because gender and age lead to changes in skull density. It is necessary to clarify and correct the influence of the phantom simulating the the skull. PURPOSE: The purpose of this study was to develop phantoms that can evaluate scattering and attenuation correction. METHODS: Skull phantoms were prepared based on the measuring the results of the average computed tomography (CT) value, average skull thickness of 12 males and 16 females. 123I-FP-CIT SPECT imaging of striatal phantom was performed with these skull phantoms, which reproduced normal and PD. SPECT images, were reconstructed with scattering and attenuation correction. SBR with partial volume effect corrected (SBRact) and conventional SBR (SBRBolt) were measured and compared. RESULTS: The striatum and the skull phantoms along with 123I-FP-CIT were able to reproduce the normal accumulation and disease state of PD and further those reproduced the influence of skull density on SPECT imaging. The error rate with the true SBR, SBRact was much smaller than SBRBolt. CONCLUSION: The effect on SBR could be corrected by scattering and attenuation correction even if the skull density changes with 123I-FP-CIT on SPECT imaging. The combination of triple energy window method and CT-attenuation correction method would be the best correction method for SBRact.

Validation of Computed Tomography-based Attenuation Correction of Deviation between Theoretical and Actual Values in Four Computed Tomography Scanners.

OBJECTIVES: In this study, we aimed to validate the accuracy of computed tomography-based attenuation correction (CTAC), using the bilinear scaling method. METHODS: The measured attenuation coefficient (µm) was compared to the theoretical attenuation coefficient (µt), using four different CT scanners and an RMI 467 phantom. The effective energy of CT beam X-rays was calculated, using the aluminum half-value layer method and was used in conjunction with an attenuation coefficient map to convert the CT numbers to µm values for the photon energy of 140 keV. We measured the CT number of RMI 467 phantom for each of the four scanners and compared the µm and µt values for the effective energies of CT beam X-rays, effective atomic numbers, and physical densities. RESULTS: The µm values for CT beam X-rays with low effective energies decreased in high construction elements, compared with CT beam X-rays of high effective energies. As the physical density increased, the µm values elevated linearly. Compared with other scanners, the µm values obtained from the scanner with CT beam X-rays of maximal effective energy increased once the effective atomic number exceeded 10.00. The µm value of soft tissue was equivalent to the µt value. However, the ratios of maximal difference between µm and µt values were 25.4% (lung tissue) and 21.5% (bone tissue), respectively. Additionally, the maximal difference in µm values was 6.0% in the bone tissue for each scanner. CONCLUSION: The bilinear scaling method could accurately convert CT numbers to µ values in soft tissues.

Application of TiO2-organobentonite modified by cetyltrimethylammonium chloride photocatalyst and polyaluminum chloride coagulant for pretreatment of aging landfill leachate.

This study investigated the treatment performance for aging leachate containing refractory organic pollutants by TiO2-organobentonite photocatalyst combined with polyaluminum chloride (PAC) coagulant. TiO2 was immobilized on organobentonite granules as a supporter modified by cetyltrimethylammonium chloride (CTAC). The prepared catalysts were characterized by ESEM, FTIR, and XRD analysis, which showed that TiO2-organobentonite catalyst had uniform coating of TiO2 on support. Chemical oxygen demand (COD) and NH3-N removal rates by combination of TiO2-CTAC2.0 photocatalysis and PAC coagulation were evaluated, optimized, and compared to that by either treatment alone, with respect to TiO2-CTAC2.0 dose, photocatalytic contact time, pH, and PAC dose. Furthermore, higher removal rates (COD 80 %; NH3-N 46 %) were achieved by response surface methodology (RSM) when TiO2-CTAC2.0 photocatalysis was followed by PAC coagulation at optimized conditions. The optimized experimental conditions were TiO2-CTAC2.0 dosage of 5.09 g/L, at pH 5.53, photocatalytic contact time for 180 min, and PAC dosage of 1062 mg/L.