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1.
Food Sci Biotechnol ; 33(13): 2971-2978, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39220306

RESUMEN

In this study, xylitol, a common sweetener and sucrose substitute in low-calorie foods, was quantified by high-performance liquid chromatography (HPLC). During the establishment of the analytical method, three representative detection approaches, ultraviolet detector (UVD), evaporative light scattering detector, and refractive index detector, were compared and applied to determine the xylitol content in various foods distributed in Korea. The results were compared for method validation, measurement uncertainty, and applicability. As a result, HPLC-UVD showed the lowest limit of detection (0.01 mg/L) and limit of quantification (0.04 mg/L) among the three methods. It showed a low range of relative expanded uncertainty (1.12-3.98%) and could quantify xylitol in the wide range of the samples, even trace amounts of xylitol. Therefore, a total of 160 food items, including chewing gum, candy, beverage, tea, other processed products, and beverage base, were applied with three replicates by the proposed HPLC-UVD method.

2.
Heliyon ; 10(16): e36039, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39247298

RESUMEN

In order to adjust and detect micro-nano periodic structure optical surface accurately and efficiently, the problem of composite scattering between micro-ellipsoidal periodic structure optical surface and pore defects is studied use the multi-resolution time domain (MRTD) approach. A calculation model is established for the intensity distribution of composite scattering, which is modulated by the micro-ellipsoidal periodic structure optical surface and microdefects. Results are in good agreement with those obtained using CST Microwave Studio software and the finite-different time-domain (FDTD) approach, which demonstrates the effectiveness of the calculation model and method. By combining the field distribution of the micro-ellipsoidal periodic structure optical surface containing microdefects with the optical response at different wavelengths, it is necessary to study the influence of various parameters of the micro-ellipsoidal structure and microdefects on the optical system of metamaterials. The effects of the parameters such as roughness, structure of micro-ellipsoidal unit, defect sizes and buried depths on the composite scattering characteristics are analyzed numerically. The results provide technical support for the fields of functional surface design, ultrasensitive detection, scattering peak orientation and frequency selection.

3.
Materials (Basel) ; 17(17)2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39274720

RESUMEN

Hybrid-carrageenan hydrogels are characterized using novel techniques based on high-resolution speckle imaging, namely image dynamic light scattering (IDLS) and ultra-small-angle light scattering (USALS). These techniques, used to probe the microscopic structure of the system in sol-gel phase separation and at different concentrations in the gel phase, give access to a better understanding of the network's topology on the basis of fractals in the dense phase. Observations of the architecture and the spatial and the size distributions of gel phase and fractal dimension were performed by USALS. The pair-distance distribution function, P(r), extracted from USALS patterns, is a new methodology of calculus for determining the network's internal size with precision. All structural features are systematically compared with a linear and non-linear rheological characterization of the gels and structure-elasticity relationships are identified in the framework of fractal colloid gels in the diffusion limit.

4.
Chem Asian J ; : e202400826, 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39222039

RESUMEN

The Zika virus (ZIKV) is a global health threat due to its rapid spread and severe health implications, including congenital abnormalities and neurological complications. Differentiating ZIKV from other arboviruses such as dengue virus (DENV) is crucial for effective diagnosis and treatment. This study presents the development of a biosensor for detecting the ZIKV non-structural protein 1 (NS1) using gold nanoparticles (AuNPs) functionalized with monoclonal antibodies employing dynamic light scattering (DLS). The biosensor named ZINS1-mAb-AuNP exhibited specific binding to the ZIKV NS1 protein, demonstrating high colloidal stability indicated by a hydrodynamic diameter (DH) of 140 nm, detectable via DLS. In the absence of the protein, the high ionic strength medium caused particle aggregation. This detection method showed good sensitivity and specificity, with a limit of detection (LOD) of 0.96 µg mL-1, and avoided cross-reactivity with DENV2 NS1 and SARS-CoV-2 spike proteins. The ZINS1-mAb-AuNP biosensor represents a promising tool for the early and accurate detection of ZIKV, facilitating diagnostic and treatment capabilities for arboviral infections.

5.
Biosensors (Basel) ; 14(8)2024 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-39194600

RESUMEN

Noninvasive in situ monitoring of viscoelastic characteristics of corneal tissue at elevated temperatures is pivotal for mechanical property-informed refractive surgery techniques, including thermokeratoplasty and photorefractive keratectomy, requiring precise thermal modifications of the corneal structure during these surgical procedures. This study harnesses Brillouin light scattering spectroscopy as a biosensing platform to noninvasively probe the viscoelastic properties of ovine corneas across a temperature range of 25-64 °C. By submerging the tissue samples in silicone oil, consistent hydration and immiscibility are maintained, allowing for their accurate sensing of temperature-dependent mechanical behaviors. We identify significant phase transitions in the corneal tissue, particularly beyond 40 °C, likely due to collagen unfolding, marking the beginning of thermal destabilization. A subsequent transition, observed beyond 60 °C, correlates with collagen denaturation. These phase transformations highlight the cornea's sensitivity to both physiologically reversible and irreversible viscoelastic changes induced by mild to high temperatures. Our findings underscore the potential of the Brillouin biosensing technique for real-time diagnostics of corneal biomechanics during refractive surgeries to attain optimized therapeutic outcomes.


Asunto(s)
Técnicas Biosensibles , Córnea , Elasticidad , Animales , Ovinos , Viscosidad , Transición de Fase , Temperatura
6.
Mar Drugs ; 22(8)2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-39195451

RESUMEN

Aquaporins (AQPs) are a family of integral membrane proteins that selectively transport water and glycerol across the cell membrane. Because AQPs are involved in a wide range of physiological functions and pathophysiological conditions, AQP-based therapeutics may have the broad potential for clinical utility, including for disorders of water and energy balance. However, AQP modulators have not yet been developed as suitable candidates for clinical applications. In this study, to identify potential modulators of AQPs, we screened 31 natural products by measuring the water and glycerol permeability of mouse erythrocyte membranes using a stopped-flow light scattering method. None of the tested natural compounds substantially affected the osmotic water permeability. However, several compounds considerably affected the glycerol permeability. Stichoposide C increased the glycerol permeability of mouse erythrocyte membranes, whereas rhizochalin decreased it at nanomolar concentrations. Immunohistochemistry revealed that AQP7 was the main aquaglyceroporin in mouse erythrocyte membranes. We further verified the effects of stichoposide C and rhizochalin on aquaglyceroporins using human AQP3-expressing keratinocyte cells. Stichoposide C, but not stichoposide D, increased AQP3-mediated transepithelial glycerol transport, whereas the peracetyl aglycon of rhizochalin was the most potent inhibitor of glycerol transport among the tested rhizochalin derivatives. Collectively, stichoposide C and the peracetyl aglycon of rhizochalin might function as modulators of AQP3 and AQP7, and suggests the possibility of these natural products as potential drug candidates for aquaglyceroporin modulators.


Asunto(s)
Acuagliceroporinas , Glicerol , Animales , Ratones , Acuagliceroporinas/metabolismo , Humanos , Glicerol/metabolismo , Agua/química , Agua/metabolismo , Membrana Eritrocítica/efectos de los fármacos , Membrana Eritrocítica/metabolismo , Acuaporina 3/metabolismo , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Transporte Biológico/efectos de los fármacos , Acuaporinas/metabolismo , Permeabilidad de la Membrana Celular/efectos de los fármacos
7.
Talanta ; 279: 126682, 2024 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-39116734

RESUMEN

Fabricating covalent organic frameworks with different morphologies based on the same structural motifs is both interesting and challenging. Here, a TTA-TFP-COF was synthesized by both solvothermal and room temperature methods, with 2,4,6-Tris(4-aminophenyl)-1,3,5-triazine (TTA) and 1,3,5-tris(4-formylphenyl)-benzene (TFP) as raw material. Using different synthesis conditions and adding aniline and benzaldehyde as regulators in the synthesis process, we found that these processes could slow down the reaction speed, increase the exchange and metathesis reactions of dynamic reversible reactions, and improve the reversibility of the reaction system. Thus, controllable synthesis of TTA-TFP-COF with different morphologies, including micro-particles, hollow tubes with controllable diameters, and micro-flowers was achieved. Our further study found that metal ions, Fe3+ and Cr3+ ions, could coordinate with N and O in TTA-TFP-COF and partially destroy the structure of TTA-TFP-COF. The particle size of the TTA-TFP-COF became smaller, thus resulting in the decrease of the light scattering intensity of the COF. An excellent linear relationship exists between the light scattering changes (ΔI) and metal ions concentration (c) from 2.0 to 350.0 µM for Fe3+ and 40.0-800.0 µM for Cr3+, respectively. Thus, rapid and selective analytical methods for detecting metal ions were developed by TTA-TFP-COF here.

8.
Small Methods ; : e2400855, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39139008

RESUMEN

Colloidal glasses (CGs) made of polymer (polymethylmethacrylate) nanoparticles are promising metamaterials for light and sound manipulation, but fabrication imperfections and fragility can limit their functionality and applications. Here, the vibrational mechanical modes of nanoparticles are probed to evaluate the nanomechanical and morphological properties of various CGs architectures. Utilizing the scanning micro-Brillouin light scattering (µ-BLS), the effective elastic constants and nanoparticles' sizes is determined as a function of position in a remote and non-destructive manner. This method is applied to CG mesostructures with different spatial distributions of their particle size and degree of order. These include CGs with single-sized systems, binary mixtures, bilayer structures, continuous gradient structures, and gradient mixtures. The microenvironments govern the local mechanical properties and highlight how the granular mesostructure can be used to develop durable functional polymer colloids. A size effect is revealed on the effective elastic constant, with the smallest particles and ordered assemblies forming robust structures, and classify the various types of mesoscale order in terms of their mechanical stiffness. The work establishes scanning µ-BLS as a tool for mapping elasticity, particle size, and local structure in complex nanostructures.

9.
Se Pu ; 42(8): 783-791, 2024 Aug.
Artículo en Chino | MEDLINE | ID: mdl-39086247

RESUMEN

Quaternary ammonium salt bactericides are broad-spectrum bactericides often used in oral care products because of their high antibacterial efficacy, strong penetration, and low toxicity. However, the excessive use of quaternary ammonium salt bactericides may cause contact dermatitis, scalding poisoning, and even death. Existing methods to determine quaternary ammonium salt bactericides are unable to meet current requirements owing to the lack of determination components. Therefore, establishing a simple and accurate method for the simultaneous detection of more quaternary ammonium salt bactericides is necessary. In this study, a method that couples sample pretreatment with high performance liquid chromatography-evaporative light-scattering detection (HPLC-ELSD) was developed for the simultaneous determination of quaternary ammonium salt bactericides in oral care products, including dodecyltrimethylammonium chloride, dodecyldimethylbenzylammonium chloride, benzethonium chloride, tetradecyl trimethyl ammonium chloride, tetradecyldimethylbenzylammonium chloride, N-hexadecyltrimethylammonium chloride, benzyldimethylhexadecylammonium chloride, trimethylstearylammonium chloride, stearyldimethylbenzylammonium chloride, and docosyltrimethylammonium chloride. Some of these bactericides do not absorb ultraviolet light, so a universal evaporative light-scattering detector was used owing to testing cost and stability concerns. The paste samples contained thickening agents, which are highly soluble in water but insoluble in organic solvents; these agents can seriously affect the results of sample pretreatment and damage the chromatographic column. Hence, sample dehydration was necessary. In this study, four dehydration methods were compared. Anhydrous sodium sulfate (Na2SO4) was selected, and the amount of Na2SO4 was optimized. Based on the solubility of the 10 target compounds and extraction efficiency, three extraction solvents were compared, and ethanol was selected. Ultrasonic extraction was the primary extraction process used in this study. The effects of different ultrasonication times, temperatures, and powers on the extraction recoveries were also investigated. Ultimately, the optimized conditions were as follows: extraction of the dehydrated paste and powder samples using ethanol at room temperature (25 ℃) for 20 min under 100 W ultrasound power, and dilution of the liquid sample with ethanol. After extraction, the samples were separated on an Acclaim Surfactant column (150 mm×4.6 mm, 5 µm) with 50 mmol/L ammonium acetate aqueous solution (pH=5.5) (A) and acetonitrile (B) as mobile phases. The gradient elution program were as follows: 0-5.0 min, 75%A-35%A, 5.0-15.0 min, 35%A-20%A, 15.0-20.0 min, 20%A, 20.0-21.0 min, 20%A-75%A, 21.0-25.0 min, 75%A. An external standard method was used for quantitative determination. The 10 compounds were analyzed within 25 min. Linear equations, correlation coefficients, and linear ranges were obtained by analyzing a series of mixed standard working solutions. The limits of detection (LODs, S/N=3) and quantification (LOQs, S/N=10) of the 10 components were determined. Stearyldimethylbenzylammonium chloride and docosyltrimethylammonium chloride showed good linear relationships in the range of 10-200 mg/L, while the other compounds demonstrated good linear relationships in the range of 5-100 mg/L. In all cases, correlation coefficients (R2) of no less than 0.9992 were obtained. The LODs and LOQs were in the range of 1.42-3.31 mg/L and 4.25-9.94 mg/L, respectively. Ten analytes were spiked in blank matrices, such as toothpaste (paste), mouthwash (liquid), and dentifrice powder (powder) at three levels, and the recoveries and precisions were calculated. The average recoveries were 87.9%-103.1%, and the corresponding relative standard deviations (RSDs) did not exceed 5.5% (n=6). The developed method was used to detect 109 oral care products. Benzyldimethylhexadecylammonium chloride and stearyldimethylbenzylammonium chloride revealed high detection rates. Moreover, the amount of stearyldimethylbenzylammonium chloride in one toothpaste sample exceeded regulatory requirements. Given its advantages of good precision and accuracy, the developed method is suitable for the quantitative analysis of the 10 aforementioned compounds in typical oral care products. The study findings can serve as a reference for the quality and safety monitoring of oral care products.


Asunto(s)
Compuestos de Amonio Cuaternario , Compuestos de Amonio Cuaternario/química , Compuestos de Amonio Cuaternario/análisis , Cromatografía Líquida de Alta Presión , Antibacterianos/análisis , Luz , Dispersión de Radiación
10.
Se Pu ; 42(8): 812-818, 2024 Aug.
Artículo en Chino | MEDLINE | ID: mdl-39086251

RESUMEN

Gel permeation chromatography coupled with light scattering (GPC-LS) is among the most common methods for determining the molar masses of polymers. GPC-LS is widely used in polymer science research and has been adopted for many industrial applications owing to its high sensitivity, accuracy, and precision. The determination of polymer molar masses using GPC-LS is an important experimental component of the "Polymer Physics Experiments" course. However, the present GPC-LS experimental teaching content tends to be overly simplistic and lacking in depth. Herein, the original experimental content is expanded and multiple sets of experiments are redesigned: (1) Using commercial polystyrene as an experimental sample, the molar mass, molar mass distribution, radius of gyration, and other molecular structure parameters are determined using GPC-LS; (2) Using two polyacrylonitriles with similar molecular structure parameters, subtle differences in the molar mass distributions of the samples are explored using differential mass distribution curves; (3) By comparing the chromatograms of a series of polyethylene glycols with different molar masses, the effect of molar mass on chromatographic peaks is investigated; and (4) For three different polymers (polyacrylonitrile, poly(methyl methacrylate), and poly(ß-cyclodextrin)), the polymer chain conformations are analyzed using conformation plots (i.e., radius of gyration vs. molar mass). In addition, the experimental teaching method is modified to convert passive learning into active learning, thereby improving the students' self-directed learning ability. This experimental teaching reform will help students obtain a more comprehensive understanding of GPC-LS principles and applications, stimulate their enthusiasm for learning, and improve the teaching quality of the experimental course.

11.
Chem Biol Interact ; 402: 111215, 2024 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-39197812

RESUMEN

Curcumin (CUR) has received worldwide attention for its beneficial effects on human health. Research report possible cytotoxic activity against various cancers, including glioblastoma. So far, little attention has been given to the binding properties of CUR to lipid membranes, which influences their electrical characteristics and can provide insight into their membrane-permeation abilities. Biophysical interactions between the polyphenol and in vitro models (liposomes and LN-18 human glioblastoma cells) were investigated by monitoring zeta potential and the membrane's surface charge as a function of pH. We focused on practical measurements and undertook a theoretical analysis of interactions in the natural cell membrane. We used the MTT assay to evaluate the viability of CUR-treated cells. Measurements performed using the Electrophoretic Light Scattering method demonstrated the dose-dependent effect of CUR on both membrane surface charge and zeta potential analyzed in vitro models. We determined theoretical parameters characterizing the cell membrane based on a quantitative description of the adsorption equilibria formed due to the binding of solution ions to the membrane of glioblastoma cells. The interaction of CUR with liposomes and human cancer cells is pH-dependent.


Asunto(s)
Curcumina , Glioblastoma , Liposomas , Fosfatidilcolinas , Curcumina/farmacología , Curcumina/química , Humanos , Liposomas/química , Concentración de Iones de Hidrógeno , Glioblastoma/metabolismo , Glioblastoma/tratamiento farmacológico , Glioblastoma/patología , Línea Celular Tumoral , Fosfatidilcolinas/química , Supervivencia Celular/efectos de los fármacos , Membrana Celular/metabolismo , Membrana Celular/efectos de los fármacos , Propiedades de Superficie , Antineoplásicos/farmacología , Antineoplásicos/química
12.
Viruses ; 16(8)2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39205208

RESUMEN

Recombinant adeno-associated viruses (rAAVs) play a pivotal role in the treatment of genetic diseases. However, current production and purification processes yield AAV-based preparations that often contain unwanted empty, partially filled or damaged viral particles and impurities, including residual host cell DNA and proteins, plasmid DNA, and viral aggregates. To precisely understand the composition of AAV preparations, we systematically compared four different single-stranded AAV (ssAAV) and self-complementary (scAAV) fractions extracted from the CsCl ultracentrifugation gradient using established methods (transduction efficiency, analytical ultracentrifugation (AUC), quantitative and digital droplet PCR (qPCR and ddPCR), transmission electron microscopy (TEM) and enzyme-linked immunosorbent assay (ELISA)) alongside newer techniques (multiplex ddPCR, multi-angle light-scattering coupled to size-exclusion chromatography (SEC-MALS), multi-angle dynamic light scattering (MADLS), and high-throughput sequencing (HTS)). Suboptimal particle separation within the fractions resulted in unexpectedly similar infectivity levels. No single technique could simultaneously provide comprehensive insights in the presence of both bioactive particles and contaminants. Notably, multiplex ddPCR revealed distinct vector genome fragmentation patterns, differing between ssAAV and scAAV. This highlights the urgent need for innovative analytical and production approaches to optimize AAV vector production and enhance therapeutic outcomes.


Asunto(s)
Dependovirus , Ultracentrifugación , Virión , Dependovirus/genética , Dependovirus/aislamiento & purificación , Humanos , Virión/aislamiento & purificación , Virión/genética , Vectores Genéticos/genética , Células HEK293 , Cesio/química , Centrifugación por Gradiente de Densidad/métodos , Transducción Genética , Cloruros
13.
Artículo en Inglés | MEDLINE | ID: mdl-39206082

RESUMEN

Background: Pseudoexfoliation syndrome (PES) is an age-related systemic condition that predominantly affects ocular structures and is characterized by the deposition of material on the lens, ciliary body, zonules, corneal endothelium, iris, and pupillary margin. We compared the corneal endothelial morphology, anterior segment parameters, corneal densitometry, and corneal topographic characteristics between the clinically affected and apparently normal fellow eyes of patients with clinically unilateral PES. Methods: This was a comparative, cross-sectional study of 34 patients with clinically unilateral PES. The anterior segment was examined using a Scheimpflug imaging system, and the corneal endothelium was assessed using a noncontact specular microscope. Corneal endothelial cell density, polymegathism, and pleomorphism were assessed using the specular microscope. Furthermore, the Scheimpflug camera was used to measure the corneal power of the flat and steep axis, mean corneal power, maximum keratometry, anterior chamber angle, anterior chamber depth, anterior chamber volume, corneal volume, and the corneal thickness at the apex point, center of the pupil, and the thinnest point. Corneal densitometry was evaluated at two concentric zones (0-2 mm and 0-12 mm). Results: In total, 68 eyes from 34 patients were ultimately included in the study. The mean (standard deviation) age of the patients was 73.38 (8.75) years (range: 50-87 years). Among the included patients, 17 (50%) were male and 17 (50%) were female. The anterior segment parameters did not significantly differ between eyes with PES and their clinically unaffected fellow eyes (all P > 0.05). Similarly, no statistically significant difference was observed in corneal endothelial morphology (all P > 0.05). Conclusions: Our measured parameters do not differ between the clinically affected eye and the clinically unaffected fellow eye. This supports the theory that PES is a bilateral disorder. Considering the variety of complications associated with PES, bilateral involvement should be assumed in the clinical and surgical management of patients with clinically unilateral PES. In the future, new research could increase our understanding of this syndrome.

14.
Mol Pharm ; 21(9): 4553-4564, 2024 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-39163212

RESUMEN

The solution viscosity and protein-protein interactions (PPIs) as a function of temperature (4-40 °C) were measured at a series of protein concentrations for a monoclonal antibody (mAb) with different formulation conditions, which include NaCl and sucrose. The flow activation energy (Eη) was extracted from the temperature dependence of solution viscosity using the Arrhenius equation. PPIs were quantified via the protein diffusion interaction parameter (kD) measured by dynamic light scattering, together with the osmotic second virial coefficient and the structure factor obtained through small-angle X-ray scattering. Both viscosity and PPIs were found to vary with the formulation conditions. Adding NaCl introduces an attractive interaction but leads to a significant reduction in the viscosity. However, adding sucrose enhances an overall repulsive effect and leads to a slight decrease in viscosity. Thus, the averaged (attractive or repulsive) PPI information is not a good indicator of viscosity at high protein concentrations for the mAb studied here. Instead, a correlation based on the temperature dependence of viscosity (i.e., Eη) and the temperature sensitivity in PPIs was observed for this specific mAb. When kD is more sensitive to the temperature variation, it corresponds to a larger value of Eη and thus a higher viscosity in concentrated protein solutions. When kD is less sensitive to temperature change, it corresponds to a smaller value of Eη and thus a lower viscosity at high protein concentrations. Rather than the absolute value of PPIs at a given temperature, our results show that the temperature sensitivity of PPIs may be a more useful metric for predicting issues with high viscosity of concentrated solutions. In addition, we also demonstrate that caution is required in choosing a proper protein concentration range to extract kD. In some excipient conditions studied here, the appropriate protein concentration range needs to be less than 4 mg/mL, remarkably lower than the typical concentration range used in the literature.


Asunto(s)
Anticuerpos Monoclonales , Cloruro de Sodio , Sacarosa , Temperatura , Anticuerpos Monoclonales/química , Viscosidad , Sacarosa/química , Cloruro de Sodio/química , Soluciones , Dispersión del Ángulo Pequeño
15.
Molecules ; 29(15)2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39125023

RESUMEN

Salt-induced diffusiophoresis is the migration of a colloidal particle in water due to a directional salt concentration gradient. An important example of colloidal particles is represented by micelles, generated by surfactant self-assembly in water. For non-ionic surfactants containing polyethylene glycol (PEG) groups, PEG preferential hydration at the micelle-water interface is expected to drive micelle diffusiophoresis from high to low salt concentration. However, micelles are reversible supramolecular assemblies, with salts being able to promote a significant change in micelle size. This phenomenon complicates the description of diffusiophoresis. Specifically, it is not clear to what extent the salt-induced growth of micelles affects micelle diffusiophoresis. In this paper, a multiple-equilibrium model is developed for assessing the contribution of the micelle growth and preferential hydration mechanisms to the diffusiophoresis of non-ionic micelles. The available experimental data characterizing the effect of NaCl on Triton X-100 aggregation number are combined with data on diffusiophoresis and the preferential hydration of PEG chains to show that the contribution of the micelle growth mechanism to overall diffusiophoresis is small compared to that of preferential hydration.

17.
Proc Natl Acad Sci U S A ; 121(33): e2323016121, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39088388

RESUMEN

Blood plasma viscosity (PV) is an established biomarker for numerous diseases. Measurement of the shear PV using conventional rheological techniques is, however, time consuming and requires significant plasma volumes. Here, we show that Brillouin light scattering (BLS) and angle-resolved spectroscopy measurements of the longitudinal PV from microliter-sized plasma volumes can serve as a proxy for the shear PV measured using conventional viscometers. This is not trivial given the distinct frequency regime probed and the longitudinal viscosity, a combination of the shear and bulk viscosity, representing a unique material property on account of the latter. We demonstrate this for plasma from healthy persons and patients suffering from different severities of COVID-19 (CoV), which has been associated with an increased shear PV. We further show that the additional information contained in the BLS-measured effective longitudinal PV and its temperature scaling can provide unique insight into the chemical constituents and physical properties of plasma that can be of diagnostic value. In particular, we find that changes in the effective longitudinal viscosity are consistent with an increased suspension concentration in CoV patient samples at elevated temperatures that is correlated with disease severity and progression. This is supported by results from rapid BLS spatial-mapping, angle-resolved BLS measurements, changes in the elastic scattering, and anomalies in the temperature scaling of the shear viscosity. Finally, we introduce a compact BLS probe to rapidly perform measurements in plastic transport tubes. Our results open a broad avenue for PV diagnostics based on the high-frequency effective longitudinal PV and show that BLS can provide a means for its implementation.


Asunto(s)
Viscosidad Sanguínea , COVID-19 , Humanos , Viscosidad Sanguínea/fisiología , COVID-19/sangre , COVID-19/diagnóstico , SARS-CoV-2 , Dispersión de Radiación , Plasma/química , Luz , Reología/métodos , Masculino
18.
Sci Rep ; 14(1): 20259, 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39217241

RESUMEN

We investigated the thermally induced surface acoustic waves in CoFeB/MgO heterostructures with different underlayer materials. Our results show a direct correlation between the density and elastic parameters of the underlayer materials and the surface phonon dispersion. Using finite element method-based simulations, we calculate the effective elastic parameters (such as elastic tensor, Young's modulus, and Poisson's ratio) for multilayers with different underlayer materials. The simulation results, either considering the elastic parameters of individual layers or considering the effective elastic parameters of whole stacks, exhibit good agreement with the experimental data. This study will help us deepen our understanding of phonon properties and their interactions with other quasiparticles or magnetic textures with the help of these estimated elastic properties.

19.
Adv Mater ; : e2408060, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39087402

RESUMEN

Organic crystals are widely used by animals to manipulate light for producing structural colors and for improving vision. To date only seven crystal types are known to be used, and among them ß-guanine crystals are by far the most widespread. The fact that almost all these crystals have unusually high refractive indices (RIs) is consistent with their light manipulation function. Here, the physical, structural, and optical principles of how light interacts with the polarizable free-electron-rich environment of these quasiaromatic molecules are addressed. How the organization of these molecules into crystalline arrays introduces optical anisotropy and finally how organisms control crystal morphology and superstructural organization to optimize functions in light reflection and scattering are also discussed. Many open questions remain in this fascinating field, some of which arise out of this in-depth analysis of the interaction of light with crystal arrays. More types of organic crystals will probably be discovered, as well as other organisms that use these crystals to manipulate light. The insights gained from biological systems can also be harnessed for improving synthetic light-manipulating materials.

20.
J Pharm Sci ; 113(9): 2817-2825, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39032825

RESUMEN

The characteristics of subvisible particles (SbVPs) are critical quality attributes of injectable and ophthalmic solutions in pharmaceutical manufacturing. However, current compendial SbVP testing methods, namely the light obstruction method and the microscopic particle count method, are destructive and wasteful of target samples. In this study, we present the development of a non-destructive SbVP analyzer aiming to analyze SbVPs directly in drug product (DP) containers while keeping the samples intact. Custom sample housings are developed and incorporated into the analyzer to reduce optical aberrations introduced by the curvature of typical pharmaceutical DP sample containers. The analyzer integrates a light-sheet microscope structure and models the side scattering event from a particle with Mie scattering theory with refractive indices as prior information. Equivalent spherical particle size under assigned refractive index values is estimated, and the particle concentration is determined based on the number of scattering events and the volume sampled by the light sheet. The resulting analyzer's capability and performance to non-destructively analyze SbVPs in DP containers were evaluated using a series of polystyrene bead suspensions in ISO 2R and 6R vials. Our results and analysis show the particle analyzer is capable of directly detecting SbVPs from intact DP containers, sorting SbVPs into commonly used size bins (e.g. ≥ 2 µm, ≥ 5 µm, ≥ 10 µm, and ≥ 25 µm), and reliably quantifying SbVPs in the concentration range of 4.6e2 to 5.0e5 particle/mL with a margin of ± 15 % error based on a 90 % confidence interval.


Asunto(s)
Tamaño de la Partícula , Dispersión de Radiación , Luz , Refractometría/métodos , Tecnología Farmacéutica/métodos , Embalaje de Medicamentos/métodos , Poliestirenos/química
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