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1.
Lipids Health Dis ; 23(1): 195, 2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38915087

ABSTRACT

BACKGROUND: Uric acid (UA), a liver-derived metabolite, is intimately tied to metabolic disorders. Although ample research underscores its connection with hypertriglyceridemia (HTG), studies focusing on adolescents remain limited. To fill the gaps in epidemiology,this study focused on analyzing the relationship between the levels of uric acid and HTG in a demographic sample comprising adolescents from the United States. METHODS: In this study, a total of 4,435 participants through the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2020. The exposure variable was serum uric acid (SUA), the effect variable was HTG, and the covariates included demographic, questionnaire, physical examination and laboratory indicators. We utilized weighted logistic regression and meticulous subgroup evaluations to discern the intrinsic link between SUA and HTG. Stratified analyses augmented the validation of this association, while smooth curve fitting probed for potential nonlinear correlations. RESULTS: The study included 4,435 participants. Male adolescents exhibit elevated SUA levels. After adjusting for all variables, the weighted multiple logistic regression model revealed that SUA was positively correlated with HTG risk (OR = 1.006, 95% CI: 1.005-1.007). This relationship was consistent across the three tertiles group of SUA (T1: OR = 1.006 [95% CI: 1.005-1.007]; T2: OR = 1.006 [95% CI: 1.005-1.007]; T3: OR = 1.004 [95% CI: 1.003-1.006]; P for trend < 0.001). Stratified analyses confirmed that the positive correlation between SUA and HTG risk was significant, irrespective of sex, age or race. CONCLUSIONS: In American children and adolescents aged 12 to 18 years, there was a pronounced association between SUA and HTG. SUA could serve as a risk indicator for HTG. It is recommended that children diagnosed with HTG should be regularly tested for SUA levels. In addition, it is recommended that SUA be included in the comprehensive care of children diagnosed with HTG.


Subject(s)
Hypertriglyceridemia , Nutrition Surveys , Uric Acid , Humans , Uric Acid/blood , Adolescent , Hypertriglyceridemia/blood , Hypertriglyceridemia/epidemiology , Male , Female , Child , Cross-Sectional Studies , Logistic Models , Risk Factors , United States/epidemiology , Triglycerides/blood
2.
Food Chem X ; 21: 101154, 2024 Mar 30.
Article in English | MEDLINE | ID: mdl-38379798

ABSTRACT

Oyster sauce (OS) is a highly processed oyster product. However, the significant price difference between OS and fresh oysters raises a question: Does authentic OS truly contain components from oysters or oyster enzymatic hydrolysates (OEH)? Therefore, the odor compounds of Lee Kum Kee oyster sauce (LKK), 4 OEHs, and 6 other seafood enzymatic hydrolysates (SEHs) were analyzed by using solid-phase microextraction and gas chromatography-olfactometry-mass spectrometry technology (SPME-GC-O-MS). The results of multivariate statistical analysis demonstrated the effective discrimination between LKK and OEHs from other SEHs. According to the VIP value and the differences in the composition of odor compounds among different samples, 15 essential odor compounds were screened out, which could distinguish whether the samples contained OEHs. Among them, acetic acid, 2-pentylfuran, 2-ethyl furan, 2-methylbutanal, and nonanal were only detected in LKK and OEHs, which further indicated the existence of OEH in LKK.

3.
ACS Appl Mater Interfaces ; 16(4): 5316-5325, 2024 Jan 31.
Article in English | MEDLINE | ID: mdl-38227431

ABSTRACT

Surface and interfacial engineering of nanomaterials is essential for improving dispersion stability in liquids. In this study, we report that oleic acid (OA)- and stearic acid (SA)-functionalized layered double hydroxide (LDH) nanosheets as lubricant additives can achieve high dispersion and reduce friction and wear. LDH is a typical layered structure, and OA and SA are long-chain organic molecules that are not only compatible with base oils but also act as friction-reducing agents. The OA and SA molecules were branched onto ZnMgAl LDH nanosheets using dehydration condensation between the exposed OH groups on the surface of LDH and the COOH groups on the OA and SA molecules. Compared with that of the pristine ZnMgAl LDH, the dispersion of OA-ZnMgAl LDH and SA-ZnMgAl LDH was significantly improved. The surface-modified LDH exhibited superior tribological properties and great stability due to the synergistic lubrication effect between OA, SA, and LDH. Even at an ultralow concentration (0.15 wt %), the coefficient of friction and wear volume were reduced by ∼65 and ∼99%, respectively, compared to those of the base oil. Due to the green and simple synthesis method and excellent tribological properties, surface-functionalized LDH has enormous possibilities for future industrial applications.

4.
World J Clin Cases ; 11(19): 4579-4600, 2023 Jul 06.
Article in English | MEDLINE | ID: mdl-37469744

ABSTRACT

BACKGROUND: Polygoni Cuspidati Rhizoma et Radix (PCRR), a well-known traditional Chinese medicine (TCM), inhibits inflammation associated with various human diseases. However, the anti-inflammatory effects of PCRR in acute lung injury (ALI) and the underlying mechanisms of action remain unclear. AIM: To determine the ingredients related to PCRR for treatment of ALI using multiple databases to obtain potential targets for fishing. METHODS: Recognized and candidate active compounds for PCRR were obtained from Traditional Chinese Medicine Systems Pharmacology, STITCH, and PubMed databases. Target ALI databases were built using the Therapeutic Target, DrugBank, DisGeNET, Online Mendelian Inheritance in Man, and Genetic Association databases. Network pharmacology includes network construction, target prediction, topological feature analysis, and enrichment analysis. Bioinformatics resources from the Database for Annotation, Visualization and Integrated Discovery were utilized for gene ontology biological process and Kyoto Encyclopedia of Genes and Genomes network pathway enrichment analysis, and molecular docking techniques were adopted to verify the combination of major active ingredients and core targets. RESULTS: Thirteen bioactive compounds corresponding to the 433 PCRR targets were identified. In addition, 128 genes were closely associated with ALI, 60 of which overlapped with PCRR targets and were considered therapeutically relevant. Functional enrichment analysis suggested that PCRR exerted its pharmacological effects in ALI by modulating multiple pathways, including the cell cycle, cell apoptosis, drug metabolism, inflammation, and immune modulation. Molecular docking results revealed a strong associative relationship between the active ingredient and core target. CONCLUSION: PCRR alleviates ALI symptoms via molecular mechanisms predicted by network pharmacology. This study proposes a strategy to elucidate the mechanisms of TCM at the network pharmacology level.

5.
J Environ Manage ; 326(Pt B): 116829, 2023 Jan 15.
Article in English | MEDLINE | ID: mdl-36417833

ABSTRACT

Forest roads are a major source of and transport pathway for eroded sediments in mountainous watersheds. When rills develop on these roads' surfaces, they amplify sediment erosion. Best management practices can decrease sediment erosion, but in order to efficiently implement these practices it is necessary to determine which factors have the most influence on rill development on forest roads. Despite this need, there is scarce literature on rill development on forest roads. To fill this gap in knowledge, based on field survey and multivariate statistical methods including redundancy analysis (RDA) and variation partitioning analysis (VPA), we investigated unpaved forest roads in the Xiangchagou watershed in China and quantified the extent to which various factors influenced rill formation. Specifically, we studied how rill erosion intensity (REI) and rill morphological characteristics (like rill length, mean width and depth, density, and severity of fragmentation) varied along the slope of a forest road. We also introduced the concept of a road's hydrological constituents (its upslope catchment, surface, and cutslopes), and determined how much each constituent contributed to REI. We found that REI and morphological characteristics decreased moving from the upper portion of road segment downward, implying that rills developed more intensely uphill. Additionally, REI increased exponentially with rill width, density, and severity of fragmentation, and increase linearly with length and depth. Conversely, REI decreased exponentially with rill width-depth ratio. These relationships suggest that the morphological characteristics of rills could be used to predict the REI of a given road segment. Finally, we found that the road characteristics that best predicted rill formation included catchment area, cutslope area, and gravel bareness. Correspondingly, the upslope catchment, cutslopes, and road surface contributed 11.56%, 30.83%, and 8.23% of the variation in REI and morphological characteristics. The interaction between upslope catchment and road surface explained 19.89% of the variation. These results suggest that when best management practices are implemented to decrease erosion caused by forest roads in mountainous watersheds, they should integrate these hydrological constituents of a road.


Subject(s)
Forests , Geologic Sediments , China
6.
Biomed Pharmacother ; 156: 113989, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36411656

ABSTRACT

Atopic disease is a kind of abnormal immune reaction caused by tissue damage and physiological dysfunction caused by allergens. Atopic diseases involve many systems and have obvious genetic tendencies, threatening the quality of life, health, and life safety of human beings. Astragalus membranaceus is an ancient and commonly used traditional Chinese medicine widely used in allergic diseases. Astragaloside IV is one of the main active ingredients in Astragalus membranaceus and is an important index component for evaluating the quality of Astragalus membranaceus and Astragalus membranaceus preparations at present. It has good antiallergic and immunomodulatory effects. Therefore, this paper reviews and summarizes the mechanism of action, pharmacokinetics, and drug optimization research progress of astragaloside IV in the treatment of atopic diseases.


Subject(s)
Hypersensitivity , Saponins , Triterpenes , Humans , Quality of Life , Saponins/pharmacology , Saponins/therapeutic use , Triterpenes/therapeutic use , Astragalus propinquus
7.
ACS Biomater Sci Eng ; 8(2): 540-550, 2022 02 14.
Article in English | MEDLINE | ID: mdl-35107009

ABSTRACT

Photothermal therapy (PTT) working in the second near-infrared (NIR-II) region has aroused a huge interest due to its potential application in terms of clinical cancer treatment. However, owing to the lack of photothermal nanoagents with high photothermal conversion efficiency, NIR-II-driven PTT still suffers from poor efficiency and subsequent cancer recurrence. In this work, we show a new and highly efficient preparation approach for NIR-II photothermal nanoagents and tailor ultrathin layered double hydroxide (LDH)-supported Ag@Ag2O core-shell nanoparticles (Ag@Ag2O/LDHs-U), vastly improving NIR-II photothermal performance. A combination study (high-resolution transmission electron microscopy (HRTEM), extended X-ray absorption fine structure spectroscopy (EXAFS), and X-ray photoelectron spectroscopy (XPS)) verifies that ultrafine Ag@Ag2O core-shell nanoparticles (∼3.8 nm) are highly dispersed and firmly immobilized within ultrathin LDH nanosheets, and their Ag2O shell possesses abundant vacancy-type defects. These unique Ag@Ag2O/LDHs-U display an impressive photothermal conversion efficiency as high as 76.9% at 1064 nm. Such an excellent photothermal performance is likely attributed to the enhanced localized surface plasmon resonance (LSPR) coupling effect between Ag and Ag2O and the reduced band gap caused by vacancy-type defects in the Ag2O shell. Meanwhile, Ag@Ag2O/LDHs-U also show prominent photothermal stability, due to the unique supported core-shell nanostructure. Moreover, both in vitro and in vivo studies further confirm that Ag@Ag2O/LDHs-U possess good biocompatible properties and outstanding PTT therapeutic efficacy in the NIR-II region. This research shows a new strategy in the rational design and preparation of an efficient photothermal agent, which is helpful to achieve more accurate and effective cancer theranostics.


Subject(s)
Nanoparticles , Neoplasms , Humans , Nanoparticles/therapeutic use , Neoplasms/drug therapy , Photothermal Therapy , Theranostic Nanomedicine/methods
8.
Molecules ; 27(4)2022 Feb 17.
Article in English | MEDLINE | ID: mdl-35209157

ABSTRACT

Supramolecular oleogel is a soft material with a three-dimensional structure, formed by the self-assembly of low-molecular-weight gelators in oils; it shows broad application prospects in the food industry, environmental protection, medicine, and other fields. Among all the gelators reported, amino-acid-based compounds have been widely used to form organogels and hydrogels because of their biocompatibility, biodegradation, and non-toxicity. In this study, four Nα, Nε-diacyl-l-lysine gelators (i.e., Nα, Nε-dioctanoyl-l-lysine; Nα, Nε-didecanoyl-l-lysine; Nα, Nε-dilauroyl-l-lysine; and Nα, Nε-dimyristoyl-l-lysine) were synthesized and applied to prepare oleogels in four kinds of vegetable oils. Gelation ability is affected not only by the structure of the gelators but also by the composition of the oils. The minimum gel concentration (MGC) increased with the increase in the acyl carbon-chain length of the gelators. The strongest gelation ability was displayed in olive oil for the same gelator. Rheological properties showed that the mechanical strength and thermal stability of the oleogels varied with the carbon-chain length of the gelators and the type of vegetable oil. The microstructure of oleogels is closely related to the carbon-chain length of gelators, regardless of oil type. The highest oil-binding capacity (OBC) was obtained in soybean oil for all four gelators, and Nα, Nε-dimyristoyl-l-lysine showed the best performance for entrapping oils.


Subject(s)
Lysine/chemistry , Plant Oils/chemistry , Chemical Phenomena , Chemistry Techniques, Synthetic , Molecular Structure , Organic Chemicals/chemical synthesis , Organic Chemicals/chemistry , Rheology
9.
Gels ; 9(1)2022 Dec 30.
Article in English | MEDLINE | ID: mdl-36661797

ABSTRACT

Nα, Nε-diacyl-l-lysine and its derivatives are excellent candidates to be used as gelators for the formation of various gels, such as hydrogels, organogels or oleogels, and ionogels. A series of alkali metal salts (Na+ and K+) of four Nα, Nε-diacyl-l-lysines (acyl including octanoyl, decanoyl, lauroyl and myristoyl) were used to study the gelation behaviors in water and alcohol-water mixtures. l-lysine-based derivatives with long-chain acyl can act as gelators to gel water and alcohol-water mixtures. In contrast, octanoyl and decanoyl derivatives cannot form gels in all solvent systems. Gelation ability, rheological behavior, and morphology vary with the molecular structure of the gelator and the nature of the solvents, as hydrophobic interaction and hydrogen bonding are responsible for the formation of gels. In general, sodium salts performed better in forming gels than their corresponding potassium salts, and myristoyl derivatives were beneficial for gel formation. Although it is challenging to form gels in t-butanol-water mixtures, the formed gels show high mechanical strength.

10.
Opt Express ; 29(10): 14582-14600, 2021 May 10.
Article in English | MEDLINE | ID: mdl-33985178

ABSTRACT

We propose a six-layer waveguide structure embedded in a single-layer grating based on guided-mode resonance (GMR), which can realize ultra-narrowband filtering with a tunable resonance wavelength. The filtering characteristics were analyzed and calculated by rigorous coupled-wave analysis (RCWA) and COMSOL Multiphysics. The narrowband resonance wavelength and absorption are tuned by changing the geometry and physical parameters of the structure such as the grating period and width, layer thickness, and materials. We designed and calculated the full width at half maximum (FWHM) and resonance absorption spectra in detail under different polarization states of electromagnetic waves. We obtained an absorption FWHM of 8.51e-5 nm for the transverse electric (TE) mode and 0.023 nm for the transverse magnetic (TM) mode, with the absorption coefficients having a value over 99.2%. The GMR filtering structure shows a good sensitivity and figure of merit (FOM) for refractive index sensing. For instance, a very high FOM of 17782.6/RIU for TM incidence is observed. These structures can have possible applications in optical information devices and sensors.

11.
J Oleo Sci ; 70(4): 571-580, 2021 Apr 02.
Article in English | MEDLINE | ID: mdl-33692238

ABSTRACT

Polyglycerol monolaurates are generally recognized as safe food additives and are commonly used as food emulsifiers. In this study, the antimicrobial effect of four polyglycerol monolaurates on two Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram-negative bacteria (Escherichia. coli and Pseudomonas aeruginosa) were investigated. The minimum inhibitory concentration (MIC) of diglycerol monolaurate (PG2ML), triglycerol monolaurate (PG3ML), hexaglycerol monolaurate (PG6ML), and decaglycerol monolaurate (PG10ML) against S. aureus was 0.16, 0.32, 0.63, and 1.25 mg/mL, respectively. The MIC of PG2ML, PG3ML, PG6ML, and PG10ML against B. subtilis was 0.32, 0.63, 1.25, and 3.75 mg/mL, respectively. No apparent antimicrobial effect of these four polyglycerol monolaurates on E. coli and P. aeruginosa was observed even up to 10.00 mg/mL. The underlying mechanism was investigated by assessing cell membrane permeability, the integrity of cell membrane, and morphology. We concluded that polyglycerol monolaurates might eliminate Gram-positive bacteria by disrupting the cell membrane, thereby increasing cell membrane permeability, releasing the cellular contents, and altering the cell morphology.


Subject(s)
Anti-Bacterial Agents , Emulsifying Agents , Food Additives , Glycerol/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Laurates/pharmacology , Polymers/pharmacology , Cell Membrane/drug effects , Cell Membrane Permeability/drug effects , Dose-Response Relationship, Drug , Drug Resistance, Bacterial , Food Microbiology , Glycerol/chemistry , Gram-Negative Bacteria/cytology , Gram-Positive Bacteria/cytology , Laurates/chemistry , Microbial Sensitivity Tests , Polymers/chemistry , Structure-Activity Relationship
12.
J Mater Chem B ; 9(7): 1888-1895, 2021 02 25.
Article in English | MEDLINE | ID: mdl-33533362

ABSTRACT

It remains a major challenge to achieve efficient oral delivery and controlled intestinal release of ions using hydrogels. Herein, we report a novel, pH/redox-dual responsive, nanoemulsion-embedded composite hydrogel to address this issue. The hydrogel was first synthesized by crosslinking a biocompatible, pH-responsive pseudopeptide, poly(l-lysine isophthalamide) (PLP), and redox-sensitive l-cystine dimethyl ester dihydrochloride (CDE). A suitable amount of magnesium acetate was encapsulated into oil-in-water nanoemulsions, which were then embedded into the lysine-based hydrogel. The resulting composite hydrogel collapsed into a compact structure at acidic gastric pH, but became highly swollen or degraded in the neutral and reducing intestinal environment. The ion release profiles indicated that the nanoemulsion-embedded composite hydrogel could well retain and protect magnesium ions in the simulated gastric fluid (SGF) buffer at pH 1.2, but efficiently release them in the simulated intestinal fluid (SIF) buffer at pH 6.8 in the presence of 1,4-dithiothreitol (DTT) as a reducing agent. Moreover, this composite hydrogel system displayed good biocompatibility. These results suggested that the pH/redox-dual responsive, nanoemulsion-embedded composite hydrogel could be a promising candidate for efficient oral delivery and controlled intestinal release of magnesium and other ions.


Subject(s)
Acetates/metabolism , Drug Delivery Systems , Hydrogels/metabolism , Intestines/chemistry , Magnesium Compounds/metabolism , Nanoparticles/metabolism , Acetates/administration & dosage , Acetates/chemistry , Administration, Oral , Emulsions/chemistry , Emulsions/metabolism , HeLa Cells , Humans , Hydrogels/chemical synthesis , Hydrogels/chemistry , Hydrogen-Ion Concentration , Ions/administration & dosage , Ions/chemistry , Ions/metabolism , Magnesium Compounds/administration & dosage , Magnesium Compounds/chemistry , Molecular Structure , Nanoparticles/chemistry , Oxidation-Reduction , Particle Size , Surface Properties
13.
J Food Prot ; 83(2): 331-337, 2020 Feb 01.
Article in English | MEDLINE | ID: mdl-31961233

ABSTRACT

ABSTRACT: Naturally occurring monoglyceride esters of fatty acids have been associated with a broad spectrum of antimicrobial activities. We used an automated turbidimetric method to measure the MIC and assess the antimicrobial activity of five monoglycerides (monocaprin, monolaurin, monomyristin, monopalmitin, and monostearin) against pathogenic strains of Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, and Escherichia coli. The antibacterial activity of monocaprin was highest because its carbon chain is shorter than those of other monoglycerides. The MICs of monocaprin against S. aureus, B. subtilis, P. aeruginosa, and E. coli were 0.32, 0.32, 2.5, and 2.5 mg/mL, respectively. Monocaprin had antibacterial activity under neutral and alkaline conditions (pH 7.0 to 9.0) but had no inhibitory effect on S. aureus, B. subtilis, and E. coli under weakly acidic conditions (pH 6.0). The antibacterial mechanism of monocaprin against gram-positive strains (S. aureus and B. subtilis) resulted from destruction of the cell membrane. In contrast, the antibacterial activity of monocaprin against gram-negative strains (P. aeruginosa and E. coli) was attributed to damage to lipopolysaccharides in the cell walls. Because of its inhibitory effect on both gram-positive and gram-negative bacteria, monocaprin could be used as an antibacterial additive in the food industry.

14.
J Oleo Sci ; 68(11): 1125-1132, 2019 Nov 07.
Article in English | MEDLINE | ID: mdl-31611516

ABSTRACT

This study aimed to investigate the highly selective production of monolaurin via enzymatic transesterification of methyl laurate and glycerol. It was determined that a binary solvent system (tert-butanol/iso-propanol, 20:80, wt./wt.) was suitable for the enzymatic production of monolaurin, especially in the continuous process. The highest mass fraction of monolaurin in the product mixture (80.8 wt.%) was achieved in a batch mode under the following conditions: a methyl laurate-to-glycerol molar ratio of 1:6, a substrate concentration (methyl laurate in the binary solvent) of 15 wt.%, an enzyme dosage of 6 wt.% of the amount of methyl laurate, and a reaction time of 1.5 h at 50°C. Compared with the results under the batch conditions, a slightly higher yield of monolaurin (82.5 ± 2.5 wt.%) was obtained in a continuous flow system at a flow rate of 0.1 mL/min, while the mass fraction of dilaurin in the product mixture was only 0.7 ± 0.6 wt.%. In addition, the yield of monolaurin remained almost unchanged during the 18 tested days of the continuous experiment.


Subject(s)
Emulsifying Agents/chemical synthesis , Laurates/chemical synthesis , Monoglycerides/chemical synthesis , 1-Propanol , Esterification , Glycerol/chemistry , Laurates/chemistry , Solvents , Temperature , Time Factors , tert-Butyl Alcohol
15.
Oncol Lett ; 18(3): 2877-2884, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31452767

ABSTRACT

Acute myeloid leukemia (AML) has a high mortality rate and its clinical management remains challenging. The aim of the present study was to identify the hub genes involved in AML. In order to do so, the gene expression data of the GSE9476 database, including 26 AML and 10 normal samples, were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were then identified via bioinformatics analysis. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses were performed on DEGs. Furthermore, the most upregulated genes were selected for further investigation in the Oncomine, gene expression profiling interactive analysis and UALCAN datasets. In total, 1,744 upregulated and 1,956 downregulated genes were detected. The GO and KEGG results revealed that upregulated genes were enriched in metabolic processes, while downregulated genes were associated with the immune response. Serine protease inhibitor Kazal-type 2 (SPINK2) ranked first among all the upregulated genes and was regarded as a hub gene in the development of AML. The overexpression of SPINK2 was validated in 12 patients with AML from the Linyi Central Hospital and in data from the Oncomine and Gene Expression Profiling Interactive Analysis (GEPIA) databases. Furthermore, the UALCAN and GEPIA datasets demonstrated that patients with high SPINK2 levels had shorter survival times. In conclusion, the results from the present study revealed that the SPINK2 gene was upregulated in patients with AML and that elevated SPINK2 expression was associated with poor outcomes in these patients.

16.
Soft Matter ; 15(4): 699-708, 2019 Jan 28.
Article in English | MEDLINE | ID: mdl-30624445

ABSTRACT

The present study was conducted to investigate the effects of the strong van der Waals interaction and sterol skeleton of surfactants on their interfacial rheological behaviors by comparing the interfacial properties of sodium cholesteryl glycylglycine (Chol-GG-Na) and sodium lauryl glycylglycine (C12-GG-Na) at the oil-aqueous interface. The interfacial dilational rheological experiment results indicate a significant increase in the interfacial activity and intermolecular interaction with the introduction of the cholesteryl group. Therefore, a compact interfacial layer with a remarkably high dilational modulus was obtained with the adsorption of Chol-GG-Na. The cholesteryl group also has a significant impact on the dynamic processes such as it slows down the motion of the molecules due to which the diffusion exchange between the bulk and the interface decreases. Besides, the rigid skeleton makes rearrangement and conformation adjustment difficult. These impacts become more pronounced when the adsorption layer approaches a close and ordered arrangement, which has been confirmed by the relaxation measurements. The reported results provide a theoretical foundation for the potential applications of cholesteryl-based surfactants in the food, pharmaceutical, cosmetic and petroleum industries.


Subject(s)
Cholesterol/chemistry , Glycylglycine/chemistry , Hydrophobic and Hydrophilic Interactions , Rheology , Cholesterol/analogs & derivatives , Diffusion , Surface Tension , Surface-Active Agents/chemistry
17.
Appl Opt ; 55(1): 70-6, 2016 Jan 01.
Article in English | MEDLINE | ID: mdl-26835623

ABSTRACT

We design and simulate a polarizing color filter with a sub-wavelength metal-dielectric grating. It manifests several advantages: a large acceptance angle (up to ±50°), high transmittance (74.3%-92.7%), low absorption loss (∼3.3%), and a high extinction ratio. This polarizing color filter can be integrated into a liquid-crystal display (LCD) backlight system to simultaneously recycle the light according to its color and polarization. In combination with a specially designed directional backlight, this newly proposed LCD system can theoretically improve optical efficiency up to ∼2.5×, and also provides a large ambient contrast ratio and a wide view. Our approach enables an ultra-low-power LCD without using the complicated field-sequential-color technique.

18.
Opt Express ; 23(8): 9881-9, 2015 Apr 20.
Article in English | MEDLINE | ID: mdl-25969029

ABSTRACT

A CW dual-frequency master oscillator power amplifier (MOPA) laser system with dozens of gigahertz (GHz) frequency separation is presented. The MOPA system consists of a monolithic microchip seed laser and a double-end pumped traveling wave power amplifier. The short length of seed laser cavity guarantees the seed signal with a large frequency separation (above 53 GHz) but low output power (below 247.8 mW). By adding a long and low-doped active medium laser amplifier stage, a significant increase in laser power and an improvement in beam quality are obtained. After fine temperature tuning of seed laser cavity for "spectra matching", a 2.40 W dual-frequency laser signal with 45 GHz frequency separation is achieved.

19.
Opt Lett ; 39(14): 4068-71, 2014 Jul 15.
Article in English | MEDLINE | ID: mdl-25121653

ABSTRACT

We propose and perform broadband angular filtering with the combination of a volume Bragg grating and a surface grating pair. The condition for broadband operation is discussed. Near-field modulation, contrast ratio, and power spectral density are used to evaluate the filtering performances in the spatial and frequency domain. Experimental results show that the bandwidth of the output beam through the grating combination is remarkably increased, and the medium and high frequencies are effectively eliminated.

20.
Dalton Trans ; 41(27): 8421-9, 2012 Jul 21.
Article in English | MEDLINE | ID: mdl-22643575

ABSTRACT

A series of platinum(II) complexes bearing a chromophore-acceptor dyad obtained by reacting 4-(p-bromomethylphenyl)-6-phenyl-2,2'-bipyridine or 4'-(p-bromomethylphenyl)-2,2':6',2''-terpyridine with pyridine, 4-phenylpyridine, 4,4'-bipyridine, 1-methyl-4-(pyridin-4'-yl)pyridinium hexafluorophosphate respectively, were synthesized. Their photophysical properties, emission quenching studies by Pt nanoparticles and methyl viologen, electrochemical properties and photoinduced electron-transfer reactions in a photocatalytic hydrogen-generating system containing triethanolamine and colloidal Pt without an extra electron relay, were investigated. A comparison of the rates of hydrogen production for the two photocatalytic systems, one containing a metal-organic dyad and the other comprising a 1:1 mixture of the parental platinum(II) complexes and the corresponding electron relay, showed that intramolecular electron transfer improves the photocatalytic efficiency. Compared with cyclometalated platinum(II) complexes, the related platinum(II) terpyridyl complexes exhibited poor performance for photocatalytic hydrogen evolution. An investigation into the amount of hydrogen generated by three platinum(II) complexes containing cyclometalated ligands with methyl groups located on different phenyl rings revealed that the efficiency of hydrogen evolution was affected by a subtle change of functional group on ligand, and the hydrogen-generating efficiency in the presence or absence of methyl viologen is comparable, indicating electron transfer from the excited [Pt(C^N^N)] chromophore to colloidal Pt. (1)H NMR spectroscopy of the metal-organic dyads in an aqueous solution in the presence of excess triethanolamine revealed that the dyad with a viologen unit was unstable, and a chemical reaction in the compound occurred prior to irradiation by visible light under basic conditions.

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